Door Alarm

Project

In this project learn how to build a simple door alarm that will use a reed switch attached to the door to sense if it is open. The alarm can be armed and disarmed using a key switch.

The alarm will use a relay to turn on a 12V siren you could swap the siren with something else that you want to get triggered when the alarm is set off. The siren can be purchased for cheap.

The alarm will sound if the reed switch is open and the key switch is not on. The alarm has a 10 second delay this allows you time to insert the key to disarm the alarm.

The alarm will sound if the reed switch is open and the key switch is not on. The alarm has a 10 second delay this allows you time to insert the key to disarm the alarm. You can use a reed switch and magnet that can be screwed into the door like the image shown below.

I have included the schematic for the circuit below. The circuit can be built on a piece of perfboard or you could make a PCB if you would like. I recommend using screw terminals for the external connections so it is easy to wire up.

Once your circuit is built you could put it in a small enclosure so that the circuit is protected and is more visually appealing. The circuit can be powered by 12V so you will need to supply power to it either using a wall outlet you could use a battery.

Acknowledgement

I thank PCBWay & LCSC Electronics for the partnership.

PCBWay Is a cheap reliable service where you can get your PCBs manufactured. All the PCBs are high quality and the engineers are very helpful and will resolve any problems you may have quickly. Sign up today and get a $5 welcome bonus. Check Out PCBWay Hackster page.

LCSC Electronics Is China's leading Electronic Components Distributor. LCSC sells a wide variety of high quality electronic components at low prices. With over 150, 000 parts in stock they should have the components you need for your next project. Sign up today and get $8 off on your first order.

Website

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