Mechatronics bicycle anti-theft alarm lock circuit principle

One-piece inductor

As shown in the figure, the electromechanical integration white driving anti-theft alarm lock circuit. The anti-theft alarm lock is composed of an audio circuit, a monostable trigger, a vibration detecting amplifier and the like. The sound circuit is composed of four analog sound integrated circuits IC2 (KD9561), transistor BG3 and the like. IC1 (555) and R5, C3 form a monostable flip-flop. The vibration detecting amplifier is composed of piezoelectric ceramic sheets HTD, C1, BG1, BG2, R1 to R3, and potentiometer W1. When there is an impact or vibration signal, the piezoelectric ceramic sheet HTD converts the signal into an electrical signal, and after being amplified by the BG1 tube, the BG2 tube outputs a negative trigger signal (less than 1/3 VDD), thereby setting the trigger circuit IC1. The output delay is a pulse of td=1.1R5C3. The delay corresponding to the parameters shown in the figure is approximately 50 seconds. At the same time, the high-level pulse output from IC1 adds voltage to IC2 (KD9561), which causes it to emit a siren sound.
In the figure, K is the lock switch. When the original key is unlocked, the power is cut off and no alarm will be caused. Otherwise it will cause an alarm. The battery was a laminated battery 4F22 or 6F22 (9V).