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Pop Up Security! Easy DIY Door Contact Sounder System

Had a recent string of break-ins in your area and need security fast? We might have the solution for you.

First off, we really think you can do a lot with a little these days, as shown in some of Zexum’s offerings such as the dummy alarm bellbox unit featured previously on this blog, which uses a 13A plug and requires no panel to operate, though it functions just as a normal unit, and sounds when tampered with!

Take a simple sounder, we’re using one Here for under £10. This thing really is loud, and will surprise an intruder and likely will cause all but the most experienced theives to get out of the property as soon as possible.

So the idea is that if you have a particularly weak or recently compromised entry point in your home or business, that you can quickly patch this up until full measures can be taken.

This unit can be easily used as a pop-up security device using a few other low cost ingredients, and below we’ll show you what you need, and how to complete this project.

Knight Grade 1 2 Terminal White Surface Door Window Alarm Contact

Door Contacts

Simple door contacts wont run you more than a few pounds, and are easy to install on windows, doors, or any entry portal. They’re also easy to wire, easy to replace, and if you’re handy, easy to install so you dont even notice them by using a flush fit contact.

We’re using 4 core alarm cable for this build, which we recommend you do the same if carrying out this project.

Multivolt Adaptor
These Zexum adaptors are admittedly a lifesaver, we use them every day at the office and warehouse, so it’s only natural we use one here now.
Set to 12V and with bare ends on the cable.

Precision Relay Timer
Finally, the powerhouse of what makes this neat little circuit possible; the PT*60 from Handy Little Modules. A simple board (half the size of a credit card if even that) which is easy to wire with just a screwdriver and our wiring instructions below, we can set this up in minutes and it allows us to set the duration of our alarm from 1 minute to 60 minutes. When an intruder breaks in, the last thing they want is an hour long alarm!

Wiring Instructions:


Your relay timer should be wired as seen above, where the blue botted wire is your power, the orange dotted wire is leading to the sounder, the pink dotted wire should end bare and be secured to the orange dotted wire, and the red dotted wire bridges between the two sets of terminals.

The Result:
Now we have a neat little circuit which sounds an alarm when a window, door, shed, or even a cupboard is opened; making it ideal for shops, nurseries or care homes, schools, visitor receptions, and more, and we’ve done this at a fraction of the cost of going through your installation company or buying a similar device already constructed at a premium on cost.

We hope you enjoy this quick project that can get you out of a security jam. Know any ways we can improve it? Remotes? Enclosures to keep it neat? Let us know in the comments below!

One way we’ve improved on this idea in our own warehouse is by adding a rotary switch or key switch to kill the alarm once we reach the door, but mean the visitor can not, making it very handy for ensuring all our customers at the click & collect hub are seen to!


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