Street light timing circuit

Published:2011/5/24 2:19:00 Author:John | Keyword: Street light | From:SeekIC

This circuit shows that light control timing lights can automatically open in the evening for several hours and automatically off afterwards. When darkness comes, under the action of the photoelectric switch, BG4 conducts. And oscillator circuit constituted by IC1 lamp begins to vibrate with constant IC 3 output pulse. As charging time constant of C3 is large and the oscillation period of oscillation circuit is T < <R7C3, the voltage at the starting moment for C3 is 1/3Vcc. The number 3 output end of IC is in high power level. As a result, bidirectional thyristor SCR is triggered to turn on and both ends of bulb ZD is energized to light.



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