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#256 - Capacitor types, characteristics, and applications
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00:00:00.030 in today's video we're going to talk 00:00:02.03000:00:02.040 about capacitors talk about the 00:00:04.22000:00:04.230 different types of capacitors that 00:00:05.66000:00:05.670 you'll run across some of their basic 00:00:07.61000:00:07.620 characteristics and the applications 00:00:09.77000:00:09.780 we'll use each of these different types 00:00:11.45000:00:11.460 of capacitors certainly the most common 00:00:14.03000:00:14.040 two types of capacitors that you'll run 00:00:15.65000:00:15.660 across and use are multi layer or 00:00:18.26000:00:18.270 monolithic ceramic capacitors and 00:00:20.52900:00:20.539 electrolytic capacitors so let's talk 00:00:22.67000:00:22.680 about both of those first let's start 00:00:24.38000:00:24.390 with the electrolytic probably the most 00:00:27.52900:00:27.539 common electrolytic capacitors you run 00:00:29.35900:00:29.369 across of the aluminum electrolytic I've 00:00:32.12000:00:32.130 got some radial and axial eated examples 00:00:35.24000:00:35.250 here as well as some surface mount parts 00:00:38.13900:00:38.149 electrolytic SAR typically you know from 00:00:40.58000:00:40.590 about 1 microfarad to maybe well over 1 00:00:43.16000:00:43.170 farad with some working voltages from 5 00:00:45.68000:00:45.690 volts to sometimes well over 500 volts 00:00:48.10000:00:48.110 just about all of them are polarized 00:00:50.38900:00:50.399 there are some non polarized examples 00:00:52.93900:00:52.949 that you can get non polarized 00:00:54.61900:00:54.629 electrolytic s-- they're typically used 00:00:56.56900:00:56.579 in like audio crossovers for speaker 00:00:58.58000:00:58.590 crossover networks but the vast majority 00:01:00.41000:01:00.420 of the electrolytic still find our 00:01:02.29900:01:02.309 polarized capacitors and there'll be you 00:01:04.46000:01:04.470 know marked as such you'll usually have 00:01:06.16000:01:06.170 one side of the other usually the 00:01:08.35900:01:08.369 negative side marked on the aluminum 00:01:09.98000:01:09.99000:01:12.77000:01:12.780 for things like power supply filtering 00:01:15.53000:01:15.540 for relatively low frequency 00:01:16.88000:01:16.890 applications typically below 100 00:01:19.16000:01:19.170 kilohertz because above that their self 00:01:21.64900:01:21.659 president frequency starts getting in 00:01:23.45000:01:23.460 the way and they don't really work like 00:01:24.83000:01:24.840 very good capacitors anymore they do 00:01:27.77000:01:27.780 have an unfortunate wear out mechanism 00:01:29.74900:01:29.759 especially accelerated by heat that 00:01:32.09000:01:32.100 causes the electrolyte within these 00:01:34.73000:01:34.740 capacitors to dry out which causes the 00:01:37.13000:01:37.140 ESR or dissipation factor can rise that 00:01:41.87000:01:41.880 causes an increase in temperature with 00:01:43.37000:01:43.380 ripple currents and that accelerates the 00:01:44.99000:01:45.000 failure and that's a very common failure 00:01:47.09000:01:47.100 mode for these types of devices they 00:01:49.37000:01:49.380 also have some what we call so kajoor 00:01:51.44000:01:51.450 dielectric absorption issues what that 00:01:53.63000:01:53.640 means is that if they've got a DC bias 00:01:55.67000:01:55.680 applied to them for a while and then you 00:01:58.21900:01:58.229 short the capacitor out to discharge the 00:02:00.31900:02:00.329 capacitor then remove the short the some 00:02:03.46900:02:03.479 voltage will actually come back due to 00:02:05.78000:02:05.790 the polarization that happened within 00:02:07.42900:02:07.439 the electric electrolyte I'll actually 00:02:09.13900:02:09.149 show you this here in a moment it's 00:02:10.52000:02:10.530 pretty interesting the other thing about 00:02:12.61900:02:12.629 these 00:02:13.69900:02:13.709 electrolytic tap so that the leakage 00:02:15.17000:02:15.180 increases pretty dramatically with 00:02:16.81900:02:16.829 temperature the capacitance will also 00:02:19.25000:02:19.260 change with temperature so and if you've 00:02:21.80000:02:21.810 got an application where you need to do 00:02:23.30000:02:23.310 rapid charge or discharge like four 00:02:25.56900:02:25.579 flashes and things like that you 00:02:27.44000:02:27.450 definitely need to specify special parts 00:02:29.72000:02:29.730 because your ordinary aluminum 00:02:31.78900:02:31.799 electrolytic sarn't designed for high 00:02:33.28900:02:33.299 currents like that but they do have a 00:02:35.11900:02:35.129 very high capacitance density per unit 00:02:37.36900:02:37.379 volume and that's what makes them very 00:02:39.61900:02:39.629 popular because they're really good for 00:02:41.66000:02:41.670 things like power supply filtering 00:02:43.25000:02:43.260 you'll often see them next to power 00:02:45.71000:02:45.720 supply regulators another places where 00:02:48.80000:02:48.810 you want to quiet down a bias or 00:02:50.33000:02:50.340 something you know bias voltage or 00:02:51.74000:02:51.750 something like that because they're 00:02:52.67000:02:52.680 really good for low-frequency power 