Motor protector with remote temperature simulation

摘要

To protect a motor from overheating, its temperature is simulated at a point remote from the motor and the motor voltage is controlled to prevent overheating. The simulator comprises a cube of copper carrying a pair of heating elements: one being heated by a current proportional to motor current and the other heated by a current proportional to motor power. A temperature detector on the cube detects temperature corresponding to critical motor temperatures and is used to control motor energization.