Digital circuit sound and light control stair delay switch circuit (1)

It is a sound- and light-controlled delay lighting switch for stairways and walkways made of (:D4011 digital integrated circuit.
In addition to having all the special features of the sub-component circuit introduced earlier, it has high delay accuracy and extremely reliable operation.
The finished product is The discrete time performance is small, which is very suitable for large-scale production in Xiaoding factory. In the figure, the thyristor VT2
    forms the path of the delay light switch, and the control return hoof is connected to the non-digital signal by the 2 input terminals.
Circuit composition. C1) 401ltp NAND gate T composed of line r earth release device. H] to release
the audio signal inputted by the speaker Ij. The NAND gate II forms an optical switch, and the NAND f JIII and IV form a single spike circuit.
The logic function of the NAND gate is: "See. Photoresistor RI during the day. When exposed to light, the voltage is low, so that
the input pin of the NAND gate I is at low voltage. ", the output terminal @ pin is high level
"1", so the ⑨ pin is also "1". The input terminals ⑤ and ⑥ pin R of gate Ⅳ are connected to ground, which is low level." ", so the input pin ④ is "1", and pin ⑧ is also "l".
Both input terminals of JEf J|H are "1", and the output pin ⑩ is ". ", the capacitor (1.) is at low level and cannot resist electricity,
and the diode VT1 has a base resistor R; it is connected to the high-level pin ④, so VTI is turned on, and the gate of the thyristor rI_2 is
grounded by wr1. When it is turned off, the light does not light up. Since pin ⑩ is at low level ".", no matter how the level of pin ⑩ changes
, the pins are blocked and the light cannot be lit.
    At night, photosensitive IU resistor RI. Without light illumination, the resistance of the high U resistor is much greater than R. Therefore, the @ pin is
a high level "1", which provides conditions for the light, but the level of the input rfi pin ⑩ The low level also depends on the level of @ pin
. When someone moves, ¨ picks up the sound F' signal and (1. Combines it with the NAND gate I for amplification, and then passes R. to
C, charging (allowing power The time constant is extremely small). Make pin ⑥ also change to high level "1". According to
the logic system of NAND r J4 all 1 is o", pin ⑩ outputs low level "o", and pin ⑨ is also " .". From "she o comes out of l", we can know that pin ⑩ is
"1", that is, pin ⑩ outputs high level and charges to c through R. According to the principle that the voltage at the terminal of capacitor I cannot change suddenly,
the pins ⑤ and ⑥ is "l", so the output terminal ④ pin is low power ~ r "o", VT1 is cut off, the door panel of the thyristor VT2
triggers the 1U current through V D1 and the 7F direction, and turns on the lamp E to energize and emit light. After about 30s life Ran, C.
After charging, pins ⑤ and ⑥ return to low level ".", pin ④ outputs high level "1", VT1 is turned on, VT2
loses the trigger current, and is cut off when the alternating current crosses zero. The electric lamp goes out. In the steady state, the ⑩ pin is low level
".", (1. It can be discharged through R. to prepare for the delay of the F times of the lamp.
    There are two characteristics of the Feng l Ji circuit: First, the electric lamp is on When it is on, it is a soft start, and when it is lit, it is semi-energized by alternating current, which can greatly
extend the service life of the bulb; secondly, the lighting time of the bulb is determined by the time constants of p. and c.
The light shines on RI. L/l .Self-brightening phenomenon will occur. This delayed energy-saving lamp has excellent effect in actual use.
The sound of ordinary footsteps can make the lamp light up. The lighting bulb iF should be an incandescent bulb with a temperature of 60W or 60WU.