Connie: Hey Hans, what are you doing?
Hans: Hi, Connie. Well, as you know I am a 555 timer IC, so I’m pretty good at sending pulses of electricity in perfect time. Normally, I can blink an LED once per second but for some reason, I can’t make this high power LED flash.
Connie: Oh - you probably just need to give it more electrical current.
Hans: Hmm - you may be right. but I can only supply a bit of current from my pins here, my integrated circuit was not designed for driving a lot of current.
Connie: Well, you are mighty lucky I came along — I can help you!
Hans: Really? How?
Connie: I may be small, but I’m pretty strong! I can push and pull ten times as much current as you can, and manage enough power to light this big LED - I just need you to tell me when to turn it on.
Hans: Oh? how do I do that?
Connie: Grab my hand like this –
Connie: So now, you just send electrical pulses through your output pin like you were doing before.
Connie: My other pin is connected to the positive leg of the LED, and all three of us are connected to ground.
Connie: Whenever you send an electrical pulse to my left pin, i’ll know you want me to do the same on my right pin. What I mean to say is - when you turn your pin on, I’ll turn the high power to the LED on. And when you turn your pin off, I’ll turn power to the LED off.
Connie: You ready?
Hans: Ok, ya - let’s give it a go!
Hans: It’s working! Connie - you *are* very strong!
Connie: Ha - just doing my job! I’m a MOSFET :)
Hans: You have Mossy Feet? What in the wide world of sports is that?
Connie: Oh, no Hans - a MOSFET. That stands for Metal Oxide Semiconductor Field Effect Transistor.
Connie: I can take weak electrical signals and strengthen them. Those small signals can then control much larger amounts of current.
Connie: I use three connections to make that happen.
Connie: My Source pin connects to the source electrons I want to control the flow of, such as ground or negative connection on a power supply.
Connie: My Drain pin connects to a positive power
Connie: … and my gate pin connects to the signal which tells me when to turn the higher current connection on or off.
Hans: So, you empower smaller electrical signals to make them bigger!
Connie: That’s true! You know - some folks even call me an amplifier.
Hans: Connie, the amplifying MOSFET - sounds like a superhero!
Connie: Ha - thanks, Hans. Well, I told Cappy I’d meet him at an audio circuit around 2:30. He wants help to make his stereo speaker louder. Sooo - how long do we have to flash this LED for?
Hans: Oh - just like another 400,000 milliseconds. So, you should be fine.
Connie: Ohh … OK.