Help with a dive torch

Wurkkos

350xfire

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So can i put a heatsink onto the led and have it dissapate heat into the air in the torch because that is really the only option:confused:

Air is NOT a heatsink! You need an aluminum (or some heat dissipating metal) and a path to the water. Otherwise you will reach a point of heat saturation and temperature will begin to rise beyond the LED rated limit. By the time you re-do your light you could have easily bought something like an Intova and be better off. That light has a magnetic switch and really compact.
 
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Packhorse

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I think I have already said this at least twice in this thread.

If you make the heat sink surface area large enough and only us a XPG or less then you will probably get away with it. But I am unsure how big of a heat sink you will be able to fit. And in the end you will have a very bulky light.

Since I have repeated that I will also repeat this.

You are far better off throwing it away ( along with your black and white TV, Atari, Commodore 64, Motorola Brick and AM radio) and buying something smaller that will be as powerful if not more so.

The Intovas like 350 suggested are a good little torch( I like the spot beam ones not the flood).

The W200's are a good torch although I replace all the O rings and also check that the "pill" is not pushed forward into the lens when its turned on. This can un seat the lens from the sealing O ring ( Only been a problem on a couple of W200's I have seen and I have had dozens of them to modify)

The W300 is a step above the W200. But its also a step bigger and heavier ( not as big as the UK600 though) and takes 2 D cells ( I'd recommend NiMh).

The PALIGHT BG-QS88 is also a light worthy of looking at. There are several versions and you can get it as a kit with 26650 batteries and charger or just the torch. It also takes 18650's.

All these lights can be had for $50us or less.
Modifying your UK600 will cost you at least half that. It may end up costing you a lot more.
 

Doc Ed

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If you post photos of what you currently have, maybe we can get our collective brains together and think of a solution for you... One thought that came to mind was that since the battery was apparently shot to begin with, this may have been the reason for the poor performance of the light.

There are some other threads on this board related to others using a UK body with LEDs. One that comes to mind was written by Rodex99 entitled cooling tested in uk housing where the bottom line was:

I think there is a clear deduction that you cannot run a LED in this kind of housing above a certain point for long without over-heating. Exactly what that point is I am not quite sure.

So it'll be a trade-off between the performance desired and the degree in which you want to modify your light, as well as the attendant expenses involved.

That said, I need to add this as well: I'm relatively new here to DIY-ing lights as well. The other posters have been doing this much longer and definitely know what they're talking about. And one common thing they say is that to DIY this light properly will cost you some money. You've stated that you want to try to save your initial investment of 40 quid - an amount I wouldn't pay for an old UK600, when they can be had for 15 quid (but then again I'd have spent the money on something else). Considering you have to replace the battery of the light already anyway, you really need to determine whether or not you wish to continue with this project in order to save money. If it was for the learning and the fun of DIY, then by all means, proceed. Otherwise, get a new light.
 

DIWdiver

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Air is NOT a heatsink!

Technically, that's true in this case. The water is your heatsink, and everything else is just a path for the heat to flow from the LED to the water. But if operating above water, the air outside would be your heatsink. The 'sink' is the point into which you can dump any amount of heat without increasing the temperature.

In practice however, the final solid surface that radiates heat into the infinite sink is what we usually refer to as the 'heatsink'. So the finned aluminum block on top of the CPU or GPU in your PC is called a heatsink, even though that's really not technically accurate. To be honest, 'radiate' isn't really accurate either, since most of the heat transfer is by convection, not radiation.

Assuming you can't or don't want to cut through the case (a choice which I applaud, by the way), the best you can do is to transfer the heat from the LED to the air inside the case as efficiently as possible. From there the heat would transfer through the case to the water. I would think you might get away with as much as 5 watts this way, so an underdriven XM-L might also be a possibility. I would suggest an aluminum disk that just fits inside the case. If you could attach some fins or blades to the disk to help carry the heat down the length of the case, that would be even better. The LED should be attached as directly as possible to the disk with thermal epoxy, or with screws and thermal compound (which doesn't harden).

