00:00:05.650 hi there and welcome to another tech 00:00:07.88900:00:07.899 tips Tuesday in this episode we're going 00:00:10.47000:00:10.480 to check out choosing the correct 00:00:11.61000:00:11.620 capacitor for its intended application 00:00:14.28000:00:14.290 so whether you have an RF circuit an if' 00:00:16.89000:00:16.900 circuit an audio circuit or whatever 00:00:18.96000:00:18.970 choosing the correct capacitor is 00:00:20.88000:00:20.890 crucial for that circuits performance 00:00:23.13000:00:23.140 temperature stability and a whole bunch 00:00:24.92900:00:24.939 of other factors that's what we're going 00:00:26.58000:00:26.590 to take a look at in this video so let's 00:00:28.71000:00:28.720 get started here are the capacitors that 00:00:31.95000:00:31.960 I'm going to be talking about at the 00:00:33.69000:00:33.700 white board not in any specific order so 00:00:37.26000:00:37.270 these first two capacitors here are 00:00:38.70000:00:38.710 paper and foil capacitors and they are 00:00:40.91900:00:40.929 both faulty by now so if you have any 00:00:42.75000:00:42.760 equipment with these capacitors in them 00:00:44.45900:00:44.469 they've got to go now you may have 00:00:46.97900:00:46.989 tested these with your capacitance 00:00:48.29900:00:48.309 tester and said to yourself well they 00:00:49.77000:00:49.780 they test okay you know this one reads 00:00:51.47900:00:51.489 104 so that's point 1 micro farad and 00:00:53.66900:00:53.679 this one is point zero 5 and it reads 00:00:55.34900:00:55.359 absolutely fine well that's not a 00:00:57.59900:00:57.609 leakage test leakage test is a 00:00:59.25000:00:59.260 completely different thing now when 00:01:02.16000:01:02.170 people say that these capacitors go 00:01:03.56900:01:03.579 leaky that doesn't mean that they're 00:01:04.89000:01:04.900 leaking a substance like liquid or 00:01:06.78000:01:06.790 anything like that it just means that 00:01:08.07000:01:08.080 they're leaking DC across them so if you 00:01:11.10000:01:11.110 have an old book with yellowing pages in 00:01:13.41000:01:13.420 it chances are that book is pretty old 00:01:15.03000:01:15.040 and the paper is going acidic now the 00:01:17.31000:01:17.320 same thing is happening inside these 00:01:18.96000:01:18.970 capacitors because these capacitors have 00:01:20.85000:01:20.860 paper and foil inside them 00:01:22.77000:01:22.780 now when the paper goes acidic it passes 00:01:25.56000:01:25.570 DC from one side to the other and that's 00:01:27.96000:01:27.970 a function that these capacitors are not 00:01:29.94000:01:29.950 supposed to do they're only supposed to 00:01:31.23000:01:31.240 pass AC and block DC so these capacitors 00:01:36.45000:01:36.460 here if you want to picture a fault 00:01:38.28000:01:38.290 condition you can put a resistor across 00:01:40.29000:01:40.300 this and that's really what's going on 00:01:42.56000:01:42.570 now I know a lot of audio guys seem to 00:01:44.76000:01:44.770 like these old Bumblebee capacitors 00:01:46.26000:01:46.270 thinking that they make their audio 00:01:47.52000:01:47.530 circuits sound better 00:01:48.48000:01:48.490 well they didn't sound like that when 00:01:49.89000:01:49.900 they came from the factory because they 00:01:51.24000:01:51.250 weren't leaky and really what these 00:01:53.28000:01:53.290 things do in an audio amplifier since 00:01:55.74000:01:55.750 they passed DC through it puts DC 00:01:58.50000:01:58.510 voltage a positive DC voltage on the 00:02:00.51000:02:00.520 grid of the next tube driving it into 00:02:02.31000:02:02.320 hard Class A driving that tube into hard 00:02:05.28000:02:05.290 Class A causes it to draw excessive 00:02:07.29000:02:07.300 current and burns out plate resistors 00:02:09.21000:02:09.220 and does all sorts of bad things in old 00:02:11.69900:02:11.709 receivers these things are responsible 00:02:13.89000:02:13.900 for destroying if' transformers and 00:02:15.95900:02:15.969 burning out power supplies and doing all 00:02:17.45900:02:17.469 sorts of things 00:02:18.73000:02:18.740 so if you have old bumblebees in any of 00:02:20.53000:02:20.540 your equipment be prepared to be 00:02:23.11000:02:23.120 repairing the power supply or you know 00:02:25.27000:02:25.280 replacing tubes on a pretty constant 00:02:27.55000:02:27.560 basis these things will read plate final 00:02:29.89000:02:29.900 tubes like the audio output tubes they 00:02:32.50000:02:32.510 put a positive bias on the grids of the 00:02:35.11000:02:35.120 say you had 6l sixes this would put a 00:02:37.24000:02:37.250 positive voltage on the grids and cause 00:02:39.37000:02:39.380 the 6l6 to read plate which in turn 00:02:41.65000:02:41.660 