# 50w halogen equivalent G4 LED bulb?



## poiihy (May 18, 2015)

*[Resolved] 50w halogen equivalent G4 LED bulb?*

My desk lamp uses 50w halogen. What LED bulb has the same brightness (or brighter ) of the 50w halogen? I only find 10 or 20w equivalent bulbs.

Or if those don't exist then I could probably use a 10w led. I'd stick the led to the reflector with thermal adhesive and replace the transformer with a power supply.


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## FRITZHID (May 18, 2015)

I'd go with a 10w LED. I have one as a reading lamp and I love it


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## poiihy (May 18, 2015)

Yeah I'd probably have to... Seems like there are no LED G4 modules that bright.

But I don't know if the metal reflector would be enough to cool the LED chip. I'd probably have to underdrive the LED. I don't want it any dimmer than the halogen though. :I


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## FRITZHID (May 18, 2015)

Depending on the fixture design, a heatsink should probably be a viable option


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## poiihy (May 18, 2015)

FRITZHID said:


> Depending on the fixture design, a heatsink should probably be a viable option



I can't really put a heatsink on this fixture though. Not on the top, but maybe on the bottom, but that would block the light...


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## FRITZHID (May 18, 2015)

Photo?


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## poiihy (May 19, 2015)

FRITZHID said:


> Photo?









Dont know why it is sideways

Send from annoying ipod


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## RoGuE_StreaK (May 19, 2015)

Be very aware of what G4 module you are getting, and what your lamp supplies; some modules are AC/DC, some AC only, some DC only, and despite the transformer in the base some (many? most?) of these desk lamps are still AC at the bulb. If AC, some of the DC-rectified G4s don't have any filtering system whatsoever, just pure diode rectification, which can lead to very visible and annoying flicker; which ain't a good thing if you are actually using your reading light for, you know, reading. I noticed that some of the cheapie G4s actually have provision on the rectification board for a smoothing cap, but did not have one populated.
I explored replacing the halogen in mine some time ago but gave up after several flickery experiences. If you come across a usable one, let us know.


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## poiihy (May 19, 2015)

RoGuE_StreaK said:


> Be very aware of what G4 module you are getting, and what your lamp supplies; some modules are AC/DC, some AC only, some DC only, and despite the transformer in the base some (many? most?) of these desk lamps are still AC at the bulb. If AC, some of the DC-rectified G4s don't have any filtering system whatsoever, just pure diode rectification, which can lead to very visible and annoying flicker; which ain't a good thing if you are actually using your reading light for, you know, reading. I noticed that some of the cheapie G4s actually have provision on the rectification board for a smoothing cap, but did not have one populated.
> I explored replacing the halogen in mine some time ago but gave up after several flickery experiences. If you come across a usable one, let us know.



I know all that. Obviously the transformer would need some modifications. You'd add a bridge rectifier and capacitor to the output of the transformer. But if I'd use a 10w led chip then I would need to replace the transformer entirely with a constant current power supply.


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## FRITZHID (May 19, 2015)

poiihy said:


> Dont know why it is sideways
> 
> Send from annoying ipod



Ah! I actually know that lamp well! It's an ideal LED retrofit lamp. I converted my mother's over to a duel xm-l2 model. She uses it in her tavern as a cash register lamp. The key is to ditch the whole reflector assembly and replace it the heatsink. Hers also uses a 12v "wall wart" style PS with the driver installed in the base (variable 2khz pwm rotary dimmable). She loves it. No bulbs to replace, great color rendition and she says it's allot cooler to work around (the prior bulb used to occasionally burn her/workers cause they'd bump into it). But she especially loves the no more bulbs thing since they used to burn out allot and usually at very inconvenient times and since it's not a normally stocked bulb, it was kinda PITA-ish. It's a 30 mile drive to town. (I also installed a small battery back up for it, runs for about 2 hrs after failure on high)


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## knife99 (May 21, 2015)

*Re: 10W is ok*

10W is OK.Now the led chip light efficacy can reach 140lm/w.


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## poiihy (May 21, 2015)

FRITZHID said:


> Ah! I actually know that lamp well! It's an ideal LED retrofit lamp. I converted my mother's over to a duel xm-l2 model. She uses it in her tavern as a cash register lamp. The key is to ditch the whole reflector assembly and replace it the heatsink. Hers also uses a 12v "wall wart" style PS with the driver installed in the base (variable 2khz pwm rotary dimmable). She loves it. No bulbs to replace, great color rendition and she says it's allot cooler to work around (the prior bulb used to occasionally burn her/workers cause they'd bump into it). But she especially loves the no more bulbs thing since they used to burn out allot and usually at very inconvenient times and since it's not a normally stocked bulb, it was kinda PITA-ish. It's a 30 mile drive to town. (I also installed a small battery back up for it, runs for about 2 hrs after failure on high)



So you know this lamp? Do you know what cover is supposed to go on the lamp? This lamp came from the restore and didnt come with the cover.

Also I found out the bulb in it is 20W (I thought I put in a 50w lamp, must've gotten confused). No wonder it is so small and dim.


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## FRITZHID (May 21, 2015)

Are you referring to the glass safety lens? Iirc it was just a standard piece of tempered glass.
make sure you don't exceed the recommended wattage for halogen lamps, they get very hot. A single xm-l2 will provide more light then a 20w halogen and much cooler temps.


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## poiihy (May 21, 2015)

The lamp says 50 watt halogen or smaller.


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## FRITZHID (May 21, 2015)

Ok, just making sure. Safety first and all that poop. Lol


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## poiihy (Aug 8, 2015)

I found a brighter bulb for the lamp. I had this larger halogen capsule and I thought it wouldn't fit because it's bigger, but turns out it does fit; the socket accepts a few different sizes.

I don't know how many watts it consumes; there is no etch on it, but I assume it's 50 watts or somewhere around that. It's much brighter now and more useful.


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## Anders Hoveland (Aug 8, 2015)

My eyes can focus better under incandescent light than LED light, for some reason. My ideal color temperature for studying and reading is probably 2800-2900K. 3000K feels just a little too bright, and 2700K feels a little too intensely orange. You can tell I have given this a lot of thought. My desk lamp _really_ matters. You can stick LED bulbs in the rest of my house, but I need a good incandescent reading lamp.

Now that being said, I _have_ seen some LED desk lamps that put out really good light. The good ones are very expensive. I mean to the point that you would really have to be a lighting fanatic to get one (but this forum is filled with lighting fanatics  ). I will admit there's something about a 4000-4500K desk lamp (we are talking about the really high CRI ones here) that an incandescent one lacks. The vibrant clean white color of light.

And I am not going to criticize the fluorescent desk lamps either. I know someone into art and then they have a really high-end artist lamp. The packaging for the replaceable tubes lists 97 CRI, 4700K. And of course the light appears very diffuse and even. It really did look nice...


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