How to Build a universal motion alarm to protect your home
This video shows us the method to make a universal motion alarm to protect your home. You will need a reed switch with an alternating contact, a 9V battery with a battery clip, a switch, a buzzer, a small plastic box and a magnet. When a magnet is brought near the reed switch, it switches to the other contact and the switch is open. If the magnet is removed, the switch is closed and the buzzer starts ringing. Make the circuit with correct polarity for battery and the buzzer. Make a hole in the plastic box for a switch. Paste the reed switch as far away from the battery as possible. Put on the switch on the box and the alarm should start. If this is not the case, connect the other terminal of the reed switch. You can use this by placing the magnet on the box and putting it in the purse. If someone tries to take away the purse, the magnet moves from its position and the buzzer starts ringing. One can also tie one end of the door to the magnet on the box so that opening the door activates the buzzer.