Re: LED night lights with PIR sensor

["toscal" <stephens@xxxxxx>]

Hi Martin,
A standard alarm PIR usually requires somewhere between 9v to 12v
and draws about 15 to 20 ma. Has a relay contact which is normally
closed , and open when they detect body heat etc.
Maplin sell a PIR Sensor Module, which requires 4.7v to 12v input.
The output is a logic pulse. Order code is YD85G . They also stock
other PIRs.
For the leds try this site www.superbrightleds.com
Rather than build completely from scratch, why not modify a
solarpowered garden light, this would solve the one night only power
problem. But the solar lights are usually only 3v and last 4hours on
full brightness.
Just been looking at more goodies on the Maplin website found this
N63AY (Pyroelectric Infrared Detector LHi968). This only needs a min
of 2v to run.
Good luck
Stephen



--- In ukha_d@xxxxxxx, Martin Howell <grizelli.projects@v...>
wrote:
> Still looking for a source for these, no luck so far so now
teetering on
> the brink of rolling my own from a cheap PIR and a stack of LEDs.
Before
> I pry one apart, anyone know how PIRs work and what power they
need?  I
> presume they are not really passive, but need some juice?   Battery
> power will allow optimum positioning,  but no good if the batteries
only
> last one night
>
> Martin