Some questions about the Shark driver

[dat2zip]

I have been able to get 4A on the input. The blue shark must be heatsinked properly and this means the gap between the copper C and the heatsink must be perfect. Any heatsink gap due to a thick layer of epoxy will not generate a proper heat transfer.

You are at the limit. I've seen improper setups fail at 3A input. With proper mounting you can get the optimum. It is hard to tell in the picture the actual contact thickness under the blue shark and thus, impossible to tell. But, in almost all cases I've seen the blue shark had a thick of gap between the copper C and heatsink.

To properly attach the blue shark should more than likely be clamped the whole time the glue is setting up. Also, some people lap the bottom of the copper C to make it even flatter.

If you are just bench testing you can use a strong fan to keep the converter attached to a heat sink cool.

If you can avoid pushing the Shark to the extreme it is always recommended.

If your heatsink is only the dark rectangle that is not enough heat sink mass and if it is just sitting on the metal plate that is not a good contact to transfer from the dark plate to the sheet metal top.

Wayne

 

[dat2zip]

Still an issue...

The driver shuts down at 3.30 amps input current, which seems well below specification.

I was able to run the driver for better than an hour at .700mA without an issue...When I turn the trim pot to feed the LED 1amp the board would overheat and shut off in under 15 seconds.

Why would this occur?

In your picture it appears the Blue shark does not have adequate heat sinking. Mount the shark to a heat sink that has 6C/W thermal transfer or better. A good heatsink is a junk CPU heat sink. These can be had for a few $$$ in surplus and make an excellent heat sink for bench setups.

Wayne

 

[dat2zip]

I would not use anything smaller than the following to test the Converter board.

http://theledguy.chainreactionweb.com/product_info.php?products_id=1190

This is what I use to test my Blue Shark on the bench. Even with this I always turn on a fan to help move the heat off the heat sink.

Wayne

 

[TranquillityBase]

The only part of the driver that will transfer heat away from the driver is the copper C, correct?

 

[cmacclel]

I would not use anything smaller than the following to test the Converter board.


Wayne

It's hard to tell from the picture but thats a Huge 1/2 thick plate of aluminum under that driver board

Mac

 

[TranquillityBase]

To properly attach the blue shark should more than likely be clamped the whole time the glue is setting up. Also, some people lap the bottom of the copper C to make it even flatter.

Wayne

I noticed the copper C is not soldered flat to the driver (one leg of the C is slightly elevated, creating an air gap (not competely soldered))...If you speak of perfect flatness and an ultra thin layer of thermo epoxy, wouldn't the copper C be more suspect with the existing air gap than the mounting of the driver to the heat sink?

 

[TranquillityBase]

There is quite a number of voids between the C and the driver board, the piece of paper depicts the largest void.

I would think the connection between this copper piece and the driver would play a bigger role in heat transfer than the epoxy that will eventually join the board to a heat sink.

 

[dat2zip]

If the heat sink burns your fingers it is not big enough. If you can hold the heat sink the blue shark burns your fingers the blue shark is improperly mounted.

You should be able to hold the heat sink the whole time it is running. If at any time after 15 seconds the heat sink gets to hot to hold it is not big enough.

Wayne

 

[dat2zip]

There is quite a number of voids between the C and the driver board, the piece of paper depicts the largest void.

I would think the connection between this copper piece and the driver would play a bigger role in heat transfer than the epoxy that will eventually join the board to a heat sink.

The heat emminates from the inside corner directly under the square IC. The outter edge where you are referring to has no heat generated at that point. The heat will spread to that whole copper C. The job of the copper C is to spread out the IC heat to a larger more manageble area that is mountable to a heat sink.

Wayne

 

[dat2zip]

If you have never used a blue shark before my recommendation is to buy three of them.

First one to test the setup on the bench and get familiar with the setup.

One is a spare in case one burns up and the third is for the final light configuration.

Wayne

 

[TranquillityBase]

If the heat sink burns your fingers it is not big enough. If you can hold the heat sink the blue shark burns your fingers the blue shark is improperly mounted.

You should be able to hold the heat sink the whole time it is running. If at any time after 15 seconds the heat sink gets to hot to hold it is not big enough.

Wayne

The plate in the photo is .395" thick x 5.500" x 8.000" aluminum...I think it's adequate.

 

[TranquillityBase]

If you have never used a blue shark before my recommendation is to buy three of them.

First one to test the setup on the bench and get familiar with the setup.

One is a spare in case one burns up and the third is for the final light configuration.

Wayne

OK :laughing:

 

[dat2zip]

It's hard to tell from the picture but thats a Huge 1/2 thick plate of aluminum under that driver board

Mac

It doesn't do any good if the converter is not mounted to it.

 

[dat2zip]

There is quite a number of voids between the C and the driver board, the piece of paper depicts the largest void.

I would think the connection between this copper piece and the driver would play a bigger role in heat transfer than the epoxy that will eventually join the board to a heat sink.

The converter must be glued to the heat sink with something like AA adhesive to move the heat to the heat sink. Is this picture taken after the setup picture? I don't see any glue on the bottom there. How did you mount the blue shark.

Bottom line. If the blue shark burns your fingers it is not properly mounted to a heat sink of sufficient size or improperly mounted.

 

[TranquillityBase]

The thermal pad material (TGF120K)

 

[dat2zip]

the only bench test I can sanction is with the black anodized heat sink I sell on the shoppe as that is what I use for all my converter board tests.

The converter board is glued to the center of the heat sink using Arctic Silver Arctic alumina adhesive (two part epoxy) and clamped until the epoxy is set.

Wayne

 

[TranquillityBase]

the only bench test I can sanction is with the black anodized heat sink I sell on the shoppe as that is what I use for all my converter board tests.

The converter board is glued to the center of the heat sink using Arctic Silver Arctic alumina adhesive (two part epoxy) and clamped until the epoxy is set.

Wayne

So if I AA the driver to this slab of aluminum and get the same results, will you site improper/unsanctioned heat sink?

Please share your clamping method so I can follow your process, and not risk damage to the driver board components.

 

[dat2zip]

I recommended three because in bench testing the converter needs to be glued down and I would not recommend removing the glued down shark and re-use it.

Converter board clamped to heat sink using a pony clamp. The pony clamp has soft rubber tips in this clamp.

Converter board after glue setup.

Bottom side view.

In the pictures are a Shark Buck. the same procedure or method applies to the Blue Shark for bench testing.

Wayne

 

[dat2zip]

a two cell lithium and 4 LEDs should be drawing around 2A.

I have done a lot of testing of the blue shark and I know when the shark gets hot it gets less efficient and the input current rises. For your Blue shark to be drawing 3+ amps has only been seen when I run the blue shark in free space and no heat sink. Then the blue shark gets extermely hot and input current rises above normal levels.

Wayne

 

[TranquillityBase]

I will AA epoxy the board to the heat sink