direct drive a lux III and V but...

davidefromitaly

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i have a TV1K and if i direct drive it with a R123A it absorb about 700mah

and a VV1T with 2 R123A absorb 1200mah (wow!!!!!!!)

it's safe or i risk to blow something? the lux V become hot in few seconds... /ubbthreads/images/graemlins/mad.gif

thank you
 

Icarus

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I think you mean 700mA for the TV1K and 1200mA for the VV1T. (capacity of batteries is expressed in mAh; current in mA or A).

Your LuxIII at 700mA is driven at spec (700-1000mA). So, you don't have to worry about this.
The VV1T emitter is overdriven (specs are 700-1000mA). But supposed heatsinking is sufficient this has not to be a problem.
Although it will shorten their life I'm pushing some WX1S emitters up to 1.5A without any problem so far. /ubbthreads/images/graemlins/grin.gif
 

davidefromitaly

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ops!!! sorry... 700 and 1200 mA... /ubbthreads/images/graemlins/icon15.gif

so the lux-III is a bit underdrived, i can espect 67 lumens from it?

the lux-V at 1000mA output 147lm? how i can limit the current at 1000ma?

how i can dissipate the heat if i put the lux-V in a dorcy spyder body?

and a little o.t. but... i have try a amber 5mm led with 2 ni-mh batts but i have blow it... is normal?

thank you for your help /ubbthreads/images/graemlins/wink.gif
 

Icarus

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The LuxIII is driven at spec but you can go up to 1000mA without any risk (but less runtime of course).

You can expect (depending on how lucky you are):
LuxIII T-binned: 67,2 - 87,4 Lumens.
LuxV V-binned: 113,6 - 147,7 Lumens.

No idea about how to dissipate heat of the LuxV in a dorcy spider because I don't own one (and even don't know how it looks like).

I don't know the specs of your amber 5mm led but if you take a look at the specs of the ADPmods 5mm amber leds then you'll see Vf = 1.7V. If your led had the same specs then it's normal you killed it using 2 NiMH batteries (2.4V - 2.8V).

/ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/au.gif
 

HarryN

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[ QUOTE ]
davidefromitaly said:
ops!!! sorry... 700 and 1200 mA... /ubbthreads/images/graemlins/icon15.gif

so the lux-III is a bit underdrived, i can espect 67 lumens from it?

the lux-V at 1000mA output 147lm? how i can limit the current at 1000ma?

how i can dissipate the heat if i put the lux-V in a dorcy spyder body?

and a little o.t. but... i have try a amber 5mm led with 2 ni-mh batts but i have blow it... is normal?

thank you for your help /ubbthreads/images/graemlins/wink.gif

[/ QUOTE ]

IIRC, the Dorcy is pretty small, but you can fit things in there. A simple solution in theory is a low ohm resistor, but to handle the current, even 2 ohm x 1000ma =2 watts. (minimum rating on the required resistor)

If you look up resistors in this power range, they tend to be large, or you need many smaller ones.

I had the same problem for a small light I am building, where I needed 3 watt resistor capacity, but in a 1206 size package (approx 3mm x 1.6mm). The typical resistor in this size range is 0.25 watts.

To solve this problem, I found a firm that supplies aerospace grade resistors, and had some custom made for 2, 10, and 25 ohm. These resistors are mil spec quality, the right size, and use AlN substrates (for high heat load). They are capable of 10x more power than you are needing to dissiplate, but you do need to bond them to something for heat sinking. (just like the Luxeon)

I had to buy many more than I need for my project, and I am thinking of putting the rest up on the Sandwich Shoppe to cover my cost. - around $ 7 for 2 each. I should have them within 2 - 3 weeks if you are interested.
 

davidefromitaly

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but i haven't understand one thing: if i drive a lux-III at 700 or 1000 ma the output is the same? i think that the minimum value is at 700ma and the maximum at 1000ma...

what is the best heat-conductor that i can use in the spyder? copper? aluminium? i try to don't use a resistor because i don't want to waste further current...

i have a nuwai Q-III and a goldengadgets S1801... with this 2 electronics i can obtain the higher output with a SV1J or with the TV1K?

thanks /ubbthreads/images/graemlins/smile.gif
 

StuU

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[ QUOTE ]
davidefromitaly said:
what is the best heat-conductor that i can use in the spyder? copper? aluminium? i try to don't use a resistor because i don't want to waste further current...


[/ QUOTE ]

Hi David-
I have modded a few Dorcy Spyders and am familiar with the internal layout....

The plastic incandescent bulb holder will easily disassemble by pulling the top upward. This leaves a flat steel section which has been pressed into the aluminum barrel. This section has prongs that penetrate the aluminum to provide a solid ground. Don't try to remove or reposition this steel section because it provides not only the main ground but also a great place to solder the negative from your led. However, you can file, shape, or drill holes in the steel (with care).

I would recommend a 1/8" aluminum plug that can be hand shaped with a file and can be fitted and glued into the top above the steel ground plate. You can glue your luxeon to this aluminum plate. Drill holes through the plate for your wires. A copper plug might also work as it can be soldered to the steel ground plate.

On the inner side of the ground plate, you have room to put a resistor/positive contact or a Downboy regulator board. The Downboy can be glued on the underside of the ground plate.

As for resistors- you must use them because the lithium batteries will burn up your luxeon very quickly without resistance. I only built one with resistor- a 10ohm that ran about 220ma initially and stabilized out around 190ma. I would recommend something like a 3ohm for you purposes.

You are probably asking for trouble if you try to run the luxeon at 1000ma with the Dorcy-too much heat for this Dorcy mod. A level of 750ma is pretty high. A better level would be a regulated 500ma with a Downboy regulator board. Besides, as you go much above 500ma, you will be generating more heat than light with the extra current.

Also, you might consider one of the 17 or 20mm Sandwich Shop reflectors to top off the mod. It makes a very nice beam. You may have trouble using the original Dorcy Spyder reflector with the lux conversion.

PM if you have extra questions

Good luck
Stu
 

davidefromitaly

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what you think if i take out the steel section and i put a big piece of copper with the arctic silver 5 beetween emitter-copper and copper-body of the dorcy? i can dissipate a lot of heat i think...

but where i can buy the arctic silver 5? i live in italy...

and what are the risks when i solder the negative of the led on the copper? i can blow the led with the welder?

thank you for your help /ubbthreads/images/graemlins/smile.gif
 

andrewwynn

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you are talking about putting copper inside a plastic light? more mass inside helps for short-term.. but for higher power inside a plastic light you need to conduct the heat outside.. check out my cellphone light i made on laborday here... some solution like that is the only way to maximize power on an LED mod in a plastic light.. else you have to throttle back the power a little (still can be quite bright).

have fun with your mod, keep asking questions.

-awr
 
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