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alarm timer help please

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New Member
I was wondering if you could point me in the right direction so I could build a timer that does exactly what the item in the link does please.

Temperature,Pressure & Humidity Monitors Alarms,SQL Central Monitoring Systems,Nitrogen Level Detectors,Freezer Backup Systems,Air Speed Monitors Controls:Hampshire Controls

Basically I have a CCTV digital recorder connected to an alarm that is giving false activations usually when its windy, it is set to activate on video loss. I need a timer that say after 1 or 2 minuites of open circuit then the alarm will activate or if the open circuit goes back to closed circuit before the 1 or 2 mins then the alarm isint activated.

I hope you understand what I am trying to do and hope you can help as well.


Well-Known Member
It's would be easy enough to do with a simple microcontroller circuit & relay. Since a 9V battery only lasts about a year according to the brochure it's not the most power efficient design (a typical home thermostat with relay can last for years on a set of AA batteries)
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