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Thread: Some questions about the Shark driver

  1. #331
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    Default Re: Some questions about the Shark driver

    Quote Originally Posted by dat2zip View Post
    The value from Remora PWM and GND should be between 0 and 20k or less depending on the ohms range and multimeter type.

    On the first board does it stay dim all the time? It sounds like there is no control if the resistance of the PWM input is near zero all the time.

    When the PWM input is at GND (clockwise) there should be no output.

    Make sure the LED Vf is actually three in series. Can you apply the battery to the LED string without the converter? Does it draw 1200mA in DD?

    You could still draw current if the Vf is lower then Vin and then the converter would be in DD mode and there would be no control.

    Wayne
    Direct drive with 8 volts in, 26.3 mA, leds dim.
    First board 8 volts in, 8 volts out, 10 mA, leds really dim, pot has no effect.

    Also, at pad 3 (next to 0.1 ohm resistor) of pot I measure 12.2 volts. Shouldn't it be below 1 v? Can I send the boards back to you to troubleshoot?
    Last edited by Tortolita; 05-20-2009 at 02:49 PM. Reason: additional info

  2. #332

    Default Re: Some questions about the Shark driver

    I just received two Blue Sharks. I like to operate 4 OSTARs (4-Chip, blue). These will be integrated in a Scuba diving lamp.
    My question is: how I could fix the Sharks to a Aluminium heat sink?
    What is the best? Is it possible to use Arctic Silver 5 ?
    Would be glad to receive suggestions.

    Horst

  3. #333

    Default Re: Some questions about the Shark driver

    I just received two Blue Sharks. I like to operate 4 OSTARs (4-Chip, blue). These will be integrated in a Scuba diving lamp.
    My question is: how I could fix the Sharks to a Aluminium heat sink?
    What is the best? Is it possible to use Arctic Silver 5 ?
    Would be glad to receive suggestions.

    Horst

    I like to receive suggestions under horst.grunz et uni.due.de

  4. #334

    Default Re: Some questions about the Shark driver

    Quote Originally Posted by LED Zeppelin View Post
    Mike, here's some info on wiring multiple Sharks. The Sharks pictured are early versions without the copper C, but the wiring should be the same.

    This is a pic of a Remora controlled tri-Shark mod (9 X Cree in a 3" Delghi head on a Leef neck adapter). The brass shapes are topside sinks I made to help cool the IC and diode.




    This is the wiring of the Sharks for use with a pot:



    How to wire multiple Sharks to one dimming control:

    - Order the Sharks with the on-board pot removed, or remove the pot yourself.
    - Locate the three pads under the pot. Viewing the board from the component side with the pads at lower right, you will see that the larger central wiper pad connects to the top soldering hole just to the right. There are two smaller pads under the large pad. The lower right pad connects to the lower right soldering hole, and the lower left pad does not connect to any hole.
    - If using a pot, order a 20K log pot. I use these from Digikey.
    - Connect the pads of one Shark to the pot. Viewing the pot with the shaft at top and the leads facing you, connect the large wiper pad (or top right hole) to the center pot lead, the lower right pad (or lower right hole) to the left lead, and the lower left pad to the right lead. I find it just as easy to solder to the pad as to the hole. The wires do not pass any current, so I use very thin flexible wire, 30 ga or so.
    - The other Sharks are wired to the mother by connecting the large wiper pads together. Any number of Sharks can be wired together. Alternatively, all three pads of each Shark can be connected in parallel, or all connected to the pot.
    - If a Remora is used, connect the Remora to one Shark, and again wire the wiper pads together. All Sharks must have the on-board pot removed.
    How did you fix the Sharks to the heatsink? By Arctic Silver or so?

