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Are Your Capacitors Installed Backwards Build this and find out
WEBVTT Kind: captions Language: en
00:00:07.810 hi there if you're into restoring old 00:00:10.62000:00:10.630 receivers or older 00:00:13.82000:00:13.830 or even building amplifiers problem 00:00:16.08000:00:16.090 we find this information rather 00:00:17.13000:00:17.140 interesting so those orange dip brown 00:00:19.95000:00:19.960 dip green dip and those little yellow 00:00:21.42000:00:21.430 axial lead capacitors and many more 00:00:23.70000:00:23.710 capacitors have a polarity in circuit 00:00:25.98000:00:25.990 and should be installed in the circuit 00:00:27.45000:00:27.460 the correct way in order for them not to 00:00:29.76000:00:29.770 pick up hum from adjacent parts of your 00:00:32.22000:00:32.230 amplifier or radio or to pick up 00:00:34.32000:00:34.330 interference from adjacent parts of the 00:00:36.11900:00:36.129 chassis whatever they're installed into 00:00:38.11900:00:38.129 so in this video what we're going to do 00:00:40.41000:00:40.420 is we're going to discuss why these 00:00:42.18000:00:42.190 capacitors have a polarity and then 00:00:44.61000:00:44.620 we're going to build a little circuit 00:00:45.90000:00:45.910 that will help us locate this polarity 00:00:47.67000:00:47.680 quickly we all know that if you're 00:00:50.01000:00:50.020 restoring a radio or an old guitar 00:00:51.33000:00:51.340 amplifier they usually have a handful of 00:00:52.86000:00:52.870 capacitors in them and you really don't 00:00:54.75000:00:54.760 want to be doing this while you're 00:00:55.88900:00:55.899 restoring the receiver or amplifier so 00:00:58.59000:00:58.60000:00:59.43000:00:59.440 that will help you grade them with an 00:01:00.95900:01:00.969 oscilloscope very quickly and then you 00:01:02.61000:01:02.620 with a little felt marker you can mark 00:01:04.32000:01:04.330 the band end or as it was called in the 00:01:06.90000:01:06.910 old days the outside foil end of the 00:01:09.27000:01:09.280 capacitor so let's get into the video 00:01:11.60900:01:11.619 and start discussing why these 00:01:13.46900:01:13.479 capacitors actually have a polarity here 00:01:16.95000:01:16.960 we have two very common circuits that 00:01:19.08000:01:19.090 you'll find in a lot of vacuum tube gear 00:01:20.79000:01:20.800 this upper circuit here you'll notice is 00:01:23.04000:01:23.050 in a lot of guitar amplifiers or high 00:01:24.93000:01:24.940 fidelity amplifiers or stereo receivers 00:01:27.30000:01:27.310 this really is just an audio 00:01:29.34000:01:29.350 amplification chain here this bottom 00:01:32.13000:01:32.140 portion of the schematic I've kind of 00:01:33.48000:01:33.490 drawn to represent either an if' 00:01:35.33900:01:35.349 amplifier or an audio amplifier of 00:01:37.35000:01:37.360 course we'd have to amend this 00:01:38.85000:01:38.860 transformer to represent either/or but 00:01:40.80000:01:40.810 we're not going to get too crazy about 00:01:42.27000:01:42.280 that right now because it's all about 00:01:43.88900:01:43.899 just learning which way we need to 00:01:45.54000:01:45.550 install our new capacitors in this 00:01:47.43000:01:47.440 circuit for the best circuit performance 00:01:49.52900:01:49.539 and the least amount of interference so 00:01:53.27900:01:53.289 way back in the day they used to make 00:01:55.19900:01:55.209 capacitors that looked like this and if 00:01:58.52900:01:58.539 you ever find a capacitor like this in 00:02:00.27000:02:00.280 any kind of gear that you're working on 00:02:02.46000:02:02.470 it has to go these are all faulty by now 00:02:05.24900:02:05.259 and they leak now when I talk about 00:02:08.49000:02:08.500 leaking I don't mean that they leak 00:02:10.38000:02:10.390 physically they're not leaking a 00:02:11.88000:02:11.890 substance like oil or goop out of them 00:02:13.86000:02:13.870 they leak DC across them so whenever you 00:02:17.01000:02:17.020 hear the term leaky capacitor that means 00:02:19.53000:02:19.540 that they're leaking direct current 00:02:21.47900:02:21.489 through them capacitors are supposed to 00:02:23.43000:02:23.440 block DC and pass alternating current 00:02:26.19000:02:26.200 through them so when they leak that 00:02:28.31900:02:28.329 means that this capacitor 00:02:29.79000:02:29.800 effectively turning into a resistor and 00:02:31.83000:02:31.840 that is no good for the next stage so 00:02:34.98000:02:34.990 what happens in these capacitors is 00:02:36.90000:02:36.910 they've got paper inside of them that's 00:02:38.97000:02:38.980 gone acidic and it's basically dis 00:02:41.61000:02:41.620 turning into a big resistor rate now and 00:02:43.86000:02:43.870 when these capacitors turn into 00:02:45.78000:02:45.790 resistors they bias up the next stage 00:02:47.76000:02:47.770 and cause the tube over here to draw 00:02:49.83000:02:49.840 heavy current it causes damage to the 00:02:51.69000:02:51.700 circuit you burn out plate resistors and 00:02:53.58000:02:53.590 AF transformers and it does all sorts of 00:02:55.77000:02:55.780 bad things so you want to get rid of 00:02:57.81000:02:57.820 these capacitors and replace them with a 00:02:59.46000:02:59.470 modern equivalent like a an orange dip 00:03:01.86000:03:01.870 or a brown dip and I'll grab one of 00:03:03.72000:03:03.730 those here in just a minute to show you 00:03:05.21000:03:05.220 so back in the day when these were brand 00:03:07.44000:03:07.450 new they're great capacitors they didn't 00:03:08.94000:03:08.950 leak or anything and they were nice 00:03:10.80000:03:10.810 enough to mark the outside foil 00:03:12.78000:03:12.790 end of the capacitor by putting a band 00:03:14.67000:03:14.680 on it and printing outside foil on it 00:03:16.71000:03:16.720 now the outside foil and means that this 00:03:20.31000:03:20.320 lead on the capacitor comes into here 00:03:23.37000:03:23.380 and it also attaches to an outside foil 00:03:25.62000:03:25.630 jacket that's just great underneath this 00:03:28.56000:03:28.570 paper here and it shields the entire 00:03:30.27000:03:30.280 capacitor so if we were to tie this to 00:03:32.97000:03:32.980 the chassis this whole capacitor would 00:03:34.71000:03:34.720 be shielded right up to this point right 00:03:36.44900:03:36.459 to where this lead goes in this lead 00:03:38.46000:03:38.470 goes it to the inside layers so in 00:03:41.31000:03:41.320 effect these capacitors actually do have 00:03:43.41000:03:43.420 a polarity now so do a lot of the modern 00:03:46.65000:03:46.660 capacitors and if they're built 00:03:48.54000:03:48.550 correctly they'll actually be made with 00:03:50.64000:03:50.650 you know metallized polypropylene or you 00:03:53.22000:03:53.230 know PVC or whatever they're building 00:03:55.35000:03:55.360 their new capacitors with and of course 00:03:56.91000:03:56.920 whichever new style capacitor that you 00:03:59.01000:03:59.020 end up buying they will have an outside 00:04:01.74000:04:01.750 foil jacket connected to one end it's 00:04:04.02000:04:04.030 just that they didn't spend the time to 00:04:06.33000:04:06.340 actually mark it and that's what we're 00:04:08.43000:04:08.440 going to do in this video is we're going 00:04:10.05000:04:10.060 to locate that odor odor foil or the 00:04:12.78000:04:12.790 outer metallized polypropylene layer so 00:04:15.47900:04:15.489 that when you install your capacitors 00:04:17.03900:04:17.049 into circuit you're going to pick up 00:04:19.02000:04:19.030 less hum and a less adjacent 00:04:21.21000:04:21.220 interference and you know either you're 00:04:23.85000:04:23.860 not going to get oscillation because you 00:04:25.32000:04:25.330 have a really large exposed surface 00:04:27.57000:04:27.580 hooked to a high impedance portion of 00:04:29.70000:04:29.710 your circuit so now these capacitors 00:04:33.15000:04:33.160 we'll just use this as an example for a 00:04:35.22000:04:35.230 modern capacitor so say this was a 00:04:37.31000:04:37.320 brand-new modern capacitor okay if we 00:04:40.62000:04:40.630 were to install this into the circuit 00:04:43.26000:04:43.270 this end here would go to the lower 00:04:44.94000:04:44.950 impedance point always so this end here 00:04:48.03000:04:48.040 with the end with the band if we were to 00:04:49.92000:04:49.930 use this as an RF bypassing capacitor 00:04:52.35000:04:52.360 would always go to the chassis and this 00:04:54.60000:04:54.610 would go to the the grid of the tubes 00:04:56.82000:04:56.830 say the screen grid if we wanted to keep 00:04:58.50000:04:58.510 RF off the screen grid or something like 00:05:00.27000:05:00.280 that it would go like this because when 00:05:02.28000:05:02.290 we tie this end of the chassis 00:05:03.81000:05:03.820 this entire capacitor is shielded right 00:05:06.30000:05:06.310 up to this point now if we hook this up 00:05:08.55000:05:08.560 in Reverse and say we tied this end of 00:05:10.80000:05:10.810 the chassis and this end of the tube 00:05:12.21000:05:12.220 socket we'd have all of this area that 00:05:14.43000:05:14.440 is completely exposed right up to this 00:05:16.83000:05:16.840 point so of course we don't want to have 00:05:19.32000:05:19.330 that because that's more exposed area 00:05:21.09000:05:21.100 and of course we're going to pick up 00:05:22.59000:05:22.600 more interference that way especially if 00:05:24.87000:05:24.880 we have a filament or a heater line 00:05:26.94000:05:26.950 running past this that's that's 00:05:29.07000:05:29.080 definitely no good we definitely want 00:05:31.29000:05:31.300 this end to the chassis side now when 00:05:34.95000:05:34.960 we're hooking this up to a standard 00:05:36.39000:05:36.400 audio amplification circuit here this 00:05:38.39000:05:38.400 capacitor would go in this way because 00:05:40.47000:05:40.480 the band end or the outside foil and 00:05:42.75000:05:42.760 always goes to the lower impedance 00:05:44.22000:05:44.230 portion of the circuit and the lower 00:05:46.41000:05:46.420 impedance portion of the circuit most of 