To save energy in our lab where several 36W lights glow most of the time when nobody is using the lab. Considering the work at lab, it would be a difficult proposition to ask the people working in the lab to switch off lights when not in use. So we designed our own PIR sensor based Switch that switches off lighting when nobody is around. Also, when someone enters the room the lights come up again.
PIR sensors rely on changes in passive infra-red light received to determine presence or non-presence of people. This combined with a controller/timer to switch off light after the preset duration of non-activity and to switch on the lights when someone enters the room solved the problem!
There are many designs of such products available in the market with different cost and features.
Issues with PIR sensors:
Like all optical sensors, Sunlight can play havoc with it and make it generate false positives. After some due exploration we found a technique to eliminate false positives from the sensors and make it work. So our prototype works very well compared to the raw sensor signals. It avoids false triggers when used indoors despite sunlight peering in from Windows/doors.
Outdoor applications?
As much as we would love to have an outdoor version of this, sunlight plays havoc with the sensor. However these sensors can be used for night time applications of security/monitoring of any movement/people inside a compound/perimeter.
To know more about the product, visit our website and check out the 'Activities' link on the left side.
We are in the process of turning it into a formal product. For any product/design enquiries, you can get in touch with us. Contact info at our website: http://www.ideas-unlimited.in
awesome ..!!
ReplyDeletethanks,
rakesh naidu