Old JEAB flashlights destined for a life in new light

[Flummo]

Three old Swedish made JEAB flashlights I've got, I do not know how old they are but they are for sure alot older than me (26). The blue one has been here for over ten years, the other two I bought today. They have probably been left in the box for decades since they were new, and they are in resonably good shape. The battery is a big 4,5V thing, don't remember what it is called, and the bulb says 3,5V and 0,2A. Not bad light if you think about how old they are, but hardly a good flashlight by todays standards. (What do you think, 15 lumens at the best maybe?)

I should have a few Cree XR-E Q5 on the way home from Hongkong now, so the destiny for one of those flashlights has already been written. It will have one of those diodes modded in, batterys and drivers remain undecided but i just happen to have a bunch of 18650 batterys from a dead laptop that might find a new home here if I dont stick with the old standard 4.5V battery.


Stand by for updates... :wave: And feel free to give advices too, to a first time modder! (Well, serious flashlight mod that is, I HAVE done other things before.)

 

[Gunner12]

I'm no modder but,

Remember the voltage the LED runs at, 3.5-3.7v, so you might need a driver to control the voltage(and current).

Also don't forget about the heatsink for the LEDs.

Good Luck!

 

[Flummo]

A driver will be used. Actually, I did order some at the same time as the LEDs, but the drivers appeared to be backordered for a month. Today when i checked the order status all items were ready and status showed as "packaging". Excellent news!
And for cooling, the LED will either sit on a flat piece of aluminium, or a sawed off piece of CPU heatsink, just fitting inside the housing. Depends on the battery, the original one is too big to allow a heatsink. Despite the charging issue, a couple of 18650's gets more appealing.

 

[Flummo]

I got the last stuff a few days ago and did some testing today.

The original bulb managed to produce 130-160 lux at about 1,5-2m distance. (Cheap meter and I doubt the accuracy, but good enough for a comparison I think.)
With the Cree Q5 @ 800mA held behind the lens in the position that gave the smallest beam possble (larger than that from the bulb anyway) i got over 6600 lux at the same distance.

I will move the LED back a bit when I fit it into the flashlight, as a wider beam will be much more useful. Still undecided about batteries, but I think 4xAA will be good - opens up space for a big heatsink and are easy to obtain.

 

[Gunner12]

130 all the way to 6600 lux seems to be a pretty big improvement.

For flood I'd move the LED forward because the lens would catch more of the light. I'm not sure what the beam would be like though.

Any pics of the mod?

 

[Flummo]

No pics yet, the measurements were taken with the LED handheld without heatsink, so there is only a limited time I can keep it running - and there isn't much point in taking pics of loose parts on the bench.

Moving the LED forward is unfortuneately impossible, the star is bigger than the hole and I get the narrowest beam when it almost touches the edges. And by the way, looking at the numbers some loss of light due to less light going to the lens really isn't an issue - there is plenty of light anyway!