Door entry alert/ door contacts

[sythai]

Morning All

Fitted for a customer a while back a door entry alert with laser beam detection.

Cost well over £100, but has now failed.

Not an off the shelf item at wholesaler so bit of a pain to take back/ spare parts etc.

Want to replace with a lower cost option, that would be easy to maintain in future.

Ideally a door bell and transformer linked to a door contact?

Never used door contacts before, could someone please advise me wether this is possible and what sort I might need.

Thanks for your help

Sy

 

[telectrix]

intruder alarm contacts are N/O. i.e they are closed when the door is closed. a 12V PSU with a relay in it could be used to activate a sounder.

 

[tazz]

Door contacts can only handle 124mA max, and will easily burn out. When you state there was a laser beam detector, do you mean a break beam, broken when a person walks past..? I presume you wish to alarm a door, and control it by a keyswitch or panel.

 

[sythai]

Door contacts can only handle 124mA max, and will easily burn out. When you state there was a laser beam detector, do you mean a break beam, broken when a person walks past..? I presume you wish to alarm a door, and control it by a keyswitch or panel.

Thats it break beam....

Don't want an alarm as such, but when someone opens the showroom door and they're out the back it rings.

Something really simple if poss.

Thanks Sy

 

[tazz]

Ok there are two problems here as i stated door switch cant handle much current, and if the door is left open the buzzer or bell will continue to sound until its shut again.......A monostable timer will sort out both problems, door contact can be wired into 1mA input, and you can adjust the timer to stop after say 4 secs. Once door is shut it will reset ready to go off for 4 secs again if the door is opened. Will work off batteries, psu or plug in psu
Pcbkit available from many places but Maplin maybe quick to find in the high street. Hope this helps. 555 Monostable Switch Kit | Maplin

You will need to find n/o door contacts, they are available from nurse call outlats

 

[sythai]

Thanks Tazz... going past Maplins tomorrow :icon4:

 

[Darkwood]

Yep the laser beam made me chuckle... too many bank heist films I fear you have watched... the are usually IR or standard light emitters and reflectors or collectors.

 

[Flanders]

Is this any Good

B1A-WIRELESS DOOR & WINDOW OPEN ALARM ALERT: Amazon.co.uk: Electronics

 

[telectrix]

if theplace has an intruder alarm, you could put the door on chime.

 

[driverman]

if theplace has an intruder alarm, you could put the door on chime.

yep, mine done like that also