| 摘要 |
PURPOSE:To reduce the size of a base driving circuit, by providing a transistor (TR) for carrier discharge between the base and emitter of a main TR and arranging a switching element between its base and emitter through a transformer which has the opposite-polarity input and output windings. CONSTITUTION:A transformer 9 for turning on a power TR constitutes the 1st control circuit which supplies a forward base current to a TRQ2 including a TRQ1 for on-control and a rectifying diode 10. The input winding 13 of a transformer 15 for turning off the power TR is connected in series to a TRQ4 for off-control and a resistance R5 for current limitation constituting a switching element, forming the 2nd control circuit. The output winding 14 of this transformer 15 has the opposite polarity to the winding 13 and is connected between the base and emitter of an NPN type off TRQ3 as the TR for carrier discharge. The TRQ2 is driven by control signals from the 1st and the 2nd control circuits. |
