When the motor is required to stop quickly, the motoring bridge shuts off and the regen bridge turns on. Due to the initial inertia of the connected load the motor acts like a generator, converting mechanical power at the shaft into electrical power which is returned to the AC line. The IaRa voltage drop (-50 VDC) is of opposite polarity then when the drive was supplying motoring power. The control logic is gating thyristors in the regen bridge at an angle of 130° and the resultant DC voltage on the bridge is 400 VDC, in the opposite polarity. Because the regen bridge is of opposite polarity, the voltage applied to the motor acts like an electrical brake for the connected load.