Recessed Halogen Light Power Suplies


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Old 09-10-14, 05:04 PM
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Recessed Halogen Light Power Suplies

Hi all, been a while since I posted anything, but I'm still here.

The other day I was going around my house and unplugging as many of the computer, cell phone, and tablet power supplies as I could, as I've been told that they consume power even when they are not plugged into and charging anything. I'm not sure how this works but I suppose that it is true, as sometimes they can feel warm even when not charging anything. I live in the SF Bay Area and our power here is not cheap.

So, this got me to thinking about my recessed lights power supplies. I have several of these lights installed around my house. They essentially do the same thing as they transform AC into DC for the 12v halogen lamps.

So, my question is are they consuming small amounts of power even when the light is turned off?

Anybody know the answer to this?

Thanks...Randy
 
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Old 09-10-14, 05:13 PM
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I would say not as the light switch kills power to them when in the off position. So, those light transformers only receive power when the switch is "on". The other power supplies you mentioned by contrast are plugged into outlets that are always on.
 
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Old 09-10-14, 05:24 PM
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Older wall warts (chargers) were strictly transformer based and did indeed consume a lot of wasted power. Most new chargers for the equipment you mentioned are switching power supplies and draw very little power when not actually charging. You may find an occasional one that feels warm when not actually charging.
 
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Old 09-10-14, 06:10 PM
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The other day I was going around my house and unplugging as many of the computer, cell phone, and tablet power supplies as I could, as I've been told that they consume power even when they are not plugged into and charging anything.
There is a truth in that but what isn't mentioned is the pennies saved are not usually significant. You might want to use a Kill-a-Watt electric monitor to determine if it is worth the effort.
 
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Old 09-10-14, 11:38 PM
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"I would say not as the light switch kills power to them when in the off position. So, those light transformers only receive power when the switch is "on". The other power supplies you mentioned by contrast are plugged into outlets that are always on."

Duh! Jeez, I should have thought of that myself as I wired most of these lights.

Of course, the switch kills the hot lead to the power supplies so there is no power to the power supplies.

Just one of those days!

Thanks for setting me straight!
 
 

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