| 摘要 |
PURPOSE:To prevent the residual energy from overcharging the smoothing capacitor of a converter in case the converter and an inverter are broken through the action of a safety circuit while the elevator is in operation. CONSTITUTION:An elevator control device includes a voltage sensor 19 to sense the voltage of a smoothing capacitor 4, a comparator 20 to emit an output when the sensing value of the sensor 19 exceeds a certain level, a discharge circuit consisting of resistance 21 and transistor 22, and a base circuit 23 which gives a base signal to the transistor 22. When the inter-polar voltage of the smoothing capacitor 4 exceeds a specified level with operation of a safety circuit, the discharge circuit is put in electrical continuity upon a signal given from the base circuit 23 so as to release electric charges from the smoothing capacitor 4. |
