I have contacted those who have purchased a Blue Shark and had them shipped on or after Jan 13th. There were 3 customers.
Some orders have not been shipped. The Blue Shark will be fixed in these orders before the order is shipped.
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?
No, a torch does not always mean flames.
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Scott, I think your input voltage is too low. As a result the shark has to work (too) hard and is overheating.
It may also help to heatsink the switcher chip and diode.
Wayne says input current should not exceed 3-4A.
I understand the driver has to work harder (boost), but isn't 4A input, 4A input?
Here's the specs;
Input voltage range: 2.7V - ~25V (Vin < Vout)
Maximum input current: 4A
Output Current: Adjustable on board trim pot - 50mA - 980mA
Output Voltage: ~32V
Regulation: Voltage or Current.
Maximum component height 3mm
Raises Vout from 22.5V and improves thermal performance over standard Shark.
I was under the impression the Blue Shark addressed the heat issues of the previous (green board) Shark driver?
I understand your frustration but... at the same page you can also read "... This will put open circuit Vout to ~32V and provide no load protection. 3-7 Lux3s/Cree XRE/Seoul P4s can be driven with this configuration as long as the boost input current does not exceed 3-4A. You can drive 5-6 Lux3s in series with 9V - 12V input and drive the string at 1A."
I suppose you want to run the 6-die Ostar off one li-ion cell, but that's a huge boost. I think you need the best possible heatsinking. Personally I always try to avoid high input currents and also don't think it's a good idea to put whatever driver to its limits.
Wouldn't a 4 die Ostar 13.2/4 = 3.3 Vf per chip equal four Lux III's, Seoul or Cree LED's?...
I didn't expect to run this particular LED with one LiIon cell from the get go, but it struggles with 2 x 18650 cells in series.
It's the IC that is overheating...If I blow air directly at the IC chip (with a small bulb duster), it will handle 6 volts...Without the air it will overheat and trip off. 6 volts = about 2.60 amps power consumption.
Here is my IC cooler...
Last edited by TranquillityBase; 02-17-2010 at 03:36 PM.
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.
I would not use anything smaller than the following to test the Converter board.
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.
The only part of the driver that will transfer heat away from the driver is the copper C, correct?
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Last edited by TranquillityBase; 02-17-2010 at 07:13 PM.
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.
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.
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.
The thermal pad material (TGF120K)
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.
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.
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.
I will AA epoxy the board to the heat sink