# Can a "special" 35w halogen "be as bright as a 50w halogen"?



## Mdemon (Nov 5, 2007)

General Electric are selling 20w and 35w halogen 12v bulbs which (in the 35w case) is supposed to be as bright as a 50w halogen.

The bulb in the MR16 package looks different and more round than the usual capsule shape.

Can this be right, or is it just wishful thinking by the Marketing Department?


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## yellow (Nov 5, 2007)

seems to be something like the Osram IRC bulb
(that the ppl here are totally crazed about for nightriding Halogen lights)

... I got one of these just for fun and to test it a bit, then have put it inside the light at my parents house (5 pc. of 12 V halogen reflectored MR bulbs).
Noone, sometimes not even me, can really see the difference, its not this obvious (imho)


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## LuxLuthor (Nov 5, 2007)

Mdemon, it really matters which two bulbs are being compared. There is a law of diminishing return once you get beyond a certain level of brightness on a practical use basis. The difference between a 200 lumen and 1200 lumen bulb is profound; between 3,000 & 4,000 less profound.

With many of these bulbs such as the various versions of 6V 35W Osram/GE/Tungsram/Chinese copy "64430" type bulbs, I am testing each out with objective Lux, optimal voltages, life, melting (flash) point, quality of beam to see how much difference there is between the variables.


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## LEDcandle (Nov 5, 2007)

You can't judge output totally by wattage either; there are 100w bulbs pushing 3,000 lumens and there are 250w bulbs putting out 950 lumens. It depends on the filament, the application the bulb was designed for, the voltage requirements etc...


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## mdocod (Nov 5, 2007)

I can take a 20W halogen and drive it to 35W and make it as bright as a 75W driven "normally"


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## LuxLuthor (Nov 6, 2007)

mdocod said:


> I can take a 20W halogen and drive it to 35W and make it as bright as a 75W driven "normally"



But will it spit nickels?


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## yuandrew (Nov 6, 2007)

I have the Sylvania version of the bulb you're describing although it is rated 37 watts. I don't have a normal 35 watt or a 50 watt bulb to compare it to though.


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## scott.cr (Nov 6, 2007)

Ah... that's an HIR lamp. They put a dichroic coating on the envelope to keep the infrared energy in the capsule, which burns the filament hotter. Generally speaking, these are brighter than a conventional halogen lamp with no dichroic coating. I've heard of these being referred to as "hot coatings" too.

What are the published specs on the lamp? Lumens of output, color temp, service life, rated volts/watts? That info will be helpful in determining overdrive output and life span...


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## yuandrew (Nov 6, 2007)

On my Sylvania lamp, I get 12 volts, 37 watts, 40 degree beam angle (flood but you can get a 10 degree narrow spot one as well), and as for light output mine is rated 2050 candela (11500 cd for the spot version) Life is 4000 hours.

You can get them in 50 watts as well.

I got mine from a local "Lamps Plus" store


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## scott.cr (Nov 7, 2007)

yuandrew said:


> On my Sylvania lamp, I get 12 volts, 37 watts, 40 degree beam angle (flood but you can get a 10 degree narrow spot one as well), and as for light output mine is rated 2050 candela (11500 cd for the spot version) Life is 4000 hours.



Do they give you a lumens rating? The only formulas I know of that predict output based on voltage are only valid using lumens. However, with that rated life span of 4000 hours, I suspect this light can take a lot of overdrive.


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## bfg9000 (Nov 7, 2007)

Just great, _another_ IRC lamp and it is also 12v.:sigh: We really need some ~6v coated lamps so we can make efficient incan flashlights that use less than 15 NiMH or 5 Li-ions...


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## mzzj (Nov 8, 2007)

bfg9000 said:


> Just great, _another_ IRC lamp and it is also 12v.:sigh: We really need some ~6v coated lamps so we can make efficient incan flashlights that use less than 15 NiMH or 5 Li-ions...


Someone should come up with step-up regulator for incans. 95% effiency wouldnt be too difficult to get. I wonder if there would be enough intrest for a small batch of 6v to 12v high-power step-up regulators.


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## bfg9000 (Nov 9, 2007)

These are _incans_ we're talking about here, that can draw up to [email protected]. Even at 95% efficiency (though boost regulators tend to be much less efficient than PWM buck ones) you're looking at over *20A continuous draw* from a 6v battery pack to run the "65w" bulb at 5,800L...

The "50w" bulb draws a more reasonable 5.0A for 91w and the "35w" is 3.7A and 67w but the electronics alone would still be far larger than the extra cells. Probably the size of a stereo amp. Not to mention the size of a 6v battery pack that could manage such high current draw wouldn't exactly be small either.


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## mzzj (Nov 9, 2007)

bfg9000 said:


> These are _incans_
> 
> The "50w" bulb draws a more reasonable 5.0A for 91w and the "35w" is 3.7A and 67w but the electronics alone would still be far larger than the extra cells. Probably the size of a stereo amp.


Stereo amp, no way. I am pretty sure that I could fit that ~67W converter on 32mm x20mm round case. (1/3 of D-size cell or so) 120W could be more tricky, but nothing unheard of. Resulting converter size would be about 16cm3 (one cubic inc) State of the art dc-dc converters operate with power densities up to 1000W/in^3 so 70W/in3 or even 120W/in3 is hardly even any hi-tech.

Battery problem is very real, but there are some cells that power up pretty much anything smaller than a wrench.


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## bfg9000 (Nov 9, 2007)

Do it! Such a tiny converter would be perfect for a handheld vehicle powered (cigarette lighter) incan spotlight, like a Light Force. No battery worries there and it would only need to boost 12-13.8v to 18v. Current designs on the market like the AccuVolt are the size... of a car stereo amp.:duh2:

Look at the efficiency numbers of the IRC at 18v--they are nearly as good as that of a handheld HID spot like a Havis-Shields, only with better color rendering and instant-on.


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## mzzj (Nov 9, 2007)

bfg9000 said:


> Look at the efficiency numbers of the IRC at 18v--they are nearly as good as that of a handheld HID spot like a Havis-Shields, only with better color rendering and instant-on.



Yup, pretty impressive numbers.


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## mzzj (Nov 9, 2007)

bfg9000 said:


> Do it! Such a tiny converter would be perfect for a handheld vehicle powered (cigarette lighter) incan spotlight, like a Light Force. No battery worries there and it would only need to boost 12-13.8v to 18v. Current designs on the market like the AccuVolt are the size... of a car stereo amp.:duh2:


How about laptop car power supplies? biggest are 120W, have selectable 15-16-17-18-19-20-22v output and and definetely smaller than car amp.

Like these http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=102


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## Mdemon (Nov 29, 2007)

That looks like them! They're either rebranded or GE do a clone. 
The round bulb seems distinctive? Hold onto your hats though - they cost about £9 per pair - ~$18!!!!!!!

I mainly use 12v but have been looking at some 6v and 9v batteries used by farmers to run electric fences. There is one quite small one which is 120Ah! Compared with my smallest 12v (2.9Ah), that's quite a huge runtime. So Stepping that up to 12v+ would be very interesting...



yuandrew said:


> I have the Sylvania version of the bulb you're describing although it is rated 37 watts. I don't have a normal 35 watt or a 50 watt bulb to compare it to though.


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