00:05:49.14000:05:49.150 the time is the plate of the preceding 00:05:51.63000:05:51.640 stage here or the earlier stage I should 00:05:53.94000:05:53.950 say so this band end will always go 00:05:57.90000:05:57.910 towards the plate and this end always 00:05:59.79000:05:59.800 goes towards the grid in this particular 00:06:02.04000:06:02.050 circuit and in this capacitor would be 00:06:04.11000:06:04.120 the same way and if we had a capacitor 00:06:05.88000:06:05.890 on the input here it would be the exact 00:06:07.83000:06:07.840 same way again on this bottom circuit 00:06:11.70000:06:11.710 here 00:06:12.06000:06:12.070 we'll notice that there is a capacitor 00:06:13.47000:06:13.480 missing on the screen grid and this 00:06:15.42000:06:15.430 would be considered an RF bypass 00:06:17.31000:06:17.320 capacitor we want to keep RF off the 00:06:19.26000:06:19.270 screen grid here because we don't want 00:06:21.06000:06:21.070 this screen grid to amplify any kind of 00:06:22.92000:06:22.930 oscillations or any kind of interference 00:06:24.78000:06:24.790 that's in the chassis so by mounting 00:06:27.96000:06:27.970 this capacitor in we would have to mount 00:06:29.88000:06:29.890 the band end to the ground or the 00:06:31.80000:06:31.810 chassis and that would tie to the screen 00:06:34.50000:06:34.510 grid now of course we don't want a lot 00:06:36.42000:06:36.430 of lead inductance there so we want to 00:06:38.43000:06:38.440 keep the lead as short as possible but 00:06:40.80000:06:40.810 again you have to use some common sense 00:06:42.81000:06:42.820 you don't want an extremely short lead 00:06:44.46000:06:44.470 so that when you're soldering it if you 00:06:46.50000:06:46.510 have a newer capacitor you're going to 00:06:48.09000:06:48.100 melt the poly the metallized 00:06:49.80000:06:49.810 polypropylene with the heat of your 00:06:51.21000:06:51.220 soldering iron you'll probably need to 00:06:53.19000:06:53.200 leave a little bit of lead so that it'll 00:06:54.75000:06:54.760 dissipate some heat 00:06:56.01000:06:56.020 so again these capacitors need to go in 00:06:59.37000:06:59.380 like this and they need to go in like 00:07:01.35000:07:01.360 this and they need to go in like this 00:07:03.81000:07:03.820 okay so depending on what stage or what 00:07:07.02000:07:07.030 what kind of schematic you've got going 00:07:09.18000:07:09.190 on so now we have new capacitors that 00:07:13.38000:07:13.390 look like this right here you can see 00:07:15.57000:07:15.580 this this has no markings on it and when 00:07:17.73000:07:17.740 these capacitors are created they're 00:07:19.59000:07:19.600 going down the assembly line this way 00:07:21.36000:07:21.370 and then they get the the writing or the 00:07:23.55000:07:23.560 printing on them this way or they'll get 00:07:25.77000:07:25.780 them on this way because it really 00:07:27.39000:07:27.400 doesn't matter they're in a machine that 00:07:28.83000:07:28.840 doesn't really pick which way they go 00:07:30.15000:07:30.160 down the line so they could be any old 00:07:32.91000:07:32.920 way and we need to find out which end 00:07:35.36000:07:35.370 which lead is attached to the outermost 00:07:38.57000:07:38.580 metallized polypropylene or we could 00:07:41.55000:07:41.560 call it the the actual shielding inside 00:07:43.89000:07:43.900 the capacitor which would be the outer 00:07:45.93000:07:45.940 the outer layer them outermost layer of 00:07:48.72000:07:48.730 this capacitor and that's very important 00:07:51.18000:07:51.190 so that we install this into the circuit 00:07:53.19000:07:53.200 the correct way because we don't know 00:07:55.38000:07:55.390 now a lot of people think that when they 00:07:58.11000:07:58.120 buy these orange dip capacitors that oh 00:08:00.27000:08:00.280 look they've been really nice and 00:08:01.98000:08:01.990 they've marked that well really have 00:08:05.22000:08:05.230 they this is how you test for the 00:08:08.88000:08:08.890 outside shielded end of your capacitor 00:08:11.04000:08:11.050 or the outside foil and or outside 00:08:13.11000:08:13.120 metallized polypropylene layer however 00:08:15.15000:08:15.160 you want to call it we're really just 00:08:16.74000:08:16.750 looking for the shielded end of your 00:08:18.90000:08:18.910 capacitor and this is how you find it 00:08:21.06000:08:21.070 using an oscilloscope and a very simple 00:08:23.28000:08:23.290 little setup like this which is 00:08:24.75000:08:24.760 basically just a BNC cable with the 00:08:26.43000:08:26.440 center conductor attached to an 00:08:27.93000:08:27.940 alligator clip and the shield is also 00:08:30.09000:08:30.100 attached to an alligator clip I have 00:08:31.50000:08:31.510 them right now just clip together to 00:08:33.00000:08:33.010 keep the noise off the screen so if you 00:08:36.09000:08:36.100 have a newer modern DSO that goes down 00:08:37.80000:08:37.810 to about 5 millivolts per division you 00:08:39.69000:08:39.700 should be absolutely fine 00:08:41.37000:08:41.380 right now this is running at 2 00:08:43.02000:08:43.030 millivolts per division and you know 00:08:45.27000:08:45.280 we're not going to get too accurate with 00:08:46.62000:08:46.630 the readings because really I'm just 00:08:47.97000:08:47.980 acting as a random hum antenna in order 00:08:50.37000:08:50.380 to determine the outside foil end of 00:08:53.28000:08:53.290 these capacitors and I'll explain that 00:08:55.14000:08:55.150 here quite shortly so the first 00:08:57.30000:08:57.310 capacitor we're going to look at is this 00:08:58.92000:08:58.930 old wax capacitor now we wouldn't want 00:09:01.32000:09:01.330 to use this in circuit because this 00:09:02.82000:09:02.830 capacitor is well past its due date but 00:09:04.92000:09:04.930 we're really just looking at a shielding 00:09:07.50000:09:07.510 aspect of this capacitor so this will be 00:09:09.54000:09:09.550 just fine for this test so what I'm 00:09:12.15000:09:12.160 going to do is I'll hook this into 00:09:13.50000:09:13.510 circuit the correct way and we'll look 00:09:15.21000:09:15.220 at the signal on the screen and the 00:09:16.80000:09:16.810 amplitude here and then we'll reverse 00:09:18.75000:09:18.760 this capacitor and see the differences 00:09:21.07900:09:21.089 so right now I'm disconnecting this 00:09:23.94000:09:23.950 thing up and this is the way that it 00:09:25.41000:09:25.420 should normally be I'm acting as the hum 00:09:27.26900:09:27.279 antenna right now I'm holding the the 00:09:29.91000:09:29.920 case of the capacitor right now so you 00:09:31.92000:09:31.930 could look at me as a very nearby heater 00:09:35.06900:09:35.079 line running past this capacitor and in 00:09:37.94900:09:37.959 a chassis or something like that so 00:09:41.13000:09:41.140 that's the amplitude that we got with it 00:09:42.66000:09:42.670 hooked up the correct way you can see 00:09:44.19000:09:44.200 the banded end is connected to the 00:09:45.96000:09:45.970 outside shield of the cable this is the 00:09:48.15000:09:48.160 lower impedance portion of the circuit 00:09:50.31000:09:50.320 this would be the chassis and we're 00:09:52.62000:09:52.630 always looking for the lowest amplitude 00:09:55.23000:09:55.240 when we have found the lowest amplitude 00:09:57.21000:09:57.220 we have the capacitor hooked up the 00:09:59.43000:09:59.440 correct way when the amplitudes high 00:10:01.47000:10:01.480 it's hooked up backwards so what I'll do 00:10:03.93000:10:03.940 is I'll hook this one up the other way 00:10:06.44000:10:06.450 and we can tell that we have this hooked 00:10:10.62000:10:10.630 up backwards because now the outside 00:10:12.99000:10:13.000 foil which is the the shielding on this 00:10:15.90000:10:15.910 capacitor is capacitively coupled to me 00:10:18.38900:10:18.399 and I'm feeding signal into my 00:10:20.22000:10:20.230 oscilloscope so that we can see here 00:10:22.29000:10:22.300 very simply that this capacitor is now 00:10:24.63000:10:24.640 hooked up backwards remember we're 00:10:26.31000:10:26.32000:10:29.25000:10:29.260 and then we know when the negative or 00:10:31.94900:10:31.959 the common lead of our oscilloscope is 00:10:33.90000:10:33.910 hooked to that and when we have the 00:10:35.61000:10:35.620 lowest amplitude that is the end that we 00:10:37.80000:10:37.810 will mark as the outside shielded end or 00:10:40.47000:10:40.480 the outside foil under whatever you want 00:10:42.60000:10:42.610 to call it so that's this capacitor here 00:10:45.99000:10:46.000 so let's grab a newer orange dip 00:10:47.91000:10:47.920 capacitor and take a look at it so 00:10:50.88000:10:50.890 here's a newer orange dip capacitor and 00:10:52.82900:10:52.839 we have a line here and we might think 00:10:55.88900:10:55.899 that oh that line indicates the outside 00:10:58.50000:10:58.510 foil and well let's test that out I'll 00:11:00.68900:11:00.699 just hook the capacitor up to it right 00:11:02.43000:11:02.440 now it's much easier to hook this up off 00:11:05.10000:11:05.110 of screen here so there we go 00:11:08.04000:11:08.050 so now I've got this outside shield of 00:11:12.42000:11:12.430 my braid hooked up to this and this 00:11:13.94900:11:13.959 would be considered the chassis and this 00:11:16.05000:11:16.060 here would be considered the part that 00:11:18.30000:11:18.310 goes into the higher impedance portion 00:11:20.57900:11:20.589 of the circuit okay so now what I'll do 00:11:23.16000:11:23.170 is 00:11:23.51900:11:23.529 flip these leads around now if I flip 00:11:26.04000:11:26.050 these leads around and the amplitude 00:11:27.86900:11:27.879 goes down that means that this side is 00:11:31.31900:11:31.329 not the outside foil and remember the 00:11:34.65000:11:34.660 side that the shielding is on is always 00:11:37.92000:11:37.930 when the amplitude is lower is the 00:11:39.78000:11:39.790 outside foil and so what I'll do is I'll 00:11:42.26900:11:42.279 reverse these leads right now and look 00:11:48.54000:11:48.550 at that we have lower amplitude here so 00:11:51.44900:11:51.459 this line here does