TRANSISTOR SWITCH CONTROL CIRCUIT

摘要

A control circuit provides current to the bases of two transistors connected in a Darlington configuration. A load in series with the Darlington collector receives the turn-on current given the improved current gain of this configuration. A diode connected between the Darlington input transistors base and collector begins conduction as soon as the input transistor is saturated. The current applied directly to the base of the Darlington output transistor is enough to saturate the latter at the operating output load current. The invention permits the use of a Darlington switch, and allows the additional advantage of the low saturation voltage of a single transistor.