Alternative source for 12v 55w Halogen bi-pins

[M@elstrom]

As you all may (or may not) be aware, I've been in the process of building up a 4D M@g Hot-wire, being unable to decide on any specific bulb type I've been experimenting with overdriven 20w Osrams (500+ Lumen), not really happy with sub P7 performance from a Hot-wire I began looking for alternative globe types/ratings to satisfy my Lumen addiction... this is when I stumbled across some old generic 55w H3s in my garage (I always upgrade stock lighting) dismantling the outer H3 shell I discovered to my joy that the bi-pin anode/cathode thickness was extremely close to the G4 spec (though admittedly slightly further apart) so I can swap between the two without ruining the high temp ceramic pin retainers! :thumbsup:



Specifications

Anode/cathode diameter - 0.67mm (same as G4)
Spacing between leads - 5mm (Versus G4's 4mm)
Glass capsule 10.12mm - G4's 9.23mm (at their widest point)
Glass capsule height 30mm - G4's 23mm

Using the information/data gleaned from HERE a stock 12v 55w H3 emits (in the vicinity of) 1450L @ 12v, hence @ 14v (11x AA NiMh) the output should be between 2000 ~ 2487 Lumen (oh yeah that makes me feel better!) :devil:

What good is telling you all about it if you can't see it for yourselves? so here you go... what where's the beam shots? they'll have to await litho's reflector & a mineral glass lens

 

[BVH]

To end up with a focused beam, (filaments in the same position relative to the reflector) it looks like the mag head will need to be unscrewed at least by 3/16". When you focus, do any of the threads show?

 

[effulgentOne]

I believe kaidomain has some halogens, but they are mostly lower wattages.

I think I've seen bulbs like that at the hardware store too, but I didn't pay much attention at the time.

 

[jasonck08]

I'd go with the Osram 64432 35W and overdrive it from 12v to between 18-20v or so. Then it will be putting out 2000-2600 lumens. It is probably one of the bulbs that can withstand the most abuse. According to Lux's tests it can withstand almost double the voltage before flashing.

I have one in my possession that I picked up locally for like $3. It's a great bulb for the price...

 

[M@elstrom]

To end up with a focused beam, (filaments in the same position relative to the reflector) it looks like the mag head will need to be unscrewed at least by 3/16". When you focus, do any of the threads show?

Yes indeed... to properly use the 55w bulb I'd need to reconfigure the Kiu high temp socket, I wasn't able to effectively test out it's focus ability as I decimated the original M@g reflector assembly (even on short 10 sec bursts) :candle:

I believe kaidomain has some halogens, but they are mostly lower wattages.

They do... up to a 35w G4 bi-pin (plus some of those blue tinted jobs) but the specifications are sketchy at best

I'd go with the Osram 64432 35W and overdrive it from 12v to between 18-20v or so. Then it will be putting out 2000-2600 lumens.

Perhaps... but seeing as I'm limited to this battery source & 4D host (for this project) that ain't gonna' happen

 

[jasonck08]

I take it you don't have any 18650 cells? Thats what I'm using in my hotwire 20W Osram.

Also just a little FYI, most AA Ni-Hm's under a fair amount load will sag from 1.2v to 1.1v. So your 11AA cells will likely only produce 14v's in the first couple minutes of usage (because fully charged AA's are upwards of 1.3v's a cell). After factoring in the sag in voltage and resistance I think you will only get about 12-13v.

 

[M@elstrom]

Yeah I suppose there's always that route... what length of runtime do you get with your 18650 lithiums with such a high load?

EDIT:

Seeing as the Osrams are highly versatile, instead of running the cell adapter with a dummy battery I could just use a full compliment of 12 cells (certainly counter act any V drop)

 

[jasonck08]

My light isn't fully assembeled yet, just finished getting the last few parts tonight. But my 20W bulb overdriven to ~25W's should last

Each battery is 8.8 Watt hours. So two is 17.7 Watt hours. A 25W bulb with 17.7 watt hours worth of batteries should last a little over 40 minutes. Realistically 20-25 minutes before it starts to dim a lot would be my guess...

With freshly charged 18650's and when taking voltage sag and resistance into consideration, the bulb should be seeing about 7.4v about 900 lumens.

My next light will probably be to overdrive the 35W 12v bulb with 4-5 18650 cells, in either a spotlight or a mag 4C. With 4 cells, it would put out about 1200 lumens, with 5 cells about 2200 lumens.