| 摘要 |
<p>The appts. for preventing overvoltage and overcurrent damage to DC motors, and wheel lockout in electrically powered vehicles having dynamic and mechanical brake assemblies, includes dynamic braking voltage and current sensing circuits. A first and a second network are responsive to detected dynamic braking voltages and currents respectively, exceeding a predetermined value. A third network is 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. An interrupting circuit is responsive to outputs from the first, second and third network for interrupting dynamic braking and substituting it for mechanical braking.</p> |
