Reply to: One for the electrical experts...

[threaded]

How do they do that then?

In a multitude of ways.

[EqualOpportunities]

Nooooo, dimmers control the temperature the filament attains, lower temperature means less light.

How do they do that then?

[threaded]

Dimmers reduce current to bulb, therefore must reduce power.

Nooooo, dimmers control the temperature the filament attains, lower temperature means less light.

[xoggoth]

Dimmers reduce current to bulb, therefore must reduce power.

[threaded]

When you dim your lights with a standard dimmer switch does it then use less electricity?

Not really, often more, until it is nearly off.

What about halogen lamps? I have one with an in line sliding dimmer, does a fat resister just burn up my Kw's?

If it is a big fat resistor it will feel warm and yes, if it is some variable mark/space thingy, yes, if it is some fancy variable frequency jobby, no.

I've been searching the net but keep coming up with conflicting answers.

You don't want to go reading any of the crap found laying about on the net, it'll do your head in, eventually.

[TheFaQQer]

Each bulb is 40W and with the dimmer on full, low and behold the power drawn was 160W exactly (bulbs strangely draw a precise amount of power). Even dimmed to an acceptable level it still draws about two thirds of the electricity. Mine was about 100W when I set it at a level you'd be comfortable with.

lo

HTH

[maverick]

Don't waste money on expensive light dimmers. Simply slip on a pair of sunglasses for that cosy relaxing ambience.

HTH

Think this should be in the Viz-esque thread

http://forums.contractoruk.com/gener...-top-tips.html

[TimberWolf]

Don't waste money buying expensive sunglasses; make your own from an old egg carton and string. Create slits to see through. You may sceptical and look like an iguana but this could save your life if you were stranded in a desert.

-- Ray Mears

[PerlOfWisdom]

Yes, dimmers work (effectively) by swithcing the light on and off rapidly, so less power is used at lower settings - the extra power isn't used up by the dimmer.

Beware of using a dimmer on low energy bulbs though because the electronics in the bulb compensates for the dimmer by using extra power in the short time that the bulb is switched on - this extra current can burn out (melt) components in the bulb.

[DimPrawn]

Don't waste money on expensive light dimmers. Simply slip on a pair of sunglasses for that cosy relaxing ambience.

HTH

[miffy]

I looked at this about 8 months ago when I was measuring the power consumption of most of the things I use on a day to day basis (in an attempt to reduce my ever increasing electricity bill).

I had a fancy lamp in my lounge which used 4 x candle type bulbs and had a foot operated dimmer. I plugged my watt meter in an measured it!

Each bulb is 40W and with the dimmer on full, low and behold the power drawn was 160W exactly (bulbs strangely draw a precise amount of power). Even dimmed to an acceptable level it still draws about two thirds of the electricity. Mine was about 100W when I set it at a level you'd be comfortable with.

So yes, it does indeed cost you less when you dim your lights but you'd have to dim them to very low levels to get any major benefit. You'd have to be sitting in near darkness!

In the end I swapped the lamp for something with a large shade that would hide those funny shaped energy saving bulbs. So my lamp went from 100W to 27W. Same level of light for much less power.

[DodgyAgent]

I don't understand but it sounds technological enough to be believable!

Thanks

"technical"

[gingerjedi]

If it's dimmed, it's not so hot...

If it's not so hot, it's dissipating less power.

Hopefully, in a halfway decent dimmer, there's a triac on burst or phase control which reduces the power efficiently, thus reducing your electricity bill.

I don't understand but it sounds technological enough to be believable!

Thanks

[TheFaQQer]

Where's Zeity when you need him??

Post this in TPD and he might find it

[PRC1964]

When you dim your lights with a standard dimmer switch does it then use less electricity?

What about halogen lamps? I have one with an in line sliding dimmer, does a fat resister just burn up my Kw's?

I've been searching the net but keep coming up with conflicting answers.

I was told (by an engineering student)that it would use just as much electricity on dimmed as full.

But it might be a load of Threaded.