destroys the tube in short order again 00:02:44.89000:02:44.900 through excessive plate current draw 00:02:46.96000:02:46.970 they even burn out audio output 00:02:48.76000:02:48.770 transformers so these guys have got to 00:02:51.22000:02:51.230 go and usually they get replaced with 00:02:52.63000:02:52.640 polypropylene style capacitors like this 00:02:55.83000:02:55.840 all right the next capacitor we're going 00:02:58.30000:02:58.310 to look at here is a mica capacitor and 00:02:59.92000:02:59.930 they are very very stable capacitors so 00:03:02.59000:03:02.600 they're stable over a very wide 00:03:03.79000:03:03.800 temperature range and you'll find these 00:03:05.62000:03:05.630 capacitors in oscillators and precision 00:03:08.14000:03:08.150 RF circuits and things like that 00:03:09.97000:03:09.980 very rarely do these things fail so if 00:03:13.00000:03:13.010 you're tempted to replace the style in 00:03:14.86000:03:14.870 this particular style of capacitor what 00:03:17.41000:03:17.420 you want to do first is make sure that 00:03:19.12000:03:19.130 it is definitely faulty in that there is 00:03:21.22000:03:21.230 some sort of a problem with it in 00:03:22.63000:03:22.640 receivers many of these capacitors are 00:03:25.15000:03:25.160 hand picked and if you replace these 00:03:27.82000:03:27.830 capacitors you'll have a real hard time 00:03:29.53000:03:29.540 getting the dial accurate again this 00:03:33.70000:03:33.710 capacitor right here is another very 00:03:35.74000:03:35.750 dependable capacitor this is a ceramic 00:03:37.48000:03:37.490 style capacitor now you never ever want 00:03:39.91000:03:39.920 to put this style of capacitor in any 00:03:42.07000:03:42.080 kind of oscillator circuit but these 00:03:44.02000:03:44.030 things are very dependable they never 00:03:45.43000:03:45.440 seem to fail so you'll find these as RF 00:03:48.34000:03:48.350 bypassing capacitors and I'll refer to 00:03:50.23000:03:50.240 all this again on the whiteboard this is 00:03:53.05000:03:53.060 a polypropylene style capacitor and 00:03:54.85000:03:54.860 these are great in audio amplifiers and 00:03:56.68000:03:56.690 they're also very good for RF coupling 00:03:58.66000:03:58.670 and things like that again not good for 00:04:01.66000:04:01.670 any kind of stability in an RF 00:04:03.13000:04:03.140 oscillator or anything like that this is 00:04:05.83000:04:05.840 an NPO style capacitor and these are 00:04:08.65000:04:08.660 extremely stable in RF oscillators they 00:04:12.04000:04:12.050 work very very well and the capacitance 00:04:14.47000:04:14.480 moves very very little with temperature 00:04:16.59900:04:16.609 change and that's very crucial in an RF 00:04:18.67000:04:18.680 oscillator so these are very very 00:04:20.86000:04:20.870 accurate this here is a 1206 part with 00:04:23.62000:04:23.630 just some legs assaulted on to it so 00:04:25.84000:04:25.850 that we can do some experiments later 00:04:27.54000:04:27.550 this is another newer style mica 00:04:30.61000:04:30.620 capacitor so really that's this 00:04:32.50000:04:32.510 that are in a different style package 00:04:33.88000:04:33.890 that's all this is these here are orange 00:04:37.06000:04:37.070 drop capacitors and these are also newer 00:04:39.34000:04:39.350 style capacitors this is an orange drop 00:04:41.20000:04:41.210 and this is a brown drop capacitor they 00:04:42.91000:04:42.920 call them they are also very very stable 00:04:45.04000:04:45.050 and you'll have absolutely no problems 00:04:47.41000:04:47.420 with these things unless of course 00:04:48.85000:04:48.860 there's been some form of temperature 00:04:50.47000:04:50.480 damage or anything like that this 00:04:52.72000:04:52.730 capacitor here is a polystyrene 00:04:53.97000:04:53.980 capacitor and you'll see these things in 00:04:56.20000:04:56.210 a lot of the newer solid state equipment 00:04:58.78000:04:58.790 they use them in oscillating circuits in 00:05:00.67000:05:00.680 tuners and all that kind of stuff these 00:05:03.10000:05:03.110 are very very stable as well but they're 00:05:04.90000:05:04.910 not very good with external temperature 00:05:06.76000:05:06.770 so you can't heat these things up 00:05:08.55000:05:08.560 polystyrene is very very soft and if you 00:05:11.77000:05:11.780 heat these things up the capacitance 00:05:13.81000:05:13.820 will change and when it cools down it 00:05:15.10000:05:15.110 will stay at that so it kind of has a 00:05:16.90000:05:16.910 memory effect so these should be used in 00:05:19.57000:05:19.580 relatively cool circuits if you're using 00:05:21.31000:05:21.320 anything like this in a vacuum tube 00:05:22.78000:05:22.790 circuit you need