CONTROL CIRCUIT FOR CLAMP VOLTAGE

摘要

PURPOSE: To reduce a discharge time of an inductive load by allowing a threshold level means with a prescribed breakdown voltage to be activated when a voltage of a load electrode of a power device reaches an ground voltage or below and then a breakdown threshold level. CONSTITUTION: A discharge circuit is provided with a means 18 having a prescribed breakdown threshold voltage and the threshold level means 18 is configured so that the means 18 is activated when a voltage at a load electrode 5 of a power device 2 reaches an ground voltage or below and then a breakdown threshold voltage. A voltage at which discharge of an inductor 1 is produced is set sufficiently higher up to a limit and the absolute value of the discharge voltage is higher than that of a conventional technology by properly selecting a breakdown voltage of the Zehner diode 18 being the threshold level means 1. Thus, the discharge time is reduced.