About this document
Simple Home Alarm Circuit Guide by Gary Nugas is a document available to read on EtoBox.
This simple home alarm project uses three 555 timers to generate an alarm siren tone when a contact is closed, such as from a motion detector. The first timer outputs a high pulse up to 220 seconds when the contact closes. The second timer generates a 1Hz square wave that frequency modulates the third timer to produce a siren tone through a speaker. Adjusting potentiometers varies the pulse timing and tone frequency to simulate a police siren.
- Author
- Gary Nugas
- Language
- EN