to use a lot of thermal 00:05:24.31000:05:24.320 decoupling and keep these things away 00:05:25.87000:05:25.880 from tubes when you're soldering these 00:05:27.94000:05:27.950 things you don't want to have very much 00:05:29.44000:05:29.450 dwell time with your soldering iron on 00:05:31.06000:05:31.070 these legs again or you'll cause damage 00:05:33.49000:05:33.500 to this particular style of capacitor on 00:05:37.18000:05:37.190 the white board here I've got all sorts 00:05:38.68000:05:38.690 of different styles of capacitors listed 00:05:40.51000:05:40.520 what I'm going to do is work down the 00:05:42.28000:05:42.290 list here and explain a little bit about 00:05:43.66000:05:43.670 each different style of capacitor and 00:05:45.64000:05:45.650 I'll give you an idea of the circuits 00:05:47.05000:05:47.060 that you'll find these in also talked a 00:05:49.48000:05:49.490 little bit about some of the capacitors 00:05:50.92000:05:50.930 on here and tell you what circuits they 00:05:52.42000:05:52.430 should be used in and shouldn't be used 00:05:54.28000:05:54.290 in after I'm done explaining what's on 00:05:56.77000:05:56.780 the board here we're going to turn this 00:05:58.00000:05:58.010 into usable experience we're going to go 00:05:59.62000:05:59.630 over to the bench and I'm going to 00:06:00.85000:06:00.860 demonstrate how the capacitance of these 00:06:03.31000:06:03.320 capacitors changes with temperature and 00:06:05.62000:06:05.630 we'll also take a look at some vibration 00:06:07.36000:06:07.370 and see how the capacitors react to some 00:06:10.06000:06:10.070 vibration very important to understand 00:06:11.89000:06:11.900 if you're designing or repairing any 00:06:13.36000:06:13.370 kind of circuitry and you're looking to 00:06:15.13000:06:15.140 substitute a capacitor alright the first 00:06:18.43000:06:18.440 capacitor we're going to talk about here 00:06:19.75000:06:19.760 is the np0 style capacitor the reason 00:06:22.33000:06:22.340 i've got 0 and brackets here is because 00:06:24.04000:06:24.050 a lot of people say NPO it's actually NP 00:06:26.80000:06:26.810 0 or C 0 G and this stands for negative 00:06:29.89000:06:29.900 positive 0 and these are extremely 00:06:32.02000:06:32.030 stable capacitors you'll find these 00:06:34.21000:06:34.220 capacitors in crystal oscillators 00:06:36.13000:06:36.140 variable frequency oscillators beat 00:06:37.87000:06:37.880 frequency oscillators and in RF coupling 00:06:40.24000:06:40.250 circuits so basically anywhere you find 00:06:42.55000:06:42.560 an NPO capacitor usually its RF related 00:06:45.73000:06:45.740 like the circuitry is RF related all 00:06:47.85000:06:47.860 right so the capacitance movement to 00:06:50.32000:06:50.330 temperature is positive negative 0 to 30 00:06:52.69000:06:52.700 parts per million per degree C and their 00:06:54.79000:06:54.800 usable temperature is negative 55 00:06:56.68000:06:56.690 degrees C to positive 125 degrees C so 00:07:00.01000:07:00.020 quite a usable range and very very 00:07:02.02000:07:02.030 stable the next capacitor down is the 00:07:05.11000:07:05.120 mica and it is also very very stable 00:07:07.18000:07:07.190 you'll also find it in the same kind of 00:07:08.95000:07:08.960 circuits that you find the NPO capacitor 00:07:11.50000:07:11.510 all right 00:07:13.03000:07:13.040 its accuracy really is positive negative 00:07:15.79000:07:15.800 50 parts per million per degrees C so 00:07:17.80000:07:17.810 not as good as the NPO but very good so 00:07:21.49000:07:21.500 you'll find you know these are mica 00:07:22.90000:07:22.910 capacitors and a lot of older receivers 00:07:24.88000:07:24.890 those dominoes style capacitors that I 00:07:26.53000:07:26.540 talked about those are mica and some of 00:07:28.75000:07:28.760 the newer style mica capacitors they 00:07:30.97000:07:30.980 almost look like a little brown piece of 00:07:32.35000:07:32.360 gum with two legs coming out of them 00:07:33.79000:07:33.800 those are also a mica style capacitor 00:07:35.95000:07:35.960 and we'll also take a look at some of 00:07:37.00000:07:37.010 these over on the bench here and you'll 00:07:38.38000:07:38.390 see what I'm talking about all right 00:07:40.57000:07:40.580 very very good for RF service as well so 00:07:43.12000:07:43.130 Mike and NPO are kind of the top of the 00:07:45.31000:07:45.320 list for any kind of oscillating 00:07:46.78000:07:46.790 circuits or you know any kind of RF 00:07:48.40000:07:48.410 circuitry whatsoever polystyrene are 00:07:51.43000:07:51.440 okay stable and they are temperature 00:07:54.06000:07:54.070 temperature sensitive so polystyrene 00:07:56.71000:07:56.720 caps are those little kind