Car Burglar Alarm using two 555 timers

Car Burglar Alarm using two 555 timers

Car Burglar Alarm using two 555 timers

This is a simple Car Burglar Alarm circuit that uses a dual contact relay and two 555 timers, each of them working as a monostable multivibrator.

The alarm will activate the car horn, approximately 5 seconds after either door is opened and has not been properly closed.

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Electronic Doorbell Circuit using a 555 and CD4017

Electronic Doorbell Circuit using a 555 and CD4017

Electronic Doorbell Circuit using a 555 timer and a CD4017 decade counter

This electronic doorbell circuit gives us all the possibility to change the tone of each of the 10 musical notes that the circuit can have. This means we can create our own sound sequence.

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