00:02:54.77000:02:54.780 supply decoupling and bypassing they're 00:02:57.89000:02:57.900 also pretty good for low to medium 00:03:00.25900:03:00.269 frequency bypassing you know in 00:03:02.62900:03:02.639 amplifiers and things like that but they 00:03:05.24000:03:05.250 are accused 00:03:05.75000:03:05.760 there's certainly applications for them 00:03:07.94000:03:07.950 there they can be used for some 00:03:09.70900:03:09.719 non-critical low frequency timing 00:03:11.86900:03:11.879 applications but because of things like 00:03:13.94000:03:13.950 the absorption characteristics the 00:03:16.33900:03:16.349 temperature changes and especially the 00:03:19.44900:03:19.459 you know some of the instabilities you 00:03:22.81900:03:22.829 don't want to use them for anything 00:03:23.99000:03:24.000 where you need any critical kind of 00:03:25.28000:03:25.290 timing but energy storage applications 00:03:28.00900:03:28.019 great at low frequency stage coupling 00:03:30.50000:03:30.510 between one stage or another they're 00:03:32.24000:03:32.250 just fine we typically do not want to 00:03:34.69900:03:34.709 use them for critical timing circuits as 00:03:36.53000:03:36.540 I measured I mentioned triggering 00:03:38.62900:03:38.639 circuits where you need really precise 00:03:40.12900:03:40.139 amount of charge stored there that you 00:03:41.71900:03:41.729 might use to to trigger another circuit 00:03:43.67000:03:43.680 and definitely not in any circuits where 00:03:46.49000:03:46.500 you need precise frequency determination 00:03:49.39900:03:49.409 or phase shift circuits and the 00:03:51.11000:03:51.120 generally don't have any place in any RF 00:03:53.68900:03:53.699 circuits because of the relatively low 00:03:56.17000:03:56.180 self resonant frequency just because 00:03:59.30000:03:59.310 it's so interesting let's take a quick 00:04:00.53000:04:00.540 look at this so future dielectric 00:04:02.68900:04:02.699 absorption issue here is just a little 00:04:05.65900:04:05.669 one microfarad electrolytic capacitor 00:04:08.42000:04:08.430 what I charged up to just about 12 volts 00:04:10.67000:04:10.680 you can see on the voltmeter there it's 00:04:13.36900:04:13.379 just about exactly 12 volts now if I 00:04:15.94900:04:15.959 pull the power supply off of this you 00:04:17.87000:04:17.880 see the voltage is starting to drop is 00:04:19.90900:04:19.919 just leakage and and some card that's 00:04:21.83000:04:21.840 going into the meter 00:04:23.57000:04:23.580 let's short these leads out here so I 00:04:26.30000:04:26.310 short the leads out look at SU 00:04:27.62000:04:27.630 drop down now - you know there's 200 00:04:29.84000:04:29.850 microvolts but watch what happens when I 00:04:31.55000:04:31.560 remove the short the boulders are 00:04:34.70000:04:34.710 ramping back up again and you know 00:04:36.86000:04:36.870 pretty soon here we are at 75 millivolts 00:04:39.62000:04:39.630 80 millivolts it's going to go well over 00:04:42.20000:04:42.210 a hundred millivolts here so we're 00:04:45.29000:04:45.300 ramping up here and oh now we're at 125 00:04:48.14000:04:48.150 millivolts and our 1% of the voltage 00:04:50.30000:04:50.310 that I was applied to it before and I 00:04:52.82000:04:52.830 had that discharge for from electronic 00:04:55.10000:04:55.110 standpoint a pretty long time 00:04:56.54000:04:56.550 let's short that out again get back down 00:04:59.27000:04:59.280 here and down around 3 micro volts there 00:05:02.03000:05:02.040 3 milli volts let go of it again and we 00:05:04.70000:05:04.710 see it ramping up again this is again 00:05:07.13000:05:07.140 dielectrics okage and it can really 00:05:10.46000:05:10.470 wreak havoc with precision timing 00:05:11.96000:05:11.970 circuits but before we leave the topic 00:05:13.67000:05:13.680 of polarized capacitors let's talk about 00:05:15.80000:05:15.810 the other type that you'll see and 00:05:17.45000:05:17.460 that's typically these tantalum 00:05:18.92000:05:18.930 capacitors I've got a couple of examples 00:05:20.93000:05:20.940 here some radial eaded and then a little 00:05:25.52000:05:25.530 surface mount device here tantalum caps 00:05:28.40000:05:28.410 are old again they're all polarized and 00:05:30.74000:05:30.750 I would say there are wildly polarized 00:05:32.78000:05:32.790 in all places I mean by that here in a 00:05:34.52000:05:34.530 moment but they're typically you know 00:05:37.43000:05:37.440 ranging from you know about you know 00:05:39.92000:05:39.930 0.12 1 microfarad up to a thousand 00:05:42.17000:05:42.180 microfarads or so but they're relatively 00:05:44.12000:05:44.130 low voltage they won't go up to the 00:05:45.56000:05:45.570 hundreds of volts typically that the 00:05:47.78000:05:47.790 electrolytic swill they do have a higher 00:05:51.05000:05:51.060 capacitance density than the 00:05:52.55000:05:52.560 electrolytic so for a given package size 00:05:54.77000:05:54.780 you can get a larger value of 00:05:57.02000:05:57.030 capacitance with the 10 ohms than you 00:05:59.48000:05:59.490 can with the electrolytic s-- they are 00:06:01.67000:06:01.680 very intolerant of reverse bias though 00:06:05.48000:06:05.490 you know a little bit of reverse bias on 00:06:07.55000:06:07.560 