Published:2011/3/30 22:53:00 Author:Ecco | Keyword: automatic control, vestibular light , photocoupler | From:SeekIC
According to the circuitry, A stands for four sets of analog electronic switches(S1~S4: the parallel connection of S1,S2,S3 is used as time-delay circuit, which could increase the driving power and anti-interference capability. When they are connected to the power, and they could control vestibular light H directly by bidirectional triode thyristor VT with driving of R4,B6; S4 and light dependent resistor Rl. etc composed environmental light measuring circuitry. When the door is closed, the reed KD in the door will influenced by magnet, its contacts will be disconnected, and S1, S2, S3 are in the state of ON . When in the night, the host come back and open the door, the magnet will separated from KD, and the contacts will be connected. At the same time, the 9V supply will charge C1 by passing R1, the voltage in two terminals rise to 9V quickly, and commutating voltage passes S1,S2,S3 and R4 to make B6 lighted and bidirectional triode thyristor breakovered. H is lit. That is torealize automatic control. When the door in closed, the magnet will make the contacts of KD disconnected, and 9v supply will stop charging for C1, the circuitry is in the time-delay state. C1 begin discharges to the R3, after a period of time delay, the two terminal voltage of C1 will lower than opening voltage(1.5V) of S1,S2,S3, and they will recover the disconnected state, and B6 and H stop working. That is to realize the function of turning off a lamp while postponing.
Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/Light_Control/The_automatic_control_circuit_diagram_of_vestibular_light_with_photocoupler.html
Print this Page | Comments | Reading(3)
Code: