Halogen Interior Light Bulbs?

[mica]

Does anyone know the cheapest source of 10w Halogen bulbs for interior lights? I have been shopping around and have been quoted various prices by different chandlers. Some as much as £7, whereas last year's Plastimo catalogue quote £2.73.

Having taken a small Halogen lamp on board, I have found the difference in light output tremendous, for the same amount of wattage (ie battery drain) and am looking to replace my existing bulbs with the halogen type.

Any info gratefully received.

MICA

 

[Stemar]

Ikea or an electrical wholesaler? NM

.

 

[JohnR]

Srewfix.com do 20watt upwards halogen dichroic 12v. £1.49 - 2.80 each depending on life.

 

[alanhanson]

dont put above the watage in the heat they generate is dangerous. it can easily melt the lens

 

[mica]

Thanks for the tip Alan.

Do 10 watt halogen create more heat than 10 watt festoon bulbs? I assumed the heat given off would be the same for the same wattage.

Regards

MICA

 

[bedouin]

No - they must give off less.

Your 10W of power is given off either as heat or light. The brighter bulb gives off more light - therefore less heat and vice verse (OK - it's not quite that simple but pretty close).

 

[peterb]

The total amount of heat is about the same, but it comes from a much smaller bulb so the bulb gets much hotter. In fact the higher running temperature is an essential part of the operation of the bulb.

 

[dickhicks]

Cheapest place is IKEA if you have a store near you - the last time I went I bought several 10 & 20W for the kitchen. Surprisingly the 20W regularly blow but the 10W I have yet to replace any - both been installed about 18 months... Don't remember the exact price but probably about 80p to £1 ea. Otherwise as suggested Screwfix(also good for stainless fasteners etc.)

 

[mica]

Thanks Dick,

Are the Ikea Halogen bulbs 12volt. I would have thought they were for domestic AC mains.

Just a thought !

MICA

 

[alanhanson]

i dont know the answer to that sorry

 

[Stemar]

You'll need to check the voltage. Certainly, 240 v types are available, but a lot of halogen lights for domestic use are 12v, and run off little transformers.

I would expect Ikea to have both types.

 

[hugh_nightingale]

Glad to see you are still around Alan.

In answer to the question and to back up another reply:
Its almost the same. Most of the energy put into the bulb (electric energy) is converted to heat, only a small portion is changed to light. This is why a small increase in efficiency gives so much more light. The efficiency of an ordinary bulb is very low, I can't remember the exact figure and can't be bothered to work it out, but its something like 2%.

Just found a link that suggests its about 7% but that halogen increases this BY 10%, note it is an increase only. Therefore I make the efficiency of halogen to be about 7.7%. However, lifetime increases also, maybe by a factor of two.

Do an "ask Jeeves" or see:

http://www.misty.com/~don/bulb1.html

Hugh

 

[JohnR]

What about an electical wholesaler or even an electical shop - 2 rooms in our house are on 12 volt halogen downlighters.

 

[Guest]

Maplin Electronics. Retail shops in many towns, or mail order. www. maplin.co.uk

12v Halogen capsule lamps , 10w and 20w @ 0.99pence each.

You will need to fit G4 lampholders @ 2.49 pence each to your present light fittings as I have done. A reasonably easy job.

I have always understood that this type produces less heat, which means that there is more power available to produce light. i.e. more lumens for your amps which means also means that you can, in some cases, get the same amount of light from a smaller wattage lamp.

 

[VMALLOWS]

Be aware that 12v Halogen bulbs are very voltage sensitive. Overrunning even at 13v will dramatically shorten their life, and of course when your engine is running it'll be at about 14.2 (or higher with a fancy charger!). They're great however as saloon lamps if you pay heed to this. I have heard theories that UNDER running them is detrimential (to do with the chemical recombination on the filament) but have never observed any effect and many people run them on dimmers.

The cheapest bulbs are the 2-pin plug-ins at about 35p each... just adapt them to suit. The 'Dichroics' with the small (aprox 35mm) reflectors can be had for around £1.20 in various beam widths from 15-50 degress.

When using Dichroics, note that by design most of the heat comes out the BACK of the lamp so that the front beam is cooler! Take this into account when installing!