Brightest bulb for a cheap 2D flashlight?

Now that I've become a flashaholic and have all these nifty lights at my disposal, my previous workhorse has been left behind. It's an old Tek 2-D cell flashlight from the late 1980s, with a heavy plastic casing and one interesting feature: the focusing cam for the bulb is controlled with a lever that sits next to the power switch. You focus with your thumb! /ubbthreads/images/graemlins/cool.gif

Anyway, I don't use this light anymore because the beam is too dim, but it would be nice to upgrade the bulb to something better. To get to the point: what's the brightest PR bulb I could use in a 2D cell flashlight with plastic lens and reflector? I want to get as bright as I can before melting the flashlight.

I would also consider running 3 CR123A cells in this light if it means additional brightness, but remember those plastic parts that might melt.

Either way, I need some advice here. In fact, I think I'd like to hear about my best option with both power sources.

Thanks all! /ubbthreads/images/graemlins/grin.gif

Walmart sells some 2v 1.2amp bulbs that are not bad.

If you really want to boost it up, consider converting it to run 3 C-cells and plug in something around a 3.8v/900mAh bulb. Should make it a good bit brighter but still be safe in a lot of plastic lights.

If the plastic (lexan?) lens on my Maglite doesn't melt @ 11 watts, I don't think you will have much to worry about. You might start with a 2 cell xenon star bulb @2.1 watts. It would be a bit brigter. Carley has a PR base 2 cell bulb for NiCads, 596 Krypton @1.2 amps & 2.5v for 3.3w. It will burn out a little faster than normal with alkaline batteries but it's a lot brighter.
For 3 CR123s you need something good for 9v. I'd be playing with some of the 7.2v bulbs for battery powered power tools. Although your battery voltage will decrease some under load, you will have close to a 25% overdrive which is as high as I would go with krypton or Xenon flashlight batteries. You might also find 6 & 7 cell bulbs for 7.5 - 9v with 6 or more watts output. Also, it's quite possible that you can get 4 123s in there, maybe without the spring.............HTH,
Russ

A M&g Whitestar Krypton 5 cell bulb, driven by 3x123A Lithiums, is a poor mans Surefire.

The flashlight is sitting in front of me now, so I have a little more info about it and its bulb. Note that I posted the info here instead of in flashlight reviews because: (1) I thought it would paint a clearer picture of the piece I'm trying to mod for improved brightness, as well as its physical limits (don't want to light it on fire! /ubbthreads/images/graemlins/mad.gif ); and (2) since this light doesn't appear to have been sold in a number of years, there's no point in writing a "real" review of it. I've never seen one for sale since I bought it in the late 1980s for my mother! (I got it back from her. /ubbthreads/images/graemlins/smile.gif )

The light itself isn't made by Tek, but rather Tekna. It's all sturdy black plastic (good, solid, thick feel) with "knurling" over the rearmost 60% of the light. The power switch is round and mounted on the side, and the cam lever is just below that (closer to the user's hand). It allows intermittent on, and a harder press allows click-on-click-off action. Strangely, there is no positive feel when the click takes place; it feels more like mashing a firm spring. Listening closely the click can be HEARD, but can't be FELT. /ubbthreads/images/graemlins/icon23.gif

The head flares outward, and unfortunately the reflector and lens assembly seems permanently embedded in the head piece. No UCL lens for this puppy. /ubbthreads/images/graemlins/icon23.gif On the other hand, the bulb is held on the focusing post by way of a retaining ring much like a certain 2D aluminum light we know so well, so this one, too, can be used candle-style. /ubbthreads/images/graemlins/cool.gif

The batteries are fed from the rear. There appears to be plenty of room in there, with a huge spring and enough excess width that the 2D cells rattle a fair bit when I jiggle the light.

Bulbwise (the important part), before taking you folks' advice we're looking at a Philips Krypton PR102 rated 2.4V at 0.7A. That's the starting point. /ubbthreads/images/graemlins/ooo.gif

One other oddity that might cause a minor wrinkle when changing the type of power source: there is a panel of "BATTERY LIFE" LEDs (that's literally what it says) with (left to right) green, yellow and red bits of plastic, behind each of which appears to be a rectangular LED. The idea is that one of the three will be lit at any given time, to give the user some idea of how much life remains in the cells. Does this mean the light is regulated? My guess would be no... but all the same, increasing voltage of the power source would either render this indicator panel completely useless (best case) or burn it out entirely (worst case). /ubbthreads/images/graemlins/frown.gif

What to do, what to do? /ubbthreads/images/graemlins/icon3.gif

They just use the differing Vf's of those leds to show the battery voltage level under load. Very simple scheme, no regulation. Red light is on at above 2 volts or so, yellow light comes on at maybe 2.3 volts, green maybe 2.6 volts. So when the batteries are fresh, all three will be on, etc.

I think there's such a thing as an XPR102 xenon bulb that should be pretty bright.

[ QUOTE ]
paulr said:
They just use the differing Vf's of those leds to show the battery voltage level under load. Very simple scheme, no regulation. Red light is on at above 2 volts or so, yellow light comes on at maybe 2.3 volts, green maybe 2.6 volts. So when the batteries are fresh, all three will be on, etc.

I think there's such a thing as an XPR102 xenon bulb that should be pretty bright.

[/ QUOTE ]

Er, not exactly, Paul. Only one of the LEDs is on at any given time: green OR yellow OR red. More than one at a time never happens.

Any ideas given this scenario?

Regarding the Xenon bulb: I'll look for it, as it's probably good advice regardless of your thoughts on the battery indicator.

Actually you can put in 6 AA size NiMH cells into a 2D flashlight. Some wiring with a soldering iron is needed or you can get two 3-To-D adaptors soon (hopefully) to be available from Elektrolumens. Result: 7.2V at 1.5-2.2 Ah depending on the cells you use. Maglite's LMSA501 for 5 alkaline cells will run quite well with this battery (I use it in a Maglite 2D). They have some new Xenon filled ones too. In the Maglite, the result is effectively a 5 cell flashlight's output in a 2D size flashlight. Run time with 1.5 Ah NiMH cells is about 2 hours. I think this is as bright as you can go with a 2D flashlight. The LEDs are a voltmeter that measures the voltage of the battery and must be disconnected for this mod. /ubbthreads/images/graemlins/grin.gif