One-way switch with minimal power loss - is fitted with switch=off stage formed by diode, capacitor and resistor

摘要

A one way power switching stage is modified to ensure minimisation of the power loss peak occuring during switch off. The one way, switch, as typified by a transistor (2), is used to control the connection of d.c. supply (3) across a resistive-inductive load (1). A diode (4) is coupled across the load. In order to minimise the power loss peak, a discharge circuit is coupled across the transistor. This consists of a diode (D), capacitor (C) and discharge resistor (R). During switch off a delay is ensured between current cut-off and voltage rise to minimise the power peak.