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Microwave Motion Detector
PN: ece-S-17-002
Figure 1
Overview:
We’ve been looking for a microwave motion detector in the one hundred dollar range for the past couple of years.
Once, we even considered developing one from scratch but then we found this one. First of all, why a microwave
motion detector. There are two basic motion detector technologies available today: motion detector and pyroelectic
infrared (PIR). PIR motion detectors are good in certain situations, but there biggest limitation is they have to have
an open field of sight to their target. You cannot bury them behind the exhibit structure and have them work. The
microwave detectors’ limitation is it cannot be behind metal, but it works great even when hidden by most non-
metallic materials (wood, MDF, fiberglass, etc). So, it can be buried in a non-metallic exhibit where it is hidden but
still detects visitors’ motion.
Most of the microwave motion detectors were developed for automatic door opener systems. Most units even use
the same German manufacturer’s microwave module for the RF portion of the sensor, as does the one we offer.
And, they are generally pretty pricey. If you contact a security/automatic door supplier, they are typically $250-$400.
In their low end, Bircher-Reglomat makes a device called “PrimeMotion” which is what most organizations use for
museum/exhibits. But, even at its most reasonable price, it is around $180. We think our unit, at $100, might be an
attractive alternative.
