Timebase circuit sensing automatic light
Posted on Mar 28, 2007 6717
Using only a NE: automatic light sensor circuit composed of 55 groups, so that people can rice lights, people take the lights off. } N supply route VD1, vS, C. , (1 and R. composition, power and (1, both ends of the Sichuan Hl 12V input DC
voltage of about .RP1 electricity for the whole composition and VTP light control circuit, daytime phototransistor VTP turned, NE5 55 feet of level is less than 0 4V, forced reset circuit, pin output low, the thyristor VTH off, light E does not shine. when night comes, VTP equivalent resistance becomes large, even completely turned off, feet elevated level , unblock base circuit when Sh , turn on the lights so as to create conditions for the state regulator RP festival circuit can control the light sensitivity. NE553 composition monoflop device, usually in a stable state, pin is low, VTH off lamp does not light if the body close to the sensing electrode films, time-based circuit foot through the distribution of power between the body and the sensor chip to obtain T AC signal frequency content through VI) 2 rectifies the negative half cycle of the signal which can trigger flip NE555 set, feet high output .VTH opened, the lamp E energized to emit light. people left after about by JOs about that after the transient, time base circuit turn with steady, lamp E goes out. If people feel should sheet to continue its activities within the effective detection range of ah, lamp F is a steady water quenching. in order to ensure an adequate trigger circuit sensitivity, the sensor chip area should not be less than iOcm 20crn see thin copper side. mosaic and two village Section surface slightly larger than the thin plexiglass plate (with 502 glue). However, before it is embedded wall. the entire circuit just installed in the sensor chip back, pay attention to the opening in the sensor chip should make a little stretch VTP out to feel the irradiation of natural light, but X itself to avoid direct light, otherwise the electrical path not often stop working. this circuit is effective sensing distance of about l-3m.