555 police car audio circuit original schematic

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

The sound circuit diagram of the 555 police car is as follows. A1 generates low frequency oscillation, and its frequency f1=0.7~14.4Hz. The specific value is adjusted by the potentiometer RP. Capacitor C1 (capacitor is usually referred to as a capacitor, denoted by the letter C. Capacitor is a 'charged container', is a device that holds a charge. Capacitance is one of the most widely used electronic components in electronic devices, widely used for blocking The charging circuit of the coupling, bypass, filtering, tuning loop, energy conversion, control circuit, etc.) is supplied by Ra, RP, and a diode VD is connected in series in the discharge loop, so it is generated on C1. A series of sawtooth waves with a range of high to low. The oscillation frequency of A2 is about 870Hz, and the duty ratio is 47%. This circuit is buffered by the VT of the A1 pin 2 and pin 6 of the A1, and the sawtooth wave of C1 is added to the control end of the A2 (5 pin). The wave modulates the high-frequency square wave so that A2 produces a high-to-low oscillating frequency, and the speaker emits a continuous "correction-correction-" sound.

555 police car audio circuit diagram