    Regards

    Horst

  5. #335
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    Default Re: Some questions about the Shark driver

    Quote Originally Posted by horstartur View Post
    I just received two Blue Sharks. I like to operate 4 OSTARs (4-Chip, blue). These will be integrated in a Scuba diving lamp.
    My question is: how I could fix the Sharks to a Aluminium heat sink?
    What is the best? Is it possible to use Arctic Silver 5 ?
    Would be glad to receive suggestions.

    Horst
    Horst, use Arctic Alumina or Arctic Silver thermal adhesive. Epoxy the copper C on the bottom of the Shark to a flat heatsink, and hold while it cures for the thinnest possible layer. I like to file the copper C flat, but be sure to remove the chips well.

  6. #336

    Default Re: Some questions about the Shark driver

    Quote Originally Posted by Tortolita View Post
    Direct drive with 8 volts in, 26.3 mA, leds dim.
    First board 8 volts in, 8 volts out, 10 mA, leds really dim, pot has no effect.

    Also, at pad 3 (next to 0.1 ohm resistor) of pot I measure 12.2 volts. Shouldn't it be below 1 v? Can I send the boards back to you to troubleshoot?

    You can send the board back. I will take a look at it. Please put a note with with the board with some of this information so I can remember what we talked about.

    Wayne

  7. #337

    Default Re: Some questions about the Shark driver

    Quote Originally Posted by LED Zeppelin View Post
    Horst, use Arctic Alumina or Arctic Silver thermal adhesive. Epoxy the copper C on the bottom of the Shark to a flat heatsink, and hold while it cures for the thinnest possible layer. I like to file the copper C flat, but be sure to remove the chips well.
    Hi LED Zeppelin,

    thank you very much for this information. I think the adhesive is easier to handle than mechanical fixing. Horst

  8. #338
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    Default Re: Some questions about the Shark driver

    Is there supposed to be a connection between the +Vout and the 0.1 ohm resistor? I think I may have bridged them when I soldered the + wire for the LED.

  9. #339

    Default Re: Some questions about the Shark driver

    The +Vout is connected to the sense resistor. A solder bridge would not not cause a short since it already connected to the sense resistor.

    Wayne

  10. #340
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    Default Re: Some questions about the Shark driver

    Wayne,

    I tested the three most recent blue sharks, pots removed, that I ordered from you and was surprised to find that one of them had significantly higher output. To test each shark individually, I drove an MC-E emitter wired as 2p2s (Vf 7.2v @ ~1.5A) from a single 3.7v battery. The first two measured outputs of .96A and .97A. The third measured an output of 1.5A. I triple checked all the wiring and got the same results.

    Undeterred by the one oddball, I wired all three sharks in parallel. Before introducing the sharks, the same setup (5s4p MC-E and 4s 3.7v IMR) in direct drive only drew ~2A from the batteries fully charged. The goal for the sharks was to maintain ~3A to the emitters even as the batteries sagged. Knowing that the one shark was putting out .5A more than expected, I anticipated a total output of ~3.5A.

    I was surprised to measure 4.89A output from the three sharks and a total draw on the freshly charged batteries of ~6A. (Swapping the 3.7v IMR batteries for 3.2v LiFePO4 batteries, draw increased to 6.8A as battery voltage decreased).

    After running the torch for only a few minutes at a time, I have not noticed any thermal events from the sharks - no dimming, flickering, strobing etc. They appear to perform very well, mounted on Led Zep sinks with AAA.

    If the draw from the batteries was distributed evenly among all three sharks (2-3A each), they would still be within spec for input current (<4A each). Unfortunately, I am unable to isolate the current drawn by each shark individually. That being the case, I do not know if two out of the three are operating exactly to spec (.97A output each) and the third, oddball shark is running way over spec (~2.96A output alone).

    What is more likely? That one of them is way out of range, or that somehow the three combined are each causing the others to run a little higher than they would individually?

    What is common behavior for ungoverned sharks (no trim pot, no remora) when they are run in parallel?

    Thanks.






  11. #341

    Default Re: Some questions about the Shark driver

    Techjunkie,

    I would guess the one Shark is not working correctly.

