My controller is a DIY build. The control board was made by Paul Holmes. He provides the software and a populated board. You can get the same board that I used by going here: Paul & Sabrina High Power DC Control Board. He says it’s good for 350v and 1000a, and that depends on the IGBTs (Insulated Gate Bipolar Transistor – don’t ask what that means, I’d have to Google it) that you use for your power stage. The IGBT is a large, solid state switching module. For mine, I used three CM600DY-12NF IGBT. These are rated for 600v and 600a each. That can be a little deceptive, since the rated total watts determines what the IGBT can really handle continuously. You can’t just put 600v at 600a through one of these. In addition, that rating will also go down as the IGBTs heat up, which is why the large aluminum plate and thermal grease are essential. I also added a small fan controller and two fans in a push-pull configuration. This helps to keep everything nice and cool, so I have yet to see the controller get more than just warm to the touch.

Anyway, the IGBTs are switched by the control board. Their output is filtered by the large capacitor (the big, black circle you see in the pictures), and that then drives the electric motor. The controller is on the positive side of the motor, making it a high-side controller. Some controllers go on the negative side, which would make them low-side controllers.

The controller has a serial interface that can be used to change the parameters in the software. Mine is set to 333 motor amps. That is a per-IGBT setting, meaning that the controller will allow 999 amps max to go to the motor.

The controller uses a signal from a throttle potentiometer. I purchased this from EV West, and I have to say that it’s very nice. You can get it here: Billet Throttle Potentiometer. I had picked up a Curtis PB-6 Throttle Box for about $70 on eBay, and that thing was terrifying. Do not risk it. You can see some pictures of it in the Miscellaneous section.

I assembled my controller by following the guide that Paul posted here: Rough Assembly Guide. In the guide, Paul builds the AC version of this board. The assembly is almost entirely the same, you just plug in the DC board rather than the AC board, and you don’t have to worry about a resolver or encoder.