What's the best way to power a 12v 90w Osram bulb?

LEDcandle

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Just for fun, I bought a 90w Osram halogen bulb (bi-pin). I know it wouldn't fit into any flashlight (at least without mods) but I thought to just buy it and decide later.

I lined up 3 unprot Li-on R123as (800 mah) to power it to try and boy did the wire get hot :D Later used my multimeter and measured 6 amps! It levelled off at about 5 amps. 3 x protected failed to light the bulb.

So what is the best way to power this bulb assuming I manage to cram it in a 3D mag or something... ?

Do more batteries means the current load is being shared or is each being loaded? As in the above scenario, are my batteries EACH being loaded at 7Cs or is each one being loaded at 2+ Cs?

Higher capacity batteries also mean they can handle more loads right?

Would appreciate comments/ideas what to do with this bulb. I remember reading about someone using an Osram 100w for something. Can't remember if its one of the harcore mag mods. (I'm a noob at mags :D) Thanks!
 

litho123

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missionaryman

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Hi - you need at least 12v but 13.2 or 14.4 is better. in a 3D mag you'll need to bore it and use 12xAA in 3 banks of 4 cells. this should run for about 8 minutes and get so hot that you can't touch the head or body around the switch. LIR123A cells will (if charged enough) just cut out if they're protected or probably explode if not because of the current. You need really high current NIMH or SLA batteries - it's a bit dissapointing when you get it going because it only floods, doesn't throw well.
 

LEDcandle

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Thanks for the info guys!
I was just ambitious and went for 90w :p

Maybe I should have just bought a 10-20w. But I guess there's still gonna be a need for getting all the basics like alum reflector, bi-pin socket, battery holder etc... ah heck, maybe I'll just dump in LEDs instead...hahah (sorry, I know this is the incan forum :nana: )
 

Meduza

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12v 90w... 12V / 90W = 7.5A

so you need something that is capable to put out at least 7.5A, propably even more in the start...

:)

The 12xAA idea will propably work with 12 x High current NiMh AA cells, but you wont get any long runtime :)
 

PlayboyJoeShmoe

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I once hit a 50W MR16 with 7x123 to get decent white and brightness.

I did it again recently with 12 NimH AA.

Neither way made me what to keep at it.

An 1185 on 9AA (2100 Energizers in this case) is MIGHTY bright!
 

missionaryman

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I have a side by side beamshot of a MAG85 (actually one of Juancho's MAG951's) and a cheap imitation 100W bi pin being run on 14.4v using the same Titanium 1800 cells that the 951 is running off in the same host and you can see that the MAG85 running an 1185 on high current cells is no where near as bright.

I did the same with a 50W MR16 and basically it's a complete waste of time, MR16's are good flood/work lights but they all have very inefficient reflectors that diffuse the beam.

Unfortunately I'm not allowed to post pictures for some reason.
 

LEDcandle

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I've read up on the Mag100 and stuff but do I have to worry about grounding and all that? It seems like when playing with such a high wattage bulb, its safer to have more precautions.

Can I just run it on the following :-

1) Aluminium reflector (which one to get and how big muz the opening be for this type of bulb? 10mm?)
2) Bi-pin socket
3) 3D-12AA battery holder + NiMh batts (14.4v)
4) UCL or Borofloat glass lens

Am I missing anything? Do I need a better switch or something?
If I need to mod too many things, what wattage of this type of bulb would be a good compromise? 50w? 20w?

Sorry for the many questions and thanks!
 

litho123

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Points 1 2 AND 4 are a must.

The most importnat part is #3.

In the Mag100 thread, they had to beef up the entire holder to handle 8+ amps coursing thru it. Then the Mag switch had to be beefed up as well, eventually installing the LDO driver, etc to reduce resistance.

We've taken the 3D lights to the 35w level with the 1185 bulb at 3.60a (overdrive). Look at what we learned along the way...
- We had to go with (glass) Borofloat or UCL lenses. (Plastic melts over 10w)
- We had to go with aluminum reflectors because of the heat. (Plastic melts over 10w)
- We have upgraded to the Kiu socket to reduce resistance (brighter output) and gone away from potted bulbs to bi-pin bulbs (ease of use, more reliable and cheaper)
- Batt holders have gone from the plastic 3AA-D holders to the Fivemega 9AA-3D holders, again reducing resistance.

Now we're going into new territory here trying to drive a whole new class of bulbs in a 3D host. Resistance is the key problem to overcome. Resistance = heat ... and lots of it. Reducing it is of utmost importance.

The batts now have to be high current batts...CBP 1650's for AA nimh seem to be the top choice at the moment.

You can use a stock modamag 12AA-3D holder, (There might be enough resistance to avoid blowing your 90w bulb on 12 batts) but you'll most likely fry some contact springs and encounter the same set of problems awr and NT went thru.

It seems to me, mistakes are less forgiving when we're at this power level, so please be careful.
 

LEDcandle

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Thanks litho, that's very concise information... I think I'll just stick to a 10w bulb until I'm sure of what I'm doing :D

What is the 90w 12v Osram bulb used for anyhow? A car application? It doesn't say on the box what its specifically for.

And about the aluminium reflector, anyone have a link to which exact one to buy to fit an Osram bi-pin bulb? I read that the 8mm ones fit WA bulbs only so I'm guessing the opening needs to be 10mm?
 

litho123

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The way the sizes work is kind of interesting.

Carley bulbs are T1.5 or T2.5
WelchAllen bulbs are mostly T2.25
Osram bulbs are T3, T3.5, T4, etc.

What does that T-number mean?

Take the T designation and divide by 8...to get the bulb diameter.
Therefore...
A T4 bulb is 4/8 = .500" diameter
A T3 bulb is 3/8 = .375" diameter

A T3 bulb will just squeek into a .377" holed reflector...so anything less than a T3 should fit into the .377" holed reflectors.

RE: what is the 12v 90w bulb good for? Some of these bulbs type are used in light fixtures...ceiling bouncing the light IIRC.
 

cmacclel

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Great way to fry or blow up your RC123's Almost 8C from EACH cell ouch :) Have you seen the Blow up catch on fire Lithium video's??


Mac
 

larryk

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After watching the first video it appears that they ran 8.4 volts at 1 amp into a single 3.7 volt Lipo cell. I do not quite understand the purpose of that experiment. It seems to me that any battery subjected to extreme over charging for that length of time would ignite. Larry.
 

LEDcandle

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Thanks for the great info guys.

The fire looks like something to worry about but fortunately I didn't push my batts anymore than a few seconds. Of course a few seconds could be bad too if the current was like 20A ? haha..
 

cmacclel

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larryk said:
After watching the first video it appears that they ran 8.4 volts at 1 amp into a single 3.7 volt Lipo cell. I do not quite understand the purpose of that experiment. It seems to me that any battery subjected to extreme over charging for that length of time would ignite. Larry.


The purpose of that experiment was to show you Never charge your lithiums unattended. If your *smart* charger hickups and try's to charge your 2 cell pack as a 3 then thats exactly what can happen. I remember the Astro top of the line charger hickuped on a few people and of they where not standing by or checking the cell count through the charging process they would have been in trouble.


Mac
 
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