00:00:24.450 hi and welcome back if you saw my last 00:00:29.22000:00:29.230 video you know I was in the process of 00:00:32.04000:00:32.050 selling my soul our capacitor tester I 00:00:34.32000:00:34.330 did the comparison between it and the 00:00:36.18000:00:36.190 two Heath kits and linked my eBay sales 00:00:41.93900:00:41.949 thing to the video and within six hours 00:00:45.57000:00:45.580 of putting it on eBay it was gone it 00:00:47.54900:00:47.559 just disappeared 00:00:48.84000:00:48.850 so that's sold and it sure is there's 00:00:52.20000:00:52.210 ticks and new hampshire in the 00:00:53.54900:00:53.559 springtime friend of mine calls me up 00:00:55.53000:00:55.540 this morning and says do you have any 00:00:57.79900:00:57.809 250 microfarad 304 well I sure do I have 00:01:05.79000:01:05.800 a bunch of capacitors in my junk box and 00:01:08.37000:01:08.380 this one here actually is a 250 plus 20 00:01:11.88000:01:11.890 plus 20 at 350 working volts but it's 00:01:16.68000:01:16.690 probably been in my junk box for some 30 00:01:19.44000:01:19.450 odd years just sitting there doing 00:01:21.99000:01:22.000 nothing and it's not wise to take these 00:01:25.13900:01:25.149 capacitors and connect them to the full 00:01:28.26000:01:28.270 working voltage right away 00:01:29.85000:01:29.860 when the capacitor has been sitting that 00:01:31.68000:01:31.690 long the electrolyte is usually settled 00:01:34.65000:01:34.660 out and you want to reform these things 00:01:36.90000:01:36.910 before you even try to put high voltage 00:01:38.96900:01:38.979 on them my soul our capacitor tester 00:01:41.76000:01:41.770 which is now gone did that very easily 00:01:44.07000:01:44.080 you just cranked up the voltage and it 00:01:46.49900:01:46.509 had a built-in milliamp meter now I 00:01:48.77900:01:48.789 could have gone to the problems or the 00:01:50.58000:01:50.590 trouble of taking my old triplet over 00:01:54.05900:01:54.069 here and hooking that up in series with 00:01:56.49000:01:56.500 my high voltage power supply up there 00:01:58.88900:01:58.899 and running test leads and test clips 00:02:01.44000:02:01.450 each and every place a little bit of 00:02:03.35900:02:03.369 table but I decided that since the 00:02:06.66000:02:06.670 solaiyur was gone I was going to put 00:02:08.99900:02:09.009 something like this together and this is 00:02:11.55000:02:11.560 just a BNC in for the DC a BNC out for 00:02:16.97900:02:16.989 the capacitor and a 5 milliampere motor 00:02:20.42000:02:20.430 motor yeah meter movement and I put a 00:02:24.36000:02:24.370 homemade shunt across there so that 00:02:26.28000:02:26.290 it'll handle 50 milli amperes as well 00:02:28.61900:02:28.629 because you don't want to start out on 5 00:02:30.27000:02:30.280 milliamps in case the capacitors shorted 00:02:32.58000:02:32.590 or 00:02:33.16000:02:33.170 from the get-go and again I could have 00:02:38.32000:02:38.330 used just the standard triplet but this 00:02:40.15000:02:40.160 makes it nice and neat and easy so I'm 00:02:42.49000:02:42.500 back in business here and we'll take a 00:02:43.99000:02:44.000 quick peek at once it's stated this 00:02:45.88000:02:45.890 thing couldn't be more dead simple we've 00:02:49.09000:02:49.100 got power in through the milliamp meter 00:02:51.79000:02:51.800 and back out to the capacitor and when 00:02:54.64000:02:54.650 we want the 50 milliampere scale we 00:02:57.49000:02:57.500 should switch in this shunt this 00:02:59.68000:02:59.690 homemade shunt and this is nothing but a 00:03:01.57000:03:01.580 length of iron wire that I had laying 00:03:03.97000:03:03.980 around that works out to about 1 ohm per 00:03:07.21000:03:07.220 foot and I needed a point 6 ohm shunt 00:03:10.78000:03:10.790 resistor to make this meter work at 50 00:03:13.87000:03:13.880 milli amperes to do a times 10 on the 00:03:16.30000:03:16.310 scale we won't bother going to the math 00:03:18.67000:03:18.680 there's a hundred websites out there to 00:03:20.56000:03:20.570 show you how to figure out the 00:03:22.09000:03:22.100 resistance of your meter and no you 00:03:23.83000:03:23.840 can't do it with an old meter you have 00:03:25.63000:03:25.640 to do it with a couple of resistors and 00:03:27.61000:03:27.620 measuring the current through it you can 00:03:29.50000:03:29.510 work out