| 摘要 |
A photoswitch includes a DC power supply, a luminance controlling circuit and a lightening apparatus. The luminance controlling circuit includes a relay RL1, a trigger circuit module, a delay discharge circuit module, a photosensitive element and an adjusting circuit module. The trigger circuit module includes a NPN triode Q1, a NPN triode Q2, NPN triode Q3, a resistor R3 and a resistor R6; the adjusting circuit module includes a resistor R4 and a resistor R5 and a resistor R7, one end of which is in connection with the current output end of the resistor R4 and the other of is in connection with the current input end of the relay RL1; a current value of a subcircuit with the resistor R7 and the relay RL1 is smaller than a pull-in current value or a release current value of the relay RL1. |
