DRIVE CIRCUIT FOR POWER SWITCHING TRANSISTOR

摘要

A drive circuit for a power switching transistor which controls a power switching transistor (QL) connected to the output terminal of a base circuit (BSC) so that it is turned on or off on the basis of signals input to a preamplifier (PAP), which circuit contains the preamplifier (PAP), the base circuit (BSC) driving the power switching transistor (QL) and a pulse transformer (PT) electromagnetically coupling the preamplifier (PAP) to the base circuit (BSC), in which the preamplifier (PAP) is connected in series with the primary coil of the transformer (PT) and a low impedance circuit is provided which forms a current loop with the primary coil with respect to the flyback voltage generated in the secondary coil of the transformer (PT).