    When you wired them in parallel, it might very well be the one Shark is contributing more than expected.

    To confirm this I would if possible only power up the two known good boards and see if the output current is the sum of the two as expected. If that is the case we can send you a replacement for the third board.

    What is common behavior for ungoverned sharks (no trim pot, no remora) when they are run in parallel?

    They should run max current as set by the sense resistor which by default is 1A for a 0.1 ohm sense resistor. The trim pot may not get to 100% and max output may be limited to 0.96 or so as you are measuring. Removing the trim pot and jumpering it would get the full 1A.

    Wayne

  12. #342
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    Default Re: Some questions about the Shark driver

    Quote Originally Posted by dat2zip View Post
    Techjunkie,

    I would guess the one Shark is not working correctly.

    When you wired them in parallel, it might very well be the one Shark is contributing more than expected.

    To confirm this I would if possible only power up the two known good boards and see if the output current is the sum of the two as expected. If that is the case we can send you a replacement for the third board.

    What is common behavior for ungoverned sharks (no trim pot, no remora) when they are run in parallel?

    They should run max current as set by the sense resistor which by default is 1A for a 0.1 ohm sense resistor. The trim pot may not get to 100% and max output may be limited to 0.96 or so as you are measuring. Removing the trim pot and jumpering it would get the full 1A.

    Wayne
    Wayne,

    Removing just the one shark from the equation just to take some measurements is a very risky maneuver that could easily end in disaster. I had to pack the wires into the neck very carefully and never intended to remove the head again. As long as everything is "working" I'd just as soon leave it alone. The added current and heat is so far manageable. I'm mostly bummed about the 90W power consumption seriously reducing runtime compared to the 63W I was expecting.

    I think you've answered my question though. If I understand you correctly, it's most likely that the added current is all coming from the single out-of-spec shark. If that's the case, then it's operating way out of spec, providing nearly 3A instead of 1A and pulling over 3.7A input on fresh batteries and even more as the batteries sag. (I'll not use the LiFePO4 batts again to keep input current to a minimum.)

    If that's actually what's happening, then will it begin to malfunction as input current exceeds 4A? If it does, will it completely burn-out eventually? Would I still be able to get it replaced then?

    I'm not eager to unassemble this torch again unless it is to make a repair.

    Also, there are no pots on any of the sharks. I ordered all three of them with the pots removed and have not modified them by adding/removing the jumper.

  13. #343

    Default Re: Some questions about the Shark driver

    If the Sharks do not have the trim pot on it then it must be jumpered if you want max output. Usually, no trim pot puts out minimum or zero output.

    Hmm, I wonder if others are having this kinda of problem with no trim pot and are not seeing any output and do not know they need to jumper the trim pot pads.

    If the one Shark is not working correctly I don't know if it will kill itself or continue to operate over time.

    We can work something out if the one unit fails.

    Wayne

  14. #344
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    Default Re: Some questions about the Shark driver

    Quote Originally Posted by dat2zip View Post
    If the Sharks do not have the trim pot on it then it must be jumpered if you want max output. Usually, no trim pot puts out minimum or zero output.

    Hmm, I wonder if others are having this kinda of problem with no trim pot and are not seeing any output and do not know they need to jumper the trim pot pads.

    If the one Shark is not working correctly I don't know if it will kill itself or continue to operate over time.

    We can work something out if the one unit fails.

    Wayne

    Wayne,

    At least one unit just failed. I ran the torch for about three minutes straight and all at once the brightness was suddenly cut way way down, lower than it was in sharkess direct drive mode. I gave it a chance to cool off and still the same problem. It looks like I'll have to unassemble it again after all. If the bad shark took the other two with it, will you replace all three? This is my second set of three sharks (I've paid for six by now and potentially have zero). Let me know please. Thanks.

