How to mount LED driver for cooling

I Use this Dx driver (SKU 3256) to drive an SSC P4 (SKU 1445) Emitter in a small bike headlight:


After about 10 minutes on 7.2Volt (I~540mA => P = 3.888W), the intensity of the emitted light reduces intermittently. I Found that the driver transistor and/or IC on the driverboard overheat, even in the open-air test setup shown above. Applying Ice-spray to the boards components restores normal function for some time.

How should I mount this driverboard in the (mostly) hollow tube to keep it from overheating? Or is this a malfunctioning board?

I've used some small pieces of copper 10 gage wire to bridge between some hot ICs and the flashlight body to help with heat removal. Based on your photo and diagram, you could probably put a good sized hunk of aluminum inside the body to act as an additional heat sink for the driver. The more metal in the heatsink and the more contact area with the body, the better the heat will be removed from the driver.

Here's a couple old pics I found. Although the pic shows just the one piece of copper, in the end I also added one to the top of the square black IC also. The last pic shows one where I attached the driver directly to the flashlight body.

Read the review on those boards says over 6V is no good.
Maybe just use the one cell?

Cheers
Dom

You could use the existing battery with a dc dc converter such as dx sku.15149, you would now have 5v going to the driver.

I Did some test with this driver using a scope. This driver board only starts regulating the current at voltages above approximately 5 Volt. Under 5V (Like with a single 3.7V cell), the transistor is continuously ON and you operate basically in direct drive mode. And I don't want that ;-)

So I will try the suggestion made above and get some metal to drain the heat away from the transistor. See how that works

EDIT: Read the forum on Dx. Maybe I should reconsider and get a 6V battery pack....
"This design note shows the ZXSC300 or ZXSC310 driving a 3W LED. The input voltage ranges from 6.2V to 3.8V with a maximum output current of 1.11A at 6V input."
http://www.diodes.com/zetex/_pdfs/3.0/appnotes/design/dn73.pdf

glue some aluminium directly onto the IC, sand the whole thing down till other parts of the driver have the same height (ENSURE no shorting!!!) and glue the whole driver on the back side of the thermal plate

(best by adding some foam in between and soak it with epoxy glue)



PS: while this ugly looking small chunk of copper at DonShocks pics might work, the description of the SHARK recommend something much different (= larger). Unfortunately mine has just been mounted like typed above, but I might take pic of the similar "modded" MaxFlex, when I am at home.

This is what I did so far:
Bonded some Aluminium to the IC and transistor (Coil and Diode remain visible, they are a bit higher than the other components).

There is thermal compound between the transistor, IC and alu, and epoxy between the board and the alu to keep it in place.

Then I crumpled up some aluminium foil and put it in the tube. the driver is pressed against by some foam.

Than another testrun:


So far, no, even after 15 minutes on my bench at 7.2 Volt

Thank you all for the advise

This is the final light mounted on my bike. A 6x AA NiCd pack allows for approximately two and a half hours of light



lovecpf

Used this driver for my and my frieds bike light for more than a year. We both use a 8 cell NiMh-setup, using 2 drivers, driving 2 SSC P4 in series each. They are then run at a bit above 1000 mA. (Higher voltage increases current to LED for this driver.) On fresh cells the driver gets more than 10V. We have the drivers just hanging in the air, and because of the windspeeds we havn't had any isuess with overheating.

For enclosing the driver like you do, I would sugest just adding heatsink directly on the driver like you have done. You probably don't need much, if any, direct contakt with the flashlight body. Adding a small heatsink to the inductor could also be an idea as it also heats up.


space

Thanks for the confirmation

I Ran a test with the battery pack and the lamp on my desk. The lamp gets fairly warm, but no more problems with flickering light. On the bike, cooling is much better, so it does not get warm.