WEBVTT 00:00:11.660 --> 00:00:22.410 >> Capacitors are devices that provide electrical energy storage of two types. 00:00:22.410 --> 00:00:31.665 One, where there's two conducting surfaces with an insulator between so that one side, 00:00:31.665 --> 00:00:34.470 when you apply a voltage to it, 00:00:34.470 --> 00:00:37.550 it can't get through the insulator, 00:00:37.550 --> 00:00:44.310 so it piles up as charge at every little atom on both sides, 00:00:44.310 --> 00:00:49.420 one plus and one minus, and stores energy. 00:00:52.580 --> 00:01:01.550 Polypropylene, when it's built in a manner where it's stretched in two sides, 00:01:01.550 --> 00:01:07.400 it comes out as a film, and then you stretch it both lengthwise and 00:01:07.400 --> 00:01:16.620 sideways to orient all the molecules in the direction of the surface of the film. 00:01:17.930 --> 00:01:23.680 Roll up the film and send it into the winding machines, so it wind 00:01:23.680 --> 00:01:32.120 it into with the aluminum foil we are making to make the capacitors. 00:01:35.990 --> 00:01:42.290 The other one was stored energy with the similar thing except that 00:01:42.290 --> 00:01:49.145 the insulator level is the metal oxide. 00:01:49.145 --> 00:01:54.980 The insulating film is deposited by anodizing aluminum, 00:01:54.980 --> 00:02:02.580 and you get very high capacitor levels with electrolytic capacitors. 00:02:02.580 --> 00:02:08.300 So, both tantalum oxide and aluminum oxide are 00:02:08.300 --> 00:02:17.930 very good preventers from electrons escaping their surfaces. 00:02:17.930 --> 00:02:20.030 That's what a capacitor is. 00:02:20.030 --> 00:02:24.270 It's a storage of electric charge.