How can I add a timer to my doorbell to stop nusciance calls at night?

saversfriend

I live in a flat and share a telephone entry system with 9 other people. There is a panel at the front door with 10 buttons on. One of them rings the phone in my flat and I can buzz them in.

Unfortunately the button sometimes gets pressed by randomers who find it funny after drinking too much or by next door neighbour's visitors (who come and go during the night) when they push the wrong button.

I considered adding a switch into the wire leading to the buzzer to silence it but it's likely that I'd forget to switch this on or off.

I would like to find a way to introduce a timer into the circuit with the buzzer in so that I can make the buzzer silent between, say 11pm and 7am.

The wire affected is low voltage - I assume 12v or 18v but I would check before cutting into it!

Any ideas how this would the achieved?

Thanks

Owain_Moneysaver

You need a timer with 'volt free' contacts. This means the switch connections are separate from the power supply to the timer

Something like this
http://www.louis-grace.co.uk/more/on/details/0101

You would have to supply it with power (12 Volt AC or DC).

This assumes that your intercom is the conventional 4 + 1 wire system where there are 4 wires to every handset (speak, listen, common, lock) and 1 wire particular each handset for the buzzer (call). A more sophissticated system will be harder to modify.

This timer
http://www.qvsdirect.com/timeguard-ntt06-24-hour-manual-slimline-immersion-heater-timer-switch-volt-free-contacts
says it's volt free. You'd have to be very careful to keep the mains supply side completely separate from the intercom side.

saversfriend

Thank you for that - I will have to be careful about how much money I spend to prevent a not too frequent disturbance but you've certainly set me off on the right lines ...

Many Thanks.

Owain_Moneysaver

An alternative to the QVS immersion heater timer would be a 1-zone central heating programmer, try ebay for the old mechanical ones which get replaced.