LED Bulb brighter than Krypton?

I just bought a torch mad-cheap (Energizer Hardcase Torch +batteries £2.99 delivered (UK)) It has a krypton bulb running at 2.4v and drawing 0.7A (1.68w) KPR102 supposed to be 70% brighter than a 'standard bulb'.

My first option is to put a 0.9A (2.16w) bulb in it but are there LED bulbs that will slot straight in and give more light?

I'd prefer LED but quantity of light is a priority. A quick look around and I found only 50 lum LED bulbs, not sure how that amount of light compares to whats already in there or 0.9A 2.16w upgrade...

This bulb here is 1.3MSCP which is about... 16 lumens, since incandescent bulb brightness scales roughly linearly with power, a 0.9A bulb should give you around 20 lumens, which is far fewer than 50 lumens.

BUT that's not the real problem you have, since the light is 4xAA, if you're using alkaline batteries you'll find that with a draw of 450mA each the performance will be less than stellar.

An LED bulb will be much brighter, but whether or not it'll look good depends on how the flashlight is designed. An LED will have a much longer life, however, and MAY draw less current, depending on the emitter/circuit used



http://www.bulbs.com/eSpec.aspx?ID=10803&Ref=B-Type&RefId=133&Ref2=Miniature+Bulbs

I am puzzled, you say the torch is 2.4v but that page says 4AA?
Also you do not divide ma over batteries in series, only if they are parallel to each other does the current divide.
If the torch draws 0.7A at 4.8v that would be 3.36 watt and at 0.9A it would be 4.32 watts.

Lynx_Arc said:

I am puzzled, you say the torch is 2.4v but that page says 4AA?
Also you do not divide ma over batteries in series, only if they are parallel to each other does the current divide.
If the torch draws 0.7A at 4.8v that would be 3.36 watt and at 0.9A it would be 4.32 watts.

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the stated spec of the bulb is 2.4v so I'm guessing its 2x2aa configuration.

gladis said:

This bulb here is 1.3MSCP which is about... 16 lumens, since incandescent bulb brightness scales roughly linearly with power, a 0.9A bulb should give you around 20 lumens, which is far fewer than 50 lumens.

BUT that's not the real problem you have, since the light is 4xAA, if you're using alkaline batteries you'll find that with a draw of 450mA each the performance will be less than stellar.

An LED bulb will be much brighter, but whether or not it'll look good depends on how the flashlight is designed. An LED will have a much longer life, however, and MAY draw less current, depending on the emitter/circuit used

Click to expand...

does that estimate cater for the '70% brighter' krypton? My maths says 30 lum. Still less than 50.

Will the alkalines perform better with the lower drain of an led?

gladis said:

This bulb here is 1.3MSCP which is about... 16 lumens, since incandescent bulb brightness scales roughly linearly with power, a 0.9A bulb should give you around 20 lumens, which is far fewer than 50 lumens.

Click to expand...

Is there a way to convert bulb specs to lum? I have a big flashlight I'm thinking of butchering into LED, it has a 55w 6v (9A?) halogen bulb in and I want to know what lum-worth of LED's would match the light output.

MarkVarley said:

the stated spec of the bulb is 2.4v so I'm guessing its 2x2aa configuration.

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Ok, that is right I guess. I looked up the bulb. Weird light for sure but could be an interesting advantage for an LED dropin you could run the light off 2AA lithiums and it would weigh a lot less.

I'm currently considering PR2-3WHP-x: 3 Watt Flashlight Bulb
1-3vdc 180lum $14.95 only concern is I'm in the UK and they have a minimum $25 for international orders (so I'm thinking of just getting two and putting one in a 2D/C maglite).

any thoughs, feedback or opinions on this bulb?

For the same price, you can get better led flash lights that are designed and will work 10 times better. Think about what you are getting for that much $? not much.
I would leave that well enough alone and spend your hard earned $ else where.

newuser

Newuser01 said:

For the same price, you can get better led flash lights that are designed and will work 10 times better. Think about what you are getting for that much $? not much.
I would leave that well enough alone and spend your hard earned $ else where.

newuser

Click to expand...

The flashlight cost me next to nothing, Can I get more than 180lum from AA's another way?

MarkVarley said:

The flashlight cost me next to nothing, Can I get more than 180lum from AA's another way?

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I guess my 220 wasn't that much more.....