Monday, October 27, 2008

Motion sensing

Don't get me wrong, I'm all for using motion sensing to improve lighting. At my previous office we installed motion sensor switches most everywhere, and the lights definitely were off a lot more. Bathroom lights tended to get left on all night and weekend, and the lights in out of the way places that people were too lazy to turn off also benefited from the motion sensor switches. However some of them would repeatedly get set back to manual. The motion sensor wasn't always good enough (so that when you were behind the server rack it didn't see you and turned off the lights and the delay was set too short). I recall that we paid about $30 for the drop in switch replacements like these
though amazon seems to have some cheaper options like this
Current cons include: jerkiness of on and off, having to wait for lights to flicker on (esp. fluorescents), extra costs of the sensor switch, sensor switch getting blocked by furniture, sensor switches getting turned on by pets or breezes outdoors. Also the first one I link to, a certain percentage will die after some amount of time and require replacement.

Note that the replacement switches are the most unobtrusive, but they don't always lend to ideal placement for the sensor. Also you need an electrician to do the replacement (though certain electrical engineers I know have done the replacements yourself, though I don't recommend it as death or hair standing on it's end can occur -- remember once you let the smoke out of your electrical system it's very hard to get it back)

My motion sensor dream:
Switch would have off, auto, 10% auto, and on.
Auto would leave the light off until motion is detected, it would quickly ramp the light from 0 to 100%.
10% auto would leave the light at 10% (so you can vaguely see and not trip) and quickly ramp to 100% when motion is detected.
When leaving a room it would gradually lower the light from 100% to either 10 or 0% depending on the setting.

I think these features would eliminate a lot of the issues that people have with motion sensors lights.

Also, a lot of houses have motion sensors already for alarms, can we build off that somehow? For that matter the alarms also know when you enter and leave a house, that could tie in to a turn off all the lights when you leave sort of scenario.

For those with incandescent sockets: screw in motion sensor

or those with plug in lamps: pluggable motion sensor

Please note that I didn't do extensive searching on amazon for the best, I just found the ones I originally bought and amazon recommended the other 3.

Note, there are cheaper generic versions of these sensors findable on google products results, though they are from unknown suppliers and unknown stores, but please report back with your findings and let us know good ones that are cheap!

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