Quote:
Originally Posted by rGS
To add to your note, I'm using some motion sensing night lights in the hallways. So "motion sensing LED based nightlights" may be better because why keep a hallway lit when no one's moving through it?
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Keep in mind that most "motion sensors" use a little power for the sensor itself (how much I'm not sure, but virtually all "motion sensors" are active circuits that do use some power even when their "load" is "off"). While this is a great trade-off when you have a higher power light/load (as the small power for the sensor will be more than recovered by not running the "light" as often as you otherwise would), the trade-off gets worse and worse as power levels for "on" get lower.
So if you are powering a really low power load anyway (say a 1/3 watt nightlight), my theory is that you may be better off (power usage wise) avoiding the motion sensor, and just powering the light/load more often then you technically "need" to. IMHO you should save the "moton sensors" for those situations where you want a fair amount of light (for example, several florescent bulbs) to come on when someone walks in the area. Because motion sensors make a lot of sense for auto-controlling less used (but still noticeable) power usage lighting situations. But for really low "night light" situations, I think you are usually better off avoiding the motion sensor, and instead just letting the low power light run more often.
Quote:
Originally Posted by rGS
The motion sensor also detects if it's daytime so the nightlights automatically stay off during the day, no matter how much motion occurs in front of it.
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FWIW the LED "nightlights" I got had built-in light sensors. So when it was "bright enough" (i.e. when the light figured it was "day" based upon it's light sensor), the nightlight shut itself off (saving even the slight power the light otherwise uses). Honestly I don't think this saves a huge amount of power (when you are talking only about 1/3 watt of power during "on" anyway), but it was a feature built into the nightlights I got. And that feature probably does save a very small amount of power, by allowing some of the nightlights to run only about 1/2 of the day (on average), instead of running 24/7.
But really, even if all my 1/3 watt "nightlights" (around the house) were running 24/7, their electrical loads would still be small compared to things like the fridge (or even just the chargers for my wireless phones). Remember, at about 1/3 watt per light, we are talking only a 10 watt load for 30 of the things scattered in stratigic places around the house. And while none of those nightlights produces much light (they really are "nightlights"), they do produce enough light to avoid tripping when walking down an otherwise "dark" hall...