Recomended driver for 3D m@g and Seul led

[Led_Blind]

Hi all

I am going to build a 3D m@g mod using a single seul led and the stock reflector and would realy like to regulate its output.

After researching drivers it seems i need a buck\boost, but not to sure. The other option is to simply use a boost circut and allow the led to be DD untill the Vf of the cells is lower than the led's Vf.

I am hoping for some advice here, ie will the 4.5v from alcaline D cells fry the led if direct driven, best solution, variable outputs etc.

 

[cqbdude]

You can just direct drive it....or you can use a shark...I have and it has worked really well....

 

[Led_Blind]

Not realy wanting to direct driving this. It is a present for my mum and being regulated means she always knows how much light comes out the other end

Acording to the spec sheets i have seen the Shark converter has a minumum input of around 2.7v. Does this mean when using alkaline cells and the converter will not fire up when the cells Vf drops below this?

I want this to be able to suck the cells dry if possible.

 

[IsaacHayes]

Wizzard circuit sounds like what you need.

Or even a Downboy since by the time the cells are below the regulation, its time to change anyways for alkaline.

 

[Led_Blind]

A downboy will run DD when the Vin is below led Vf, this means i cannot suck alkalines dry and will result in sudden darkness. Is that right?

Wizard sounds ok, but again it has a minimum Vin of 2.5v. The same question here, will the converter start if the Vin is below 2.5v and will it continue to drain cells well below this level if needed?

 

[Mel_PL]

Hi all

I am going to build a 3D m@g mod using a single seul led and the stock reflector and would realy like to regulate its output.

I've just ordered GD500 for such configuration.

-- M.

 

[IsaacHayes]

2.5v /3 cells = .8volts. Thats beyond dead for an alkaline. way beyond dead.

A DB after it falls out of regulation, will simpy direct drive the led from the batteries, so you'll get dimming light.

A wizzard will flicker once or twice when it kicks out of regulation (due to too dead of batteries) and will slowly dim too, with a little random flickering here and there.

A GD500 is like a wizzard but more efficient.

honestly with the low vf of the p4, and alkalines being dead at the certain voltage, I dont know if a buck/boost is needed. Probably just buck.

But a buck/boost wont hurt... might give you more solid on time, but then when it runs out, you got pretty fast dimming light since the cells are so dead.

 

[Led_Blind]

THanks Isaac,

on the GD500, is it easy to increase the output here to about 700ma?

 

[qip]

how are you guys attaching the driver and led to the mag switch & threaded socket?
do you fit it in a pr adapter or something?

 

[Led_Blind]

There was a thread on that somewhere with pictures... I will probably use a dab of epoxy to hold the driver still.

To connect to the switch you can pull it apart and solder directly to the switch mehanism .

i am getting errors when searching cpf. Can someone post the links to the Mag c and d modding threads with the helpful pictures?

 

[IsaacHayes]

LED_Blind, they use SMT resistors which are like grains of sand. Some people are able to replace them, I however am not one of them! The resistors set the driver circuit's output current.

gip, were not. You use a heatsink like an o-sink to mount the led on, (which then is pressed into the body of the flashlight with thermal grease), and underneath the heatsink, you pot the driver board in artica alumina epoxy so it has a thermal path to heatsink it'self too. You remove the bulb post and solder the wires directly from the driver to the switch itself.

 

[PhotonAddict]

Led_Blind, do you mean these by 3rd_shift:

3c Cree XRE Maglite modding with a megabyte of pics to show you how.
4D cell K2 Magmodding step by step with a megabyte of pics to show you how

They are direct drive mods but adding a driver to the mix is pretty simple.

 

[qip]

yikes ,more parts to buy....i see engrpaul did a swap of emitters off the maxstar drop in , now i have a 2dmag with a db-1w-d ,it has a zetex driver which regulates output at 350ma powered by 2 d alkalines....would the seoul work if i swapped the emitter like what engrpaul did to the maxstar .....the diamond led in there now has output of 45 lumens i figure a seoul at 350ma is what 100lumens ....the thing im worried about is the maxstar runs off 3 or more cells unlike the diamond zetex off 2 cells less voltage

 

[Led_Blind]

Thanks again Isac.

Yep they are the pnes PhotonAddict. It is helpful to show what goes where Thanks mate.

I supose 500ma is enough drive current and would still yeild more than 100 lm and give 20hr runtimes SOLD!

 

[Led_Blind]

qip, the seul would work fine. Just ensure you use some arctic silver or aluminia to give it a good thermal path. Also make sure you electricaly isolate the slug as i am not sure if your setup has an electricaly isolated heatsink. The seul's slug is +

 

[qip]

so just put a layer of thermal epoxy under the emitter and make sure it has no contact with the drop in module except for + & - leads to solder ....and is the positive lead the one with cathode mark

 

[qip]

i would pretty much be doing this http://candlepowerforums.com/vb/showthread.php?t=148993&highlight=seoul+mag

i see he has a arctic silver coating under the emitter