Just A Quick Dumb Question About Bulbs

[Databyter]

I was just looking at this,

http://i61.photobucket.com/albums/h75/pike444/bulbs/64623.jpg

For a tube build (based on the Osram 64623 "Torch" Bulb) I am in planning stages on and I noticed that with the voltage range already supplied by my mag85 this bulb puts out about double the lumens under-driven.

Now I like my mag85 and I'm not anxious to ruin the G4 holder for it by experimenting with another bulb size, but here's my question,.

If the bulb lumens underdriven at mag 85 levels of say 11-12 volts is 2x higher with the Osram why don't people use the Osram bulb with lower voltages.

Is it that yellow?

I'm hoping not because I'm hoping that my build with a 30-60 100 switch is going to be somewhat useful, at least on 60 and 100.

If the low end is unusable a regulated driver is looking better.

I'm tempted to buy another bulb holder just to try the Osram bulb on my mag 85 and see how it looks, at twice the lumens I'm not sure I'd care if it was a bit yellow.

I'm wondering how different the size of the bulb itself is. I notice there is a G5.3 holder available, but so far I'm unable to find out if the TORCH bulb is this form, I'm thinking it is a G4 with thicker pins from what I've read, and so the remaining question is will it fit thru the same refelector holes as the MAG85 bulbs or do I need to go bigger.

 

[Databyter]

No takers huh?

 

[DM51]

I'll move it to the Incan section for you. Maybe someone will answer you there; in brief, it's not a good idea to under-drive bulbs. A deposit will form on the inside of the envelope, and the light emitted will be yellow.

 

[Databyter]

Thanks

 

[lctorana]

The 64623 is a GY6.35 bulb, with thicker pins 6.35mm apart, so you need to go with the ceramic MR16 socket in your Maglite, such as the famous "Kiu socket kit". That means cutting off the bulb tower and making a permanent, non-reversible mod.

As for voltage drive, first think of the voltage the actual bulb will see, after circuit resistance and battery internal resistance losses.

Now think of your car headlights running at that voltage. If you are OK with the colour, and your batteries can stand up to the >8A draw, then you're good to try it. 64623's are common stage lighting store items, and aren't very dear, but please be careful not to touch the glass.

 

[LuxLuthor]

As DM51 said, when you underdrive most incan lights below their manufacture's default rating, they get an increasingly sickly yellow color proportionate to the degree of underdrive.

I recommend using Ictorana's graph charts to find a bulb closer to your battery voltage output.

 

[Databyter]

Yea, I was just curious. For the most part as a "flashoholic" I am more interested in overdriving. I was just so surprised to see the incredible lumens still provided by the lower voltage and wondered if anyone used them this way, and curious whether anyone ever used the bulbs underdriven with any degree of usefulness. You guys answered my question, and thanks for the bulb size info, despite reading many threads here I somehow missed the pin form factor data.

 

[KiwiMark]

An overdriven incan bulb is a thing of great beauty!

 

[R@ndom]

An overdriven incan bulb is a thing of great beauty!

The reverse hold true for underdriven bulbs.