Some questions about the Shark driver

[Icarus]

Wayne,

After swapping the Remora board with a new one everything works fine.

Freddy

[Edjusted]

Wayne,

I've seen this question asked a few times, however I did not see an anwers (sorry if it's there and I overlooked it) What frequency do you recommend if I want to PWM the control pin from a separate microcontroller. Also, I assume a 100% Duty Cycle PWM would cause the driver to output max current (980mA) is this correct?

Thanks,
Ed

[dat2zip]

Wayne,

I've seen this question asked a few times, however I did not see an anwers (sorry if it's there and I overlooked it) What frequency do you recommend if I want to PWM the control pin from a separate microcontroller. Also, I assume a 100% Duty Cycle PWM would cause the driver to output max current (980mA) is this correct?

Thanks,
Ed

I would filter the PWM to make a DC control from 0 - 2.5V which would give you 0 to 100% of full output.

Applying PWM directly to the control pin works just fine. You risk audible PWM frequency coming from the converter board components. If you must PWM keep the PWM frequency below 1KHz for best results. Getting rid of the audible buzz is near impossible once it is created.

Wayne

[Edjusted]

Now that's a fast response! Thank you very much Wayne!

Ed

[nein166]

I want to use 6x 17670 with 5-6 cree Q5's config and need a PWM input.
So can I use the shark ? (as it is no more boost in this config?)

Any other ideas ?

Thanks

d1dd1

No
~18-21.6vf with 5-6 Cree Q5
22.2-25.2v from the battery pack

With the shark you need to keep the battery voltage lower than the series voltage of the leds.
Look for a driver that is setup for Buck configuration where the battery voltage is higher.

Or set up your battery pack differently. 3series-2parrallel 11.1-12.6v and 3200mah. That could run a 5 or 6 cree well with the shark and remora.

A buck converter won't work efficiently unless theres a few volts higher in the battery pack. The 5 cree setup on 6 17670s is okay. 6 crees will be pushing it.

[bryan24]

Is there any way to get rid of the memory function on the remora board? I find it VERY irritating. I want a simple 3 mode switch like the Fenix or Romisen.

[jhanko]

Is there any way to mod the Shark to get the Vout up to 28V.? Thanks

[dat2zip]

Is there any way to mod the Shark to get the Vout up to 28V.? Thanks

The next batch of boards will have improved thermal performance and also be blue. The blue Sharks will raise the output voltage to 32V or so. Also, the input current can be up to 3A with proper heatsinking. The max usable on the existing Shark is around 2A on the input.

Wayne

[Greg G]

Awesome! I want two. Do I need to get on a list or pre-pay?

Greg

[jhanko]

The next batch of boards will have improved thermal performance and also be blue. The blue Sharks will raise the output voltage to 32V or so. Also, the input current can be up to 3A with proper heatsinking. The max usable on the existing Shark is around 2A on the input.

Wayne

That is excellent news! Any idea on when they'll be available? Accepting pre-orders? I need one BAD!

[dat2zip]

What the heck are you guys driving that requires more than 28V? Just curious.

Wayne

[jhanko]

What the heck are you guys driving that requires more than 28V? Just curious.

Wayne

I'm going to be driving (7) Cree R2's @ 1A. I already have them mounted & wired in series. Running them with my power supply, the Vf @ 1A is 28V.

[Greg G]

What the heck are you guys driving that requires more than 28V? Just curious.

Wayne

I'm going to run 8 Crees. 30'ish volts?

You know I'm your b*tch Wayne. Tell me what I gotta do to get a couple of these.

[dat2zip]

I'm going to mod a few Sharks. They will be more than 28V limit. These will not be the blue sharks. They will be the current inventory modified.

I would not test the open circuit voltage. If you want to test the open circuit voltage I would do the following.

Hook up 3-4 LEDs in series and fire up the Shark with ~6-10V input and turn the trim pot towards minimum. When the LEDs are turned down hook up the voltmeter to the output and GND and then remove the LED- lead to open the circuit. Quickly read the open load voltage limit and turn off the power.