the resistance of the meter 00:03:31.21000:03:31.220 from that you can work out the 00:03:33.28000:03:33.290 resistance needed to make your times 10 00:03:35.32000:03:35.330 shunt that the it's dead simple as a 00:03:37.56900:03:37.579 hundred people have done it we won't 00:03:39.03900:03:39.049 bother just wanted to show you how 00:03:40.90000:03:40.910 stupid simple this was inside so what do 00:03:43.69000:03:43.700 we do with this thing well we hook up a 00:03:45.58000:03:45.590 BNC cable to the DC N and up here on our 00:03:51.27000:03:51.280 Keith get high voltage supply we have a 00:03:54.16000:03:54.170 BNC adapter over here we plug that in 00:03:58.30000:03:58.310 I'm going to turn the voltage all the 00:04:00.49000:04:00.500 way down to start with then we come back 00:04:05.62000:04:05.630 down here and I've got a BNC cable it 00:04:12.64000:04:12.650 plugs in on the capacitor side got a 00:04:17.74000:04:17.750 couple of clips on the end of it wrong 00:04:22.09000:04:22.100 capacitor now this one that's - and 250 00:04:27.52000:04:27.530 volt 250 micro farad's there so I'm 00:04:30.01000:04:30.020 going to clip this here we start on the 00:04:33.13000:04:33.140 50 milli ampere scale just in case 00:04:35.32000:04:35.330 everything goes to hell clip this on 00:04:40.06000:04:40.070 here and I'm going to start slowly 00:04:43.45000:04:43.460 turning the voltage up let's try to get 00:04:45.76000:04:45.770 this in the shot 00:04:47.55000:04:47.560 start bringing the voltage up see what 00:04:50.02000:04:50.030 happens you can see the current starts 00:04:51.73000:04:51.740 to rise and it's falling off pretty 00:04:53.41000:04:53.420 quickly so this looks like a fairly 00:04:54.91000:04:54.920 decent cap I'm going to flip over here 00:04:57.52000:04:57.530 in the 5 milliampere scale and slowly 00:05:01.45000:05:01.460 start working this thing up and you can 00:05:04.42000:05:04.430 see that plots a little noisy up there 00:05:06.46000:05:06.470 so I'm going to kick this back down but 00:05:09.61000:05:09.620 it looks like we're staying down in the 00:05:12.52000:05:12.530 1 milliampere range 00:05:14.73000:05:14.740 there's a hundred 150 and it's dropping 00:05:19.51000:05:19.520 off pretty quick it looks like this caps 00:05:21.34000:05:21.350 in fairly good shape there's 200 it's 00:05:29.08000:05:29.090 starting to fall a little bit slower now 00:05:31.48000:05:31.490 at 250 and it's sitting right up around 00:05:33.82000:05:33.830 5 milli amperes and you can see it's 00:05:38.41000:05:38.420 falling off so the capacitor is doing 00:05:41.02000:05:41.030 alright the current in it is fairly low 00:05:43.36000:05:43.370 you want to keep it down to a couple of 00:05:45.67000:05:45.680 milli amperes during this process you 00:05:48.01000:05:48.020 don't stress the capacitor so I'm going 00:05:52.78000:05:52.790 to let that sit right at that level for 00:05:54.88000:05:54.890 a few minutes and now it's falling off 00:05:59.20000:05:59.210 let's go back up here I'm going to bring 00:06:02.83000:06:02.840 it up to 300 volts and again it's 00:06:07.87000:06:07.880 falling off no it's jittering around a 00:06:10.18000:06:10.190 little bit not settle down or under 5 00:06:13.87000:06:13.880 milliamps I'll let that sit and lay our 00:06:17.38000:06:17.390 cap has been reforming for about an hour 00:06:19.69000:06:19.700 and I've been keeping an eye on it 00:06:22.66000:06:22.670 occasionally sneaking the voltage up and 00:06:24.88000:06:24.890 keeping it around 1 milliampere or less 00:06:28.27000:06:28.280 not to stress the cap and now that we're 00:06:31.03000:06:31.040 up to the working voltage of 350 we're 00:06:33.70000:06:33.710 down to about a hundred micro amperes so 00:06:36.46000:06:36.470 I think this capacitor is going to be ok 00:06:38.53000:06:38.540 for his little science project he's 00:06:40.24000:06:40.250 going to build the last step is going to 00:06:42.46000:06:42.470 be disconnect the cap and thoroughly 00:06:45.19000:06:45.200 discharge it and then I'll use my ESR 00:06:47.62000:06:47.630 meter to see how good the cap really is 00:06:51.42000:06:51.430 okay so we've discharged the cap and 00:06:54.28000:06:54.290 we've let it sit here for a couple of 00:06:56.59000:06:56.600 minutes with a shorting bar or shorting 00:06:59.80000:06:59.810 