openinverter forum

Sorry if this is a FAQ. When using the open source SDU board, is it necessary to place flyback diodes across the contactors, or does the board completely protect against the contactor coil inductance? Obviously adding the diodes is easy enough, but I wanted to confirm whether this was necessary.

It varies. Some boards have specialized drivers with overvoltage protection (BTS133) but some don't if these weren't in stock. Just use a diode to be sure. Or check the printing on the drivers.