rpaus

I am constructing a burglar alarm for a home as a school project. I plan on using a 12V switching power supply with a battery charger as a backup supply. A microcontroller and keypad will be used to activate and deactivate the alarm with a 4 digit code. Sensors will include magnetic reed sensors for door and window, and inertia sensors for door and window. My questions are as follow:

1. I need to find a schematic for a 12 volt switching power supply which will also charge a rechargeable battery so incase the power fails, the battery will take over until main power is restored.

2. I have looked at many schematics for burglar alarms to control the sensors, delay time, reset, and panic button, and have found a couple decent ones, any suggestions?

3. I want to use wireless modules so I don't have to run wires from the far sensors to the main control circuitry. I don't really have any experience with these and would like some feedback on how to interface these with the sensors and with the main control circuit.

THANKS A TON!

Sceadwian

I'd recommend an X10 like protocol rather than a wireless system. Sending a signal over wire is ALWAYS prefered to sending one over the air as long as the situation allows for it, especially something that needs to eventually be hooked up to power anyways. Even if the power goes out the wires are still there for communication.

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rpaus

how does the x10 system work? Haven't looked into it at all. Do you happen to have any schematics or similar I can refer to?

ljcox

Also, wireless needs a continuous energy supply, thus it adds to global warming. Whereas, one connected by cable need not consume as much power.

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Len

rpaus

but exactly how does the x10 system operate?

Sceadwian

rpaus, have ever heard of either of these two websites?
http://www.google.com
http://www.wikipedia.com
You're wasteing time asking questions in a forum for basic information that is available elsewhere.

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