PIR sensors

[Mike B]

In my quest to find cheap stuff I found that you can buy battery operated PIR
sensor lights from Ebay for less than $5.
The build quality isn't great, so you wouldn't trust them as primary sensors in
a monitored alarm system, but for the price and what you get, they are good
value.
The one I got works down to less than 1 volt and has duration, brightness and
light dark sensitivity adjustments.


Mike

 

[T.T.]

"Mike B" <someone@noplace> wrote in message
news:j4kct611dtbl6po4d37v41knnfr8e60u3e@4ax.com...

In my quest to find cheap stuff I found that you can buy battery operated
PIR
sensor lights from Ebay for less than $5.
The build quality isn't great, so you wouldn't trust them as primary
sensors in
a monitored alarm system, but for the price and what you get, they are
good
value.
The one I got works down to less than 1 volt and has duration, brightness
and
light dark sensitivity adjustments.


Mike
I use them to trigger cameras to photograph birds. I hide them near

waterholes in the bush, and they sense even a small bird within half a
metre.

 

[atec77]

On 20/05/2011 9:55 PM, Mike B wrote:

In my quest to find cheap stuff I found that you can buy battery operated PIR
sensor lights from Ebay for less than $5.
The build quality isn't great, so you wouldn't trust them as primary sensors in
a monitored alarm system, but for the price and what you get, they are good
value.
The one I got works down to less than 1 volt and has duration, brightness and
light dark sensitivity adjustments.


Mike
Replacing them every few months might be irritating though

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[Ian Field]

"Mike B" <someone@noplace> wrote in message
news:j4kct611dtbl6po4d37v41knnfr8e60u3e@4ax.com...

In my quest to find cheap stuff I found that you can buy battery operated
PIR
sensor lights from Ebay for less than $5.
The build quality isn't great, so you wouldn't trust them as primary
sensors in
a monitored alarm system, but for the price and what you get, they are
good
value.
The one I got works down to less than 1 volt and has duration, brightness
and
light dark sensitivity adjustments.

Are the motion sensors any good in those sound emitting novelty items, such
as the plastic frog that makes an appropriate noise when someone walks past?

Some might be more familiar with the farting gnome & farting Santa
novelties - the latter of which always goes out of stock by early December
by the time I think of buying one.

 

[Mike B]

On Fri, 27 May 2011 17:08:16 +0100, "Ian Field" <gangprobing.alien@ntlworld.com>
wrote:

Are the motion sensors any good in those sound emitting novelty items, such
as the plastic frog that makes an appropriate noise when someone walks past?

Some might be more familiar with the farting gnome & farting Santa
novelties - the latter of which always goes out of stock by early December
by the time I think of buying one.

If it's really cheap then the sensor may be nothing more than a LDR and band
pass filter rather than a PIR. At least that is what I found in a $3 movement
sensor disguised to look like a typical PIR sensor. There's a delicate balance
between stuff that is unbelievably dirt cheap and just plain cheap.

Interestingly these types of devices can sometimes be a cost effective way of
buying components - you pull it apart instead of actually using it for what is
was designed for. My $5 PIR LED light sensor consists of a plastic enclosure, 4
magnets, AAA battery compartment, two thumb wheel pots, some LEDs and the actual
PIR sensor itself.

Mike