摘要 |
The present invention involves an inductively activated silicon switch (TRIAC, SCR) for a control and protection circuit for motors and compressors. The circuit includes a logic gate (G1) for combining both motor control and protection functions. The logic gate has inputs from a thermostat (7), a compressor shell temperature circuit (21), a fan overheat detection circuit (28), a motor start relay circuit (29), and motor load sensing circuits (24, 25, 26). The logic gate output is connected to an oscillator (30) for inductively activating the power output stage (31), as well as a compressor shell temperature hysteresis circuit (22), and a fan timer circuit connected to the fan control circuit (27). The control circuitry further includes an over-ride circuit (23) for manually allowing a limited number of immediate restart attempts. <IMAGE> <IMAGE> |