an electrolytic it may leak a little bit 00:06:09.68000:06:09.690 you might accelerate the failure 00:06:11.18000:06:11.190 mechanism but they're going to be pretty 00:06:13.25000:06:13.260 tolerant of it but atoms can get pretty 00:06:15.83000:06:15.840 exciting when tantalum fail they 00:06:18.62000:06:18.630 generally fail short-circuit and then 00:06:21.05000:06:21.060 oftentimes will burn catch fire close 00:06:24.29000:06:24.300 some damage and things like that so as 00:06:26.36000:06:26.370 long as you treat them right they're 00:06:27.83000:06:27.840 actually pretty good reliable capacitors 00:06:29.75000:06:29.760 but do not over voltage them and do not 00:06:33.11000:06:33.120 reverse bias them they don't have the 00:06:36.20000:06:36.210 wear out mechanism not the aluminum 00:06:38.60000:06:38.610 electrolytic stew but they are pricier 00:06:40.64000:06:40.650 than the 00:06:41.23900:06:41.249 electrolitic generally I've got nice low 00:06:43.51900:06:43.529 ESR there a bit more temperature and 00:06:46.03900:06:46.049 voltage stable than the aluminum 00:06:47.86900:06:47.879 electrolytic SAR but again they're a 00:06:50.89900:06:50.909 little bit pricier so you do have to pay 00:06:52.36900:06:52.379 for that so the applications are very 00:06:54.88900:06:54.899 similar to the aluminum electrolytic 00:06:57.28900:06:57.299 power supply filtering low to medium 00:07:00.25900:07:00.269 frequency bypassing energy storage and 00:07:03.01900:07:03.029 long duration timing again that is not 00:07:04.93900:07:04.949 super critical 00:07:06.10900:07:06.119 although the characteristics okage 00:07:09.04900:07:09.059 characteristics and tolerance 00:07:11.05900:07:11.069 characteristics of the ten ohms are 00:07:12.34900:07:12.359 general a little bit better than the 00:07:13.85000:07:13.860 aluminum electrolytic s-- but they're 00:07:15.88900:07:15.899 not good for high voltage applications 00:07:17.58900:07:17.599 or cost sensitive applications of course 00:07:20.44900:07:20.459 or anything it's got any large AC 00:07:22.39900:07:22.409 signals that might even momentarily 00:07:24.07900:07:24.089 reverse bias them and similarly their 00:07:27.31900:07:27.329 self resident frequency is low enough 00:07:29.08900:07:29.099 that you're not going to really use them 00:07:30.64900:07:30.659 too much for RF applications although 00:07:32.53900:07:32.549 they the ESR of them is a little bit 00:07:34.85000:07:34.860 better and than it is with the aluminum 00:07:37.75900:07:37.769 electrolytic outside of the 00:07:41.44900:07:41.459 low-frequency power supply filtering and 00:07:43.87900:07:43.889 decoupling caps and things like that 00:07:46.11900:07:46.129 you'll most likely find ceramic 00:07:48.79900:07:48.809 capacitors certainly the most common 00:07:50.60000:07:50.610 that are out there and with most modern 00:07:52.27900:07:52.289 electronics being surface mount is a 00:07:54.25900:07:54.269 vast majority of small surface but 00:07:56.65900:07:56.669 capacitors or these multi-layer ceramic 00:07:58.18900:07:58.199 devices like are shown here lots of 00:08:01.06900:08:01.079 different package styles from the disc 00:08:03.46900:08:03.479 capacitors to these kind of molded 00:08:05.89900:08:05.909 monolithic type devices and dipped 00:08:07.69900:08:07.709 monolithic devices like that one there 00:08:09.87900:08:09.889 now the capacitance and voltage range 00:08:12.70900:08:12.719 for these can range anywhere from you 00:08:14.20900:08:14.219 know under a Pico farad to well over 500 00:08:16.33900:08:16.349 micro farad and even available with 00:08:18.43900:08:18.449 working voltages to well over a thousand 00:08:20.86900:08:20.879 volts now there are a lot of different 00:08:23.23900:08:23.249 types of ceramic capacitors and they're 00:08:25.36900:08:25.379 kind of divided among the different 00:08:27.61900:08:27.629 types of dielectric and the 00:08:29.83900:08:29.849 characteristics of that dielectric the 00:08:33.35000:08:33.360 class 1 dielectrics different types 00:08:36.43900:08:36.449 called np0 and c 0g these class 1 00:08:41.86900:08:41.879 devices are very very stable devices 00:08:44.92900:08:44.939 with temperature they male they vary by 00:08:46.51900:08:46.529 a few percent over a very wide 00:08:47.92900:08:47.939 temperature range they're available with 00:08:50.11900:08:50.129 a very tight tolerance and but they're 00:08:52.34000:08:52.350 typically low value devices from 00:08:54.65000:08:54.660 send a picofarad - maybe up as high as a 00:08:56.84000:08:56.850 micro farad but typically you know tens 00:08:59.54000:08:59.550 of nano ferrets or less now because 00:09:02.48000:09:02.490 there are low values of capacitance and 00:09:05.00000:09:05.010 they're very stable they find themselves 00:09:06.41000:09:06.420 to work very very well in RF 00:09:09.14000:09:09.150 applications and that's where you'll 00:09:10.55000:09:10.560 find these very common there now the 00:09:13.40000:09:13.410 class - dielectric materials they vary a 00:09:17.42000:09:17.430 bit more with both temperature and with 00:09:20.72000:09:20.730 applied voltage so they're not quite as 00:09:25.82000:09:25.830 precise and not quite as stable but they 