Boost Converter

After watching a couple of YouTube videos about buck, boost converters and switching mode power supplies, I decided to take a closer look at this Arduino based approach:

http://playground.arduino.cc/Main/RegulatedPositiveVoltageBooster

I just had to find an inductor to start with. Desoldering inductors and capacitors from an old power supply left me with more than enough material to start playing.

For those interested in the details of my setup, here is a Fritzing of my breadboard. This is more or less following the schematic that can be found under the URL mentioned above.

The source code of the sketch I used and the Fritzing drawing can be found here:

https://github.com/fredvj/Arduino/tree/master/Boost-Converter

The three LEDs will indicate the status of the output voltage:

Green: Specified output voltage reached.
Yellow: Minor changes of the PWM duty cycle are required.
Red: Significant change of the duty cycle required.

When starting, the red LED will be on. If the desired output voltage can be reached, you should see the yellow LED within a second. Do not expect the green LED to be on all the time. Yellow will show whenever there are changes being made to the value of the duty cycle. It will depend on your ripple voltage if you just get the green or a mixture of the green and yellow status LED.

For low current loads (LED in my case) I have been able to triple or even quadruple the input voltage (5V -> 20V). The limiting factor is probably the PWM frequency of the Arduino. The sketch is setting the pre-scaler for a PWM frequency of 62500 Hz. Commercial integrated circuits will run at higher frequencies, but this is the maximum we can reach with an Arduino.