jumper 00:07:00.49000:07:00.500 and the reason I've done that is you'll 00:07:03.10000:07:03.110 find these capacitors if you discharge 00:07:05.29000:07:05.300 them with a resistor or even a 00:07:06.67000:07:06.680 screwdriver and you come back a couple 00:07:08.74000:07:08.750 minutes later you'll get another spark 00:07:10.42000:07:10.430 out of them you come back a few minutes 00:07:11.86000:07:11.870 after that you'll get another spark out 00:07:13.54000:07:13.550 of them it's a known effect with big 00:07:15.67000:07:15.680 electrolytic that they will rebuild some 00:07:18.16000:07:18.170 of the charge and that's why you see 00:07:20.38000:07:20.390 these great big oil filled high-voltage 00:07:22.30000:07:22.310 capacitors they always have a shorting 00:07:25.03000:07:25.040 wire across them because if they've been 00:07:27.97000:07:27.980 charged and yet they're disconnected 00:07:30.25000:07:30.260 they can build up a good portion of that 00:07:32.71000:07:32.720 charge again it won't have as big a 00:07:34.75000:07:34.760 current hit but they can build up to 00:07:37.51000:07:37.520 many thousands of volts and some of 00:07:39.82000:07:39.830 those big capacitors so you discharge 00:07:42.94000:07:42.950 them for a period of time to make sure 00:07:44.50000:07:44.510 it's down and I'll turn on my little 00:07:46.69000:07:46.700 Chinese esra meter here got this guy off 00:07:50.35000:07:50.360 eBay and it works extremely well you can 00:07:53.80000:07:53.810 test the equivalent series resistors 00:07:56.22000:07:56.230 resistance of a capacitor in circuit 00:07:58.63000:07:58.640 with this because it uses an extremely 00:08:01.54000:08:01.550 low voltage that won't turn on the 00:08:04.18000:08:04.190 transistors and diodes in the circuit 00:08:06.01000:08:06.020 and it's zeroed so I'm going to 00:08:08.86000:08:08.870 disconnect my short and I'm expecting 00:08:11.77000:08:11.780 about less than a tenth of an ohm there 00:08:14.71000:08:14.720 should be less than a tenth of an ohm 00:08:16.21000:08:16.220 here for this sized capacitor if it's 00:08:19.42000:08:19.430 any good and it's very good that's point 00:08:24.21900:08:24.229 zero six now our brand-new modern 00:08:26.46900:08:26.479 capacitor can you see that in the point 00:08:29.89000:08:29.900 zero 6 ohms a brand-new modern capacitor 00:08:33.79000:08:33.800 might get down to point zero four or 00:08:36.13000:08:36.140 point zero three ohms but for something 00:08:39.01000:08:39.020 this age that's been sitting in the junk 00:08:40.95900:08:40.969 box forever that's a pretty decent cap 00:08:43.98000:08:43.990 so now that we've reformed the 00:08:46.87000:08:46.880 electrolytic capacitor will hand this 00:08:49.45000:08:49.460 off to my buddy for his science project 00:08:51.10000:08:51.110 maybe I had to charge it up and hand it 00:08:53.23000:08:53.240 off no I won't do that 00:08:54.55000:08:54.560 and he'll be able to build his project 00:08:57.19000:08:57.200 and he'll be a happy camper so I'm going 00:08:59.29000:08:59.300 to give him a call and for now that's it 00:09:01.42000:09:01.430 we'll see you again okay okay okay I 00:09:03.88000:09:03.890 heard all of you out there yelling and 00:09:06.22000:09:06.230 hollering at me why didn't you put a 00:09:08.71000:09:08.720 discharge function on it so I did now we 00:09:12.88000:09:12.890 have operate 00:09:14.45000:09:14.460 and discharge so I won't have to 00:09:16.70000:09:16.710 disconnect the capacitor to discharge it 00:09:18.88900:09:18.899 all I have to do is flip the switch that 00:09:22.09000:09:22.100 is a double pole double throw two amps 00:09:26.63000:09:26.640 switch with both contacts or both poles 00:09:30.13900:09:30.149 parallel so that it's four amps worth 00:09:32.75000:09:32.760 going through a 5,000 ohm resistor and 00:09:36.28000:09:36.290 since my power supply will only produce 00:09:38.81000:09:38.820 about 400 volts that's about 80 million 00:09:41.54000:09:41.550 peers without a handle left with ease so 00:09:44.62000:09:44.630 there you have it now we have an operate 00:09:47.44900:09:47.459 discharge switch as well as the current 00:09:49.51900:09:49.529 switch that wills that's it this is 00:09:52.16000:09:52.170 really the end this time take care bye
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