If you got bare emitter sample(s), then you're going to have some trouble connecting to the electrodes, which are on the bottom. It's generally easier to work with emitters that are pre-mounted on stars, which are small aluminum circuit boards which can be screwed or glued to your heatsink, and have larger electrodes on top, making connections much easier.
 

DIWdiver

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I also heard that led's need a resistor, now do i need a resistor for it or would there be one on the sample led coming? Also what is the driver? is it the pcb? And what battery would i need?
There will NOT be a resistor on the LED sample.

The rest of your question is both huge and very important to being able to control the light output, LED lifetime, and battery burn time. A thorough explaination is not going to be achieved in a single post, or even in several, so I won't even attempt it. But maybe I can simplify it enough to be helpful.

In a very simple view, a battery can be considered to be a voltage source. Ideally, it will give you any amount of current at a fixed voltage until it is fully discharged.
But of course no battery really does that. The more current you draw, the lower the voltage is. The voltage also drops as the battery discharges. A fully charged Lithium cell is 4.1-4.2V, and you can discharge it to 3.5, 3.2, 2.7, 2.5V, or even lower. The more deeply you discharge it the more energy you get per charge, but the fewer charges the battery will last.

In a very simple view, the LED can be considered to be a fixed voltage load. Ideally, it will absorb any amount of current at a fixed voltage. By the way, the amount of current through the LED is the primary factor in how much light it puts out.

So if you connect a voltage source to a voltage load, what happens? If the source voltage is higher than the load voltage, an infinite current will flow. Clearly this can't happen. A college professor of mine used to say that this would cause an 'anihilation wave' to propogate from the event at the speed of light. Not something I relish experiencing. If the source voltage is less then the load voltage, no current flows. This is pretty boring, as it looks a lot like unconnected parts laying on the bench. If the voltage source and voltage load are exactly the same, the current could be anything from boring to anihilation. I want something more reliable.

So what do we do? This is where the driver comes in. The driver's job is to control the current in the LED when the battery and LED voltages don't match.

A resistor is a really crude form of driver. If you wire battery, resistor, and LED into a loop (and get the polarity correct), the current in the loop will be determined by the Battery voltage, LED voltage, and resistor value according to the following equation:

Current = (battery voltage - LED voltage) / resistance

You can see from this that as the battery voltage changes, the current will change, which means the light output will change. It will start dropping as soon as you turn on the light and continue dropping until you turn it off.

A better driver would be a variable resistor, that automatically adjusts to keep the current the same no matter what the voltages do. A linear driver is essentially this.

Even better (in most cases) is a switching driver. If the voltages are much different (like 3.4V LED and 6-8V battery), a resistor or linear driver is very inefficient. A good swtitcher can handle the voltage difference, regulate the current, and maintain high efficiency.

I am also going to need some help on the reflector a swell. Would the current one suffice? ( i can upload a photo of it if need be)

The current reflector will work poorly with an LED, even after you to modify it. The reason for this is that it was designed to catch light coming out the bulb sideways, backward, and slightly forward, and focus that into the 'spot'. Light that comes out more forward will not hit the reflector, and will spread wide to form the 'spill'. An LED has mostly 'more forward' light, so only a little will hit the reflector and form a very weak spot.
For an LED you need a much deeper, narrower reflector, or a lens of some sort.
 

Klem

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If you still insist on upgrading that existing housing but are dead against building a more efficient thermal path to the outside then once again I stress...you will not be able to maximise the potential of that torch. Your light output will be limited to the point where the inside turns into an oven and cooks everything; roast LED, driver and slow-stewed batteries.

It can be done but only by limiting the power draw.

Here's a similar project to yours that underwhelmed me two years ago;
PCMiniwave.jpg

Using a Princeton Tec Miniwave which operates from 4 C Cells and a single halogen and reflector. Swapped out for a brighter LED emitter. Replacement is a Terralux 12Watt 3*XR-E giving 600lumens, but also changed the carbon cells to Li-ion to cope with the higher power draw. Note, there's more metal and a ring of nuts behind the emitters in an attempt to draw as much heat away from the LED's and delay the heating of the emitter as possible. But in the end where does that heat go? Into the batteries (which are also producing heat due to internal resistance) and back to the LED. It had a very short life as I gave it away to a mate who has all the dive gear but doesn't dive. For its size, bulk and thermal inefficiency it was otherwise destined for the bin. I hope you realise I risk my questionable reputation by even showing it to you! BTW you can put the same emitter in a converted 2D Maglite; less bulky, more robust and far more thermal-efficient for a modest increase in cost.

