RC speed control for LED regulator for 3 D mod?

dimwatt

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Jan 23, 2005
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When I was reading through various posts I saw where a speed controler for remote control was used to regulate an LED light but now I can't find the post again.

Would any of you that are experienced in this area please post or pm me the info? Plleeeease??/ubbthreads/images/graemlins/bowdown.gif

How would this compare to the regulators made for this purpose? The advantages of one over the other? Can you, or should you have both a voltage booster and regulator or is there something available that does both?

I am gathering ideas for a future mod to my 3 D M*g possibly using 3 AA to D adapters and 3 3 watt Luxeon emiters or at least a 5 watt LS.

What would the result be if you placed a five watt in the center and surrounded it with three 3 watt emitters?

I have seen several mods on these lights that I admire but the urge to be different overrides common sense. /ubbthreads/images/graemlins/grin.gif

I would also like to incorporate either a dimmer or maybe a two or three position switch to adjust the output.

I would also like to have a small red LED low voltage indicator similar to the Opalec NewBeam.

Any other neat features that you could suggest would be appreciated.

I apologize for asking for info that has been posted already
but I have read so many posts with different mods that it's hard to assemble all of it so that it is halfway simple to understand. /ubbthreads/images/graemlins/wink.gif

dimwatt
 

rwolff

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Dec 22, 2004
Messages
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Location
Ontario, CA
Re: RC speed control for LED regulator for 3 D mod

For small DC motors, there are basically 2 types of speed control: those that vary the speed by changing the voltage (steady voltage to the motor), and those that vary the speed by changing the duty cycle (voltage is a square wave flipping between 0 and full at a moderate frequency - duty cycle refers to the percent of the time it's at full). In a flashlight, the second would be a better bet, since you could set your driver circuit (resistor or constant-current source) to run from the speed control's output. Since LEDs are current-driven devices, a variable voltage source isn't a good way to change the brightness.

[ QUOTE ]

I am gathering ideas for a future mod to my 3 D M*g possibly using 3 AA to D adapters and 3 3 watt Luxeon emiters or at least a 5 watt LS.

What would the result be if you placed a five watt in the center and surrounded it with three 3 watt emitters?


[/ QUOTE ]

You'd be asking for trouble in a number of areas:
1. The Luxeon V is actually 4 Luxeon I elements in a single package (series/parallel connection). As a result, it has a significantly higher forward voltage than either a Luxeon I or a Luxeon III (Lux III white ranges from 3.03V to 4.47V, Lux V ranges from 5.43V to 8.31V). Designing driver circutry that can handle 2 separate voltage requirements while still delivering high efficiency would be a real bear.

2. There are commercial triple optics that will fit inside the head of a D Mag, and triple Lux III setups are fairly common. You'd be on your own designing the optics for a "LeMat style (Civil War era revolver, with the cylinder pin being a single-shot shotgun)" lighting arrangement. Also, 4 is a bad number if you want a symmetrical beam. 3 works well (imagine the meeting point of 3 hexagons), as does 7 (one hexagon surrounded by 6 others), but "1 surrounded by 3" leaves a lot of "dead" space.

3. What you're describing would be a very hot mod. From what I've heard, the limiting factor in multiple-Luxeon flashlights is heat dissipation, and that a triple Lux III setup is about the maximum you can have in a D Maglite. Your setup would boost the heat output by roughly 50%, so you'd have to underdrive your emitters to keep the heat to manageable levels - easier, and cheaper, to simply run 3 Lux III emitters at their rated output.
 

dimwatt

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Central valley, California
Re: RC speed control for LED regulator for 3 D mod

Thanks for the usefull info. I'm not that swift on the electrical end of things but do ok on mechanical stuff. Looks like I will abandon that thought and come up with something else. I have an idea for a heat sink that should keep cool anything that you could fit in a light /ubbthreads/images/graemlins/grin.gif I wish I could afford either 3 or five Luxeon 5 watt emiters to test the theory /ubbthreads/images/graemlins/grin.gif

Your occupation says toolmaker. Do you have access to the equipment to make the heat sinks that Lambda and other moders use? I had read somewhere that they are looking for someone to do these projects for them as they are having trouble lining up machine shops to do small runs.

dimwatt
 

rwolff

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Dec 22, 2004
Messages
224
Location
Ontario, CA
Re: RC speed control for LED regulator for 3 D mod

[ QUOTE ]

Your occupation says toolmaker. Do you have access to the equipment to make the heat sinks that Lambda and other moders use?


[/ QUOTE ]

The equipment I have access to on a daily basis is for "at work" use only. When I have some of my own projects to do, I sign up for a continuing education "introduction to machine shop" course at the local community college (where I completed the full-time program, so the instructor knows that I know what I'm doing) to gain access to the equipment. Also, most of the flashlight work looks like lathe stuff - where I work, there's one guy who handles all the turned parts, while the rest of us do milling/drilling/grinding/assembly.

As for people trying to line up shop services for small runs, smaller shops (1- or 2-person) are a better bet than larger shops, especially if the timeframe is somewhat flexible (i.e. you let them know up front that there's no firm deadline, but you would like to get the parts within a month or two). After all, a larger job will bring in more money, so the big customers get top priority, but if they've got idle time they'd rather be making chips (and money) with a small job.
 
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