of clear caps 00:07:58.24000:07:58.250 and you can see the foil wound inside 00:08:00.13000:08:00.140 and the ends kind of look like they've 00:08:02.05000:08:02.060 got a pattern on them with two leads 00:08:03.67000:08:03.680 sticking out you'll find them a lot in 00:08:05.29000:08:05.300 tuners and solid-state equipment so when 00:08:08.62000:08:08.630 I say okay stable they're not as stable 00:08:10.42000:08:10.430 as the NPO or the mic up but they are 00:08:13.42000:08:13.430 very temperature sensitive and I'm 00:08:14.98000:08:14.990 talking about external temperature 00:08:16.45000:08:16.460 sensitive so if you get the actual case 00:08:18.25000:08:18.260 of a polystyrene capacitor hot it will 00:08:20.98000:08:20.990 move in capacitance and then when it 00:08:22.87000:08:22.880 cools down it will stay there so it will 00:08:25.06000:08:25.070 keep moving if you keep getting it hot 00:08:26.62000:08:26.630 so what I'm trying to say is you don't 00:08:28.45000:08:28.460 want to tie polystyrene capacitors to 00:08:30.61000:08:30.620 any hot tube pins if you're soldering 00:08:33.19000:08:33.200 them you got to be very very careful 00:08:35.17000:08:35.180 because the soldering iron will again 00:08:36.79000:08:36.800 change the capacitance a little and when 00:08:38.41000:08:38.420 it cools off it will stay there it won't 00:08:40.15000:08:40.160 return all right so polystyrene caps 00:08:43.24000:08:43.250 again in a lot of solid-state equipment 00:08:45.22000:08:45.230 you very very rarely find them in 00:08:47.14000:08:47.150 anything vacuum tube and if they are 00:08:48.91000:08:48.920 they have quite a bit of thermal relief 00:08:50.32000:08:50.330 and they are far away from the vacuum 00:08:52.39000:08:52.400 tubes these capacitors here are ceramic 00:08:55.72000:08:55.730 style capacitors the x5r x7r y5v 00:08:59.62000:08:59.630 zedd five you are either those disks 00:09:02.38000:09:02.390 tile capacitors with a leg on each side 00:09:04.24000:09:04.250 or you'll find them as small chip 00:09:05.95000:09:05.960 capacitors for surface mount use okay 00:09:09.79000:09:09.800 the X is the lower temperature the five 00:09:12.58000:09:12.590 is the higher temperature all right in 00:09:14.50000:09:14.510 the R is the actual usable range I 00:09:16.42000:09:16.430 didn't have enough space to write the 00:09:18.19000:09:18.200 usable range in here but that's really 00:09:19.66000:09:19.670 how this coding goes now these 00:09:22.30000:09:22.310 capacitors are great for RF bypass you 00:09:25.42000:09:25.430 don't ever want to use them in any 00:09:26.98000:09:26.990 oscillator circuits alright any kind of 00:09:29.68000:09:29.690 tuned circuits RF coupling is okay from 00:09:32.56000:09:32.570 stage to stage as long as there really 00:09:34.36000:09:34.370 is no interlock between the stages and 00:09:36.40000:09:36.410 when I say interlock one stage will 00:09:38.92000:09:38.930 affect the other all right 00:09:40.60000:09:40.610 so that's really what you want to you 00:09:43.57000:09:43.580 know use this particular style of 00:09:45.82000:09:45.830 capacitor for RF bypass they work 00:09:48.10000:09:48.110 absolutely great I use them for our 00:09:49.72000:09:49.730 bypassing everywhere all right 00:09:52.92000:09:52.930 polypropylene caps are good for audio 00:09:55.24000:09:55.250 and RF stage coupling they're not very 00:09:58.15000:09:58.160 very stable nowhere near as stable as 00:10:00.13000:10:00.140 anything up here but they are great for 00:10:02.23000:10:02.240 audio polychrome caps you find them a 00:10:03.94000:10:03.950 lot in audio amplifiers and in some RF 00:10:06.91000:10:06.920 circuits as well they are okay for that 00:10:08.50000:10:08.510 no oscillating circuits again absolutely 00:10:11.17000:10:11.180 not oscillating circuits are pretty much 00:10:13.78000:10:13.790 NPO and mica capacitors and maybe 00:10:16.54000:10:16.550 sometimes polystyrene all right 00:10:19.44000:10:19.450 tantalum capacitors are horrible for 00:10:21.52000:10:21.530 audio they're nonlinear but they are 00:10:23.41000:10:23.420 great audio are great RF bypassing 00:10:25.84000:10:25.850 capacitor or timing capacitors so if 00:10:28.33000:10:28.340 you're making a circuit with a 555 timer 00:10:29.92000:10:29.930 or something like that and you need some 00:10:31.99000:10:32.000 sort of stability you don't want 00:10:33.46000:10:33.470 anything to move around tamerlan's are 00:10:35.26000:10:35.270 great because they go above a micro 00:10:36.94000:10:36.950 farad quite easily and they are pretty 00:10:39.28000:10:39.290 temperature stable all right paper again 00:10:42.82000:10:42.830 no good if you find any