Newbie Questions: please help with Golston mod

PhotonsExciteMe

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Joined
Jan 29, 2007
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First, I'm new to flashlight obsession and I hope I'm not stepping on any toes asking questions that have already been answered many times, but I've searched both the candlepowerforum and google to no avail. I'm looking for a comprehensive guide on what every modder should know. Does anyone have a link to one? Short of finding that perfect guide, however, I have some specific questions that I would be most greatful if someone could answer.

I just purchased a Golston 7W LED torch (specifically, the "7w Super Bright Waterproof USA", "power 3.6vx2 charge battery" version from Dae with the DSD charger and some LIR123A, 3.6V 800mAh cells,) after having read the entire 17 page thread on it. I'm quite impressed with its beam; however, I would like to add current regulation, and I have a few concerns:

1) sandwhiches: I would like to simply buy and drop in a sandwich and be done with it, but I don't know what exactly I need to get. Are the sandwiches all the same standard size(they appear to be from the pics)? The bare aluminum piece that the star sits on, is it the heatsink or is it the top of the "can"? Do I take the whole piece (can and all) out of the flashlight tube and pop in a whole new one? Do the "sammiches" from the sandwich shoppe come inside of a can, or do people generally remove their old sammich from the can and put in a new one? As you can see, I'm a little confused about the terminology and components which reside between the cells and the optics. Could someone break it down for me please?

2) wasted energy: I understand that the diodes themselves get pretty hot and that's why most LED torches are heatsinked well, but the "Golston" seems to run quite hot and I was wondering if the fact that my version uses a stronger resister (~3.8 ohm) compared to the original 1 ohm resister creates a lot of wasted energy in the form of heat from the resister. Would this effect be a significant drain on the batteries? If so, would a downboy (or similar converter), also waste this much energy in the form of heat during the process of kicking down the voltage from a potentially > 8V source (when freshly charged)? If this is the case, then would I be correct in assuming it would be more efficient to use a lower voltage power source (but with a high capacity still of course)? (I was hoping this wasn't the case, because I prefer not to have to bore out the tube to fit protected 18650s. I think the regulated runtime on my LIR123As will be fine for me; I just don't want to use them if they're causing energy to be wasted as heat.)

3) give me photons: Which white LED (appropriate for a Golston sized torch of course) currently puts out the highest lumens/watt, and a what wattage would the additional lumens/watt start to decrease drastically? To be clear, I guess I'm interested in a graph of wattage versus lumens rather than just the average value of lumens/watt, since even though the average value may be highest on LED A, the maximum lumen value may be higher on LED B. Are there any graphs like these available? I'd rather have a higher maximum lumen output than a higher average lumens/watt value. In other words, my goal in regulation is not to get max runtime, but rather to get max lumens at a steady level, even if that level doesn't last very long. Also, not to concerned about tint, as long as it's not horrible.

Well, I think that's it. Thank you very much for your time!
 

tebore

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May 10, 2006
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Toronto, Ontario. CAN.
I can only help you with Q3. Use a Seoul Semiconductor P4 U-Bin LED and it'll be brighter. This is the 240lm at 1A emitter. Do a search for more specific info on it.
 

FirstDsent

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Jan 4, 2006
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Columbia, South Carolina
PEM,

I have written extensively about the "Golston" lights. Feel free to get my attention if you post more questions.

"Sandwiches" don't apply to the Golston. The Golston uses a can as both a heat sink and a housing for the electronics. Sandwiches take the place of both of thses components using a "can" specially designed for them. They are also not the best at thermal management. Your Golston is already more efficient at removing heat from the die. That's why the body gets hot. Hotter body equals cooler die in a good flashlight.

In the Golston, the LED is mounted to the heat sink surface, and the electronics are mounted to the PCB/battery contact. In your case, the "electronics" is just a resistor. However, it is simple to remove the PCB, and install a converter (not sandwich) from the Sandwich Shoppe, or a Flupic from Goldserve. There are others, but I am most familiar with these.

Wasted heat: Wayne's boards from the Shoppe use LDOs to buck or boost the power. They do not create much excess heat. Search for LDO on the Forum's search utility, or the Google domain search.

The Flupic uses PWM, not resistors to regulate the variable light output. This also does not create much if any heat.

Any Luxeon LED is a direct drop-in mod for the Golston, however only a W-binned Luxeon V, the brightest U-binned Luxeon III or a highly overdriven K2 will be brighter than what you have now. Most Golstons have a really good LED in them already.

A Cree XR-E mod is tricky because you have to do some fabricating to change the heat sink hight, and to adapt the reflector focal length. I have heard that the Soul Semiconductor P4 is a drop-in and does not require reflector mods, but care must be taken to insulate the body from the heat sink to avoid a short. No spec-sheet is available yet for the new Edixeon LED from Edison Opto, so keep your eyes peeled for that.

Bernie
 

beefy6969

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May 29, 2006
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Bay Area, CA
tebore said:
I can only help you with Q3. Use a Seoul Semiconductor P4 U-Bin LED and it'll be brighter. This is the 240lm at 1A emitter. Do a search for more specific info on it.

Wow is it that simple? Just drop in the Seoul P4 Star? No resistor necessary? If so what type of resistor is needed?
 

modamag

Flashlight Enthusiast
Joined
Aug 16, 2004
Messages
2,101
Location
Bay Area, CA
No resistor necessary if you use a converter.
However, no FluPIC in this case because 2x RCR123 will kill the LED.

All you need is a converter (downboy from Sandwich Shoppe, or nFlex from taskled).
And replace the Luxeon with a Seoul P4 and you'll get double the brightness with almost double the runtime.

Come by the next modfest and we'll help you put one together.
 
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