    John

  15. #345

    Default Re: Some questions about the Shark driver

    Yes, I'll replace all three if that is what happened.

    I'd like to know more info if any when you disassemble it.

    Thanks,

    Wayne

  16. #346
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    Default Re: Some questions about the Shark driver

    Wayne,

    I think all three sharks are toast. I disconnected all of them and measured current draw between the batteries and the emitters in direct drive and noted 1.7A draw. One at a time I tested each of the sharks and noted only 1.01A-1.05A draw between shark and emitters. Any two combined and all three combined yielded only 1.15A of current between the output of the three parallel sharks and the emitters.

    I haven't pried the sharks from the shark sinks yet in case there is any further testing you need me to do.

    I'm out the $$ for 6 blue sharks now. I'm hoping you will arrange a swap for me on these last three, as I believe it was the defective shark that fried caused itself and the other two to fail. (Maybe you can fix them, I don't know.)

    John

  17. #347

    Default Re: Some questions about the Shark driver

    I need to sweat on more copper C's on Blue Sharks. As soon as I get another batch built up we can send you replacements.

    I do caution anyone trying to use parallel drivers. When they work it is great. When one fails the failing one will take out the other drivers. The Shark drivers have open circuit protection, but, do not have short circuit protection. If the output is shorted to GND it will take out the driver.

    I caution everyone to make 100% sure the drivers are fully functional before final assembly. Failure to do this in the future will void any replacement.

    I also recommend if possibly you buy at least one spare converter board as they come untested and if there is one defective you will still have enough to make your build. The defective one if there is one can will get a replacement.

    Wayne

  18. #348
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    Default Re: Some questions about the Shark driver

    Thanks Wayne, I really appreciate it. Any idea how long it will be before you have enough inventory to be able to send me the replacements? I see that the shoppe only shows 7 blue sharks in stock at the moment.

  19. #349

    Default Re: Some questions about the Shark driver

    The analog pin will control the output from 0 to 100% if done correctly. How the Remora was implemented did not give the full range of control.

    To PWM the Blue Shark or the Shark Buck you will need to do the following.

    The fixed resistor on the Blue shark that is part of the voltage divider for the Analog control should be used as the pullup to an open collector output from the microprocessor.

    The open collector output should then have a voltage divider/filter to divide the PWM signal in half. This will be the proper signal level for the analog input. 100% on is 1/2 Vref. Zero volts is full off on the analog input.

    Code:
    PWM ---R----+----------+---- Shark Control input
    Input | |
    | |
    R C
    | |
    | |
    GND-----+----------+
    Is "the analog pin" the trace that connects to the wiper of the pot? Is that the same as the "Shark Control Input"? Or is "Shark Control Input" the microcontroller pin?

    Does "PWM input" refer to the "Remora PWM" solder pad on the Shark?

    Does the pot need to be removed?

    I'm sorry, i don't understand your post well at all. Thanks for your help.

  20. #350

    Default Re: Some questions about the Shark driver

    The center pad of the trim pot is the control input of either Shark. The control is DC from 0V (off) to 0.8V (full on).

    You can PWM control this pin. You need to filter it to DC and have the PWM filtered DC values correspond to the DC voltages as noted above.

    This does require removing the trim pot if you want to control it with something else.

    Wayne

  21. #351
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    Default Re: Some questions about the Shark driver

    Wayne,

    I see that the Shoppe's inventory has climbed to 16. Can you send my 3 replacements from that stock? Thanks.

    John

    Quote Originally Posted by dat2zip View Post
    I need to sweat on more copper C's on Blue Sharks. As soon as I get another batch built up we can send you replacements.

    I do caution anyone trying to use parallel drivers. When they work it is great. When one fails the failing one will take out the other drivers. The Shark drivers have open circuit protection, but, do not have short circuit protection. If the output is shorted to GND it will take out the driver.

    I caution everyone to make 100% sure the drivers are fully functional before final assembly. Failure to do this in the future will void any replacement.

