Fault protection apparatus for traction motor circuit

Abstract From the Canadian patent

13-, Abstract of the Disclosure, Fault Protection Apparatus For Traction Motor Circuit Motor control circuits having fault protection devices are in commerical use today. Such devices typically include logic elements requiring a conditioned power supply, and are incapable of operation directly from the main motor power supply. The subject apparatus includes a timing circuit for monitoring the electrical conduction of a power switching element associated with an electrical motor. The apparatus produces a fault signal in response to the power switching element continuing to conduct for longer than a predetermined continuous period of time. A latch receives the fault signal and responsively …