Since i have heard that people have damaged the Shark measuring the open voltage I would assume it's from a cold start applying power and no load except the voltmeter. I'm only guessing that the initial turn on overshoots the output and damages the IC when it overshoots.

By applying power with a load and getting the output up to some initial value before disconnecting there is less likely to overshoot and kill the IC during this process.

Another method would be to just test it with the final configuration and verify you can get the full 1A of current to the load. If you can get 1A then all is fine.

I limited qty are here.


I have tested or modified one in the garage that open circuit voltage read 38V. That's great, but, too high since the output capacitor is only rated for 35V.

I will be setting the custom ones for ~30V maximum output voltage.

Wayne

[Binary]

Hi all,
Purchased the Shark/Remora combo board to upgrade a Romisen RC-T5 4-Cree while ago (23rd of last month) and finally got around to installing it. As recommended powered it up for a quick test before heatsinking her all down. So I put 12DVC on and problem is I have no light & no output. The 4 LED's wired in series and output voltage is 0VDC. Where do I start looking?

[copperfox]

About when will these much-anticipated blue sharks be available? I'm in the process of building my first multi-LED mag.

[Greg G]

Hi all,
Purchased the Shark/Remora combo board to upgrade a Romisen RC-T5 4-Cree while ago (23rd of last month) and finally got around to installing it. As recommended powered it up for a quick test before heatsinking her all down. So I put 12DVC on and problem is I have no light & no output. The 4 LED's wired in series and output voltage is 0VDC. Where do I start looking?

First, check the wring diagram and make sure the wires are soldered where they should be, and that the solder doesn't short either positive wire to something.

The only time I had a Shark not power up was one where I removed the trimpot myself and got a little too careless doing it. Some creative soldering/jumping corrected it.

Also make sure the LED isn't grounded somehow.

[dat2zip]

About when will these much-anticipated blue sharks be available? I'm in the process of building my first multi-LED mag.

The blue sharks are some two weeks out if not longer. All the parts should be here tomorrow. The kit and boards will then goto the CM for assembly. But, there is always a chance of little hiccups where the kit isn't complete or something is missing. Once the kit is at the CM and verified complete it will only take a week for them to run the boards. I will need to verify they were loaded correctly and then they need the copper C installed.

I would guess no sooner then mid June or so allowing for hiccupps.

Wayne

[Binary]

Hi all,
Purchased the Shark/Remora combo board to upgrade.......

Thanks everyone, finally got some time to get back to it and yes a bad connection on my part All good and shes going like a rocket now!

[copperfox]

I have a question.

My new build uses two AW "c" li-ions, so obviously maximum input voltage is 8.4v and the lowest voltage is around 7v (is this correct?).

I was planning to run four crees or SSC LEDs (not decided yet), but I'm wondering -- can I run five LEDs at the shark's max output without a problem? If so, would a blue shark be better or is a green shark good enough?

[Greg G]

The new Sharks will be out so. I think I'd wait for them.

[Northern Lights]

What the heck are you guys driving that requires more than 28V? Just curious.

Wayne

I have a 25V board that came out before the copper C was put on it. Still in the wrapper.
I calculate I need 26.25 volts!
I will wait for the modified or new higher blue fish.
I have 7X Cree Q5 that fit into a mag head.
I can provide 14.4, maybe 18 Vbat for it.

[copperfox]

HELP! I don't understand how Voltages and Amps get consumed.

When LEDs are wired in series (positive to negative and so forth) you add the Vfs together. So for 4 LEDs of 3.4Vf each, the total Vf is 13.6v.

Right so far?

Now if I intend to run this string of LEDs so that each LED gets 980ma, does that mean the shark has to be able to output 13.4 volts at 3.92a? Or do I not add the amps together such as with the volts?