    I also recommend if possibly you buy at least one spare converter board as they come untested and if there is one defective you will still have enough to make your build. The defective one if there is one can will get a replacement.

    Wayne

  22. #352

    Default Re: Some questions about the Shark driver

    Can you send an email with your real name and order number?

  23. #353
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    Default Re: Some questions about the Shark driver

    Quote Originally Posted by Ms_SS View Post
    Can you send an email with your real name and order number?
    I didn't see your email listed in your contact info, so I sent you a PM instead.

  24. #354

    Default Re: Some questions about the Shark driver

    Rec'd your PM. Use the Shoppe email: theledguy@comcast.net

  25. #355
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    Default Re: Some questions about the Shark driver

    Quote Originally Posted by Ms_SS View Post
    Rec'd your PM. Use the Shoppe email: theledguy@comcast.net

    Mail sent. Thanks.

  26. #356
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    Default Re: Some questions about the Shark driver

    I received the replacement Sharks on Saturday and am happy to report that all three tested fine. I measured 970mA output from each of them in the same test configuration. I then installed them, mounting them to the shark sinks by applying a little AAA to their copper Cs, and then wired them in parallel. The three sharks in parallel are driving the 5 MC-E string at 2.73A and drawing a total of just over 3A from almost fully charged batteries. Thats approximately 50 Watts in and 45-48 Watts out (estimating voltage), pretty efficient. I was expecting more like 2.9A out, but 2.73 is even better for heat and runtime and visually, no different.



    I'm considering adding a 5A fuse (or circuit breaker if I can find one small enough) to the battery pack to avoid damage to the batteries or sharks if the pack is drained below spec (10V).


    Many thanks to Wayne and Cindy for replacing the dead Sharks and excellent customer service!
    Last edited by Techjunkie; 06-29-2009 at 09:50 AM.

  27. #357
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    Default Re: Some questions about the Shark driver

    Im looking for a Driver for a 4 chip ostar, the ostar needs 14-16volts @1amp if im not mistaken.
    Which Shark driver do i need? what is this trimpot you guys have been talking about on here?

    How do i set the ouput voltage of the shark? my input voltage will be 9.6volts. 8 x AA Nimh, roughly 11volts freshly charged.

    Thanks

  28. #358
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    Default Re: Some questions about the Shark driver

    Hi,
    the driver you'll need is the "Blue Shark" boost driver. You can't set the output voltage of the Shark as it is a constant current driver. The trimpot is used to set the output current that you require. Once you set the current, the driver will automatically vary the output voltage so that the current remains constant.

  29. #359
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    Default Re: Some questions about the Shark driver

    Quote Originally Posted by steve6690 View Post
    Hi,
    the driver you'll need is the "Blue Shark" boost driver. You can't set the output voltage of the Shark as it is a constant current driver. The trimpot is used to set the output current that you require. Once you set the current, the driver will automatically vary the output voltage so that the current remains constant.
    Hi Steve,
    Sorry im confused.. How do i get the 14-16volts output i require?
    Is is depentdant on Vin and current that is set by the trimpot?

  30. #360
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    Default Re: Some questions about the Shark driver

    Quote Originally Posted by Goldigger View Post
    Hi Steve,
    Sorry im confused.. How do i get the 14-16volts output i require?
    Is is depentdant on Vin and current that is set by the trimpot?
    The Shark driver does the work of getting the proper voltage. It takes the input voltage and boosts it up to the amount needed to get the set current to flow. There is a "sensing" resistor that measures the amount of current flowing to the LED. The driver will only raise the voltage enough to get the set amount of current flowing and then will stop at that level. And as current changes slightly due to things like the LED temperature changing or the battery voltage changing, the driver will automatically adjust the voltage to maintain that same preset current flow through the LED. That's the Shark driver's whole purpose in life, adjust voltage to maintain a constant current to the LED.

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