Wednesday, October 5, 2011

Arduino Fan Controller

Well I've managed to get back on my projects lately, so here's an update.

First on my list, if you'll remember was my SMD Exhaust Fan for my soldering station. Thats now done for the most part. I followed the schematic on and built myself a nice fan controller with it. I only changed a few things due to the power requirements of the fans (Im using two, 0.5A 7W Computer Fans) and parts available to me. I used a 4N25 Optocoupler to isolate the microcontroller from the 12V power supply line. I also beefed up the Transistor with a TIP121 Darlington. Based on power requirements, Ive decided that the 1/4W resistor and the 1A diode are fine and dont need to be beefed up. Only the transistor will be handling a high power load, and the TIP121 is rated for 3A, so Im fine. The diagram shown below is linked from

Ive been toying around with it to make sure it works, and it does with both fans. Designed an enclosure for it to sit in, just gotta send it to the shop to get made. Still gotta build the exhaust hood so that everything can function in its final setup. I'll show pics of it once I get my new circuit PCB in and solder all the parts on. In the meantime, here is a picture of the non-populated board.

Next on the list of things is my IR Temp Controller for the SMD Hotplate. I've already gotten started designing the system and the schematic. This one will be using a IR Temp unit from Harbor Freight (probably one of those cheaper ones), since I found a tutorial somewhere describing how to hook it up to an Arduino and get data out of it. I'll post updates once I get this project done.

Two links I'd like to share that I thought may be useful to everyone: the OSHW Eagle Library, and the NBITWonder Eagle Library.

Stay safe. Peace out.