00:09:27.62000:09:27.630 are available in larger values now the 00:09:30.26000:09:30.270 letter designations actually will relate 00:09:32.90000:09:32.910 to the temperature range and the amount 00:09:35.18000:09:35.190 of variation that they have over a given 00:09:37.16000:09:37.170 temperature range it's probably worth a 00:09:39.11000:09:39.120 whole other video just to talk about 00:09:40.37000:09:40.380 that but we'll just kind of leave it put 00:09:42.29000:09:42.300 some of the common values that you'll 00:09:43.52000:09:43.530 see here some of the common class to 00:09:45.92000:09:45.930 dielectric types that you'll see are x7r 00:09:48.05000:09:48.060 capacitors y5v z5u these are all kind of 00:09:53.00000:09:53.010 class two dielectrics let's take a look 00:09:55.07000:09:55.080 at this little chart over here this is a 00:09:57.29000:09:57.300 chart showing relative capacitance 00:09:59.63000:09:59.640 change versus temperature and this is 00:10:02.90000:10:02.910 very shallow little linear line here 00:10:05.24000:10:05.250 that's your NP 0 and C 0 G capacitors 00:10:08.18000:10:08.190 the x7r capacitors might vary plus or 00:10:12.62000:10:12.630 minus 10 or 15% around their original 00:10:15.53000:10:15.540 value or their nominal value over that 00:10:18.23000:10:18.240 temperature range so that's not too bad 00:10:20.18000:10:20.190 but that's still a pretty good variation 00:10:22.45000:10:22.460 the y5v and z5u they're kind of horrible 00:10:27.59000:10:27.600 it comes to a temperature variation they 00:10:30.14000:10:30.150 may go up as high as 10 or 15% over 00:10:32.84000:10:32.850 their nominal value but drop down to 60 00:10:35.84000:10:35.850 or 70 or even 80% of their look below 00:10:39.47000:10:39.480 their nominal value at the temperature 00:10:41.72000:10:41.730 extremes they also have got a higher 00:10:44.57000:10:44.580 dissipation factor and well and both of 00:10:47.03000:10:47.040 the class twos are somewhat voltage 00:10:50.30000:10:50.310 dependent as well where the capacitance 00:10:52.64000:10:52.650 will change with applied voltage but you 00:10:55.94000:10:55.950 get larger capacitance values so you 00:10:58.94000:10:58.950 know you'll find that the y5v and z5u 00:11:01.76000:11:01.770 caps you know they're available in very 00:11:03.44000:11:03.450 large values they'll be used for 00:11:05.00000:11:05.010 non-critical bypass applications where 00:11:07.89000:11:07.900 you can accept that kind of a large 00:11:09.63000:11:09.640 tolerance and the value the x7r is a 00:11:13.11000:11:13.120 reasonable compromise between the 00:11:16.17000:11:16.180 stability of the class 1 dielectrics but 00:11:19.35000:11:19.360 the larger values of the y5v and z5u 00:11:22.38000:11:22.390 materials so if you have a choice for a 00:11:24.87000:11:24.880 given value in your application between 00:11:29.16000:11:29.170 x7r caps and the Y or Z type caps go 00:11:32.70000:11:32.710 with the x7 RS are going to be a bit 00:11:34.26000:11:34.270 more stable all of the ceramic caps are 00:11:37.23000:11:37.240 generally pretty low cost they got low 00:11:39.56000:11:39.570 dissipation factor loius are good RF 00:11:43.47000:11:43.480 performance but ceramic materials are 00:11:46.01900:11:46.029 also microphonic so if they're in a high 00:11:48.30000:11:48.310 vibration environmental things like that 00:11:50.42000:11:50.430 that can actually cause the capacitor to 00:11:53.07000:11:53.080 become a little bit microphonic almost 00:11:55.26000:11:55.270 like a quartz type of device so you have 00:11:57.63000:11:57.640 to kind of be aware of that so again 00:12:00.15000:12:00.160 typically good for RF applications 00:12:02.25000:12:02.260 they're very low cost bypassing 00:12:04.20000:12:04.210 interstage coupling decoupling around 00:12:08.22000:12:08.230 gain stages and things like that the 00:12:09.99000:12:10.000 good applications for that generally not 00:12:12.75000:12:12.760 so good for use in voltage controlled 00:12:15.48000:12:15.490 oscillator designs or frequency 00:12:17.16000:12:17.170 generation designs because of the 00:12:20.13000:12:20.140 variation over temperature the class one 00:12:23.43000:12:23.440 like MP 0 and C 0 G are the exception 00:12:26.13000:12:26.140 here they certainly can work very well 00:12:27.63000:12:27.640 in those applications they're not really 00:12:30.87000:12:30.880 good for low frequency filtering where 00:12:34.89000:12:34.900 you can't really withstand this kind of 00:12:37.17000:12:37.180 tolerance with temperature so especially 00:12:39.44900:12:39.459 the Y 5 e and z 5 you are really bad an 00:12:42.72000:12:42.730 x 7r wouldn't be so bad for that 00:12:44.61000:12:44.620 application but very very common types 00:12:46.92000:12:46.930 of capacitors you'll find all over the 00:12:48.96000:12:48.970 place in many many different packaged 00:12:51.32900:12:51.339 styles now something I'll mention at 00:12:54.48000:12:54.490 this point is if you're reviewing a 00:12:56.04000:12:56.050 schematic or you see something online 00:12:57.72000:12:57.730 they're going to go build and the 00:12:59.43000:12:59.440 capacitors aren't labeled in terms of 00:13:01.38000:13:01.390 what types they