Learn how to make a simple door alarm to enhance your home security with our step-by-step guide. This DIY theft alert alarm ...

After construction and testing, carefully mount switch S1 in the door (or doorcase) so that it is in “open” condition when the door is in closed state. Next, set up the alarm unit at a remote location ...

This simple alarm timer circuit is made with 4060 which has an integrated oscillator with a good stability with a relatively wide frequency range. In the circuit diagram the oscillator frequency is ...

Make a Simple and Safe Trip Wire Alarm to Catch Intruders in Your Home or Liquor Cabinet. David ... and the complete wiring diagram can be found at the source link below.