fire alarm clock

Feb 11, 2010 2 Replies
J

I want to build an alarm clock with a 120v ac fire alarm bell rigged to ring with the clock alarm.



I'm planning on using the signal to the clock alarm to activate the 5v coil of a relay with contacts rated for 6 amps. If the signal is pulsing I want to use a capacitor to even it out.



I've made about 3 of this kind of alarm clock before, but the technology is always changing. No two digital alarm clocks are the same. I just have to take it apart and test the circuits until I find the alarm signal, then go from there.



Any recommendations?



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E

Use a sensitive gate SCR to activate the relay. No need for the cap. To reset the SCR, you'll need to interrupt the coil circuit.

Ed

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J

ring=20

coil=20

want=20

is=20

to=20

go=20

Roll your own clock with a micro of your choice?

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