Sunday, 13 July 2008
PWM controller done
Sat down this afternoon and built the PWM Controller board. Everything went smoothly apart from a slight soldering hiccup.
I arranged a fan so that it was gently blowing across the work area to remove the smoke and fumes, but my next couple of solder joints took a long time and did not look right. After re-reading a couple of soldering tutorials, I turned the fan off - the extra airflow cools the iron down, making the joints difficult to form. I re-melted the dodgy joints and added a bit more solder, and everything was fine again.
Plugging the completed board in, all the LEDs fired up and things looked good. I connected a small (3v?) old motor that I used for testing the DC Motor driver board.
Now, while the DC Motor board can supply 0.75 Amps, the PWM board can theoretically supply 5 Amps. My little motor ramped up (as expected) and then started to smoke. I thought it best to turn it off at this point.
A couple of minutes later, I had replaced it with an old PC fan which handled the load a lot better. Testing all three channels worked, so I'm declaring the PWM board a success. Now on to the next!