Patent ID: 6667652
Filing Date: 2003-12-23
Classification: G05F

Abstract:
A dropper-type stabilized power circuit comprising:a PNP-type power transistor for obtaining an output voltage at a collector of the power transistor by dropping an input voltage; a high-temperature-leak compensating resistance provided between an emitter and a base of the power transistor; a compensating resistance switch provided in series with the high-temperature-leak compensating resistance between the emitter and the base; an output terminal; and compensating resistance switch controlling means, an input of the compensating resistance switch controlling means detects a voltage at the output terminal, the compensating resistance switch controlling means conducts the compensating resistance switch when a resultant voltage resulting from the detecting resembles the output voltage under normal operating conditions when the input voltage is dropped, and not conducting the compensating resistance switch when the resultant voltage is higher than the output voltage under normal operating conditions and is not less than a predetermined value wherein the predetermined value is set to be not more than a value at which a current begins to flow from the collector to the base of the power transistor.