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Please I need to build a passive infrared occupancy sensor. I need help please. Answered

Great community, my supervisor actually want me to develop a passive infrared occupancy sensor from the scratch, I want this great community to help me the components that I will need, the physics of the circuits,  the block and circuit diagram and possibly, if anyone has an idea of what could serve as a reference for me to work with.
Great community of scientists, thank you so much.


Great scientist, thank you so much for the reaction. Appreciate it so much but I still need assistance. here are the components that my supervisor wants me to use; Pyroelectric motion sensor, fresnel lens, 5V dc relay, switching diode, Quad operational amplifier, CMOS one shot IC, general purpose switching purpose transistor, 1disc capacitor, capacitors, resistor.
Please help me more on how to compile my literature.
Thank you so much.

I have never built a PIR people-sensor, so the place I would start is by studying some examples of devices that others have built. For example this search query:
returns a bunch of instructables that  somehow involve a PIR sensor.

For building such a device from its components, like the ones you mention  (pyroelectric motion sensor, fresnel lens, 5V dc relay), you can go to the places that sell such things, e.g. digikey.com, jameco.com, and look up these parts separately.  Then download their datasheets.  Then work out a design.  Then buy some parts. Then build a prototype or two, and see if these work the way you expect them to.   Then you will have a design that you can deliver to your boss, and be confident that it will work. 

That's probably going to be a lot of work, and it is not work I am going to do for you.

I think a good first step, would be to take apart one of those fragrance dispensers, like in the 'ible I linked to previously
and see if this gives you any enlightenment  into how such devices function. 

Also I think the Wikipedia page on PIR sensors has some good background info too:

Thank you so much. I am getting somewhere with those resources.

The circuitry for amplifying a PIR device is very sensitive to any electrical
A working design has to be very stable and noise immune.

BTW Jack is giving you excellent advice.

PIR element, ~4 op amps, job done. Unless you want to MAKE the PIR element (impossible, on a small scale), what's the problem.



6 years ago

Hey, Iv been trying to make such a sensor commercially available for
motel hotel rooms a third of my life and you want all the engineering
handed to you free the first day you join without thinking about dogs
and cats. Try a better sensor kiddo ;-)