Type of bulbs in a GU10 holder

[ericmark]

duplicate

 

[JohnW2]

Depends how old the dimmer is I suppose. ... A modern dimmer doesn't just use a rheostat, they electronically 'chop' the sine wave.

Even with a rheostat (in series with the lamp), the current (through the rheostat+lamp) would reduce when the lamp was dimmed - so there would be some reduction in electricity/energy usage (even though there was also some energy 'wastage' in heating the rheostat), although not as much reduction as with the modern more efficient methods.

Kind Regards, John

 

[winston1]

A dimmed filament lamp gives less lumens per watt so dimming is generally inefficient. Better to switch some lamps off.

 

[JohnW2]

A dimmed filament lamp gives less lumens per watt so dimming is generally inefficient. Better to switch some lamps off.

I agree, but that wasn't the question I was responding to. Dimming (even with a resistor/rheostat) certainly reduces electricity usage (which is what was asked), but, as you say, might well reduce light output even more.

Kind Regards, John