not denote the 00:11:54.32900:11:54.339 outside foil and this side here is the 00:11:57.86900:11:57.879 shielded end of this capacitor so again 00:12:02.51900:12:02.529 I'll hook this back into circuit the 00:12:06.50900:12:06.519 other way and we can see that we have 00:12:08.75900:12:08.769 more amplitude this way and then if I 00:12:12.11900:12:12.129 change these around and see that there's 00:12:18.67900:12:18.689 almost nothing there so this side here 00:12:22.29000:12:22.300 would be the side that we would want to 00:12:24.98900:12:24.999 connect to the chassis we would mark 00:12:26.57900:12:26.589 this side here with a line as the 00:12:28.76900:12:28.779 outside foil okay 00:12:31.43900:12:31.449 so let's grab another orange dip 00:12:34.19900:12:34.209 capacitor right here and test it out the 00:12:36.84000:12:36.850 same way so I'll hook this up the way 00:12:39.21000:12:39.220 that we would think that it's hooked up 00:12:40.74000:12:40.750 this is the band end here so we'd figure 00:12:43.07900:12:43.089 that that is the outside foil alright so 00:12:47.22000:12:47.230 now what I'll do is I'll reverse the 00:12:48.56900:12:48.579 leads and we can clearly see with this 00:12:55.61900:12:55.629 capacitor that this side here is 00:12:57.72000:12:57.730 definitely not the outside foil or the 00:13:00.24000:13:00.250 outside metallized polypropylene or 00:13:02.22000:13:02.230 whatever metallized PVC this here this 00:13:05.46000:13:05.470 side is so this here would be considered 00:13:08.93900:13:08.949 the shielded end of the capacitor this 00:13:10.65000:13:10.660 is the side that would attach to the 00:13:12.32900:13:12.339 chassis 00:13:13.18900:13:13.199 again I'll reverse this 00:13:18.73000:13:18.740 and you can very clearly see that this 00:13:22.03000:13:22.040 is not the shielded end so let's test an 00:13:28.24000:13:28.250 older capacitor here I have an older 00:13:30.04000:13:30.050 kind of a burgundy dip I don't know what 00:13:31.99000:13:32.000 you would call this but let's consider 00:13:34.42000:13:34.430 the line end on this one as the outside 00:13:37.72000:13:37.730 foil so I'll just hook this one up now 00:13:43.08000:13:43.090 okay so here we go alright you see the 00:13:48.73000:13:48.740 line is on this end and we have the 00:13:50.20000:13:50.210 common or the negative lead hooked up 00:13:52.03000:13:52.040 here alright now I'll reverse the leads 00:13:54.61000:13:54.620 and we can see on this capacitor that 00:14:01.72000:14:01.730 line does denote the outside shielded 00:14:05.02000:14:05.030 end of the capacitor so on this 00:14:07.75000:14:07.760 capacitor you could regard this line as 00:14:10.48000:14:10.490 correct now whether these capacitors are 00:14:13.09000:14:13.100 going down the run like this and they're 00:14:14.53000:14:14.540 going down the run like this we don't 00:14:15.97000:14:15.980 really know because I don't have more of 00:14:17.47000:14:17.480 these to test but it just so happens on 00:14:19.57000:14:19.580 this capacitor that this and here is the 00:14:22.24000:14:22.250 shielded end okay so let's take a look 00:14:27.07000:14:27.080 at this old general Instruments 00:14:29.56000:14:29.570 capacitor alright and let's test it out 00:14:31.84000:14:31.850 and see if this band end is the outside 00:14:34.81000:14:34.820 foil so I'll hook this one up the way we 00:14:37.36000:14:37.370 would think it would be hooked up 00:14:38.47000:14:38.480 properly again we have the band end 00:14:42.25000:14:42.260 hooked to the ground or the common this 00:14:44.86000:14:44.870 would be considered the chassis okay now 00:14:48.91000:14:48.920 I'll reverse it 00:14:56.00000:14:56.010 and we can clearly see that this is not 00:15:00.11000:15:00.120 the outside foil and on this capacitor 00:15:02.48000:15:02.490 either 00:15:03.02000:15:03.030 so really the bands on the ends really 00:15:06.14000:15:06.150 can be considered either way with a lot 00:15:08.27000:15:08.280 of these capacitors so really you need 00:15:11.06000:15:11.070 to test them in order to really know 00:15:12.77000:15:12.780 what side is the outside foil and you 00:15:15.32000:15:15.330 can verily very clearly see that there 00:15:18.23000:15:18.240 is a polarity to these capacitors so 00:15:23.42000:15:23.430 I'll grab one of my my Brown dip ones 00:15:26.15000:15:26.160 here all right and I'll hold this one 00:15:29.30000:15:29.310 this one has absolutely no markings on 00:15:31.34000:15:31.350 it so we'll test this one out here and 00:15:35.09000:15:35.100 see this one here okay and I'll reverse 00:15:38.48000:15:38.490 the leads 00:15:46.69000:15:46.700 it's just shorting here got these leads 00:15:48.79000:15:48.800 I'll twist it up there we go so we can 00:15:51.79000:15:51.800 clearly see that this end here is the 00:15:54.49000:15:54.500 band end right here even though there 00:15:57.37000:15:57.380 are no markings on this capacitor so you 00:15:59.95000:15:59.960 can see the difference is there there's 00:16:01.27000:16:01.280 the lower amplitude this way and I'll 00:16:03.04000:16:03.050 reverse the leads and we can see that we 00:16:08.74000:16:08.750 have higher amplitude this way so this 00:16:14.05000:16:14.060 end here is the shielded end so now what 00:16:17.80000:16:17.810 we want to do is since we're going to be 00:16:19.42000:16:19.430 testing these things you know we're 00:16:21.31000:16:21.320 going to you know if you're replacing a 00:16:22.81000:16:22.820 whole lot of these things in a radio 00:16:24.22000:16:24.230 you're going to be you know basically 00:16:26.17000:16:26.180 have a small bag full of these things so 00:16:28.51000:16:28.520 you don't want to be doing this as 00:16:29.86000:16:29.870 you're you know putting these things in 00:16:31.69000:16:31.700 the radio you kind of want to pre grade 00:16:33.16000:16:33.170 these things and find out which end 00:16:34.66000:16:34.670 really is the Bandon so that you do 00:16:36.37000:16:36.380 install these things correctly to short 00:16:38.89000:16:38.900 these leads out here so so what we're 00:16:41.77000:16:41.780 going to do is create a small circuit 00:16:43.18000:16:43.190 that does this a little bit easier for 00:16:44.92000:16:44.930 us and we'll check out maybe a couple of 00:16:48.28000:16:48.290 different ideas and see what we can 00:16:49.95000:16:49.960 design here and make a little make a 00:16:52.90000:16:52.910 little test jig for these things before 00:16:55.93000:16:55.940 I start building a small project I 00:16:57.61000:16:57.620 usually like to check my own stock and 00:16:59.68000:16:59.690 see if I have enough parts and pieces to 00:17:01.75000:17:01.760 make this with the with the parts that I 00:17:03.52000:17:03.530 have on hand so I would like to build 00:17:07.06000:17:07.070 this into a smaller project box and it 00:17:09.55000:17:09.560 just so happens that I have another one 00:17:10.93000:17:10.940 around 00:17:11.50000:17:11.510 I built the TDR out of the same one I 00:17:13.36000:17:13.370 can't find the other project box I put 00:17:16.06000:17:16.070 it in a very safe place so that I would 00:17:18.19000:17:18.200 find it the next time as I can as I can 00:17:20.92000:17:20.930 now see so anyways I'll locate this 00:17:22.84000:17:22.850 other project box it looks just like 00:17:24.16000:17:24.170 this one here except of course there's 00:17:26.47000:17:26.480 nothing in it it's just a solid you know 00:17:28.42000:17:28.430 cast box here so I'll end up using this 00:17:31.48000:17:31.490 box here and the reason I want to use 00:17:33.67000:17:33.680 this box over a plastic box is this is 00:17:36.67000:17:36.680 completely shielded you got to remember 00:17:38.47000:17:38.480 we have an oscilloscope that's down at 00:17:40.51000:17:40.520 about 5 millivolts per division and 00:17:42.31000:17:42.320 maybe even 1 millivolt per division so 00:17:45.04000:17:45.050 if we have a plastic box a lot of noise 00:17:47.32000:17:47.330 is going to get into there from anything 00:17:49.21000:17:49.220 that's basically around it the thing is 00:17:51.19000:17:51.200 any kind of wire length inside this box 00:17:53.68000:17:53.690 if it was plastic would act as an 00:17:56.23000:17:56.240 antenna and we'd be picking up all sorts 00:17:57.73000:17:57.740 of just noise and random garbage so 00:18:00.82000:18:00.830 we want to do is we want to have 00:18:02.11000:18:02.120 everything enclosed in a solid a cast 00:18:04.89900:18:04.909 box here another thing that we have to 00:18:07.89900:18:07.909 think about is you know a battery so I'm 00:18:10.53900:18:10.549 going to need to install a battery in 00:18:11.95000:18:11.960 here now most likely going to end up 00:18:13.21000:18:13.220 using a 9-volt battery for this so you 00:18:15.73000:18:15.740 know it's going to take up a small 00:18:16.87000:18:16.880 portion of this box so I have to locate 00:18:19.65900:18:19.669 things inside of this project box so 00:18:22.02900:18:22.039 that you know this whole thing will work 00:18:23.62000:18:23.630 out you know I need to put a BNC jack on 00:18:26.20000:18:26.210 here you know all I need to put a switch 00:18:27.82000:18:27.830 on it somewhere the battery will have to 00:18:30.07000:18:30.080 be mounted in here they'll have to be a 00:18:31.33000:18:31.340 small circuit board in here that you 00:18:34.29900:18:34.309 know all of our parts and pieces are 00:18:35.71000:18:35.720 going to be on and we also have to think 00:18:38.04900:18:38.059 if we're going to say I'm going to have 00:18:39.63900:18:39.649 two alligator clips sticking out of the 00:18:41.62000:18:41.630 top of this box or something like that 00:18:44.15900:18:44.169 alright now I'm going to also have to 00:18:46.41900:18:46.429 have an LED beside each alligator clip 00:18:49.69000:18:49.700 so that I know when this thing is moving 00:18:51.66900:18:51.679 around like this one it's reversing the 00:18:53.40900:18:53.419 polarity of the capacitor so that we can 00:18:55.77900:18:55.789 note that you know the amplitude 