So this year I transferred from my physics PhD to a Masters in electrical engineering. In only a few months, I’ve learned a bunch of stuff about circuits, including op-amps and ICs.

I’ve decided that I’m going to put my knowledge to good use, and start building a few things. I’m going to chronicle my attempts here :)

I ordered a bunch of components and a breadboard on eBay and they all arrived today! Resistors, capacitors, diodes, LEDs, transistors, the works!



So I mocked up a test circuit for the first project that I want to complete: A PC fan controller. I want to be able to control the speed of all my internal PC case fans, and turn them off if they’re not needed.

Here’s the circuit diagram, everything modelled as resistors for simplicity in the simulation software that I use (LTSpice):



I used a 9V battery and one of my purrrdy blue LEDs to set up a test circuit with a 500Ω potentiometer and a spare fan, and voila! It worked!



Muahahaha! I have harnessed the power of electricity! While admittedly pretty basic, this circuit is the first step on the road to building some of my more ambitious projects, like a pocket amplifier, or signal generator. I need to learn how to solder properly and actually take a project all the way through from circuit diagram to physical realisation.

Updates will follow, stay tuned! :)

  • May 22
  • , 2012