Normal open door buzzer

[mg170]

Hi

Thank you already for your help.

I would like to hook up a door buzzer to a 16 Volt DC transformer, when my main door at the business opens, that I will be notified. I am looking for something like when a car backs up just normal beep beep. Not too loud.

I bought already a 12VDC electric mini buzzer (300-500hz), which works ok. Also bought a 2 tone 6-16VDC buzzer (3200hz), which is a little bit loud.

If you could point me into the correct direction of what I might need, I would really appreciate it.

-Marc

 

[KrisBlueNZ]

Hi Marc and welcome to Electronics Point

First, you need a way to detect when the door is opened. The usual way is with a little microswitch in the hinge area or elsewhere on the door itself. Many of the switches on this page will be suitable: http://www.digikey.com/product-sear...ion-limit-switches/1114207?stock=1&quantity=1

The switch will generate a contact closure or contact opening, either briefly as the door is opened (and again when it closes), or during the time that the door remains open.

Then you need a circuit to handle the timing and generate the ON-OFF-ON-OFF control signal for the beeper. This part we can help you with. It can be powered from 16V DC.

Have a look at the switches, and perhaps buy a selection of them and see what will work best. Once you have a signal that changes when the door is opened, the rest can be done pretty easily, once you define exactly what you want to happen. We will also need some information on the 12V beeper that you want to use - manufacturer and part number, or a link to a sales page.

I or someone else here can design a circuit for you, or we may be able to find one already designed that will do what you want. Try Googling door open alarm or something like that, and see if there are any projects out there. They may also have good advice about fitting the switch.