These Bosch Sensors have high WAF!

[Del91574]

They're pretty slick when you put them in, also PI when adjusted properly, only downside is you really can't bury them because at some point you'll need to get to them for service.

I don't think their controller is as intricate as you believe, however. From what I know, I believe the pulsors are basically what boils down to piezos and what the analyzer is for all intents and purposes is an amplifier and pulse extender, but I typically don't re-engineer the wheel once I find the product..

Location is key especially when factoring in pets, since a cat may not trigger one normally, but a cat landing may, and from my experiences with them, they will pick up the added weight of someone sitting/standing in a location until the circuit board times out.

 

[kwilcox]

I did read about the coverage oval but that shouldn't be a big deal (unless these things cost an arm and a leg) because I could overlap several pulsars to cover a room. All off would then = room unoccupied. "circuit board timeout" would be a bad thing however. I'm assuming this can be adjusted.

 

[Del91574]

From memory, if you're not causing the pulsor to flex, it's not going to be able to be picked up by the board, the board just extends the pulses and provides a dry contact that opens long enough to trip a burg zone.

How you set it to work would be dependent on logic.

 

[kwilcox]

Well, after a full week with no false triggers, I decided to install the second one in the fireplace room today. It works very well, covering the entire 20 x 10 area. I was hoping it would sense somebody trying to break in through the sliding glass door while they were still outside there but the glass itself must interfere with detection. It easily saw me in front of the door but nothing when I was on the outside. As soon as I started to move the door, it tripped though. I'm guessing that the microwave detector is blocked by glass.

 

[Del91574]

PIR's will not see through glass. Microwave, however will pass through most building materials easily.

 

[drozwood90]

PIRS sense long wave IR. It doesn't pass through glass.

This phenomenon is actually why cars heat up in the sun. Shortwave and to some extent mid-wave IR passes through glass. Then strikes the interior of your car. At that point it heats the material. What is re-radiated is a 3 "types" of IR (as well as other energies, but let's keep this simple). The short and mid (to some extent) passes BACK out of the car's windows. The remaining Long wave stays IN the car and keeps striking surfaces and radiating out, and well, increases the energy content of the car. It is also freaky to someone who spent over 5 years working with Long Wave IR sensors, to then mess with a Short wave sensor and see through glass.

Pretty neat when you think about it.

--Dan

 

[kwilcox]

of course. If I had just stopped to think about it a moment.... Thanks for the explanation!

 

[Big517]

PIR's will not see through glass. Microwave, however will pass through most building materials easily.

Could I hide a microwave sensor behind a speaker grill, or even drywall? Or to they rely on ir to some extent to eliminate false positives?

 

[Del91574]

You could install a microwave detector concealed, however adjustment and the typical false alarms with them usually preclude their installation. Dualtec type detectors typically trip on the PIR side, which then turns on the MW section of the detector for verification purposes (watch the LED's on a well installed and adjusted unit sometime).

GE offered RCR detectors (range controlled radar) as a specific technology and also a "dualtec alternative" that I've used in a semi-concealed application, but I was forced to do such when I encountered a lot of old PE beams that were flush mounted (they used to make them look like electrical outlets) and I had no alternatives.

 

[aksor]

I myself was looking for an affordable occupancy sensor that would react fast and to slight movement so I moded an eagle eye motion detector as per KWicox's instructions, and bought a few panasonic slight movement occupancy pir modules from digikey. They are tiny measuring ~ 1/2" long and 3/8" in diameter. I added a transistor switch to invert the output and they are super sensitive.

Will have to test them and see how they work out.
if anybody is interested the Panasonic part# is AMN42122 low voltage3V low current digital out.

 

[TurboSam]

aksor: I'm familiar with KWilcox's hawk eye (eagle eye) motion sensor mods (Indeed, I've lusted after the ultimate in occupancy sensing ever since I saw his Fortress thread), but could you give us a little more detail (or even a diagram) about how you have combined a modified eagle eye with the Panasonic PIR and a transistor switch?

Did you do something different than what is shown on the digital output wiring diagram on the data sheet for the PIR?

Thanks!

 

[George M]

I would be interested in this also. My goal is for very quick activation for lighting control. Right now I have 10 PIR contolling lights, but yearn for something that would react quicker.

 

[kwilcox]

Indeed, my two Bosch sensors drive modded Eagle-eyes as well. Looking at my logs I can see that they are triggering about every 30 seconds in bursts of two when somebody is moving about within their field of view. By this I mean that when motion is detected they trigger once, then two seconds later if there is still motion, they trigger again. Then, there's a 30 second delay before the detection process starts over. Since Eagle eyes send 4 transmissions for each trigger, this behavior creates the desired flurry of activity on my detector handler macros. IMO, these sensors are more than good enough for accurate room occupancy determination with low light-off latency. Plus, they have the added benefit of being cat immune as well. I spend lot of money lighting up rooms for our two cats which I'm sure they don't even appreciate...

The Bosch sensors also have a very wide field of view, pretty much covering wall to wall when mounted in the corner of a room right up against the ceiling. This makes them good candidates for my finished basement where getting wiring to a ceiling mounted sensor is a considerable challenge. Because of this, I'm currently using hawkeye detectors there with all of the usual drawbacks...

 

[kwilcox]

Well, these sensors are not suitable for sensitive motion detection. You've really got to be walking even with the PI disabled to trigger them. I'm going to try a Honeywell 216 next. I need something as sensitive as the 997 but in a corner mount package. Anybody have any recommendations?

 

[Del91574]

How about 998's or Auroras? Pretty cheap units.