# Halogen bulb overdriving Qs.



## rizky_p (Dec 28, 2007)

Hi i have this [email protected] in the making running with 9xAA Sanyo 2700. I dont have the bulb yet but i have Philips 6v G4 bulb. How hard can i push this one? will itu burn with 9xAA? What is a typical maximum voltage for 6V and 12v normal G4 halogen?

thanks.


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## mdocod (Dec 28, 2007)

*Re: 6v G4 bulb overdriving Qs.*

You're asking a question that has infinite answers until you narrow down the bulb more.

There is a chinese mystery bulb, G4, 6V, 30W, it can be overdriven to ~12V without many problems. 

There are medical and projector bulbs rated 6V 20-35W that will flash at ~7.5V

It depends on how many hours it is rated to last at 6V, and then minor deviations in predicted re-rated life tend to be the result of different variations on fill gases and pressure. 

Some 12V bulbs can be driven to around 23V, Others will flash at 14V. 

Also it depends on how much resistance you have in your pack, are you using cheap adapters or something fancy and low resistance, have you done resistance mods to the mag, and how much will the 2700s sag under the load, which will depend on the wattage of the bulb.


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## rizky_p (Dec 29, 2007)

*Re: 6v G4 bulb overdriving Qs.*

Okay that explain my limited knowledge about [email protected] and bulb in general.

I am running DIY 9xAA Sanyo 2700 each soldered to the next with metal strip as i am planning to run 6v bulb at least 9v when loaded. The bulb is a normal halogen filled with G4 fitting and it is a 20w type. 

Update(another story): i tried 12v 20w bulb with 4x18650 color is nicer and alot brighter but i am not brave enough to push any further. will it explode when flashing?

Any experience with philips G4 6v 20w and 12v 50w bulb how hard can i push them?

thanks.


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## mdocod (Dec 30, 2007)

*Re: 6v G4 bulb overdriving Qs.*

need to know how many life-hours the bulbs are rated for to really make any estimates. Also what CCT they are at when driven to spec would be additionally helpful. 

Assuming you have common 2000 hour bulbs, the 6V bulb can handle ~9V without a problem and the 12V can handle ~18V, they will last about 10-20 hours at this amount of overdrive and be about 4X as bright as they run at their rated input voltage. 

If your 6V bulb is a "4000-6000" hour bulb, you might be able to hit it with 10+V without a problem. 

If your 12V bulb is a "4000-6000" hour bulb it can probably handle 5 li-ion cells in series without instaflashlight. (no garantees, depends on resistance in the light)


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## RoyJ (Dec 30, 2007)

*Re: 6v G4 bulb overdriving Qs.*



mdocod said:


> need to know how many life-hours the bulbs are rated for to really make any estimates. Also what CCT they are at when driven to spec would be additionally helpful.
> 
> Assuming you have common 2000 hour bulbs, the 6V bulb can handle ~9V without a problem and the 12V can handle ~18V, they will last about 10-20 hours at this amount of overdrive and be about 4X as bright as they run at their rated input voltage.
> 
> ...


 
That's good info to know, as I'm building a similar setup.

I've got a whole bunch of 5000 hrs 6V 20W G4 bulbs. I'm using an 8aa to 2D holder with rayovac 2500s. The batts will be around 1.1V under the 3+ amps.

I'll try running it directly, and hope the additional resistence of the stock Mag would help with the startup voltage shock. If that doesn't work I'll add .23 ohms of resistence (3x .67 resistors) and see if that helps.


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## mdocod (Dec 30, 2007)

*Re: 6v G4 bulb overdriving Qs.*

I don't think you'll have any problems there Roy. 

You can expect to run over 4 amps on that setup (it will become about a 35W bulb at that drive level)... At that power the mag should introduce about 0.5-1V of voltage loss depending on how old and corroded it is. Even fresh off the charger I DOUBT you'll be able to break 10V at the bulb.


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## rizky_p (Dec 30, 2007)

*Re: 6v G4 bulb overdriving Qs.*



mdocod said:


> need to know how many life-hours the bulbs are rated for to really make any estimates. Also what CCT they are at when driven to spec would be additionally helpful.
> 
> Assuming you have common 2000 hour bulbs, the 6V bulb can handle ~9V without a problem and the 12V can handle ~18V, they will last about 10-20 hours at this amount of overdrive and be about 4X as bright as they run at their rated input voltage.
> 
> ...




yes i have 2000 hours bulb your answer is spot on. Just bought several other bulbs today to overdrive.