00:18:56.91900:18:56.929 difference on the screen we're going to 00:18:58.69000:18:58.700 have to have something that's going to 00:19:00.00900:19:00.019 mark the side that's the band end so I'm 00:19:03.25000:19:03.260 going to have to have maybe some rubber 00:19:04.53900:19:04.549 grommets and then you know maybe some 00:19:06.54900:19:06.559 LEDs on the top of the box so everything 00:19:09.22000:19:09.230 has to be taken into account because we 00:19:10.81000:19:10.820 can't you know push the battery down on 00:19:12.34000:19:12.350 top of the LEDs and we also need space 00:19:15.12900:19:15.139 for the for the wires to come out of the 00:19:17.83000:19:17.840 top of the box so the battery will have 00:19:20.04900:19:20.059 to sit over to one side and this is all 00:19:21.63900:19:21.649 stuff that you have to think about 00:19:22.62900:19:22.639 before you plan this so what you do is 00:19:25.65900:19:25.669 of course you get your box and you know 00:19:27.12900:19:27.139 you put the battery inside and you move 00:19:28.89900:19:28.909 things around and you know you pawned 00:19:31.14900:19:31.159 over some things for a little while and 00:19:33.10000:19:33.110 then when you you know come to thinking 00:19:35.52900:19:35.539 okay you know this layout is going to 00:19:37.33000:19:37.340 work then of course you can start 00:19:38.86000:19:38.870 building with that layout so now in 00:19:42.39900:19:42.409 order for this to make testing easier we 00:19:45.27900:19:45.289 obviously need some form of a circuit 00:19:46.96000:19:46.970 that's going to take this you know 00:19:49.29900:19:49.309 capacitor and it's going to reverse it 00:19:51.43000:19:51.440 and of course we don't want any imposed 00:19:53.47000:19:53.480 noise from the circuit that it's around 00:19:55.83000:19:55.840 so in order to make a circuit that's 00:19:58.89900:19:58.909 going to reverse this we're going to 00:20:00.61000:20:00.620 need something that's going to look like 00:20:03.03900:20:03.049 this 00:20:14.77900:20:14.789 so we can look at this as right here if 00:20:18.04900:20:18.059 we were to have the capacitor under test 00:20:20.29900:20:20.309 right here this is the capacitor under 00:20:23.93000:20:23.940 test okay and say this here is the the 00:20:27.82900:20:27.839 scope common and this is the scope you 00:20:31.90900:20:31.919 know that the center conductor will just 00:20:33.64900:20:33.659 put plus here for just for ease of 00:20:36.43900:20:36.449 drawing okay so this is the center 00:20:38.62900:20:38.639 conductor of the oscilloscope probe and 00:20:40.81900:20:40.829 this here is the scope probe common so 00:20:44.59900:20:44.609 if we want to have this in the circuit 00:20:46.96900:20:46.979 say this is the negative side of the 00:20:48.37900:20:48.389 capacitor here we're going to need to 00:20:50.65900:20:50.669 close this switch and we're going to 00:20:53.26900:20:53.279 need to close this switch in order for 00:20:55.24900:20:55.259 the positive probe of our oscilloscope 00:20:57.97900:20:57.989 or the center conductor of the cable to 00:21:00.01900:21:00.029 be attached to this side of the 00:21:01.43000:21:01.440 capacitor which then would make this 00:21:03.58900:21:03.599 this side here and then of course this 00:21:06.04900:21:06.059 would run to ground so you can see we 00:21:07.69900:21:07.709 have a circuit here now so then in order 00:21:10.48900:21:10.499 to reverse this capacitor in order to 00:21:12.55900:21:12.569 flip it these two switches would have to 00:21:14.38900:21:14.399 open and then this switch and this 00:21:17.32900:21:17.339 switch would have to close and then of 00:21:19.36900:21:19.379 course that would make this side running 00:21:22.00900:21:22.019 up to the to the center conductor here 00:21:23.86900:21:23.879 and then this side here would end up 00:21:25.81900:21:25.829 becoming the common side because this 00:21:28.43000:21:28.440 switch is connected to ground and we're 00:21:30.22900:21:30.239 going to also need some form of say an 00:21:33.16900:21:33.179 LED or something at this point to denote 00:21:37.81900:21:37.829 when this side here is the the common 00:21:41.38900:21:41.399 side or whether this side here is going 00:21:43.51900:21:43.529 to be the common side so we're going to 00:21:45.07900:21:45.089 also need two LEDs to do that so now we 00:21:48.68000:21:48.690 can do this with relays and of course 00:21:50.71900:21:50.729 we're going to have a little bit of 00:21:51.55900:21:51.569 current consumption if we do that we're 00:21:53.18000:21:53.190 going to here click click click click 00:21:54.34900:21:54.359 inside this box or we can do this within 00:21:57.40900:21:57.419 IC and I'll probably end up using an IC 00:22:00.43900:22:00.449 because there's a you know limited 00:22:02.49900:22:02.509 current draw with n IC we you know 00:22:05.02900:22:05.039 there's a bunch of ICS that that 00:22:06.46900:22:06.479 basically work as a single pole single 00:22:09.22900:22:09.239 throw switches and you know I'll find 00:22:12.37900:22:12.389 something that's rather common to use 00:22:14.35900:22:14.369 and we'll make this particular circuit 00:22:17.38900:22:17.399 using a bunch of ICS now if we use an IC 00:22:19.51900:22:19.529 and it's got a bunch of fats inside it 00:22:21.52900:22:21.539 we're going to also want to have 00:22:23.18000:22:23.190 something on you know this particular 00:22:25.12900:22:25.139 point here which basically is you know 00:22:27.82900:22:27.839 to do 00:22:28.61000:22:28.620 like this one diode like this and one 00:22:31.40000:22:31.410 diode like this and that's going to also 00:22:33.35000:22:33.360 limit this basically to about point six 00:22:36.79900:22:36.809 or 0.7 of a volt on each side so just 00:22:38.87000:22:38.880 say there's a bit of a charge on that 00:22:40.40000:22:40.410 capacitor so you forgot to discharge it 00:22:42.59000:22:42.600 a little bit or if there's you know you 00:22:44.57000:22:44.580 have static you're not going to zap this 00:22:46.94000:22:46.950 I see if we use an IC so this is 00:22:49.19000:22:49.200 basically just going to protect it and 00:22:50.63000:22:50.640 limit the voltage that goes into the 00:22:53.09000:22:53.100 circuit now of course you would always 00:22:54.74000:22:54.750 make sure every single capacitor is 00:22:56.69000:22:56.700 discharged before you stick it into 00:22:58.54900:22:58.559 circuit and all this is going to do is 00:23:00.74000:23:00.750 protect the eye see that these switches 00:23:02.72000:23:02.730 are in and of course we would want the 00:23:04.40000:23:04.410 same thing on this particular side here 00:23:07.28000:23:07.290 and it would be exactly like this so 00:23:11.03000:23:11.040 basically all that's doing is this is 00:23:12.44000:23:12.450 limiting this input circuit were cap 00:23:15.02000:23:15.030 acid or under test is to about point 00:23:16.79000:23:16.800 seven of a volt now keep in mind that 00:23:18.71000:23:18.720 we're testing most of this down at 00:23:20.48000:23:20.49000:23:20.99000:23:21.000 oh no 10 you know maybe you know with 00:23:23.87000:23:23.880 our amplitude maybe we're exceeding 50 00:23:26.15000:23:26.160 60 70 millivolts with the humming are 00:23:28.22000:23:28.230 and that we're imposing into this 00:23:30.41000:23:30.420 capacitor who knows but this is going to 00:23:32.93000:23:32.940 be up around six or seven hundred 00:23:35.20000:23:35.210 millivolts just about a volt so you know 00:23:39.02000:23:39.030 this is a well beyond our our our test 00:23:42.20000:23:42.210 so this is just protecting this here so 00:23:45.71000:23:45.720 now we're going to also need to do is 00:23:47.03000:23:47.040 we're going to need to implement some 00:23:48.62000:23:48.630 sort of a circuit that's going to close 00:23:50.03000:23:50.040 these two and close these two and then 00:23:52.40000:23:52.410 it's going to have to do this right in 00:23:53.96000:23:53.970 order to flip this capacitor back and 00:23:56.39000:23:56.400 forth and back and forth so we're going 00:23:59.03000:23:59.040 to need some sort of a flip-flop 00:24:00.62000:24:00.630 probably a D type flip-flop or something 00:24:03.16900:24:03.179 like that and then if this is an in and 00:24:05.81000:24:05.820 I see these are going to be controlled 00:24:07.66900:24:07.679 so this side here right and this side 00:24:11.51000:24:11.520 here would go to one leg of the 00:24:13.66900:24:13.679 flip-flop and then this side here and of 00:24:16.40000:24:16.410 course this side here would go to 00:24:17.90000:24:17.910 another part of the foot flip-flop now 00:24:20.29900:24:20.309 keep in mind that this is just only a 00:24:22.01000:24:22.020 rough sketch and I'm just trying to get 00:24:24.14000:24:24.150 the idea across when it comes to 00:24:26.36000:24:26.370 actually designing this we'll go over to 00:24:28.16000:24:28.170 the whiteboard and take a look at it 00:24:30.20000:24:30.210 there so now that we have a flip-flop 00:24:32.39000:24:32.400 that's basically just going back and 00:24:33.77000:24:33.780 forth like this you know once this one 00:24:36.08000:24:36.090 this side is positive say you know we're 00:24:38.90000:24:38.910 going to probably not use a just a 74 Hz 00:24:42.35000:24:42.360 we will probably use a CD 74 HCI C's for 00:24:47.48000:24:47.490 this because we are dealing with a 00:24:48.86000:24:48.870 9-volt battery just 74 Hz logic is 00:24:51.89000:24:51.900 usually only good to between both 5 & 7 00:24:54.08000:24:54.090 volts maximum so we're going to be using 00:24:56.33000:24:56.340 a 9-volt battery so we're going to be 00:24:57.77000:24:57.780 wanting to use parts that start with CD 00:25:00.68000:25:00.690 and of course we'll take a look at the 00:25:02.09000:25:02.100 data sheet just to make sure that you 00:25:04.34000:25:04.350 know it will be fine around the 9-volt 00:25:06.59000:25:06.600 area so now that we have this this this 00:25:10.22000:25:10.230 type flip-flop here now we need also a 00:25:12.02000:25:12.030 timer that's going to