Incandescent bulb recommendation for a 4 AA cell torch

Dr Phil Panter

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Hi,

I've dug out a 4 AA torch that I haven't used for a while, however the bulb has blown. I'm planning to use 2100 mAH rechargeable batteries to power it what would be the ideal PR Incandescent bulb to use?
 

Chrontius

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Is it one of those double-barrel torches? If the four cells are in serial, a Mag xenon bulb may be called for, but the double barrel ones are two stacks of two cells.
 

Icebreak

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I'm just going to guess based on some experience.

A Magnumstar would be an upgrade. It's Xenon.

Overdriving an incandescent lamp increases brightness (lumens), color temperature (Kelvin) and CRI (color rendition index). Overdriving can be accomplished by using a power source that is higher than the specifications of the lamp.

If you were running 4 AA alkalines the winner is the RS XPR103 (3 cell Xenon) but it is hard to find as it is out of production. Some have reported Sears and Dorcy still offer similar lamps but I haven't tried them. Here's a long thread about that. THREAD.

I'm going to guess that a RS KPR103 (3 cell Krypton) would work for NiMhs. If you want a smoother beam you can frost the lamp envelope with sand paper or glass etching chemicals.

What flashlight do you have? Using the on board Google search might reveal what others have done with it.
 

ampdude

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I've been using a 3 cell Krypton bulb with 4AA Alkalines for awhile now. I've tried the same combo in a 4C light, but it didn't last long.
 

ZMZ67

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Not sure what bulbs are readily available accross the pond but I like the Magnum Star Xenon from Maglite.The Magnum Stars are common and reasonably priced here and they seem to offer a cleaner beam than most of the krypton bulbs.Overdriving a 3-cell krypton is probably the cheapest route and it an easy way to provide better output.Xenon bulbs generally can't be overdriven very much so you should get a 4-cell if you go the Magnum-Star route.
 

Mr Happy

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I have a 4AA torch that I have experimented with every replacement bulb I can find. If you are going to use NiMH cells (as I do), you have many options.

By the way, where did you get a 4AA torch? It is my holy grail of incan configurations but darned near impossible to obtain. :grin2:

The stock bulb that came in my light is a Philips HPX40 xenon (4.8 V, 0.79 A), but I have searched in vain to find more of those. It is nice and white with a very good focus and beam pattern. As far as I can tell the Philips HPX bulbs have only been supplied to OEMs and are rare as hen's teeth in the retail market.

Basically though, 4AA NiMH lets you use any 4D bulb. The best alternative to the Philips I have tested is the Mag 4D xenon bulb.

I've tried a Halogen HPR50 (5.2 V 0.85 A), but it was little different from the best of the xenons.

A bulb I am still looking to try is a 4 V 1.2 A designed for NiCad rechargeable lights. However I have not yet found one. My local hardware store has the packages but the bulb inside is a 2 V 1.2 A one. It's great for 2 cell lights but not what I want.
 

Dr Phil Panter

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Hi all,

The batteries stack in a unusual way, like a gun magazine on top of one another in parallel. The casing is plastic with a belt clip and the head is semi- angled.

I've googled the torch but its a novel one that I haven't seen on the net or the market for years and could not find on the net.

When I get my phone back this week I will take a picture of it and post it.

I uses to use it a lot when I visited my holiday caravan out of season, The holiday park where its stationed cuts the electric and gas at the end of the season.

I own two of these torches and found them brighter than the standard army angled head torch and due to the head being 45 degrees instead of at a 90 degree rigtht angle, better for illuminating the caravan interior.

Also I found it more compacted than my 3D cell maglite and brighter, although due the design it has some strange artefacts.

To compensate for this the plastic len comes with a defused centre spot that has is slightly magnified, giving a fairly good throw, with the rest of the lens clear.

Its a simple construction, with a chunky compact appearance, in a grey light blue colour. Its got that 80's design feel to it, something that would not be out of place in a workman's tool bag.

I was thinking of over driving the 3D maglite bulb in the torch, but I don't think the torch could handle a overheated bulb.
 
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Chrontius

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You know, this gives me an interesting idea for a new light - the "Fatboy" ROP. It'd need a custom body, but it'd be a pocketable hotwire with the batteries stacked in a 2x3 brick configuration...
 

Dr Phil Panter

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You know, this gives me an interesting idea for a new light - the "Fatboy" ROP. It'd need a custom body, but it'd be a pocketable hotwire with the batteries stacked in a 2x3 brick configuration...

Hi Chrontius,

I found out today that there is a six AA version of the torch available, with a price tag of only £1.

Yes you read right only a mere £1, that's got to be the cheapest ROP type pocket torch on the market.

However I don't think everyone will warm to the torch appearance, that looks like a plastic brick.

Also the torch is not very modifiable, only a bulb change.
 

Flash_Gordon

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You might try a KPR139. (5 watt 1.32 AMP 3.85 volt) I run this bulb in my PT TEC40 with good results. It is a 3 cell bulb but seems quite robust.

A big part of the final result is the size, shape and quality of the reflector. If that is poor, you will have a poor quality beam no matter how many watts or lumens you are pumping out.

This bulb runs a little hot, so it might be a factor if the light is not up to it.

Looking forward to pictures so we can see what you have.

Mark
 

Dr Phil Panter

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Pictures of the 4 AA cell torch in question

Hi,

Well got my phone back (at last) and took these pictures of the torch in question.

This is the 4 AA battery version.

torch1.jpg


torch2.jpg


torch3.jpg


I'm going to take the torch out tonight and and compare it against a 20 lumen's 0.5 watt LED torch, I will take some pictures.
 
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