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Jon[_12_] Jon[_12_] is offline
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Default alarm clock question

I have a digital alarm clock. I want to wire the alarm signal to activate a
fire bell. The fire bell is 120vac @ 40mA. The alarm signal from the clock
is around 1.5 vdc.

I found a connection on the alarm clock that is 7.5 vdc all the time.

I have 5vdc relays with contacts rated for 6 amps. I have some 5vdc reed
relays. None of them work for the 1.5 vdc alarm signal. I tried messing
with some transistors but I don't know enough about them to rig something
up. I have a bunch of resistors and capacitors.

I have a second alarm clock where the alarm is connected to a small speaker.
I'd like the fire alarm to go off when the speaker beeps a signal or when
the radio alarm goes off.

Any suggestions?

Jon