paper caps and 00:10:44.68000:10:44.690 anything old you want to get rid of them 00:10:46.87000:10:46.880 there are some new paper and oil 00:10:48.46000:10:48.470 capacitors that are maybe ok some of the 00:10:51.34000:10:51.350 audio guys really like that kind of 00:10:52.99000:10:53.000 stuff but any kind of old paper 00:10:55.48000:10:55.490 capacitor you want to just get rid of so 00:10:57.52000:10:57.530 whether it's a bumblebee or a black 00:10:59.08000:10:59.090 beauty or just a regular you know foil 00:11:01.45000:11:01.460 paper style capacitor in the trash they 00:11:04.06000:11:04.070 go and replace them with a polypropylene 00:11:05.83000:11:05.840 style capacitor and that's really what's 00:11:09.67000:11:09.680 on this board here so what I'm going to 00:11:11.38000:11:11.390 do now is take the information that I've 00:11:13.15000:11:13.160 shown 00:11:13.40000:11:13.410 you hear and we'll go over to the bench 00:11:15.11000:11:15.120 and I'll demonstrate this with a 00:11:17.03000:11:17.040 capacitance meter an oscilloscope and 00:11:18.65000:11:18.660 some other tools what I've got set up 00:11:21.68000:11:21.690 here is a mica capacitor in the test 00:11:24.41000:11:24.420 leads of my capacitor tester this is 00:11:26.32900:11:26.339 just a drill vise holding them steady so 00:11:28.43000:11:28.440 this is our little test jig for now 00:11:30.00900:11:30.019 right here you'll see a green clip 00:11:32.54000:11:32.550 that's just an attempt to keep noise off 00:11:34.67000:11:34.680 the actual drill vise itself so now what 00:11:38.05900:11:38.069 I'm going to do is I'm going to take my 00:11:39.55900:11:39.569 hot air tool alright and I'm going to 00:11:41.50900:11:41.519 heat this thing up now I'm not going to 00:11:43.91000:11:43.920 take any temperature measurements of the 00:11:45.25900:11:45.269 actual capacitor itself our temperature 00:11:47.11900:11:47.129 measurement for today is screaming hot 00:11:49.15000:11:49.160 so basically you can picture this thing 00:11:51.74000:11:51.750 strapped to the side of a 10 watt 00:11:53.24000:11:53.250 resistor so I'm going to heat this thing 00:11:55.61000:11:55.620 up very very hot and we're going to see 00:11:57.41000:11:57.420 how much it actually moves in 00:11:59.05900:11:59.069 capacitance now of course this is going 00:12:00.71000:12:00.720 to get way way hotter than it would 00:12:02.62900:12:02.639 actually get in real service but still 00:12:04.67000:12:04.680 in a worst case scenario we can get an 00:12:06.47000:12:06.480 idea of how much this mica capacitor is 00:12:08.66000:12:08.670 going to move so I'll move you over here 00:12:11.60000:12:11.610 to the capacitor tester all right so 00:12:15.86000:12:15.870 really all we're going to be paying 00:12:16.93900:12:16.949 attention to is you know maybe these 00:12:18.65000:12:18.660 digits here at maximum this here is 00:12:21.41000:12:21.420 really just you know random air current 00:12:23.92900:12:23.939 moving over that capacitor at this point 00:12:26.80900:12:26.819 and maybe some noise mixed in there as 00:12:28.67000:12:28.680 well so we're at ninety six point three 00:12:31.42900:12:31.439 six eight picofarad and even if I move 00:12:33.62000:12:33.630 my hand close to it here I'll just put 00:12:35.17900:12:35.189 my hand close to it you can see how much 00:12:36.55900:12:36.569 it alters what we're seeing on the 00:12:38.99000:12:39.000 capacitor tester here so when I move the 00:12:42.43900:12:42.449 actual hot air tool in front of it 00:12:44.38900:12:44.399 you're going to see the digits go all 00:12:45.65000:12:45.660 crazy here but in the end we'll have a 00:12:48.43900:12:48.449 reading here so I'll give you an example 00:12:50.42000:12:50.430 I'll turn this thing on right now so let 00:12:52.42900:12:52.439 my my hotter tool get nice and hot 00:12:56.71000:12:56.720 so we're at ninety six point three six 00:13:00.26000:13:00.270 something like that Pico farad 00:13:02.56000:13:02.570 all right this hot air tool is already 00:13:04.82000:13:04.830 hot enough to melt solder so what I'm 00:13:06.53000:13:06.540 going to do is I'm going to bring the 00:13:08.06000:13:08.070 hotter to a close to the actual device 00:13:10.34000:13:10.350 under test and I'm going to heat it up 00:13:11.72000:13:11.730 so we'll keep a keep in mind here ninety 00:13:14.51000:13:14.520 six point three six so here we go 00:13:21.15000:13:21.160 okay so that's screaming hot I move the 00:13:23.13000:13:23.140 tool away so now we can get an accurate 00:13:25.11000:13:25.120 reading 00:13:25.74000:13:25.750 so from ninety six point three six to 00:13:28.44000:13:28.450 ninety six point five and as you