摘要 |
<p>Apparatus for preventing overvoltage and overcurrent damage to direct current motors, and wheel lockout in electrically powered vehicles having dynamic and mechanical brake assemblies includes dynamic braking voltage and current sensing circuits, a first network responsive to detected dynamic braking voltages exceeding a predetermined value, a second network responsive to dynamic braking currents exceeding a predetermined level, and a third network responsive to dynamic braking current exceeding a different predetermined level at the same time that excessive mechanical braking occurs and for providing an output when such conditions coexist for more than a predetermined time period, and an interrupting circuit responsive to outputs from the first, second, and third networks for interrupting dynamic braking and substituting therefor mechanical braking.</p> |