| 摘要 |
PURPOSE:To obtain a highly reliable power supply method having no short circuit trouble and the like by the simultaneous ignition of the thyristor in forward and backward directions even when a momentary service interruption occurs when a forward-backward switching operation is conducted by a method wherein, after the momentary service interruption of power source has been detected, a forward-backward switching operation is made impossible for the period of time prescribed in advance. CONSTITUTION:In a DC power supply device of inductance load by a thyristor provided with forward-backward switching function, after the momentary service interruption of power source has been detected, a forward-backward switching operation is made impossible for the period prescribed in advance. For example, when supply of power is interrupted by power failure at the timing (t1), the supply of an excitation current to inductance load is suspended, and at the same time, the forward-backward switching performance against the forward and the backward thyristor is prohibited. Then, when the restration of power supply is detected by the timing (t2), a timer is started, and the state of suspension of the forward- backward operation is continued. When the preset time (p) of the time (r) of the timer has come, the trigger pulse for ignition of thyristor on the prescribed side is outputted in accordance with the command set in the control device. |