can see 00:13:32.79000:13:32.800 it's coming down rather quickly so we 00:13:37.65000:13:37.660 have maybe point two of a Pico farad 00:13:39.66000:13:39.670 movement there still ninety six Pico 00:13:42.84000:13:42.850 farad so we haven't even moved one Pico 00:13:45.93000:13:45.940 farad that's pretty good just turn that 00:13:50.40000:13:50.410 off so maybe point two of movement there 00:13:55.19000:13:55.200 very very stable excellent for 00:13:57.54000:13:57.550 oscillator service these things and of 00:13:59.79000:13:59.800 course again we've made this thing you 00:14:01.86000:14:01.870 know way hotter than it would actually 00:14:03.15000:14:03.160 get in real service here and as you can 00:14:05.04000:14:05.050 see it's coming down to room temperature 00:14:06.36000:14:06.370 and it's coming back alright so I'll 00:14:10.02000:14:10.030 remove that from the test fixture now 00:14:15.15000:14:15.160 I'll put this NPO 00:14:16.11000:14:16.120 capacitor in here that we looked at on 00:14:18.06000:14:18.070 the piece of paper earlier it's that 00:14:19.47000:14:19.480 1206 part and I'll just put that in here 00:14:25.37000:14:25.380 okay let everything settle down here for 00:14:28.68000:14:28.690 a second so at 101 Pico farad 0.47 00:14:36.05000:14:36.060 okay so I'll turn the tool back on here 00:14:38.40000:14:38.410 again 00:14:40.60000:14:40.610 keep in mind when I get the tool close 00:14:42.22000:14:42.230 to it it's going to get all crazy 00:14:43.24000:14:43.250 because of the noise 00:14:46.47000:14:46.480 so 101.4 seven I'll heat this up move it 00:14:53.05000:14:53.060 away so on a 1.5 00:15:00.52000:15:00.530 you can see how quickly that returns now 00:15:02.65000:15:02.660 that was almost hot enough to D solder 00:15:04.51000:15:04.520 the leads off that part 00:15:06.81000:15:06.820 all right so very very stable component 00:15:11.29000:15:11.300 here we go right back at 101 point four 00:15:13.24000:15:13.250 seven again so extremely stable part 00:15:18.40000:15:18.410 excellent for oscillators so now what 00:15:20.44000:15:20.450 I'm going to do is I'm going to show you 00:15:21.25000:15:21.260 the opposite end of the spectrum here 00:15:22.96000:15:22.970 I'll remove this thing and I'll 00:15:25.36000:15:25.370 demonstrate just a standard ceramic 00:15:27.43000:15:27.440 capacitor like you see right here 00:15:29.20000:15:29.210 all right standard ceramic 00:15:38.34000:15:38.350 okay so it's in the vise I got my hands 00:15:41.88000:15:41.890 off of it and as you can see it is still 00:15:44.07000:15:44.080 moving and that's just because the heat 00:15:45.96000:15:45.970 of my fingers is settling off now into 00:15:51.39000:15:51.400 the test fixture all right this is 00:15:55.38000:15:55.390 supposed to be 103 or point zero one 00:15:58.05000:15:58.060 micro farad and we're coming up to that 00:15:59.67000:15:59.680 there we go okay now what I'm going to 00:16:03.87000:16:03.880 do is turn on the tool again 00:16:08.48000:16:08.490 and I'll just swipe this across the face 00:16:11.90000:16:11.910 of this capacitor a few times now this 00:16:14.24000:16:14.250 would be Oh opponent to Zed five you or 00:16:18.17000:16:18.180 something like that something yeah 00:16:22.57900:16:22.589 Zed five you would be close enough there 00:16:24.80000:16:24.810 is no actual rating on this so it's 00:16:26.42000:16:26.430 probably like I said five you said five 00:16:28.34000:16:28.350 be something like that here we go I'm 00:16:30.71000:16:30.720 gonna heat this thing up 00:16:36.10000:16:36.110 so now we're at point zero zero two 00:16:38.40000:16:38.410 micro farad point zero zero three point 00:16:43.81000:16:43.820 zero zero four as it's cooling down 00:16:45.97000:16:45.980 point zero zero five and so on you can 00:16:50.41000:16:50.420 see it counting up point zero zero seven 00:16:54.45000:16:54.460 point zero zero eight so now just think 00:16:58.33000:16:58.340 if you put one of these ceramic 00:16:59.44000:16:59.450 capacitors inside of say a vfo or any 00:17:03.13000:17:03.140 you know sensitive oscillator that 00:17:05.49000:17:05.500 oscillator would move all over the place 00:17:08.29000:17:08.300 and it would be uncontrollable just even 00:17:09.91000:17:09.920 slight chassis temperature changes would 00:17:12.28000:17:12.290 cause this thing to move right so I'll 00:17:14.86000:17:14.870 just touch it with my finger it's still 00:17:16.32900:17:16.339 climbing okay that's just holding it 00:17:20.80000:17:20.810 with my fingers let go of it incredible 00:17:25.60000:17:25.610 amounts of movement in these ceramic 00:17:27.25000:17:27.260 capacitors so definitely no good for 00:17:30.73000:17:30.740 