are whether they're 00:13:03.12000:13:03.130 ceramics electrolytic so film or mica or 00:13:05.46000:13:05.470 whatever the most likely case is that 00:13:08.04000:13:08.050 any of the polarized caps are 00:13:09.84000:13:09.850 electrolytic caps and in many cases 00:13:11.85000:13:11.860 could be substituted with tantalum x' 00:13:13.68000:13:13.690 any of the others that are non polarized 00:13:16.62000:13:16.630 to generally lower value caps the most 00:13:18.87000:13:18.880 likely ceramic capacitors if the 00:13:21.06000:13:21.070 application 00:13:21.66000:13:21.670 you know really warranted something 00:13:23.73000:13:23.740 other than those two you know hopefully 00:13:25.83000:13:25.840 the schematic would be labeled that way 00:13:27.69000:13:27.700 but it's a pretty safe assumption that 00:13:29.46000:13:29.470 for the polarized caps will be 00:13:31.02000:13:31.030 electrolytic non polarized or ceramic 00:13:33.36000:13:33.370 but that being said let's go take a look 00:13:35.79000:13:35.800 at some of the other common types of 00:13:37.14000:13:37.150 capacitors that are out there and some 00:13:38.97000:13:38.980 of their characteristics and see where 00:13:40.47000:13:40.480 they'd be applicable probably the next 00:13:43.08000:13:43.090 most common type of capacitors are the 00:13:45.30000:13:45.310 film capacitors now they're again just 00:13:47.61000:13:47.620 like the ceramics there are many 00:13:49.02000:13:49.030 different types of film capacitors one 00:13:52.08000:13:52.090 of the differences though here is that 00:13:53.58000:13:53.590 there are that many film capacitors that 00:13:56.16000:13:56.170 are available in surface mount or 00:13:57.66000:13:57.670 certainly not nearly as many as there 00:13:59.55000:13:59.560 are for ceramic but there's actually 00:14:01.62000:14:01.630 some really nice characteristics of film 00:14:03.51000:14:03.520 capacitors that make them worth taking a 00:14:05.28000:14:05.290 look at so some of the things that film 00:14:07.71000:14:07.720 capacitors have in common is that 00:14:09.15000:14:09.160 they're generally available from you 00:14:11.04000:14:11.050 know the low tens of Pico farad's to you 00:14:13.41000:14:13.420 know in the neighborhood of you know 00:14:14.70000:14:14.710 even a thousand microfarad very large 00:14:16.83000:14:16.840 values and working voltages from 00:14:19.59000:14:19.600 relatively low voltages to well over a 00:14:22.17000:14:22.180 thousand volts so very wide capacitance 00:14:27.51000:14:27.520 and voltage range generally the film 00:14:29.91000:14:29.920 caps have got really tight tolerances 00:14:31.80000:14:31.810 and very little leakage very low 00:14:33.66000:14:33.670 absorption very low ESR and dissipation 00:14:36.09000:14:36.100 factor all really good characteristics 00:14:38.70000:14:38.710 for capacitors they're very stable with 00:14:40.98000:14:40.990 temperature and voltage but they're 00:14:42.96000:14:42.970 moderately too high price with respect 00:14:44.82000:14:44.830 to ceramics they're relatively large 00:14:47.58000:14:47.590 they don't have as good of a volumetric 00:14:49.80000:14:49.810 efficiency 00:14:50.67000:14:50.680 you know capacitance per unit volume 00:14:52.56000:14:52.570 that the aluminum electrolytic or the 00:14:56.57000:14:56.580 tan alums do but they're also not 00:14:59.19000:14:59.200 polarized and they're they're going to 00:15:01.74000:15:01.750 have a you know probably not even as 00:15:03.03000:15:03.040 good of volumetric efficiency as even 00:15:05.34000:15:05.350 the multi-layer ceramic caps they are 00:15:08.07000:15:08.080 available in two kind of broad different 00:15:10.32000:15:10.330 types there's a metallized film or metal 00:15:13.65000:15:13.660 foil and film so what's all about film 00:15:17.07000:15:17.080 capacitors because the what we're 00:15:18.78000:15:18.790 talking about is the dielectric material 00:15:21.24000:15:21.250 the the insulator between the two plates 00:15:23.61000:15:23.620 of the capacitor is some type of a film 00:15:25.85000:15:25.860 plastic type of a film typically and 00:15:28.53000:15:28.540 that film can either be metallized on 00:15:31.56000:15:31.570 one one side and then rolled 00:15:33.62000:15:33.630 up and that's the metallized film 00:15:34.94000:15:34.950 capacitors they've got the highest 00:15:36.98000:15:36.990 density because you don't have a 00:15:38.39000:15:38.400 separate foil in there where the metal 00:15:40.82000:15:40.830 and foil film is you've got alternating 00:15:42.89000:15:42.900 layers of plastic insulator metal foil 00:15:45.62000:15:45.630 plastic insulator metal foil and that's 00:15:47.60000:15:47.610 rolled up they generally have lower ESR 00:15:50.42000:15:50.430 they can operate with higher AC currents 00:15:52.55000:15:52.560 but they're not going to have as many as 00:15:54.53000:15:54.540 higher value because they're not as 00:15:57.04000:15:57.050 it'll get as much capacitance per unit 00:15:59.15000:15:59.160 density with those that's kind of a 00:16:01.52000:16:01.530 common characteristics of these film 00:16:03.59000:16:03.600 caps as I mentioned there are many 00:16:06.44000:16:06.450 different film types that can be used