Use CD4011 to create sound, light and touch three-control delay lamps

NAND gate I. It serves as the microphone audio amplifier and NAND gate II forms a light control circuit, NAND gate III forms a thyristor delay switch,
and NAND gate IV forms a touch control circuit. In the waiting state, the NAND gate III outputs a low level, the thyristor V is turned off, and the lamp
H does not light up.
    During the day, the photoresistor RG has low resistance when exposed to light, the NAND gate II outputs a high level, and VD1 is cut off, so the circuit
blocks the sound channel so that the sound pulse cannot pass through, that is, the light bulb turns on and off without sound control. But the touch circuit can work.
If you need to turn on the lights during the day, just touch the touch electrode piece M with your hand. The clutter signal induced by the human body is injected into
the input end of the NAND gate IV through R9, making its input end high level "l '', the output terminal outputs low level "o,'. At this time, VD2 is turned on, so that
the input terminal of NAND gate III is also low level "0,', and the output is high level "l", so the thyristor vS can obtain the trigger
current and turn on, and the lamp H point Lights up. At the moment when VD2 is turned on, capacitor C3 is charged rapidly, and after the human hand leaves the electrode sheet M.
Although VD2 resumes cutoff, the charge stored in C3 needs to be slowly discharged through the high-value resistor R5, so the output of NAND gate III
The input terminal still maintains low level "o,', so the light H will not go out immediately. As C3 discharges, the input level of NAND gate III
continues to rise. When it rises to the NAND gate threshold level, NAND gate II flips, and the output becomes low level "0", which can The silicon controlled
silicon is turned off when the alternating current crosses zero, and the lamp H goes out.
    At night, RG has a high resistance due to no light exposure, so that one input terminal of NAND gate II is a logic high level "l", which
creates conditions for the sound channel to be opened. If someone is walking or talking on the stairs at this time, the sound signal picked up
by microphone B is amplified and output by NAND gate I, and is coupled to the other input of NAND gate I at both ends of R3 through C2 coupling. When
the peak level of the positive half cycle of the audio signal exceeds the input value level of the NAND gate, since both input terminals of NAND gate II are logic "1,"
, the output terminal is logic "O" and VDI is turned on. , so that the input terminal of NAND gate III is logic "o'', then the output terminal is logic "l",
as can be seen from the above analysis. vs is turned on, and the light H is on. At night, the lighting can also be turned on by touch , and the process
is the same as above.
    The delay time of this circuit, that is, the time the lamp lights up each time, is mainly determined by the discharge time constant of resistor R5 and capacitor C3. The
delay time of the circuit can be adjusted by increasing or decreasing the value of R5 or C3.