Let me phrase it another way. Lets say the electricity leaves the shark and is headed toward my string of 4 LEDs. Is it accurate to say that the first LED it reaches consumes its own forward voltage of around 3.4 volts, but it doesn't decrease the amperage that the next LED in the string gets? In other words, the second LED to get electricity will see 10.2v at 980ma, the third LED will see 6.8v at 980ma, and the fourth LED will see 3.4v at 980ma?? Then what travels back to the shark--0v 980ma? Zero volts doesn't seem logical to me. Also, since you control the brightness of an LED by varying the current it sees, not the voltage, then how does current not get consumed in this example? It seems contradictory to say that the first LED uses ~1a, but at the same time the next LED gets the same amount.

OR, does the first LED see 13.6v @3.92a, the second LED see 13.6v @2.94a, the third LED see 13.6v @1.96a and the last LED see 13.6v @980ma? This also doesn't seem logical because then the first LED would probably fry immediately from 4ams of current.

Do you see what I'm getting at?
Someone please clear this up for me.

[Greg G]

The Shark regulates *current*. That will be 980 ma max. As you add led's in series only the required voltage goes up. The current remains the same.

Your two AW C's are above 1/2 the front voltage of the string so you'll be fine.

[Jarl]

Disregard, I'm doing some reading on how to use a remora board

edit: Ok, is the remora really 20/50/100% at 1A? I'm looking for something I can use to give varying power to an MC-E, and even 20% is in the region of 200 lumens. I can't use a shark/external pot due to the nature of my host, so I was hoping shark/remora would be a solution for me.

[jhanko]

Wayne,
Any update on the Blue Shark? I'm anxiously waiting...

Jeff

[dat2zip]

Wayne,
Any update on the Blue Shark? I'm anxiously waiting...

Jeff

The kit was dropped off today. Many delays... I still need to order the copper C's. I don't know how long that will take, but, if the vendor has the copper sheet in stock it shouldn't be a problem.

Once the boards are assembled then they will all have the copper C's installed as a separate task.

Wayne

[Doh!Nut]

Wayne (or someone who knows)

What causes the driver to (over)heat? Power or Voltage boost?

I am looking at making a dive light broadly in line with my bike light.
http://www.candlepowerforums.com/vb/...d.php?t=167735

The most important thing is to keep the power output the same to give me the battery life I require. This will mean I can get two dives out of the light and not have to open and re-charge on the boat.

Option1
5 Cree/SSC at 1 amp for 1000 lumen, a configuration I use on the bike light and know works - the Vf is only just above Vbatt so shark not boosting voltage much.

Option2
But I have a 26v Shark and the space to fit 7 led running at a lower current to keep the battery drain the same. This would produce a bit more light due to the LED running at a lower current but it would be boosting the voltage to very nearly the maximum voltage.

The shark would be AA'd to a big lump of metal with the North Sea on the other side but I dont have any copper C's or anything like that.

Will the 7 LED arrangement be easier or harder on the shark?

Cheers
Nick

[steve6690]

Nick,
I'm doing pretty much the same as you and building an Led dive light although mine is based on the MaxFlex. I'm using 6 cree q5's because the driver won't handle 7 even though there is room inside my housing. I found that the heat in the driver was produced by the input current. I've had to rebuild my light because it disappeared to the bottom of Moray Firth on it's maiden dive two weeks ago. It was recovered but the cables were ripped out of the canister. I was running it at 700ma because the driver got too hot at higher drive currents, however I'm changing the battery from a 12volt Ni-Mh to a 14.8 volt Li-Ion (4s) homebuilt pack. Because the supply voltage is higher, the input current will be lower and therefore the driver won't have to work as hard to drive the string which translates to lower heat. I have tested the theory with Li-Ion batteries and it works fine. The shark is a boost driver like the maxFlex so the same rules apply. If I were you I'd go for more led's and a lower drive current. I had to make the same choice ie 5 led at 1A or 6 at 700ma. Once I did the sums - power vs total lumens etc - I went with 6. Hope this helps

Steve

[Doh!Nut]

Hi Steve

Thanks for the response, interesting what you say about the different battery packs, I am working with a 14.4 Li-Ion also.
It does appear to confirm that if I trim the output voltage back to keep the input voltage the same as before it should work ok.

Pretty lucky to get your light back

Nick