in 00:16:09.65000:16:09.660 these film capacitors and they have some 00:16:12.32000:16:12.330 slightly different characteristics that 00:16:14.30000:16:14.310 make them useful for certain 00:16:15.50000:16:15.510 applications the polyester or mylar caps 00:16:19.76000:16:19.770 are very very common and they're 00:16:22.19000:16:22.200 moderately stable with temperature you 00:16:23.90000:16:23.910 know 5 to 15 percent variation over 00:16:25.70000:16:25.710 temperature they they're pretty good 00:16:28.88000:16:28.890 with dissipation factor a little bit 00:16:30.38000:16:30.390 higher than some of the other types but 00:16:33.02000:16:33.030 they're generally lower cost probably 00:16:35.69000:16:35.700 the other most common type is a 00:16:37.04000:16:37.050 polypropylene RPP type caps 00:16:39.79000:16:39.800 polypropylene z' are very common like 00:16:42.14000:16:42.150 these orange drop caps and the brown 00:16:43.88000:16:43.890 drops over here they're generally very 00:16:46.76000:16:46.770 low absorption they're very stable 00:16:48.41000:16:48.420 temperature they're just a bit pricier 00:16:50.00000:16:50.010 than the polyester or mylar caps one of 00:16:53.63000:16:53.640 the problems though with some of these 00:16:55.01000:16:55.020 types of caps like a polypropylene 00:16:56.78000:16:56.790 polyester is that you can't often tell 00:17:00.65000:17:00.660 from the packaging what type it is you 00:17:03.35000:17:03.360 can get you know a mylar cap or a 00:17:06.98000:17:06.990 polypropylene cap that looks like it's 00:17:09.53000:17:09.540 packaged the same way in these little 00:17:11.05900:17:11.069 plastic encapsulated packages here you 00:17:13.55000:17:13.560 know rolled up in these type of axial 00:17:16.13000:17:16.140 type of devices or dipped in some of 00:17:17.92900:17:17.939 these others I've seen the polypropylene 00:17:20.96000:17:20.970 and polyester in both of those package 00:17:22.93900:17:22.949 styles so you can't always tell by 00:17:24.89000:17:24.900 looking at them what they are you can be 00:17:26.90000:17:26.910 pretty sure that it's a film cap but you 00:17:29.93000:17:29.940 can't necessarily tell what type of film 00:17:31.76000:17:31.770 they are now some of the other types of 00:17:34.25000:17:34.260 film is a polystyrene capacitor these 00:17:36.41000:17:36.420 are really stable with temperature with 00:17:38.24000:17:38.250 very low dissipation factor and 00:17:40.04000:17:40.050 absorption a little bit harder to find 00:17:42.23000:17:42.240 they're pricey I don't have any here 00:17:44.71000:17:44.720 oftentimes the what these look like they 00:17:47.18000:17:47.190 look 00:17:47.45000:17:47.460 almost like a clear tube like a clear 00:17:50.14900:17:50.159 plastic tube almost like a glass diode 00:17:52.90900:17:52.919 if you will but it's made of plastic 00:17:54.04900:17:54.059 with a foil inside of it they're not 00:17:57.62000:17:57.630 really good in operating in very high 00:18:00.62000:18:00.630 temperature environments like next to a 00:18:02.24000:18:02.250 vacuum tube or next to some power 00:18:04.31000:18:04.320 resistors because the polystyrene 00:18:06.20000:18:06.210 plastic itself will begin to deform and 00:18:09.23000:18:09.240 melt but they're but an applications 00:18:11.96000:18:11.970 where it's low power type applications 00:18:13.66900:18:13.679 or actually are a pretty superior to 00:18:15.44000:18:15.450 some of the other films but they are 00:18:17.57000:18:17.580 harder to find a little bit pricey 00:18:19.89900:18:19.909 polycarbonate caps very high reliability 00:18:23.00000:18:23.010 they're also pretty pricey performance 00:18:25.88000:18:25.890 is about the same as the polypropylene 00:18:27.22000:18:27.230 there are lots of other different types 00:18:29.48000:18:29.490 of film caps at different types of films 00:18:32.53900:18:32.549 that are used and you almost have to 00:18:33.83000:18:33.840 look up and see what the characteristics 00:18:35.63000:18:35.640 are but the two most common istra come 00:18:37.85000:18:37.860 across will be the polypropylene or the 00:18:40.31000:18:40.320 polyester and with the polypropylene 00:18:43.07000:18:43.080 generally being the higher performance 00:18:45.23000:18:45.240 of the two they're really good for high 00:18:47.60000:18:47.610 voltage applications they're really good 00:18:50.02900:18:50.039 and stable for temperature and voltage 00:18:51.85000:18:51.860 they've got pretty low dissipation 00:18:54.28900:18:54.299 factor and dielectric absorption and 00:18:57.47000:18:57.480 they're really good from everything from 00:18:58.66900:18:58.679 audio to RF applications here the 00:19:01.34000:19:01.350 downsides is is that they're pricey 00:19:02.96000:19:02.970 they're physically a bit large and 00:19:05.09000:19:05.100 they're a bit limited in the package 00:19:07.25000:19:07.260 styles that you can get these film caps 00:19:10.39900:19:10.409 are often the ones that if you're doing 00:19:11.89900:19:11.909 some restoration of of old antique 00:19:14.63000:19:14.640 radios and things like that you're going 00:19:17.09000:19:17.100 to be replacing some of these early film 00:19:20.18000:19:20.190 caps these are a little