Discrete component sound and light control stair delay switch circuit (1)

-A real sound and light stair delay lighting +F switch circuit. Its special feature is that during the day, the lights
automatically turn off and turn on: in the evening, as long as there are people walking on the stairs or there are people talking, the lights will light up.
After a delay of a few seconds, the lights will automatically go out. The circuit adopts the "= line system" The connection method does not require only two connecting terminals,
which can be connected instead of ordinary connectors. 1nj There is no need to change the original photo route.
    220V
AC interpretation bulb E,
VDl - VD4 rectifier , the positive anode voltage is formed between the anode and cathode of
the thyristor VT4 to form the main circuit of the light switch . The control circuit is composed of Vl l - wi 3 and other devices, and its T_ is used as the power supply to white R, and the voltage reduction and current limiting, Vnj isolation, Vs voltage stabilization and (j filtering) are in ((, the curve terminal can obtain about 10V Stable DC voltage. During the day, the photoresistor RI has a low resistance when exposed to natural light, so that V2 and VT3 cannot enter the conductive state, so the lamp E will not light up . At night, R1 shows high resistance, thereby eliminating the need for VT2 , VT3 is blocked. At this time, if someone is walking or talking in the stairway , the footsteps or conversation will be picked up by the microphone H and converted into an electrical signal, which is amplified by (1- through VT1, and the amplified signal is passed through ( j coupling. The positive half cycle of the H signal can make vD2 conductive, and VT3 also conducts one after another. (, the stored charge is quickly charged to (j through VTS, VD6, and the thyristor wn is opened , and the lamp E is energized and emits light. After eight steps, (, the stored charge passes through R. The gate of V1 is discharged, and VT4 can still be kept on, so the light will go out immediately. Until C, after the charge wall is discharged, VT4 loses gate triggering Current, when the alternating current crosses zero, VT4 is turned off and the lamp E goes out. The circuit delay time should be determined by / s, (: The value is determined according to the need.     VT-i should select the trigger current Smaller 0 8 ~ 1A, 400 -6 (] 0V coin-oriented crystal VI arm, such as VILR100-S, 2N6ii5, ljT1 69, etc. I<l, the larger the difference between the light resistance and the dark resistance, the better MG44, M(;45) and other photosensitive electric speakers. Small electret condenser microphones with higher sensitivity should be used, such as LRZ, 113F type, etc. This component will be studied many times by Benlu. The requirements are the same, so I won’t elaborate on Shui Ran.