Motion detectors used on their own in a circuit, such as in an area
intrusion system or burglar alarm, will always work while the system is
armed.
Motion detectors used in conjunction with a day/night electric eye, of
the type used in outdoor floodlights, will work only when the electric eye
senses that the ambient light is low enough to turn on the floodlight. The
motion detector and the electric eye are in effect two switches wired in
series between the source power and the floodlight. If either switch is open
then the floodlight remains off.

Tom

"geezer" wrote in message
...
Do they work 24 hours or just at night? That is, will the light sense
motion and turn the light on even at noon?

Dumb and curious.

Geezer