BLMC for smart pump for trucks
This is a brushless motor control for a smart water pump for the automotive industry. The project got stalled because the kickback from the motor inductance was blowing up boards. I was hired in on a temporary contract to help diagnose and recommend improvements to this project. We had weekly meetings with the customer and field application engineers for the integrated circuits involved to come up with tests and share results until the problem was resolved. We ended up putting an RC circuit on the output transistor drive circuit. The resistor was in series with the gate of the FETs, and the capacitor was on the pin of the half-bridge driver that operated the FET. The resistor acted to slow down the turn off time. And the capacitor acted to filter out the kickback spike that would otherwise blow up ICs.