set out a pulse 00:25:14.33000:25:14.340 into this that's going to tell this to 00:25:16.61000:25:16.620 go back and forth like this so of course 00:25:19.76000:25:19.770 when this side is high this side is low 00:25:21.74000:25:21.750 right and then when this side is high 00:25:23.39000:25:23.400 this side is low so basically what this 00:25:25.37000:25:25.380 is going to do is it's just going to 00:25:26.51000:25:26.520 close these two switches and then close 00:25:28.58000:25:28.590 these two switches and then close these 00:25:30.32000:25:30.330 two so you know when these two are 00:25:32.09000:25:32.100 closed these are open obviously and it's 00:25:34.07000:25:34.080 just going to go back and forth like 00:25:35.45000:25:35.460 this and we also want to set the timing 00:25:38.21000:25:38.220 rate of this timer so that when we have 00:25:41.57000:25:41.580 this thing on the bench and we're 00:25:43.25000:25:43.260 looking at say our oscilloscope here we 00:25:45.65000:25:45.660 want it to go slow enough so that when 00:25:47.36000:25:47.370 we can see the amplitude change on our 00:25:49.40000:25:49.410 oscilloscope the amplitude goes down and 00:25:52.16000:25:52.170 then the amplitude goes up we want to 00:25:53.72000:25:53.730 have a chance when it goes down again to 00:25:56.06000:25:56.070 look at the box and note which led on 00:25:58.64000:25:58.650 which side of the box is going to be led 00:26:01.01000:26:01.020 up so when we know that you know the 00:26:03.35000:26:03.360 amplitude is low and this led is lit up 00:26:05.45000:26:05.460 we'll know that this side here would be 00:26:07.49000:26:07.500 the band end of the capacitor so that's 00:26:10.22000:26:10.230 what we want to try and do so these are 00:26:11.72000:26:11.730 the parameters that we're basically 00:26:12.95000:26:12.960 dealing with we have a 9-volt battery so 00:26:15.44000:26:15.450 we know that we're going to need like 00:26:16.61000:26:16.620 you know is s CD 74 HC parts or just CD 00:26:20.06000:26:20.070 parts the 555 timer is good for nine 00:26:23.21000:26:23.220 volts so we don't really have to worry 00:26:24.44000:26:24.450 about that we'll use a five five five 00:26:26.00000:26:26.010 over here probably a D flip-flop or 00:26:28.31000:26:28.320 something like that and I'll have to 00:26:31.13000:26:31.140 figure out some really common part for 00:26:33.29000:26:33.300 this so that way you know it's easy to 00:26:35.84000:26:35.850 put together now if you have a bigger 00:26:37.73000:26:37.740 box you don't need to use a small box 00:26:39.44000:26:39.450 like I'm doing you can build this onto 00:26:41.21000:26:41.220 that dumb you know that proto board 00:26:43.01000:26:43.020 stuff and you can use through-hole icees 00:26:45.14000:26:45.150 I'll probably end up building this for 00:26:47.45000:26:47.460 myself with surface mount stuff just so 00:26:49.31000:26:49.320 that I can fit it right inside this box 00:26:51.62000:26:51.630 and then you know this box will have a B 00:26:53.30000:26:53.310 and C come off of it and a power switch 00:26:55.91000:26:55.920 and it'll probably have two little 00:26:56.78000:26:56.790 alligator clips now the the cables that 00:26:59.69000:26:59.700 are going to come out of this box I want 00:27:01.10000:27:01.110 to be shielded right up to the alligator 00:27:03.38000:27:03.390 clips because you know if we have just 00:27:05.36000:27:05.370 two long wires sticking out of here 00:27:06.77000:27:06.780 those are really to acting as two 00:27:08.54000:27:08.550 antennas so the more shielding we can 00:27:10.76000:27:10.770 get right up to the alligator clips the 00:27:12.68000:27:12.690 better so I'll have two small shielded 00:27:14.93000:27:14.940 pieces of coax coming up here and of 00:27:16.79000:27:16.800 course we want you know a little bit of 00:27:18.20000:27:18.210 lead length so we can move them around 00:27:19.55000:27:19.560 if we have you know large axial 00:27:21.62000:27:21.630 capacitor we can clip them onto the ends 00:27:23.69000:27:23.700 or if we have one of the newer style 00:27:26.33000:27:26.340 ones we have this one here we have one 00:27:28.64000:27:28.650 of the newer style ones like this you 00:27:30.14000:27:30.150 know we can just you know put the two 00:27:31.58000:27:31.590 leads together and clip them in like 00:27:33.08000:27:33.090 this so the whole idea is to make this 00:27:35.42000:27:35.430 thing functional especially if you're 00:27:37.10000:27:37.110 going through all sorts of different 00:27:38.21000:27:38.220 types of capacitors you know we want 00:27:40.16000:27:40.170 this thing to be about just as versatile 00:27:42.02000:27:42.030 as we can make it so now that we have 00:27:44.66000:27:44.670 the plan here I'll figure out an actual 00:27:47.21000:27:47.220 circuit and I'll draw it up and we'll 00:27:48.68000:27:48.690 head on over to the white board and I'll 00:27:50.51000:27:50.520 explain it there this is the circuit 00:27:53.78000:27:53.790 I've designed for our little capacitor 00:27:55.34000:27:55.350 testing so I ended up using a CD 74 HC 00:27:59.24000:27:59.250 four zero six six to flip the capacitor 00:28:02.33000:28:02.340 around in circuit now this is an IC and 00:28:04.43000:28:04.440 it's a CD 74 HC four zero six six it's 00:28:08.39000:28:08.400 not just a 74 HC four oh six six and the 00:28:10.73000:28:10.740 reason that I use this one is that it 00:28:12.98000:28:12.990 will go up to ten volts remember that we 00:28:15.08000:28:15.090 need to keep the supply voltage of our 00:28:16.85000:28:16.860 ICS well within a safe zone I'm using a 00:28:19.67000:28:19.680 nine volt battery over here to power 00:28:21.53000:28:21.540 this and again this is all just due to 00:28:23.30000:28:23.310 size constraints I have that little 00:28:25.58000:28:25.590 aluminum box or that little cast box 00:28:27.56000:28:27.570 that I showed you that I'm going to end 00:28:28.97000:28:28.980 up fitting this all in if it's around 00:28:31.10000:28:31.110 here somewhere I still haven't found it 00:28:32.45000:28:32.460 but I'll fit all that into that box 00:28:35.50000:28:35.510 again you know you can build this into 00:28:37.67000:28:37.680 any kind of size box if you have a 00:28:38.93000:28:38.940 larger aluminum box you can you know of 00:28:41.42000:28:41.430 course use a different kind of battery 00:28:43.73000:28:43.740 style power source for this at you know 00:28:46.01000:28:46.020 a bunch of double-a batteries or 00:28:47.09000:28:47.100 whatever fits in that box just keep in 00:28:48.89000:28:48.900 mind that the box has to be either solid 00:28:50.81000:28:50.820 metal or solid aluminum or a cast box 00:28:53.12000:28:53.130 some sort of conductive box because 00:28:55.40000:28:55.410 again our Cilla scope is running down 00:28:57.35000:28:57.360 you know between 1 and 5 millivolts it's 00:28:59.24000:28:59.250 going to pick up any kind of noise no 00:29:01.28000:29:01.290 power supplies running into this thing 00:29:02.75000:29:02.760 at all it should be battery-powered so 00:29:06.08000:29:06.090 we'll get back to the circuit I've drawn 00:29:07.43000:29:07.440 this I see the same way that you would 00:29:09.32000:29:09.330 kinda 00:29:09.65000:29:09.660 look at Relays just yet make it a little 00:29:11.51000:29:11.520 bit easier to understand so how this IC 00:29:13.97000:29:13.980 works is really quite simple it really 00:29:15.74000:29:15.750 is just four switches inside of one IC 00:29:18.44000:29:18.450 so pin 13 pin 5 pin 12 and pin 6 are the 00:29:22.04000:29:22.050 control pins so say pin 13 goes high 00:29:24.58000:29:24.590 that'll connect pin 2 and pin 1 so 00:29:27.14000:29:27.150 technically it just closes the switch 00:29:28.31000:29:28.320 inside so pin 13 and pin 6 are tied 00:29:31.43000:29:31.440 together pin 12 and pin 3 are tied 00:29:33.53000:29:33.540 together so basically it's just closing 00:29:35.42000:29:35.430 the switches like this and this is all 00:29:37.40000:29:37.410 done within an IC there's very low 00:29:39.44000:29:39.450 current consumption you don't get the 00:29:40.85000:29:40.860 clicking from a relay and you know it's 00:29:43.55000:29:43.560 a it's a real consistent test because 00:29:45.38000:29:45.390 we're using FETs inside this in order to 00:29:47.30000:29:47.310 switch this in circuit now there will be 00:29:49.70000:29:49.710 a little bit of resistance in the switch 00:29:52.01000:29:52.020 and I'll explain that a little bit it's 00:29:53.96000:29:53.970 between 15 and 20 ohms but that's 00:29:56.15000:29:56.160 absolutely fine for testing these 00:29:57.80000:29:57.810 capacitors there'll be no issues with 00:29:59.54000:29:59.550 this whatsoever 00:30:00.35000:30:00.360 so this was a really good solution the 00:30:02.33000:30:02.340 cd70 for AC 4 0 6 6 is a really common 00:30:05.66000:30:05.670 part it's an off-the-shelf part you 00:30:07.40000:30:07.410 should be able to find out with no 00:30:08.42000:30:08.430 problems again you can build this 00:30:09.95000:30:09.960 through-hole you don't need to build a 00:30:11.45000:30:11.460 surface mount the only reason I'm 00:30:12.62000:30:12.630 building this surface no it's because in 00:30:14.18000:30:14.190 my little box it's is hiding here 00:30:16.55000:30:16.560 somewhere and I'll put all the stuff 00:30:18.35000:30:18.360 inside that little box so ah these are 00:30:21.53000:30:21.540 b'av 99s these are just their two diodes 00:30:24.95000:30:24.960 in 1 SOT 23 package you don't need to 00:30:28.22000:30:28.230 use the Vav 99 you can use a 1 and 4 1 5 00:30:31.22000:30:31.230 2 or a 1 and 9 1 4 or if you think 00:30:34.55000:30:34.560 you're going to be crazy and leave a 00:30:35.75000:30:35.760 capacitor charge and stuff it into the 00:30:37.64000:30:37.650 circuit you can use a 1 in 4 double O 7 00:30:41.00000:30:41.010 s or whatever you want to use remember 00:30:42.50000:30:42.510 this is just working at a really low 00:30:44.69000:30:44.700 frequency is you know you're coupling 00:30:46.67000:30:46.680 the 60 cycle