PLEASE, PLEASE, don't buy another brand or model of
motion sensor and try to make the modifications we have work. The electronic
circuit boards in these motion sensors are NOT all the same. The PIRs with
sensitivity adjustment are tough to modify, several of us have found that
they are too expensive and time consuming to modify for home brew use.
AmerTac
PIR Sensor - Wal-Mart, Lowe's Home Depot, Sears, Ace Hardware, Menard's,
K-Mart and True Value have them, they're called Automatic Motion Activated
Utility Lite. Uses 4AA or AC/DC Adaptor(sold seperately). On the back of the
package just above the UPC code, 73090 Motion Utility Lite. $12.00 for one.
The Amertac is a closet/garage light that has a built in daylight
sensor. I just clip the light sensor off and use the power for the light to
run the 5 vdc relay. It has a 30 second run time and wiring it up is like
wiring up the Radio Shack 49-425 at the speaker output. It has a built in
holder for 4 AA's. I'm using 4 C's with a 5vdc reed relay. It has a plug in
for a power adapter (5.5x2.5) that I'm using. I pulled the board out and tossed
the housing. I still use the built in frame for a fixed distance to the fresnal
lense. - GregA.
Dimango
(aka Lamson Homes) HS3100 and HS3110 PIR - This sensor draws a small
amount of current but costs more than the others models available. $34.95
from Dimango but there are retailers online that have them for under $20.00
Info on how to hack the Lamson HS3100 here
.
Mainstay
Model WM2 - This sensor used to be sold as the Regent part # MS20W, MS20C
or MS20B. $8.94 from Wal-Mart. It comes in a light green and white box. Same
specs, 110 degree coverage, 70 foot range etc. and it is made by Cooper Lighting.
This sensor draws a moderate amount of current but costs less than the others
models available. Info on how to hack the Mainstay WM2 or Regent MS 20 here
.
Radio
Shack Part #49-426 - This sensor used to be sold as Radio Shack part #49-425.
$24.95 usually but they do go on sale for under $20.00 from time to time.
This sensor draws a small amount of current but costs more than the others
models available. Info on how to hack the Radio Shack #49-426 here
.
Radio
Shack Part #49-425 - This sensor has been replaced by the Radio Shack
part #49-426. This sensor draws a small amount of current but costs more than
the others models available. Info on how to hack the Radio Shack #49-425 here
.
Regent MS35 - I picked up an MS35 at Lowes the other day. It was $12.50
also, and I thought "Hey! An MS20 with adjustable gain and three delays!"
It looked nearly just like the MS20 externally. Unfortunately, it was not
to be, though it uses an LM324 quad op amp like the MS20, the guts of the
MS35 run from the full 24 volts (no 5 volt regulator -- just the regulated
24 VDC derived from the power line). Several parts are run from resistive
dividers from the 24 volts, and doesn't look like it could be made to work
if reduced to 9V without replacing a gaggle of parts (and maybe not even then).
They're taking advantage of the higher voltage to get more signal from the
PIR element -- it's run common-source like the MS20 (with a biasing resistor),
but they're developing the output voltage across a 1M resistor from the drain
to the +24 Volts (where it was 100K to 5 V in the MS20). They definitely weren't
looking out for us homebrewers when they designed it. - Jon5ja.
X10
Eagle Eye Sensor - $24.99 online and at many electronic stores. Hamiltoe's
plans on how to hack the X-10 are here
.
Indoor Burglar Alarm PIR Sensors - We have found from
testing that indoor PIR sensors and burglar alarm PIR sensors do not work
well below freezing (32 F degrees), and most of the outdoor PIR sensors work
down to almost 0 F degrees. Also, most burglar alarm PIR sensors use a normally
closed (N.C.) output.