How do i estimates how bright the bulbs are while being overdriven?

do you think 6v 2000 hours rated push to ~9v is brighter than WA111 and 12v 2000 hours rated push to ~18v brighter than wa1185?

thanks.


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## mdocod (Dec 31, 2007)

*Re: 6v G4 bulb overdriving Qs.*

here's the formulas (off the top of my head) for halogen re-rating...

Vd=design voltage
Va=applied voltage

[(Va/Vd)^3.5]x rated lumen = re-rated lumens
[(Vd/Va)^12]x rated life = re-rated life
[(Va/Vd)^0.317]x rated CCT = re-rated CCT
[(Va/Vd)^0.55]x rated current = re-rated current. 

So... you have a 6V 20W G4 bi-pin halogen...
Stock it runs at ~6V, ~3.33..A, (20W), ~300 Lumen, ~2950K CCT, ~2000 hour life, ~15 lumen/watt

Overdriven to 9V you can use the formulas above to ESTIMATE that it will run ~4.166A, (37.5W), 1240 lumen, 3350K CCT, ~15 hour life, ~33 lumen/watt. 

This is not an exact science, many factors can make these estimates unrealistic. But is a guideline to start with to get an idea where to shoot for..





> do you think 6v 2000 hours rated push to ~9v is brighter than WA111 and 12v 2000 hours rated push to ~18v brighter than wa1185?



Assuming you are talking about the same bulbs you mentioned above (both 20W at rated power) then they will both run close to the same output with close to the same overdrive (both being driven at 150% of design voltage). The 12V 20W driven to 18V might be slightly more efficient than the 6V bulb just because of the better filament shape on most 12V bulbs. But the difference is probably not noticeable. I suspect both your 6V and 12V 20W bulbs overdriven to 1.5X design voltage will run in the 1100-1500 lumen range depending on various factors. 

The WA1111 driven to a similar estimated life (15 hours) will run at about 750 bulb lumen. 
The 1185 driven to ~15 hours estimated life with run at about 1150 bulb lumen. 

So will your 6V and 12V 2000 hour bulbs be brighter? depends on how hard you drive em in comparison to how hard someone else drives em.... Fractions of a volt make huge differences in output on incans.


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## rizky_p (Dec 31, 2007)

*Re: 6v G4 bulb overdriving Qs.*

Thanks i was about to ask the formula that everyona is talking about.


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## rizky_p (Jan 1, 2008)

*Halogen bi-pin lumens?*

Does anyone knows where can i get typical lumens numbers on standard bi-pin Halogen rated at 5,10,20,35,50,75,100watt?

thanks


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## DM51 (Jan 1, 2008)

*Re: 6v G4 bulb overdriving Qs.*

LuxLuthor has put together some very useful data about popular hot-wire bulbs in this thread.

It is worth looking at the Threads of Interest sticky in this forum for useful information. You will see it at the top of the page. Luxuthor's thread referred to above is there, as is mdocod's Incan guide and other important reference threads.


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## JimH (Jan 1, 2008)

*Re: Halogen bi-pin lumens?*

I don't think there are typical lumin numbers. It depends on the design of the bulb. Here's an example

OSRAM 64610, 50W 1600 lumins, 50 hr life
OSRAM 64450, 75w 1450 lumins, 4000 hr life

WA1331, 18.5W, 533 lumins, 35 hr life
WA1079, 20W, 314 lumins, 2000 hr life

WA1185, 30W, 817 lumins, 50 hr life
WA1154, 37W, 754 lumins, 500 hr life

Efficacy (lumins per watt) is inversely proportional to bulb life. Also, the longer the design life, the more you can push the voltage before the bulb flashes.


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## DM51 (Jan 1, 2008)

*Re: Halogen bi-pin lumens?*

You already have another thread running on this subject. Starting a second one is unnecessary - it causes confusion and cross-posting.

Threads merged.


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## rizky_p (Jan 2, 2008)

Thanks Mod.


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