signaling from your body 00:30:49.10000:30:49.110 really and you know just you know 00:30:51.14000:30:51.150 inducing hum into the circuit so that 00:30:52.97000:30:52.980 you can see which end is the shielded 00:30:54.59000:30:54.600 end so really not too picky so I use the 00:30:57.41000:30:57.420 Vav 99s just because they fit on a 00:30:59.06000:30:59.070 little circuit board quite nicely so and 00:31:01.55000:31:01.560 all I'll get into this here in a little 00:31:03.95000:31:03.960 bit I've already got that little circuit 00:31:05.57000:31:05.580 board already pre drawn and ready to go 00:31:07.94000:31:07.950 and we'll get into that next I'll show 00:31:09.71000:31:09.720 you how I've drawn that up so that's one 00:31:11.78000:31:11.790 of the reasons that I use these they 00:31:12.98000:31:12.990 just they fit on there really quite 00:31:14.27000:31:14.280 nicely so now here I've got a CD 401 3 00:31:18.71000:31:18.720 which is a flip-flop is a D style 00:31:20.42000:31:20.430 flip-flop and what that what this 00:31:23.38900:31:23.399 really does is when it receives a pulse 00:31:25.45900:31:25.469 in pin 11 of this I see what it does is 00:31:28.33900:31:28.349 it just basically this pin will go high 00:31:30.64900:31:30.659 this will go low and then it will 00:31:32.26900:31:32.279 receive another pulse and it turns the 00:31:33.68000:31:33.690 other way and it just keeps going back 00:31:35.20900:31:35.219 and forth like this now you can see I've 00:31:37.60900:31:37.619 got two really high brightness LEDs here 00:31:40.21900:31:40.229 and the reason that they're high 00:31:41.53900:31:41.549 brightness is because I'm using a 22 K 00:31:44.41900:31:44.429 to ground resistor and you can use one 00:31:47.29900:31:47.309 or two it really doesn't matter the 00:31:49.15900:31:49.169 reason they're I'm using this is because 00:31:50.71900:31:50.729 they pull very very low current and they 00:31:53.26900:31:53.279 are still pretty bright at that point so 00:31:55.33900:31:55.349 I don't want to use up my battery power 00:31:57.34900:31:57.359 lighting LEDs you got to remember in the 00:31:59.47900:31:59.489 circuit one LED will always be on it's 00:32:01.90900:32:01.919 just going back and forth so when this 00:32:04.82000:32:04.830 side here goes high this LED will glow 00:32:07.48900:32:07.499 now this LED here should be positioned 00:32:11.14900:32:11.159 by the negative part of the switch so 00:32:14.29900:32:14.309 pin eight and pin nine it were pin pin 00:32:17.69000:32:17.700 four and pin eight run out to your 00:32:19.09900:32:19.109 alligator clip that's where this LED 00:32:21.61900:32:21.629 should be located alright so where this 00:32:25.03900:32:25.049 LED should be located should be close to 00:32:27.58900:32:27.599 pin 1 and pin 11 so what's going to 00:32:30.13900:32:30.149 happen is is when this side goes high it 00:32:32.81000:32:32.820 closes this switch and that what that's 00:32:35.38900:32:35.399 doing is that's bringing this side of 00:32:37.00900:32:37.019 the capacitor to ground and we remember 00:32:40.31000:32:40.320 that we're looking for the negative side 00:32:41.74900:32:41.759 of the capacitor or the shielded side of 00:32:43.51900:32:43.529 the capacitor and you want this LED 00:32:45.88900:32:45.899 close to this side you want the red LED 00:32:48.20000:32:48.210 close to this side so when this side 00:32:50.41900:32:50.429 goes high this one here is pulling this 00:32:52.57900:32:52.589 side of the capacitor to ground again 00:32:54.73900:32:54.749 we're looking for the shielded side of 00:32:57.07900:32:57.089 the capacitor if you have the LEDs 00:32:59.02900:32:59.039 reversed you'll end up marking the wrong 00:33:01.07000:33:01.080 side of your capacitor and I'll show you 00:33:02.81000:33:02.820 how to test for that in the end to make 00:33:04.48900:33:04.499 sure that you have the LED on the right 00:33:06.25900:33:06.269 end just in case that's a little bit 00:33:08.06000:33:08.070 confusing again the we have a pulse 00:33:11.57000:33:11.580 going into pin 11 here so again this is 00:33:13.31000:33:13.320 just going like this and you can see the 00:33:14.93000:33:14.940 action with the LEDs the LED you'll see 00:33:16.90900:33:16.919 the LEDs move back and forth this is a 00:33:19.12900:33:19.139 five five five timer and what this 00:33:21.40900:33:21.419 little 555 timer is doing is just 00:33:22.96900:33:22.979 creating the pulses in order to tell 00:33:24.73900:33:24.749 this flip-flop to do its flip-flopping 00:33:26.93000:33:26.940 so it's just going to keep it doing this 00:33:28.84900:33:28.859 now I chose a 180 K resistor in a 1k 00:33:32.41900:33:32.429 resistor because I find that to be a 00:33:34.03900:33:34.049 very nice balance you don't want this to 00:33:36.37900:33:36.389 go too 00:33:37.13000:33:37.140 because you're not going to be able to 00:33:38.15000:33:38.160 look at the screen and then all you know 00:33:39.47000:33:39.480 really quickly look down to the box and 00:33:40.82000:33:40.830 then see which LEDs letting mark the 00:33:42.29000:33:42.300 line on it right you want enough time so 00:33:44.27000:33:44.280 that you know when you see the the 00:33:45.86000:33:45.870 amplitude goes small you can look at the 00:33:47.90000:33:47.910 box see which LEDs lit and draw a line 00:33:49.97000:33:49.980 on and then by that time it's already 00:33:51.35000:33:51.360 back over to the other side again and 00:33:53.24000:33:53.250 I'll explain all this in the end and 00:33:55.58000:33:55.590 you'll see how this actually functions 00:33:57.14000:33:57.150 so you can speed this up if you want if 00:33:59.69000:33:59.700 you find that this is a little bit too 00:34:01.07000:34:01.080 slow and you know you want to be 00:34:02.54000:34:02.550 Superman as you're you know grading all 00:34:04.76000:34:04.770 your capacitors in your uterus hammering 00:34:06.71000:34:06.720 them through really quick you can change 00:34:08.41900:34:08.429 this 180 K resistor down to 150 K and 00:34:11.36000:34:11.370 it's going to go quicker 120 K and 00:34:13.55000:34:13.560 you're really working alright if you 00:34:15.88900:34:15.899 find that 180 K is too fast up into 220 00:34:18.86000:34:18.870 and you'll have plenty of time to sit 00:34:20.75000:34:20.760 there and have a sleep between the LEDs 00:34:22.85000:34:22.860 as they're switching back and forth okay 00:34:25.04000:34:25.050 so this hundred an eighty K resistor you 00:34:27.35000:34:27.360 can put a VR in there again I'm keeping 00:34:29.57000:34:29.580 it simple I'm I'm dealing with size 00:34:31.49000:34:31.500 constraint because of that little box 00:34:33.16900:34:33.179 that I've got so I just want this thing 00:34:35.87000:34:35.880 basically turn on a switch and the thing 00:34:37.58000:34:37.590 just starts doing its action and I can 00:34:39.13900:34:39.149 great cap so it's just a happy medium so 00:34:41.63000:34:41.640 180 K and 1 K work very well I'm using a 00:34:44.54000:34:44.550 22 mic tantalum capacitor down here and 00:34:47.69000:34:47.700 the reason I'm using a 22 mic tantalum 00:34:49.73000:34:49.740 capacitor is because I have a lot of 00:34:51.16900:34:51.179 them so that's really the only reason 00:34:53.47000:34:53.480 there's a point 0 1 cap coming off of 5 00:34:56.18000:34:56.190 just to keep noise out of the 5 5 5 00:34:58.87000:34:58.880 you'll see here that these are all the 00:35:00.98000:35:00.990 supply lines for all the ICS we have pin 00:35:03.83000:35:03.840 14 and pin 14 pin 7 and pin 7 for both 00:35:06.62000:35:06.630 of these ICS 00:35:07.61000:35:07.620 and for 8 and 1 for the 5 5 5 so 14 14 4 00:35:12.62000:35:12.630 and 8 are all positive so 4 & 8 and this 00:35:15.02000:35:15.030 is pin 14 and there's a pin 14 on this 00:35:16.97000:35:16.980 that also has to be tied to positive and 00:35:18.71000:35:18.720 we have pin 7 pin 7 and pin 1 so there's 00:35:21.89000:35:21.900 a pin 7 on this IC that has to go to 00:35:23.63000:35:23.640 ground there is a pin 7 on this IC as we 00:35:26.78000:35:26.790 can see here that goes to ground and 00:35:28.22000:35:28.230 then we have pin 1 here going to ground 00:35:29.87000:35:29.880 and that's really just the supply again 00:35:31.61000:35:31.620 you can put the switch in the positive 00:35:32.84000:35:32.850 or the negative side absolutely fine 00:35:34.43000:35:34.440 whatever you think will work just fine 00:35:36.95000:35:36.960 for you so I've got a 22 mic cap on the 00:35:40.22000:35:40.230 supply here just to keep noise out of 00:35:42.59000:35:42.600 the circuit when this thing is switching 00:35:44.65000:35:44.660 what else can I tell you here I think 00:35:47.60000:35:47.610 that's pretty much it this will draw 00:35:50.27000:35:50.280 between 00:35:50.96000:35:50.970 to eight milliamps somewhere in there 00:35:53.21000:35:53.220 depending on the ICS and the 00:35:55.19000:35:55.200 manufacturer and everything that's 00:35:57.71000:35:57.720 really quite nice if you use release 00:35:59.30000:35:59.310 you're going to end up with quite a bit 00:36:01.25000:36:01.260 more current consumption so that was the 00:36:03.53000:36:03.540 whole idea of of using a 9-volt battery 00:36:06.50000:36:06.510 and a bunch of ICS we can you know we'll 00:36:08.56900:36:08.579 get a really long life out of this out 00:36:11.66000:36:11.670 of this little switch so everything 00:36:13.40000:36:13.410 should work just fine 00:36:14.39000:36:14.400 scope common goes to pin 10 and pin 9 so 00:36:17.45000:36:17.460 basically pin 9 and pin 10 of the 406 6 00:36:20.18000:36:20.190 we'll just tie to the chassis or to the 00:36:22.06900:36:22.079 box and then the BNC Center that you 00:36:24.98000:36:24.990 have coming rate that goes right out 00:36:26.93000:36:26.940 into your oscilloscope will tie rate to 00:36:29.08900:36:29.099 pin 2 and pin 3 so and of course that's 00:36:32.69000:36:32.700 that's you know a continual and then you 00:36:35.63000:36:35.640 know this isn't moving this is your 00:36:37.22000:36:37.230 scope pot