Q. Smallest motion dectors commercially available ?

[Jim]

Hi,


Two questions about motion detectors.

1) How do they work? Is it the same technology as in a remote control?
Microwave? Infrared, that detects the motion?

2) Are there motion detectors sensitive enough to detect the motion
of a common house fly ?

Can you provide any sites that discuss such devices ?

Thank,
Jim

 

[WEBPA]

Hi,


Two questions about motion detectors.

1) How do they work? Is it the same technology as in a remote control?
Microwave? Infrared, that detects the motion?

2) Are there motion detectors sensitive enough to detect the motion
of a common house fly ?

Can you provide any sites that discuss such devices ?

Thank,
Jim

First, define what you mean by "motion detector." A device to detect motion
can be as simple as a string...or as complicated as an international network of
gigawatt radars and supercomputers.

If you refer to yard lights that are activated by "motion" in front of their
detectors: These are called PIR (passive infra red). The sensors inside
(disassemble one!) are often a single IC in a transparent package with an
integrated lens, sensor, and processing circuitry. Given the right power and a
few resistors and caps to set levels and times, it will drive a small relay
directly.

Detect a fly? Probably, if it is close enough. Easy enough to test.
webpa

 

[Andre]

harley.davidsno@mailcity.com (Jim) wrote in message news:<3f419160.321853@nntp.ix.netcom.com>...

Hi,


Two questions about motion detectors.

1) How do they work? Is it the same technology as in a remote control?
Microwave? Infrared, that detects the motion?

2) Are there motion detectors sensitive enough to detect the motion
of a common house fly ?

Yeah, at 3" a normal PIR minus the lens will work . With a beam
stopper of course .

-A

Can you provide any sites that discuss such devices ?

Thank,
Jim