Alter Existing PIR Circuit
Alter Existing PIR Circuit
(OP)
Hi,
I have a board with an existing PIR circuit designed for close operation. This circuit was used as a handwave signal.
I wondering how I would alter this circuit to work for whole room motion sensing using the same PIR sensor
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Any ideas are greatly appreciated.
David
OrbitalD
I have a board with an existing PIR circuit designed for close operation. This circuit was used as a handwave signal.
I wondering how I would alter this circuit to work for whole room motion sensing using the same PIR sensor
h
Any ideas are greatly appreciated.
David
OrbitalD





RE: Alter Existing PIR Circuit
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Sometimes I only open my mouth to swap feet...
RE: Alter Existing PIR Circuit
I'm familiar with the off-the-shelf offerings and would agree that it would be simpler and cheaper for most applications.
However, I working on a non-profit interactive art project that will use between 500-1000 sensors and these boards are available relatively inexpensively, much cheaper than the $10 per sensor.
So I’m going to try if I can to modify them to work although I’m not exactly sure that they will.
And yes, lens design is important and we will need to consider that as well.
Thanks again,
David
OrbitalD
RE: Alter Existing PIR Circuit
You could also check out the OEM discounts available: my prices were single quantity retail - for 1000 modules I would expect to see that virtually halve.
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Sometimes I only open my mouth to swap feet...
RE: Alter Existing PIR Circuit
We will start looking around at other options if we are sure these wont work but the price is right and the idea of re-using these reject parts goes with the environmental thrust of the art installation.
Thanks again,
David
RE: Alter Existing PIR Circuit
RE: Alter Existing PIR Circuit
Nice photos and the same circuit as given by the original poster, plus some extra psu stuff. They are not using the selected grade of opamp.
Of course if they biassed the opamp to 2V rather than 2.5V nominally they would have got a bit more range since these opamps don't like going above about 3.5V on the output.
RE: Alter Existing PIR Circuit
Original poster here:
When you say that that "they are not using the selected grade of opamp" exactly what do you mean?
I'm kind of new to Op-Amps.
Thanks,
David
RE: Alter Existing PIR Circuit
Beware of the “A” and “B” grading in general. It used to be the “A” grades were better than “B” so you have to check for each opamp which is the best grade part.
Having seen the design details, I am not surprised that these types of products are so unreliable. I got a complete PIR sensor light and it only worked for a few hours before failing. It was of course ridiculously cheap.