Princeton Tec no longer produces the old halogen Miniwave but have upgraded the housing with LEDs and call it the 'Shockwave'. The point being, the most this manufacturer believes they can squeeze out of this plastic self-contained configuration is 370 lumens.
http://princetontec.com/?q=miniwave-led

At roughly 100lumens/Watt I'd say DIW is right on the money...500 lumens max out of your slightly larger housing and without a more efficient thermal path to the outside.


FOOTNOTE: I see that Terralux have upgraded their old 700lumen TLE-300 Maglite upgrade to a 1000 lumen version
http://www.terraluxportable.com/product/tle-310-m-ex/
 
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deepbluediver

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If you post photos of what you currently have, maybe we can get our collective brains together and think of a solution for you... One thought that came to mind was that since the battery was apparently shot to begin with, this may have been the reason for the poor performance of the light.

There are some other threads on this board related to others using a UK body with LEDs. One that comes to mind was written by Rodex99 entitled cooling tested in uk housing where the bottom line was:



So it'll be a trade-off between the performance desired and the degree in which you want to modify your light, as well as the attendant expenses involved.

That said, I need to add this as well: I'm relatively new here to DIY-ing lights as well. The other posters have been doing this much longer and definitely know what they're talking about. And one common thing they say is that to DIY this light properly will cost you some money. You've stated that you want to try to save your initial investment of 40 quid - an amount I wouldn't pay for an old UK600, when they can be had for 15 quid (but then again I'd have spent the money on something else). Considering you have to replace the battery of the light already anyway, you really need to determine whether or not you wish to continue with this project in order to save money. If it was for the learning and the fun of DIY, then by all means, proceed. Otherwise, get a new light.

I thought that i was getting a good deal with two reachargeable batteries and a charger and a torch. he said they were in working order so i thought why not. I really regret this decision
 

Doc Ed

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Maybe you can still get your money back - considering the batteries are actually dead and all. Might be the best option.

I'm sure we've all been in a similar situation like yours at one time or another, and sometimes it gets difficult to see that the most reasonable thing to do is sometimes the hardest - ie moving on.

You could keep the housing and use it for something else down the line... say like a small video camera ;)
 
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deepbluediver

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Maybe you can still get your money back - considering the batteries are actually dead and all. Might be the best option.

I'm sure we've all been in a similar situation like yours at one time or another, and sometimes it gets difficult to see that the most reasonable thing to do is sometimes the hardest - ie moving on.

You could keep the housing and use it for something else down the line... say like a small video camera ;)

I tried contacting him, but no success. I knew he was ignoring me because i sent him several emails several times. I tried several ways to try and get my money back all with no success. This was just a last ditch attempt, anyway i can only 'live and learn' as they say. Also it would be quite a funky little video camera wouldnt it
 

deepbluediver

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Hi guys,

Thank you so much for all your help so far. I am pobably beginning to annoy a few of you now but like i said i'm new to this field and don't know very much. All the info you have given me though has cleared the mist a little. Anyway converting this torch to LED was going to be alot harder than i thought. Maybe i should just keep the torch as it was designed to be, a halogen, bi pin uk 600r dive torch. Or maybe in this case in THE BIN!!! I shall be uploading the photos in a little bit so if you guys can come up with something then i'd definately have a good think about it...

Cheers,
James

P.S i may not be on for the next few days due to the fact i have an exam on wednesday and need to do some revision!
 
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deepbluediver

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May 9, 2012
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Hi all,

Sorry i haven't been on in a while but there has been a new development,

A member of my dive club has heard about my story and just errr well.... gave me a uk c4 dive torch. Its certainly alot brighter than the 600!!!

Thaks guys for all your help.
Cheers,
Deepbluediver.
 

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