Power consumption of PIR lamp on standby? [OT]

  • Thread starter Thread starter Lem
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Lem

I have one of those outdoor lamps which come on if the PIR senses
motion.

What sort of power consumption do these devices have when they are
on standby?
 
Lem said:
I have one of those outdoor lamps which come on if the PIR senses
motion.

What sort of power consumption do these devices have when they are
on standby?
Click to expand...

Not sure about the actual wattage, but it can't be much, battery powered
PIR's in alarm systems seem to last for over 12 months, so that should
give you a rough idea.

It amazes me how some people leave these lamps blazing away all day,
without taking the trouble to adjust them, or even switch them off. Most
of these are 500watt, which, if I am correct, is the like leaving a two
bar electric fire on for 6 hours every day.
 
Lem said:
I have one of those outdoor lamps which come on if the PIR senses
motion.

What sort of power consumption do these devices have when they are
on standby?
Click to expand...

Try asking in ........ free.uk.diy.home
 
In uk.comp.vendors GwG said:
Not sure about the actual wattage, but it can't be much, battery powered
PIR's in alarm systems seem to last for over 12 months, so that should
give you a rough idea.
Click to expand...
It's as near to nothing as makes no odds I would guess, cost a few
pence a year.

It amazes me how some people leave these lamps blazing away all day,
without taking the trouble to adjust them, or even switch them off. Most
of these are 500watt, which, if I am correct, is the like leaving a two
bar electric fire on for 6 hours every day.
Click to expand...
500 watts is half of one bar of an electric fire actually (the
'typical' electric fire is taken to be 1kW). That will cost around
3.5 or 4p per hour, a pound a day, enough to be worth turning off
certainly.
 
I have one of those outdoor lamps which come on if the PIR senses
motion.

What sort of power consumption do these devices have when they are
on standby?
Click to expand...
Few hundred milliamps.
 
Lem said:
I have one of those outdoor lamps which come on if the PIR senses
motion.

What sort of power consumption do these devices have when they are
on standby?
Click to expand...

You could try asking in sci.electronics.misc


Tim
 
In message <[email protected]>
Few hundred milliamps.
Click to expand...

That would be many tens of watts, or at least volt-amps: I've an ancient
one (so perhaps relatively inefficient) that draws 18 mA.

That would be a mere 4.1 watts with an unlikely 'worst case' 100% power
factor, but my only wattmeter can't measure true power around/below
that.
 
I have one of those outdoor lamps which come on if the PIR senses
motion.

What sort of power consumption do these devices have when they are
on standby?
Click to expand...

A modern burglar alarm PIR uses about 15ma at 12v, so its practically
nothing for the electronics, if it had a 240/12v transformer i guess
that would use a bit, but id guess a only a few watts a year in
standby.
 
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