| 摘要 |
<p>PURPOSE:To prevent the damage of a surge current due to high voltage application and simultaneous conduction by connecting relay contacts of 2 poles in series. CONSTITUTION:When a triac 2a is conducted, the drive coil 3a of a relay 3 is driven to close at NO contact side, a voltage is applied to the main winding of a motor 4, and the motor 4 is normally rotated. Then, when the triac 2a is turned OFF and the triac 2b is conducted, the relay 3 is closed at the contact NC side, the auxiliary winding side of the motor 4 is conducted, and the motor 4 is reversely rotated. When thus constructed, a voltage higher than the AC power source voltage is not applied, but a power semiconductor having lower withstand voltage can be used. Even if the triacs are simultaneously conducted, they are not damaged by the discharging surge current of the capacitor.</p> |
