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Pulpo
4th December 2007, 02:03 PM
Down Lights

There seems to be a move away from dc to ac.

I only need a few what sort for a bathroom?

I know the typical halogens are not energy efficient.

The LED are just extremely expensive.

Thanks

Pulpo

Ausyuppy
4th December 2007, 02:49 PM
Pulpo,
The original halogens were always AC. They transformed from 240v AC to 12v AC. 240v halogens in my mind are better as it eliminates the tranformer which tend to fail from time to time.
Cheers
Steve

another termite
4th December 2007, 02:53 PM
Down lights are definatly AC can't say as i have ever used a DC one.

malb
4th December 2007, 03:15 PM
Actually, the light doen't care whether its fed AC or DC, provided that the voltage is correct. But it can be damn inconvienient transfering DC from the power station to the light, so they are mostly run on AC. However for a solar storage situation, there is no practical reason why 12VDC from a battery bank won't operate the bulb properly if fed to it in isolation (i.e no step down transformer connected). After all most car headlights are 12VDC halogen.

elkangorito
4th December 2007, 03:27 PM
The low voltage halogen lamps are more efficient than the higher voltage ones. There is a debate over the use of DC with the non-automotive halogen lamps - it is argued that DC will cause "polarisation" on the filament, which reduces the lamps life.

The automotive halogen globes are a different lamp in design ie that is, they are designed to be used with a DC supply.