yours in your scope comm 00:36:38.80900:36:38.819 there's nothing moving there that's that 00:36:40.04000:36:40.050 stays there and then of course the 00:36:41.63000:36:41.640 switching is going to do its switching 00:36:42.95000:36:42.960 at that point inside the IC and flip 00:36:44.96000:36:44.970 that capacitor around as this 555 timer 00:36:48.17000:36:48.180 is telling this flip-flop to go back and 00:36:49.97000:36:49.980 forth and that's pretty much it so what 00:36:53.83900:36:53.849 I'll do is I'll take you over to the 00:36:54.85900:36:54.869 computer now and I'll show you the 00:36:56.80900:36:56.819 little layout that I've got designed up 00:36:59.51000:36:59.520 and it's a service mount layout again 00:37:01.04000:37:01.050 you don't have to do it surface mount 00:37:02.39000:37:02.400 you can build it through-hole or however 00:37:03.55900:37:03.569 you want to build this you can build a 00:37:05.12000:37:05.130 dead bug style whatever works for you 00:37:08.15000:37:08.160 so let's head on over to the computer 00:37:10.48000:37:10.490 this is the surface mount version 00:37:12.62000:37:12.630 circuit board that I've come up with for 00:37:14.21000:37:14.220 this little capacitor tester so this is 00:37:17.63000:37:17.640 really quite blown up this is a really 00:37:19.28000:37:19.290 small circuit board but I've just 00:37:20.96000:37:20.970 enhanced it so that it's easier to see 00:37:22.64000:37:22.650 on camera here so this is the top layer 00:37:26.59900:37:26.609 the green layer is the top and the black 00:37:28.49000:37:28.500 is the backside of the circuit board so 00:37:30.23000:37:30.240 this is a double-sided circuit board 00:37:31.81900:37:31.829 this little I see here is the 555 timer 00:37:34.52000:37:34.530 this is pin 1 this is the timing cap 00:37:36.71000:37:36.720 that 22 micro farad tantalum here these 00:37:39.34900:37:39.359 are Oh 402 parts this is 180 K resistor 00:37:42.58900:37:42.599 this is the 1k resistor and this is the 00:37:44.48000:37:44.490 point 0 1 micro farad capacitor off pin 00:37:47.00000:37:47.010 5 this here is the other 22 micro farad 00:37:49.73000:37:49.740 tantalum that's across the supply this 00:37:52.40000:37:52.410 here is the cd40 1 3 which is the the 00:37:56.24000:37:56.250 flip-flop and this is the 4 0 6 6 over 00:37:59.93000:37:59.940 here the is CD 74 HC 406 6 this is 00:38:03.34900:38:03.359 what's going to be doing 00:38:04.31000:38:04.320 switching here these here are the screws 00:38:07.79000:38:07.800 where it mounts to the chassis of that 00:38:10.25000:38:10.260 little aluminum or a cast box that I've 00:38:13.13000:38:13.140 got these are the resistors that's on 00:38:15.92000:38:15.930 the back side this resistor is a 22 K 00:38:18.29000:38:18.300 resistor and this is the LED this LED 00:38:20.57000:38:20.580 correlates to this side this is the test 00:38:23.51000:38:23.520 lead that runs out this side this is the 00:38:25.46000:38:25.470 center conductor and I will solder the 00:38:27.20000:38:27.210 shield or the braid of that little piece 00:38:28.91000:38:28.920 of coax to this piece of the circuit 00:38:30.80000:38:30.810 board here and then of course we want 00:38:32.84000:38:32.850 the LED close to that rubber grommet 00:38:35.15000:38:35.160 where the where the test lead runs out 00:38:37.28000:38:37.290 and it's the same for this side this is 00:38:38.63000:38:38.640 where the center conductor of our test 00:38:40.40000:38:40.410 lead runs up to the alligator clip the 00:38:42.41000:38:42.420 shield of the coax will solder to here 00:38:44.24000:38:44.250 and this LED correlates with this side 00:38:47.92000:38:47.930 so these are the high brightness LEDs 00:38:50.66000:38:50.670 here these are 1206 parts here these are 00:38:53.51000:38:53.520 22 22 K resistors this is where the 00:38:56.78000:38:56.790 supply or nine volt supply runs in right 00:38:59.12000:38:59.130 here and this is where the BNC signal 00:39:02.36000:39:02.370 runs out this goes to the BNC jack on 00:39:04.61000:39:04.620 the box and that goes out to our Scylla 00:39:06.11000:39:06.120 scope from this little point here and 00:39:08.18000:39:08.190 that's really how this works so this is 00:39:11.12000:39:11.130 really quite small and I'll show you 00:39:12.62000:39:12.630 exactly how this is going to go together 00:39:14.54000:39:14.550 here in the next shot here is the 00:39:18.41000:39:18.420 completed little capacitor testing box 00:39:20.45000:39:20.460 here we can see that I've got my 00:39:22.82000:39:22.830 alligator clips fastened to some 00:39:24.44000:39:24.450 shielded Koh access to some teflon coax 00:39:26.60000:39:26.610 here the shielding runs up to about this 00:39:28.52000:39:28.530 point here and about this point here you 00:39:30.77000:39:30.780 don't need to use teflon coax you can 00:39:32.30000:39:32.310 use any kind of coax you want I just 00:39:33.65000:39:33.660 have a bunch of this stuff around I've 00:39:35.87000:39:35.880 put some heat shrink on the ends here 00:39:37.49000:39:37.500 just to stiffen things up where that the 00:39:39.53000:39:39.540 center conductor runs out to the 00:39:41.03000:39:41.040 alligator clip because you know we're 00:39:42.32000:39:42.330 going to be moving this around and 00:39:43.52000:39:43.530 moving in in and out of circuit quite a 00:39:45.41000:39:45.420 bit and I want to get some longevity out 00:39:47.09000:39:47.100 of this without having the connections 00:39:48.62000:39:48.630 break now of course nothing sticks to 00:39:50.66000:39:50.670 teflon very well so I've left a little 00:39:53.12000:39:53.130 bit of braid exposed and this heat 00:39:55.19000:39:55.200 shrink here it has a little bit of glue 00:39:56.78000:39:56.790 inside of it so it sticks to the braid 00:39:58.25000:39:58.260 quite nicely and we see the 00:40:00.92000:40:00.930 corresponding LED for this wire here and 00:40:03.32000:40:03.330 the corresponding LED for this wire here 00:40:05.30000:40:05.310 when this LED is lit this one here is 00:40:08.06000:40:08.070 tied to ground and when this LED is let 00:40:10.64000:40:10.650 this side here is tied to ground so we 00:40:12.47000:40:12.480 know which end to mark our band on these 00:40:14.99000:40:15.000 are two little rubber grommets here that 00:40:16.49000:40:16.500 I put in this 00:40:17.63000:40:17.640 is the BNC Jack here that will run out 00:40:19.51900:40:19.529 to the oscilloscope and there's a bunch 00:40:21.98000:40:21.990 of screws here that just hold the 00:40:23.26900:40:23.279 circuit board in and this is the on and 00:40:24.98000:40:24.990 off switch on the side so on the bottom 00:40:28.19000:40:28.200 half you can see here I've got a little 00:40:29.50900:40:29.519 9-volt battery stuck in there and 00:40:31.25000:40:31.260 there's a little piece of butyl tape 00:40:32.32900:40:32.339 that's just holding it in this is the 00:40:34.88000:40:34.890 circuit board that I built and this is 00:40:37.09900:40:37.109 the little switch in the negative lead 00:40:38.56900:40:38.579 I'll just zoom in to this here so we can 00:40:40.94000:40:40.950 take a little closer look at the surface 00:40:43.22000:40:43.230 mount stuff so you can see the ICS here 00:40:49.70000:40:49.710 that's the little 555 timer that's the 00:40:52.06900:40:52.079 406 six down in there and that's the 401 00:40:54.62000:40:54.630 3 flip-flop and that's the little 00:40:56.93000:40:56.940 tantalum capacitor the timing cap and so 00:40:59.75000:40:59.760 on and so forth just like on the layout 00:41:01.37000:41:01.380 those are all the little Oh 402 parts 00:41:04.00900:41:04.019 right down there the hundred and eighty 00:41:05.24000:41:05.250 K the 1k and the the point zero one mic 00:41:08.56900:41:08.579 capacitor you can see how I've soldered 00:41:12.25900:41:12.269 the braid of the coax right to the 00:41:14.18000:41:14.190 circuit board here and then the center 00:41:15.58900:41:15.599 conductor runs up to this little spot 00:41:17.15000:41:17.160 this little SOT 23 package part here is 00:41:20.35900:41:20.369 that b'av 99 diode that's just 00:41:22.37000:41:22.380 protection so I don't zap the IC in 00:41:24.28900:41:24.299 there that's the same on this and I 00:41:26.02900:41:26.039 soldered them in sideways because if I 00:41:27.55900:41:27.569 ever need to replace them their be 00:41:28.97000:41:28.980 pretty easy to get out this way and put 00:41:31.27900:41:31.289 back in again you can use a 1 in 400 00:41:33.20000:41:33.210 seven or a nine one four or anything 00:41:35.87000:41:35.880 like that you know it's again we're you 00:41:38.59900:41:38.609 know we're dealing with 60 cycle 00:41:40.16000:41:40.170 frequency here so there's nothing that 00:41:41.50900:41:41.519 needs to be too incredibly fast see what 00:41:44.63000:41:44.640 else can I tell you those are the LEDs 00:41:45.92000:41:45.930 that are soldered in you'll see that 00:41:47.59900:41:47.609 there's a space between the circuit 00:41:48.92000:41:48.930 board here in the actual case and that's 00:41:50.69000:41:50.700 because there's parts on the backside of 00:41:52.09900:41:52.109 the circuit board and there's also a 00:41:53.56900:41:53.579 soldering on there so when I put the the 00:41:57.38000:41:57.390 bottom portion of the box together here 00:41:59.93000:41:59.940 I had to cut this out on the corner here 00:42:02.63000:42:02.640 and on this corner because the circuit 00:42:04.27900:42:04.289 board goes you know very close to the 00:42:05.96000:42:05.970 corner here and they've got this kind of 00:42:07.81900:42:07.829 extruded lip that runs all the way 00:42:10.22000:42:10.230 around the entire box here so there's 00:42:13.27900:42:13.289 enough space between the backside of the 00:42:14.99000:42:15.000 circuit board and the case to leave this 00:42:16.75900:42:16.769 strip in here it just goes between the 00:42:18.98000:42:18.990 circuit board and the case you can see 00:42:21.52900:42:21.539 here here's the circuit board that will 00:42:23.05900:42:23.069 go right in between here and that's 