Damn Koneg is on a roll now - that's two things he's gotten right in one thread!!!


/Three Cheers for Metalface!

 

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You should never roll against the decider. He's deciding stuff. And it's right. Otherwise why would he have decided it? Think about it.

 

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This thread is weird.


paul asks a question that is not really stupid


IMHO provides a lot of useful information and is the clear expert


Koneg admits he was wrong

 

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BIZARRO WORLD

 

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((tl;dr the other shite in the thread))

All other things equal, the low volt bulb will use some more power.

Cause all transformers have some loss, even if it can be very minute on a high tech expensive one.

hth.

 

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120v/20w. Plugged into a 120v outlet, this will draw 20w. (if you leave it on for 50 hours, you will pay for 1kwh of electricity)

12v/20w. One of 2 options here. There is a transformer that converts 120VAC to 12VDC. It's unlikely it is more than 80% efficient (and probably worse). If the bulb draws 20w, then the 80% transformer is drawing 25w. If the transformer draws 20w, then its a 16w bulb. Likely it's the first case (20w bulb, using 25w or better of metered power). If it has a battery built in as well, total efficiency is likely closer to 50%. Also, any time the transformer is connected to power, it wastes a watt or 3 (this is why your phone charger is always slightly warm, even without a phone plugged into it).

The one with the transformer also has more parts to break, and probably costs more.

 

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