paper and wax 00:19:22.15900:19:22.169 though so it wasn't really a film that 00:19:24.56000:19:24.570 with the dielectric was actually a paper 00:19:25.97000:19:25.980 that was used it was a paper and foil 00:19:27.95000:19:27.960 wrapped up and then stuffed in the tube 00:19:30.08000:19:30.090 and sealed with wax these capacitors by 00:19:32.69000:19:32.700 now are all kind of dried out and leaky 00:19:34.90900:19:34.919 and all need to be replaced and 00:19:36.56000:19:36.570 replacing them with you know mylar or 00:19:38.89900:19:38.909 polypropylene caps is the most common 00:19:41.45000:19:41.460 thing that you would do in these type 00:19:43.97000:19:43.980 applications now one other point I'll 00:19:46.73000:19:46.740 make about these film caps especially 00:19:49.01000:19:49.020 those that are around you know wound up 00:19:50.99000:19:51.000 like a coil here is oftentimes you'll 00:19:53.48000:19:53.490 see they've got a band marking on them 00:19:55.22000:19:55.230 that would make you think that they're 00:19:56.75000:19:56.760 polarized well the reality is they're 00:19:58.70000:19:58.710 not really they're not polarized caps or 00:20:00.52900:20:00.539 not 00:20:00.79900:20:00.809 like the tan alumns or the aluminum 00:20:03.35000:20:03.360 electrolytic s-- what that band 00:20:06.11000:20:06.120 indicates is which you know terminal on 00:20:09.64900:20:09.659 the capacitor is connected to the outer 00:20:12.76900:20:12.779 foil wrapping so if you think about it 00:20:15.04900:20:15.059 you've got a basically an insulating 00:20:17.69000:20:17.700 layer and a conductive layer that are 00:20:19.15900:20:19.169 wrapped up so one of the conductors is 00:20:23.53900:20:23.549 going to be on the inside of that last 00:20:25.61000:20:25.620 wrap the other conductors will be on the 00:20:27.71000:20:27.720 outside that last wrap with the 00:20:29.33000:20:29.340 insulator being in the middle so the 00:20:31.54900:20:31.559 band indicates the outer wrapping is 00:20:34.87900:20:34.889 connected to that wire and oftentimes in 00:20:37.51900:20:37.529 the electronics we're going to want to 00:20:38.77900:20:38.789 do is connect that to the lowest 00:20:41.41900:20:41.429 potential low-voltage potential in the 00:20:44.41900:20:44.429 circuit so that you don't have a high 00:20:46.19000:20:46.200 voltage on the outer perimeter up here 00:20:48.91900:20:48.929 but there may be applications where you 00:20:51.35000:20:51.360 may choose one end or the other to be 00:20:53.77900:20:53.789 connected up in a certain part of the 00:20:55.54900:20:55.559 circuit to prevent coupling you know to 00:20:57.49900:20:57.509 the to the the capacitor you might want 00:21:01.03900:21:01.049 to connect the outer foil edge to the 00:21:03.79900:21:03.809 lowest impedance node in the circuit but 00:21:06.25900:21:06.269 that's why these film capacitors are 00:21:08.38900:21:08.399 often marked with a band you'll see them 00:21:10.48900:21:10.499 like on that and even on this this dip 00:21:12.76900:21:12.779 variety you've got the band marked here 00:21:14.60000:21:14.610 that means that this lead here is 00:21:16.48900:21:16.499 connected to the outer foil wrapping of 00:21:18.85900:21:18.869 the capacitor inside this molded case 00:21:21.46000:21:21.470 the next type of capacitor we'll talk 00:21:23.69000:21:23.700 about our mica capacitors with the 00:21:26.06000:21:26.070 dielectric material is actually a mica 00:21:28.24900:21:28.259 of material some of the older ones were 00:21:30.64900:21:30.659 in these were called Domino packages and 00:21:32.89900:21:32.909 typically have these colored dots that 00:21:34.43000:21:34.440 would indicate though what they the 00:21:35.98900:21:35.999 value is another typically in these kind 00:21:38.65900:21:38.669 of molded packages again typically 00:21:41.18000:21:41.190 relatively low value you know a 00:21:42.88900:21:42.899 picofarad to maybe 10 nano flowers or so 00:21:45.32000:21:45.330 but can operate at very high voltages 00:21:47.33000:21:47.340 mica caps are really stable with 00:21:50.14900:21:50.159 temperature really stable with voltage 00:21:52.12900:21:52.139 they're available in very tight 00:21:53.86900:21:53.879 tolerances not these particular devices 00:21:55.54900:21:55.559 but they are available in some very 00:21:57.35000:21:57.360 tight tolerances and they got really 00:21:59.29900:21:59.309 good RF performance that the dissipation 00:22:02.11900:22:02.129 factor is very low are very very 00:22:04.34000:22:04.350 commonly used in RF applications and 00:22:06.88900:22:06.899 filters and voltage controlled 00:22:08.53900:22:08.549 oscillators or other oscillator of 00:22:10.75900:22:10.769 frequency generation circuits 00:22:13.22000:22:13.230 very common places to have mica cats 00:22:14.84000:22:14.850 because they're very very stable the bad 00:22:17.45000:22:17.460 thing is that they're smaller values 00:22:18.79900:22:18.809 they're limited and package styles and 00:22:21.20000:22:21.210 things like that now we use you might 00:22:23.99000:22:24.000 say these look an awful lot like those 00:22:25.46000:22:25.470 molded film caps now the way you can 00:22:29.27000:22:29.280 generally tell the