00:42:26.02900:42:26.039 pretty much the box so when we turn the 00:42:28.19000:42:28.200 thing on this is about the speed that it 00:42:29.80900:42:29.819 runs out with the 00:42:31.60900:42:31.619 with the 180k resistor here you can see 00:42:36.12000:42:36.130 how fast that moves back and forth so 00:42:39.54000:42:39.550 that gives us enough time to mark our 00:42:40.98000:42:40.990 capacitor and you know of course look at 00:42:43.65000:42:43.660 the screen in the you know load a new 00:42:45.24000:42:45.250 capacitor I think that's about a nice 00:42:47.07000:42:47.080 comfortable speed for grading these 00:42:48.81000:42:48.820 capacitors so next let's hook this thing 00:42:51.45000:42:51.460 up to an oscilloscope and see how it 00:42:53.58000:42:53.590 works we're ready to check the polarity 00:42:57.54000:42:57.550 of some capacitors in our test jig so 00:43:00.78000:43:00.790 I've got the oscilloscope set to 5 00:43:02.40000:43:02.410 millivolts per division I've got the 00:43:04.65000:43:04.660 alligator clip shorted here and I'll 00:43:06.33000:43:06.340 plug this in and I'll show you that it's 00:43:07.56000:43:07.570 a relatively quiet circuit and see how 00:43:10.77000:43:10.780 quiet that is right now now you got to 00:43:13.83000:43:13.840 keep in mind that through this I see 00:43:15.51000:43:15.520 when this side is grounded it's about 17 00:43:18.27000:43:18.280 ohms to ground and then when this side 00:43:19.98000:43:19.990 is on at 17 ohms to ground so we have 00:43:22.41000:43:22.420 217 or around that own paths 1 from 00:43:25.44000:43:25.450 positive and 1 to ground and that's just 00:43:27.99000:43:28.000 the basically the resistance imposed by 00:43:31.05000:43:31.060 the IC itself so even though we still 00:43:34.41000:43:34.420 have this you know we're going to still 00:43:36.12000:43:36.130 pick up noise from the oscilloscope if 00:43:37.92000:43:37.930 we bring it close to it in everything 00:43:39.96000:43:39.970 but you know for this actual test this 00:43:42.54000:43:42.550 is absolutely fine and for this little 00:43:44.31000:43:44.320 test jiggets is fine so when we open 00:43:46.71000:43:46.720 these alligator clips you're going to 00:43:47.91000:43:47.920 see lots of noise on the screen and 00:43:49.80000:43:49.810 that's absolutely normal because these 00:43:51.48000:43:51.490 are acting as antennas and this is 00:43:54.12000:43:54.130 actually just picking up noise from the 00:43:55.68000:43:55.690 scope itself even you can see the amount 00:43:57.45000:43:57.460 of noise that comes in from the CRT so 00:44:00.72000:44:00.730 when we put the capacitor in here under 00:44:02.94000:44:02.950 test it actually acts as a filter across 00:44:05.19000:44:05.200 the circuit itself so there is no 00:44:06.75000:44:06.760 problem with the amount of noise that we 00:44:08.52000:44:08.530 see so what we'll do now is we'll put a 00:44:11.94000:44:11.950 capacitor in here let's take this orange 00:44:13.68000:44:13.690 dip capacitor and test it out and Mark 00:44:16.14000:44:16.150 the band end so here we have me being 00:44:20.60900:44:20.619 the 60 cycle antenna again and you can 00:44:24.93000:44:24.940 see the difference in amplitude here as 00:44:27.08000:44:27.090 its switching so we see this LED is on 00:44:31.14000:44:31.150 and the amplitude is lower so this is 00:44:33.48000:44:33.490 the band end you see so now that we see 00:44:37.62000:44:37.630 this LED on we would mark this end as 00:44:39.66000:44:39.670 the band remember we're always looking 00:44:41.13000:44:41.140 for the lowest amplitude 00:44:47.58000:44:47.590 so I'll take my Philip marker and I'll 00:44:50.71000:44:50.720 put a little line on this end and I'll 00:44:53.74000:44:53.750 know that that now would be the lower 00:44:55.96000:44:55.970 impedance portion of the circuit this 00:44:57.60900:44:57.619 would go to the chassis or this side 00:44:59.65000:44:59.660 would go to the plate side if we have 00:45:01.57000:45:01.580 this in an amplifier again we can see 00:45:04.83900:45:04.849 that this side has a band on it but we 00:45:06.46000:45:06.470 can see that it doesn't really mean 00:45:07.81000:45:07.820 anything you know according to the 00:45:10.27000:45:10.280 outside shielding or anything this might 00:45:12.16000:45:12.170 be some sort of coating that they've put 00:45:13.66000:45:13.670 on or I don't know what they're doing 00:45:15.25000:45:15.260 and why they've put this on this one end 00:45:17.02000:45:17.030 but this side here you know clearly 00:45:20.50000:45:20.510 denotes the outside foil or the outside 00:45:22.96000:45:22.970 metallized polypropylene or metallized 00:45:25.35900:45:25.369 PVC layer okay so there's one so we've 00:45:29.68000:45:29.690 marked this one and you can see the 00:45:31.81000:45:31.820 speed is comfortable so that you know 00:45:33.43000:45:33.440 what's you know you're not losing 00:45:35.02000:45:35.030 control of what you're doing so put this 00:45:37.33000:45:37.340 one in all right and I'll put my fingers 00:45:41.05000:45:41.060 on here all right so we know that this 00:45:47.02000:45:47.030 end is the band end also okay so I'll 00:45:53.56000:45:53.570 mark this as the band end now if you 00:45:57.13000:45:57.140 don't want to leave your felt marker on 00:45:58.66000:45:58.670 there you know you can use an ink that 00:46:00.76000:46:00.770 will easily come off I find that you 00:46:03.52000:46:03.530 know a little bit alcohol will just 00:46:04.69000:46:04.700 remove these lines even if it is one of 00:46:06.40000:46:06.410 these sharpies so you know a lot of 00:46:09.16000:46:09.170 people don't want that line on the 00:46:10.39000:46:10.400 capacitor when it's in circuit I've kind 00:46:13.51000:46:13.520 of learned to live with it I kind of 00:46:15.28000:46:15.290 like to have the the capacitors clean 00:46:16.93000:46:16.940 myself but that's fine for underneath 00:46:19.39000:46:19.400 the chassis I'm now just beginning to 00:46:21.16000:46:21.170 leave the lines on like you will end up 00:46:22.63000:46:22.640 seeing in most of my videos so this one 00:46:25.30000:46:25.310 here this side here the this opposite 00:46:27.73000:46:27.740 side here this one on this side is the 00:46:29.77000:46:29.780 band end where I've drawn that little 00:46:31.24000:46:31.250 black line so let's test another one 00:46:45.65000:46:45.660 so we can see that the opposite end on 00:46:48.10900:46:48.119 this capacitor is the band end so this 00:46:51.55900:46:51.569 end is the band end on this capacitor so 00:46:54.04900:46:54.059 you can see there really is no rhyme or 00:46:55.40000:46:55.410 reason for these capacitors you know 00:46:58.03900:46:58.049 they're just kind of going down the line 00:46:59.48000:46:59.490 any old way they're the same capacitor 00:47:01.81900:47:01.829 and they're just printing the the the 00:47:04.22000:47:04.230 labeling on any side there so it really 00:47:06.49900:47:06.509 is important to mark that off let's test 00:47:10.57900:47:10.589 out this one here and check out its band 00:47:13.40000:47:13.410 and okay is that in the shot there it is 00:47:18.04900:47:18.059 okay I'll put my fingers on here okay so 00:47:26.74900:47:26.759 this end is the band end right here 00:47:28.72000:47:28.730 so now we would mark this end as the 00:47:32.26900:47:32.279 band end and that's just how simple it 00:47:34.67000:47:34.680 is to grade and check your capacitor so 00:47:37.19000:47:37.200 you know that you're putting them in 00:47:38.48000:47:38.490 circuit the correct way and that's how 00:47:41.39000:47:41.400 this little fixture works so what we're 00:47:44.45000:47:44.460 going to end up doing next is I'll show 00:47:45.76900:47:45.779 you how to measure which end is actually 00:47:48.95000:47:48.960 supposed to be the the negative end so 00:47:52.13000:47:52.140 that you have your LEDs corresponding to 00:47:54.07900:47:54.089 the correctly just in case you did find 00:47:55.78900:47:55.799 that a little bit confusing 00:47:57.81900:47:57.829 alright this is how we tell how we've 00:48:00.76900:48:00.779 got the right LED on the right lead so 00:48:04.22000:48:04.230 this is the lead here that we're going 00:48:05.56900:48:05.579 to test and we want to know if this LED 00:48:08.35900:48:08.369 is corresponding to this connecting to 00:48:10.78900:48:10.799 ground so we've got our our meter on 00:48:12.79900:48:12.809 ohms and we have our lead going into the 00:48:15.92000:48:15.930 alligator clip here and you can see that 00:48:18.52900:48:18.539 at 17 ohms when this LED comes on see 00:48:22.97000:48:22.980 that so we know that this end is 00:48:24.47000:48:24.480 connecting to ground and we have our 00:48:26.05900:48:26.069 polarity right so what I'll do now is 00:48:29.72000:48:29.730 I'll move this over to this side and 00:48:31.64000:48:31.650 you'll see roughly the same measurement 00:48:33.28900:48:33.299 on this side isn't LED there and lamp 00:48:45.27900:48:45.289 all right let's me trying to get a good 00:48:48.01900:48:48.029 ground on the box here there we go so 00:48:53.12000:48:53.130 that's how you tell so if you wire your 00:48:55.75900:48:55.769 LEDs up and you have them backwards if 00:48:57.44000:48:57.450 you leave some lead length you can just 00:48:59.21000:48:59.220 swap them around if you don't build a 00:49:01.03900:49:01.049 circuit board or something like that and 00:49:02.87000:49:02.880 that's how you tell that you've got the 00:49:04.88000:49:04.890 LED connected to the right side well 00:49:11.63000:49:11.640 we've come to the end of another video I 00:49:13.64000:49:13.650 hope you find this little circuit useful 00:49:16.19000:49:16.200 and I hope you enjoyed the video if you 00:49:18.04900:49:18.059 did give it a big thumbs up and hang 00:49:19.60900:49:19.619 around I'll try to make more videos just 00:49:21.65000:49:21.660 like this in the very near future take 00:49:23.69000:49:23.700 care bye for now 00:49:32.65000:49:32.660 you
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