Motor Drives Achieve 600V, 75A Rating

The Magnum 75 series consists of three unique half-bridge drives rated at 600V and 75A that can drive brushless dc, induction and brush motors. The first of these universal modular motor drives, the basic Magnum 75, contains an isolated power supply, a pair of gate drivers, and an IGBT power stage with flyback diodes. Switch control, power-down control, and fault status are located on the input or command side of the isolation barrier. The input side requires a single 5V supply to operate. A second drive, the current-sense Magnum 75, includes all the elements of the basic drive plus an isolated current-sense circuit. Isolated from the sense amp, the current-sense resistor provides a unipolar, 0V to 5V, microprocessor-compatible signal. The third drive, the "regen" Magnum 75, includes all the features of the basic drive plus an isolated regenerative clamp circuit that monitors the high-voltage bus. The adjustable bus monitor trips an IGBT that clamps the bus when the motors are back-driven and operate in the generator mode. The clamp prevents bus pump-up and possible damage to the drive.