Re: Help with normally closed relay on motion sensor

Elephant wrote:
I have a motion sensor that has a normally closed relay. When motion is
detected, the relay opens. There is no option for a normally open
connection.

If I hook the contacts up to a buzzer, the buzzer of course will sound
all the time unil motion is detected.

What would be the best way to get around this. Another relay, an
opto-isolator.........??????

Any help would be appriciated. Don't want to have to construct too
complicated circuit.
The normally closed contact is ideal for adding to an alarm
system. contacts at windows, doors etcetera are also closed,
and you can just add the motion alarm in series to any alarm
system.
Then when a prowler is detected, your break in alarm will sound.
Else, add another relay,to invert the motion alarm.
.

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