WEBVTT 1 00:00:01.460 --> 00:00:19.820 [unclear opening audio] 2 00:00:31.560 --> 00:00:35.060 Hi Hans, what are you doing? 3 00:00:35.420 --> 00:00:41.240 Hi Connie, well as you know I am a 555 timer IC, 4 00:00:41.620 --> 00:00:43.920 so I'm pretty good at sending out pulses 5 00:00:43.920 --> 00:00:46.220 of electricity in perfect time. 6 00:00:47.040 --> 00:00:52.900 Normally I can blink an LED just fine, but for some reason I can't make this high 7 00:00:52.900 --> 00:00:54.440 power LED flash. 8 00:00:54.960 --> 00:00:59.120 Oh, you probably just need to give it a little more electrical current. 9 00:00:59.620 --> 00:01:05.240 Hmm, you may be right. But I can only supply a bit of current from my pins here. 10 00:01:05.600 --> 00:01:10.000 My integrated circuit was not designed for driving a lot of current. 11 00:01:10.260 --> 00:01:14.540 Well, you're mighty lucky I came along. I can help you. 12 00:01:14.540 --> 00:01:15.960 Really? How? 13 00:01:16.320 --> 00:01:19.560 I may be small, but I'm pretty strong. 14 00:01:20.160 --> 00:01:23.500 I can push and pull ten times as much current as you can, 15 00:01:23.700 --> 00:01:26.260 and manage enough power to light this big LED. 16 00:01:26.600 --> 00:01:29.440 I just need you to tell me when to turn it on. 17 00:01:29.820 --> 00:01:31.760 Oh? How do I do that? 18 00:01:32.020 --> 00:01:33.900 Just grab my hand, like this. 19 00:01:44.740 --> 00:01:49.440 So now, you just keep sending electrical pulses through your output pin like you 20 00:01:49.440 --> 00:01:50.200 were doing before. 21 00:01:50.520 --> 00:01:55.220 My other pin is connected to the positive leg of the LED, and all three of us are 22 00:01:55.220 --> 00:01:56.100 connected to ground. 23 00:01:56.580 --> 00:02:00.820 Whenever you send an electrical pulse to my left pin, I'll know you want me to do 24 00:02:00.820 --> 00:02:01.980 the same on my right pin. 25 00:02:02.280 --> 00:02:07.620 What I mean to say is, when you turn your pin on, I'll turn the high power to the 26 00:02:07.620 --> 00:02:08.360 LED on. 27 00:02:08.500 --> 00:02:12.240 And when you turn your pin off, I'll turn power to the LED off. 28 00:02:12.700 --> 00:02:13.400 You ready? 29 00:02:13.400 --> 00:02:15.780 Okay, yeah. Let's give it a go. 30 00:02:17.600 --> 00:02:18.700 It's working! 31 00:02:19.200 --> 00:02:21.920 Connie, you are very strong. 32 00:02:22.880 --> 00:02:25.840 Just doing my job. I'm a MOSFET. 33 00:02:26.040 --> 00:02:29.980 You have a mossy feet. What in the wide world of sports is that? 34 00:02:30.140 --> 00:02:32.540 Oh, no, Hans, a MOSFET. 35 00:02:33.980 --> 00:02:37.360 That stands for metal oxide field effect transistor. 36 00:02:37.920 --> 00:02:41.340 I can take weak electrical signals and strengthen them. 37 00:02:41.340 --> 00:02:45.060 Those small signals can then control much larger amounts of current. 38 00:02:45.340 --> 00:02:47.720 I use three connections to make that happen. 39 00:02:48.100 --> 00:02:52.180 My source pin connects to the source electrons I want to control the flow of, 40 00:02:52.320 --> 00:02:56.020 you know, such as ground or negative connection on a power supply. 41 00:02:57.540 --> 00:03:00.280 My drain pin connects to positive power. 42 00:03:00.480 --> 00:03:03.080 And my gate pin connects to the signal, 43 00:03:03.180 --> 00:03:06.400 which tells me when to turn the higher current connection on or off. 44 00:03:08.700 --> 00:03:14.120 so you empower smaller electrical signals to make them bigger 45 00:03:14.120 --> 00:03:18.080 that's true you know some folks 46 00:03:18.080 --> 00:03:23.340 even call me an amplifier Connie the amplifying MOSFET 47 00:03:23.340 --> 00:03:27.860 sounds like a superhero thanks Hans 48 00:03:27.860 --> 00:03:33.620 well i told Cappy i'd meet him at an audio circuit around 2 30 49 00:03:33.620 --> 00:03:35.280 he wants help to make his 50 00:03:35.280 --> 00:03:40.860 stereo speaker louder. So how long do we have to flash this 51 00:03:40.860 --> 00:03:45.040 LED for? Oh, just like another 400,000 52 00:03:45.040 --> 00:03:51.080 milliseconds. So you should be fine. Oh, okay. 53 00:04:13.440 --> 00:04:16.220 I'll see you next time.