Overheat protector for a dc-to-dc converter or the like

摘要

A Schottky barrier diode is employed for temperature sensing, being capable of indicating temperatures above 110° C. or so by the magnitude of its reverse current. The overheat protector is disclosed as incorporated in a dc-to-dc converter in which, connected in series with the primary winding of a transformer, a current control switch is driven by a switch control circuit so as to hold the converter output voltage constant. The Schottky barrier diode is connected to the gate of a thyristor, triggering the same by its reverse current when a preselected part of the converter, to which the Schottky barrier diode is thermally coupled, heats up to a predetermined limit. The conduction of the thyristor results in disconnection of the switch control circuit from its power supply.