Temperature protective circuit for supply voltage switching circuit of microcomputer of electric refrigeration compressor, has monitoring unit connected with supply unit, where power supply of circuit is maintained in high temperature mode

摘要

The circuit (1) has a temperature monitoring unit (4) comprising a temperature sensor (5) and a temperature relay (6) and connected with an auxiliary power supply unit (10) over a supply voltage line (14) and with an electrical device (3) over a signal line (12). A supply voltage switching circuit (2) of the electrical device is switched to a high temperature mode by an inhibit signal on branching signal lines (7, 7a) when actual temperature lies above upper temperature threshold. A power supply of the circuit is maintained in the high temperature mode by the monitoring unit.