Musical doorbell without buttons
Source: InternetPublisher:常思一二 Keywords: Music doorbell production upc1373 ne555 Updated: 2023/11/20
This article introduces a musical doorbell that does not require buttons. As long as the visitor stands in front of the doorbell, the doorbell will automatically sound. The circuit principle of the musical doorbell is shown in the attached figure. IC1 and other components form an infrared emission circuit. IC1, RP, R1, and C1 form a multivibrator frequency. According to the component data shown in the figure, the oscillation frequency is about 40kHz and the output current is 100--200mA. It can drive the infrared light-emitting diode D1 to emit 40kHz Modulated infrared pulses. IC2 is an infrared receiving chip with high sensitivity, high gain, good output waveform, and frequency identification function. After the infrared receiving tube D2 receives the infrared pulse with a frequency of 40kHz, it is converted into an electrical signal and sent to the ⑦ pin of IC2. After amplification, C5, L tuning, and IC2 internal circuit detection and shaping, the pulse signal is output from the ① pin. Normally, IC2 pin ① outputs low battery, D3 is cut off, music integrated circuit IC3 has no trigger pulse, does not generate music signal output, and speaker B does not produce sound. When someone stands in front of the door and blocks the infrared signal emitted by D1, the potential of IC2 pin ① instantly changes from low level to high level, and IC3 is triggered by D3 to output a music signal, which is amplified by V to drive the speaker to sound. IC1 uses NE555, IC2 uses μPC1373, and IC3 uses 9300 series music integrated circuits. D1 can use SE303A or LM66R 5mm round infrared light-emitting diode, and D2 can use PH302 square infrared receiving diode. V is 9013NPN tube, β≥100. B selects YD58--1 type, 8Ω/0.25W small diameter speaker. L uses 0.08mm high-strength enameled wire and tightly wraps 30 turns on the intermediate frequency transformer frame of the small transistor radio.
Latest Optoelectronic Circuits Circuits
- LED acceleration and deceleration motion display composed of CD4017
- Measurement and analysis of automatic emergency lighting circuit
- battery charging circuit
- Infrared remote control device circuit
- Motor speed photoelectric control circuit
- Desk lamp dimming soft switch circuit
- Simple light-controlled street light circuit (7)
- One of the circuits that control one light in multiple placesb
- Mains undervoltage and overvoltage alarm circuit 2
- Photoelectric adjustment circuit
Popular Circuits
- NE555 exponential voltage controlled oscillator circuit diagram
- Low power timer circuit
- NE555 timing circuit using ±15V power supply
- Use NE555 to make voice-controlled music lanterns
- Sound and light logic pen composed of NE555 circuit
- Overvoltage and overcurrent protection circuit diagram using NE555
- Nickel-cadmium battery fast charger circuit diagram using NE555
- Circuit diagram of small boost switching regulated power supply composed of NE555
- Bipolar DC and DC voltage stabilizing converter circuit diagram composed of NE555
- Pulse width modulation switching regulated power supply circuit diagram composed of NE555