audio as well because they have a thing 00:17:32.35000:17:32.360 called the piezoelectric effect and they 00:17:35.08000:17:35.090 become quite microphonic in audio 00:17:37.51000:17:37.520 service and I will show you an example 00:17:39.22000:17:39.230 of that here so ceramic capacitors you 00:17:42.07000:17:42.080 know like this here or the like should 00:17:44.47000:17:44.480 not be in any kind of audio signal path 00:17:46.96000:17:46.970 again great for you know RF decoupling 00:17:49.45000:17:49.460 or RF bypass service but um even at that 00:17:52.66000:17:52.670 you know I wouldn't I wouldn't try to 00:17:55.03000:17:55.040 have this thing in any kind of a signal 00:17:56.92000:17:56.930 path other than to you know drain our 00:17:58.75000:17:58.760 after ground really all right so now 00:18:01.75000:18:01.760 what I'll do is I'll put this capacitor 00:18:05.20000:18:05.210 in here it's polypro cap alright I'll 00:18:08.53000:18:08.540 put it in there this one is rated point 00:18:10.69000:18:10.700 one micro farad okay it's in the test 00:18:15.79000:18:15.800 fixture there we go pretty close so now 00:18:20.80000:18:20.810 what I'm going to do is apply a bit of 00:18:23.29000:18:23.300 heat to this 00:18:25.53000:18:25.540 now again I keep in mind that this is a 00:18:27.15000:18:27.160 polypropylene cap so I really don't want 00:18:28.92000:18:28.930 to heat this too hot or damage the unit 00:18:30.77000:18:30.780 but you know I'll heat it to the point 00:18:32.97000:18:32.980 to where it would you know get warm and 00:18:34.68000:18:34.690 service 00:18:42.21000:18:42.220 all right so that would be about the 00:18:44.07000:18:44.080 temperature would get in service look at 00:18:46.61900:18:46.629 that no problems at all as you can see a 00:18:51.72000:18:51.730 lot more stable than the other capacitor 00:18:54.48000:18:54.490 way way way more stable all right and 00:18:58.20000:18:58.210 grab it here with my fingers as you can 00:19:01.98000:19:01.990 see as I put my fingers on it very 00:19:05.78900:19:05.799 stable 00:19:06.41900:19:06.429 that was me moving it in the vise 00:19:08.39900:19:08.409 they're very very stable capacitors so 00:19:11.54900:19:11.559 great for audio and stuff like that that 00:19:13.90900:19:13.919 really is the three capacitors of 00:19:16.32000:19:16.330 interest here actually I could go grab a 00:19:18.69000:19:18.700 tantalum as well I'll go grab a tantalum 00:19:20.49000:19:20.500 it will be right back I have a dipped 00:19:23.61000:19:23.620 tantalum capacitor in the Vice here I'm 00:19:26.22000:19:26.230 sure we have lots of interesting horror 00:19:28.01900:19:28.029 stories about dipped alum capacitors if 00:19:30.24000:19:30.250 you got some let's hear about them so 00:19:32.66900:19:32.679 anyways what I'm going to do is I'll 00:19:34.52900:19:34.539 heat this and we'll take a look at the 00:19:35.99900:19:36.009 gen right here again alright so we're at 00:19:42.26900:19:42.279 about 4.7 micro farad we're not going to 00:19:44.61000:19:44.620 really get too much more particular than 00:19:46.35000:19:46.360 that so 00:19:48.58000:19:48.590 they're all this is it an NGO style 00:19:51.73900:19:51.749 capacitor anything so I'm heating the 00:19:53.14900:19:53.159 tool up here again and I'll run it 00:19:55.48900:19:55.499 across here just a couple of times and 00:19:58.46000:19:58.470 that would be blazing hot right now four 00:20:02.02900:20:02.039 point seven nine not too bad not bad at 00:20:07.15900:20:07.169 all so you can see these are relatively 00:20:09.98000:20:09.990 stable they're good in timing circuits 00:20:11.48000:20:11.490 and things like that of course I've 00:20:13.75900:20:13.769 heated this thing way hotter than it 00:20:15.10900:20:15.119 would ever get in service but still 00:20:17.23000:20:17.240 gives you an idea of how much they 00:20:19.27900:20:19.289 really move especially when they get 00:20:20.86900:20:20.879 screaming hot for this next 00:20:23.65900:20:23.669 demonstration I'm going to use this 00:20:25.12900:20:25.139 Tektronix 00:20:26.02900:20:26.039 type 547 oscilloscope with this high 00:20:30.08000:20:30.090 gain plugin so right now I've got this 00:20:32.86900:20:32.879 calibrated to show 500 micro volts per 00:20:36.59000:20:36.600 division on the screen what I'm going to 00:20:39.49900:20:39.509 do is take this ceramic capacitor I'm 00:20:42.13900:20:42.149 going to put it on the front here this 00:20:43.90900:20:43.919 is a point 1 micro farad capacitor 00:20:46.24900:20:46.259 it's a Zed 5 V style and I'm going to 00:20:50.60000:20:50.610 tap it ever so slightly with this 00:20:53.32000:20:53.330 insulated rod