HomeMade Motor Controllers

[Joe Ross]

The circuit inside the Victor speed controllers is called a H-Bridge. You can Google H-Bridge and find a multitude of schematics and explanations.

If you're really industrious, I posted a link a while ago that listed the exact type of FETs used in the Victor speed controller. Realize, however, the Victor uses 9 FETs, while most H-Bridge implementations use 4. That's why the Victors can handle such a high current. However, it gets very dangerous to handle such a high current.

What are you building this on? Most breadboards use wire in the range of 22awg which is rated for less then an amp.

The Victor does amplify and condition the incoming PWM signal because the incoming signal is pulses between 1 and 2ms every 20ms. The FETs need pulses ranging from 0 to 100% duty cycle. You'll probably find out more about that from other sites about h-bridges and motor controllers.

Normally I'd suggest buying an IC with the H-Bridge integrated, but I have a feeling you'll blow off that suggestion.