| 摘要 |
PURPOSE:To simplify the circuit constitution by using the optical control thyristor, the thyristor located in the opposite phase to the optical control thyristor, the transistor controlling the gate current of these thyristors and the two-way thyristor each. CONSTITUTION:The signals are supplied to terminals 1a and 1b before the voltage of load terminal 16a increases to plus (+) from zero, and the light is irradiated to optical control thyristor 13. In that instant, transistor Tr15b is turned off with thyristor 13 turned on respectively. And the gate current flows to two-way thyristor 17 to turn it on. Then in case the input signal is applied in the state under which the voltage of terminal 16a is plus (+) along with Tr15b turned on, thyristor 13 cannot be turned on along with thyristor 17 never turned on. Then in case the input signals are applied before terminal 16a increases to minus (-), the backward current flows to thyristor 13 since Tr15a is off. Thus thyristor 23 is turned on with thyristor 17 turned on respectively. Then if the input signal is applied when terminal 16a features the minus (-) state, thyristor 23 is turned off since Tr15a is on. And thus thyristor 17 is never turned on. |