my caps apart is that 00:22:31.43000:22:31.440 they're a bit lumpy if I if you will if 00:22:34.10000:22:34.110 you'll take a look at this package it's 00:22:35.90000:22:35.910 kind of bulged at the ends or maybe 00:22:38.48000:22:38.490 almost a little bit dog bone shaped you 00:22:40.49000:22:40.500 know if you can think about it that way 00:22:41.81000:22:41.820 in terms of the way the package is 00:22:43.31000:22:43.320 compared to the film caps which are 00:22:45.53000:22:45.540 generally a bit more smooth and with pay 00:22:49.49000:22:49.500 you know cylindrical or just don't have 00:22:51.83000:22:51.840 the lumpiness especially associated at 00:22:53.69000:22:53.700 the ends that's almost you know the only 00:22:55.88000:22:55.890 way you can kind of really tell whether 00:22:58.07000:22:58.080 that's a mica capacitor or a film cap 00:23:01.19000:23:01.200 because the the molded caps kind of look 00:23:03.77000:23:03.780 the same but generally if it's kind of a 00:23:06.20000:23:06.210 lumpy kind of a package that would 00:23:08.24000:23:08.250 almost tell you that it's a mica 00:23:09.38000:23:09.390 capacitor and also you can often tell 00:23:11.57000:23:11.580 from the application if it's in an RF 00:23:14.39000:23:14.400 circuit a VCO or something like that 00:23:16.25000:23:16.260 if a mica cap was available it likely 00:23:19.03900:23:19.049 would have been used in that application 00:23:21.22000:23:21.230 now of course there are lots of 00:23:23.24000:23:23.250 varieties of variable capacitors as well 00:23:25.70000:23:25.710 some of these larger and air dielectric 00:23:28.31000:23:28.320 kind of bread slicer variable caps and 00:23:31.21000:23:31.220 smaller called poly very cons because 00:23:34.37000:23:34.380 they like a poly film variable capacitor 00:23:37.90900:23:37.919 typically got some trimmers as well as 00:23:40.03900:23:40.049 kind of main tuning on them find these 00:23:42.56000:23:42.570 in some of the older transistor radios 00:23:44.81000:23:44.820 might find some of these in some of the 00:23:46.49000:23:46.500 older larger transistor radios or 00:23:49.07000:23:49.080 tabletop or even tube radios and things 00:23:51.35000:23:51.360 like that to make the tune local 00:23:54.65000:23:54.660 oscillators for tuning the radio around 00:23:57.13000:23:57.140 there you'll also have tremor capacitors 00:23:59.75000:23:59.760 that might be small little ceramic type 00:24:03.08000:24:03.090 trimmer caps I've got a bag full of 00:24:04.66900:24:04.679 different types here maybe some 00:24:06.98000:24:06.990 compression caps these these guys are 00:24:09.62000:24:09.630 basically two plates that when you 00:24:11.53900:24:11.549 loosen the screw the plates separate and 00:24:13.90900:24:13.919 they'll often have a mica insulator 00:24:15.50000:24:15.510 between them these types of caps 00:24:18.14000:24:18.150 obviously all used in RF applications 00:24:20.04900:24:20.059 here's kind of a slug tuned variable cap 00:24:23.93000:24:23.940 here as well lots of different types of 00:24:26.51000:24:26.520 very 00:24:27.02000:24:27.030 capacitors that you'll run across but in 00:24:30.11000:24:30.120 general all of these are typically used 00:24:32.54000:24:32.550 for 00:24:33.83000:24:33.840 you know RF applications where devices 00:24:36.59000:24:36.600 like these - designed to be kind of 00:24:38.54000:24:38.550 tuned and operated all the time where 00:24:40.91000:24:40.920 the trimmers are typically you know set 00:24:43.25000:24:43.260 and adjusted you know to tune or align a 00:24:45.44000:24:45.450 circuit and then they're if they're left 00:24:46.91000:24:46.920 alone and never adjust it again so if 00:24:48.71000:24:48.720 they don't have the durability of some 00:24:50.72000:24:50.730 of these continuously variable devices 00:24:54.10000:24:54.110 of course really kind of impossible to 00:24:56.75000:24:56.760 cover all the different types of 00:24:58.34000:24:58.350 capacitors and all the specific 00:25:00.08000:25:00.090 applications and characteristics in one 00:25:02.60000:25:02.610 short video but I hope this this brief 00:25:05.21000:25:05.220 introduction to the different types of 00:25:07.10000:25:07.110 capacitors their characteristics and 00:25:10.19000:25:10.200 their basic applications and where 00:25:12.11000:25:12.120 you'll find them was been helpful and 00:25:13.73000:25:13.740 again just remember that the vast 00:25:16.01000:25:16.020 majority of the polarized caps that you 00:25:18.65000:25:18.660 see will be a luminal aluminum 00:25:20.54000:25:20.550 electrolytic or possibly tantalum and 00:25:22.82000:25:22.830 the vast majority of the non polarized 00:25:25.76000:25:25.770 capacitors you see in a design are most 00:25:28.01000:25:28.020 likely ceramic whereas you could use 00:25:31.88000:25:31.890 film capacitors or even you know mica 00:25:35.09000:25:35.100 capacitors in those applications 00:25:37.34000:25:37.350 particularly if you're operating it at 00:25:40.01000:25:40.020 over a wide temperature range or at 00:25:42.83000:25:42.840 higher frequency so I hope it's been 00:25:44.87000:25:44.880 helpful if you like what you see give me 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