Current overload protection circuit

Abstract

Abstract A constant potential power supply with current overload protection having a series switching regulator including a series switching circuit controlled by both a Schmitt-trigger circuit controlled by an output voltage detector to maintain the output load voltage within a predetermined range during normal operation and a current overload protection circuit having a foldback characteristic which operates when the output current goes above a predetermined value. The Schmitt-trigger circuit is actuated by a signal from an output voltage detection circuit when the output load potential decreases below a certain value to enable the series switching circuit to conduct current to the load from an input voltage source and is disabled as the output load potential goes above a certain value. After actuation of the series switching circuit and until it is disabled, charging current passes into an integrating capacitor. This integrating capacitor, is coupled across the load, and discharges through it when the series switching circuit is cut-off. The current overload protection circuit, which senses the output load current, exclusively controls and enables and disables the series switching circuit of the regulator when the output current increases above a predetermined level. The particular arrangement between the series switching circuit and the current overload protection circuit is such that the current overload circuit is not within the output voltage detection loop thereby improving the overall regulation of the constant potential power supply and provides significant current overload protection thereto.

Inventors

• 👤 David Morris

Bibliographic Details