Does the Downboy need to be potted

Hey guys,

I hope this isn't a stupid question, but searches came up empty.

I've used 2 db1000's and 1 db 750 so far and potted all of them. But they were used in o sinks and an aleph.

My latest project was a L6 head with a db 1000 driving a uwok, but the housing is plastic. Right now the converter is just sitting in free air, but I'm a little hesitant to use it for more than a few minutes if it infact needs to be potted. I guess I was a little excited about seeing the results and couldn't figure out a clever way to sink it properly. (The stock 3 cell buck converter isnt potted or sinked at all)

So what do you guys think? Running off two primaries in an L5 body at 1000ma should it be potted or not? All I can think of is just filling the large plastic housing with AA. Don't know if that will be very effective since it doesnt have any real path to the aluminum body.

It turned out nicely, but I'm worried I'll fry the converter if I use it as I intended.

Any insight or ideas would be fantastic.
Thanks

Potting into plastic will give zero benefits. It will just slow the rate of thermal saturation. Once the thing heats up with the heat nowhere to go, you're back to where you were. Was there something wrong with the stock converter?

No there was nothing wrong with the stock converter, well untill I broke two of the leads off. I was originally worried about too high a voltage to the luxIII. I have since read where you have done this and retained the stock board.

Is there a big difference between the two boards? Is the factory board more efficient? I plan on using this light often. Should I try to repair the stock board or will the downboy be ok as is? I guess I could build the DB it into an ecan and AA it to the bottom of the emitter sink plate. I wouldn't mind tidying it up a bit anyway, but at the moment I'm out of teflon wire.

Obviously I'm pretty new to this. Thanks for the reply, and any additional info you could lend.

I'd say fix the stock board and save the DB1000 for another project (there's always other projects aren't there :devil:

I haven't done a measurement as far as efficiency goes. The FET in the KL6 is pretty beefy and the circuit was designed to drive at constant current--not voltage so it is perfectly serviceable for any application where the supply voltage is higher than the LED voltage.

Hey Cris:

when we say "pottong", do we mean using Arctic Alumina thermal epoxy or thermo compound?

270winchester said:

Hey Cris:

when we say "pottong", do we mean using Arctic Alumina thermal epoxy or thermo compound?

Click to expand...

Sorry, I mean epoxy.

A Downboy 1000 will eventually self-destruct if run in non-moving free air. You need to pot it for longevity. Thickening your favorite epoxy with alumina powder (available from the Sandwich Shoppe) will be an effective and cheap potting compound.

I think a more robust Downboy is in the works, but I don't believe it has been released yet.

Thanks wasBlinded. I'll have to use an ecan or something so I can pot it directly to the emitter sink. There really isn't much metal in that big head, just a thin plate.
I'd much rather use the DB since the stock converter only drives the lux at around 700ma. I'm quite pleased with the output of the luxIII at 1 amp in this head.

I've heard 700ma, and then also 900ma for the Kl6.. I think different SF luxV lights run at different drive levels... I think the l4 is a little under 700ma, and the L5/6 are higher?

CM can you confirm that the stock circuit pushes 900ma to the emitter?

I have talked to CM and the KL6 runs the emiter in the 700mA range. I had him up my bias to about 850mA to led. We tried 1100mA's to led, but it was too hot with not enough built in heat sinking.

Bill