right here the noise you 00:20:57.01900:20:57.029 see on the screen of the oscilloscope 00:20:58.12900:20:58.139 right now is from me I'm standing about 00:21:00.01900:21:00.029 three feet away from the oscilloscope 00:21:01.78900:21:01.799 and just that capacitor poking out of 00:21:03.68000:21:03.690 the front is acting as an antenna 00:21:04.99900:21:05.009 picking me up and a little bit of the 00:21:07.19000:21:07.200 tripod and camera as well so what I'm 00:21:09.16900:21:09.179 going to do is touch the face of the 00:21:11.86900:21:11.879 oscilloscope and that will ground my 00:21:13.58000:21:13.590 body out a little bit keep that 00:21:15.88900:21:15.899 interference down just a bit if I was to 00:21:18.10900:21:18.119 ground the tripod out it probably almost 00:21:19.97000:21:19.980 get a nice clean trace so now what I'm 00:21:22.54900:21:22.559 going to do is I'm going to tap this 00:21:23.77900:21:23.789 capacitor with this rod and watch what 00:21:25.60900:21:25.619 happens on the screen when you see the 00:21:28.00900:21:28.019 trace moving up and down like that don't 00:21:29.57000:21:29.580 pay any attention to that that's just my 00:21:30.95000:21:30.960 hand moving here that's how sensitive 00:21:32.62900:21:32.639 this is but you'll see another effect 00:21:34.63900:21:34.649 here in just a moment so here I go 00:21:41.24000:21:41.250 see all that there how it's going below 00:21:43.95000:21:43.960 the line that's creating voltage when 00:21:48.00000:21:48.010 I'm tapping this capacitor and that's 00:21:49.92000:21:49.930 called a piezoelectric effect and that's 00:21:52.53000:21:52.540 why these capacitors here are absolutely 00:21:55.65000:21:55.660 no good in audio amplifiers or in any 00:21:58.29000:21:58.300 kind of high vibration atmosphere so 00:22:00.87000:22:00.880 just think if this was in an amplifier 00:22:02.64000:22:02.650 on the stage of an auditorium and it was 00:22:04.53000:22:04.540 very very loud and this was leaning up 00:22:06.24000:22:06.250 against the chassis and just ever so 00:22:07.89000:22:07.900 slightly buzzing the amount of noise 00:22:10.32000:22:10.330 that this would create into the circuit 00:22:12.36000:22:12.370 would be absolutely incredible 00:22:14.09000:22:14.100 so from the trace deflected downwards we 00:22:17.40000:22:17.410 had from what I could see about 1.5 to 2 00:22:20.22000:22:20.230 millivolts worth of you know spikes 00:22:23.16000:22:23.170 there it was exceeding the graticule 00:22:24.87000:22:24.880 just a little bit there on one or two of 00:22:26.70000:22:26.710 little bumps and I'm just ever so 00:22:28.83000:22:28.840 slightly tapping that so it's creating 00:22:31.83000:22:31.840 quite a bit of voltage alright so what 00:22:34.47000:22:34.480 I'll do now is I'll plug in this 00:22:39.00000:22:39.010 polypropylene capacitor and we'll see 00:22:41.31000:22:41.320 what it does so again I'll get rid of 00:22:45.84000:22:45.850 some of that hum now I'm going to tap 00:22:49.05000:22:49.060 this here again don't pay any attention 00:22:50.31000:22:50.320 to that bobbing of the trace that you 00:22:52.11000:22:52.120 see there that's just me moving my hand 00:22:53.58000:22:53.590 up and down so when I'm tapping it 00:22:55.17000:22:55.180 that's just the movement of my hand as 00:22:57.06000:22:57.070 you can see so again we're just looking 00:22:58.83000:22:58.840 for those spikes so here I go as you can 00:23:06.00000:23:06.010 see absolutely no spikes there 00:23:08.01000:23:08.020 whatsoever and I'm hitting this actually 00:23:10.83000:23:10.840 pretty hard and that's why polypropylene 00:23:15.99000:23:16.000 capacitors are great for audio 00:23:19.02000:23:19.030 amplifiers and high vibration atmosphere 00:23:21.24000:23:21.250 because they don't have any of that 00:23:22.71000:23:22.720 piezoelectric effect now again these 00:23:25.77000:23:25.780 other capacitors are great for RF 00:23:27.39000:23:27.400 bypassing these ones here are great for 00:23:29.64000:23:29.650 RF bypassing but in a low vibration 00:23:31.44000:23:31.450 environment again I hope you found the 00:23:36.30000:23:36.310 information in this tech tips Tuesday 00:23:38.34000:23:38.350 useful if you did you can let me know by 00:23:40.38000:23:40.390 giving me a big thumbs up and hang 00:23:42.45000:23:42.460 around there will be many more videos 00:23:43.83000:23:43.840 just like this in the very near future 00:23:45.15000:23:45.160 touching on all sorts of different 00:23:47.04000:23:47.050 topics related to electronics so until 00:23:49.80000:23:49.810 that time take care bye for now 00:24:00.65900:24:00.669 you
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