low voltage versus mains voltage lights?

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Extra low voltage lamps (12v) will provide more light per watt than low voltage lamps (230v).
Therefore a 12v, 50w lamp will be brighter than a 230v, 50w lamp.

However both types are grossly inefficient, and do a poor job of lighting a room.
 
LV lamps tend to last a bit longer; MV lamps seem to blow quite easily (not sure if they just react worse to vibration?).
 
lets adress the "LV" bit..

12V is not LV, it's ELV, extra low voltage.

LV is in fact 50V - 1000V ( ac rms ) or 120V - 1500V ( dc ripple free ) between conductors.

there is no MV..
 
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ban all sheds has changed his name to coljack. how did he do that?
 
It's just another alias he uses :LOL:

Oh, and FWIW, I prefer the light from an ELV lamp.
 
Depends.

Both of them will burn your house down if they are installed incorrectly
 
50mm down lighters
GU10 beam angle 40º normal 230vac
GZ10 = dichroic beam angle 36º normal 230vac heat not reflected.
MR16 = GU5.3/ GX5.3 beam angle 36º - 38º 10.8 to 30vac normal 12vac
The above lamps are the two normally considered as low voltage and extra low voltage lamps. Dichroic is a special reflective coating which does not reflect as much heat so the subject lit does not get as hot however behind the lamp needs ventilation so a GU10 lamp will fit in GZ10 holder but a GZ10 lamp will not fit in GU10 holder.
There are specials available with both types with different angles, wattages, and voltages also different types of lamp from quartz halogen to LED and compact florescent lamps. The latter is not readily available for MR16 type and as a result the GU10 is at the moment more adaptable to energy saving lamps.
Unless Class A or better we are not allowed to call them energy saving but that does not mean that all the other lamps use the same power for same light output.
Because of the control a switched mode power supply can give. The extra low voltage lamps can be run more efficient than the low voltage lamps. However if any dimming unit is used all these gains are lost. Also with the inverters often special dimming units are required. The whole idea of a quartz halogen lamp is the hot envelope reflects the tungsten back to the filament and if not run at recommended temperature this function will be lost so rather pointless fitting a dimmer to a quartz halogen lamp. It is also this process of reflecting the active material which means the 12v versions with thicker filaments last longer.
However because the inverters can overheat so easy what is gained in lamp life is lost in inverter life.
Note:- an inverter is similar to a transformer but it is more efficient and it corrects the voltage output however they not only have a maximum output but also a minimum output so sometimes LED lamps can not be used with some inverters.
Because of the problems involved in replacing inverters and that the range of lamp wattages and types are also more limited there has been a move to the GU10 230vac low voltage lamps.
However the energy saving versions are often longer so sometimes will not fit in holders designed for quartz halogen lamps. But where they will fit an up grade is far simpler with even dimmable CFU available which can use a standard dimming switch.
Where used in bathrooms and outdoors there is the added safety of using a SELV lamp and I am sure the MR16 has a big advantage there. It is also more efficient than the GU10 and lasts longer. But the problems associated with the short live of inverters and extra cost nullifies the advantage so except for special locations I would recommend the GU10 type.
There will be exceptions where special colours or reflector angles are required and 12º reflectors with MR16 lamps allows them to be mounted further away from the darts board so less likely to be damaged.
As with most things there is no real best there is only better suited.
 
flameport said:
Extra low voltage lamps (12v) will provide more light per watt than low voltage lamps (230v). Therefore a 12v, 50w lamp will be brighter than a 230v, 50w lamp.

ELV filament lamps are invariably halogen types. Their filaments run hotter than a standard 230V lamp (3200K as opposed to 2800K) and thus give more visible light per watt.

However both types are grossly inefficient, and do a poor job of lighting a room.

Quite correct. Most of their 'light' output is still infra-red. To get the peak of the spectrum up into the visible range, you would need to run the filament at 6000K. Needless to say, no such filament exists. :LOL: The future of domestic lighting probably lies with the much more efficient LED in which electrons generate light directly as they cross the energy gap in a semiconductor.

handysquad said:
LV lamps tend to last a bit longer; MV lamps seem to blow quite easily (not sure if they just react worse to vibration?).

The filament in an 'MV' lamp must be longer and thinner than one in an equal powered 'LV' lamp. Ohm's law says so. This will inevitably make them more fragile.
 
flameport said:
However both types are grossly inefficient, and do a poor job of lighting a room.

Quite correct. Most of their 'light' output is still infra-red. To get the peak of the spectrum up into the visible range, you would need to run the filament at 6000K. Needless to say, no such filament exists. :LOL: The future of domestic lighting probably lies with the much more efficient LED in which electrons generate light directly as they cross the energy gap in a semiconductor.
One manufacture has produced a quartz halogen lamp with some sort of filter which converts the infra-red light to useful light but it still does not fall into the 40 lumens per watt so is still not classed as energy saving. Also only available as extra low voltage.
handysquad said:
LV lamps tend to last a bit longer; MV lamps seem to blow quite easily (not sure if they just react worse to vibration?).

The filament in an 'MV' lamp must be longer and thinner than one in an equal powered 'LV' lamp. Ohm's law says so. This will inevitably make them more fragile.
What is a MV lamp? I would think a LV lamp refers to Low Voltage i.e. 230v and these will "be longer and thinner than one in an equal powered" EVL lamp.

Extra low voltage is up to 50vac.
Reduced Low voltage is centre tapped 110v
Low voltage is 50 to 1000vac.
Some lamp do run on high voltage neons for example and there needs to be a firemen's switch when these are used. But these will be discharge lamps I know of no filament lamps that use over 1000 volt.
 

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