Automatically notify the bus to close the door based on the 555 design

Car Audio Crystal 3.2*2.5mm 3225 24M (24.000MHZ) 20PF 10PPM 20PPM 30PPM

Probe domestic switch needle KG300B head diameter 3.0 normally closed switch needle total length is 5

As shown in the figure, the bus closes the automatic notification circuit. The circuit consists of a monostable delay circuit, a chirp integrated circuit integrated circuit KD-153, and a dual power amplifier integrated circuit integrated circuit. The semiconductor fabrication process is used to fabricate a plurality of transistors on a small single crystal silicon wafer. Components such as resistors and capacitors are combined into a complete electronic circuit in accordance with the method of multilayer wiring or ramp wiring. It is represented in the circuit by the letters "IC" (also with the literal "N", etc.).
KD-28, audio circuit (speaker speaker is an electro-acoustic device that converts electrical signals into sound signals. To be precise, the operation of the speaker actually turns a certain range of audio electric power signals into distortion through the conversion mode. Small and audible sound with sufficient sound pressure level.
The monostable delay circuit consists of IC1 (555) and R1, C1, R2, and C2. When the micro switch K1 and K2 are closed, the voltage on C1 cannot be abruptly changed. 555 is set because the 2 pin is low level (<1/3VDD), and the high level of the 3 pin output turns BG1 on. The corresponding KD-153 is powered, and the output 叮咚 signal is amplified by KD-28 to drive two speaker speakers. The speaker is an electro-acoustic device that converts electrical signals into sound signals. Specifically, the operation of the speaker is actually to convert a range of audio electric power signals into a audible sound with a small distortion and sufficient sound pressure level. The speaker is one of the weakest devices in audio equipment, and it is the most important component for sound effects. There are many different types of speakers, and the prices vary greatly. The audio power passes through electromagnetic, piezoelectric or electrostatic effects, causing the cone or diaphragm to vibrate and resonate (resonate) with the surrounding air to produce sound. The speaker is divided into a built-in speaker and an external speaker, while the external speaker is a general speaker. Refers to the speaker. The built-in speaker means that the MP4 player has a built-in speaker, so that the user can listen to the sound of the MP4 player through the headphone jack or through the built-in speaker. C2 is charged. When C2 is charged to make the potential of pin 6 reach 2/3VDD, 555 is reset. The corresponding speaker stops sounding. The period corresponding to the speaker sounding is the delay of the one-shot circuit td=1.1R2C2, and the graphical parameters correspond to about 3 seconds. The sound time can be adjusted by changing the charging time constant R2C2.