Driver board list / regulator board list.

[TorchBoy]

Re: Driver board list / regulator board list

But, there seem to be very few of them that have a true constant current output with good efficiency.

When the output ends up just as variable as using enough voltage and a resistor, what's the point? Am I correct in thinking of them as "drivers", not "regulators"?

The DX and KD drivers are an unknown quantity on both constant current and efficiency so it hard to pick one of them.

Wading through them all is certainly a mission. Most I see little use in.

 

[Stereodude]

Re: Driver board list / regulator board list

When the output ends up just as variable as using enough voltage and a resistor, what's the point?

You got me. I would suspect that the output varies less than direct drive via a resistor though.

Wading through them all is certainly a mission. Most I see little use in.

If I had a lot of spare time I would buy a bunch of them and test them, but I'm not sure it's worth the effort.

I guess there's a market for someone to make a proper driver board. :naughty:

 

[Essexman]

Re: Driver board list / regulator board list

One word - Micropuck !!!!!

I can't believe you've not included this little bit of torch/flashlight modding history. Shame on you.

Great list BTW, thanks for doing this.

 

[W-c.Scenario]

Re: Driver board list / regulator board list

One word - Micropuck !!!!!
I can't believe you've not included this little bit of torch/flashlight modding history. Shame on you.
Great list BTW, thanks for doing this.

There is a link posted containing the Micropuck etc, he just havent updated the list with it though ,
well heres another link to the luxdrivers

 

[Mr Happy]

Re: Driver board list / regulator board list

Quote:
Originally Posted by TorchBoy
Fatman. $22. Boost regulator, 2.7-12V in. User adjustable constant current at 3-16V. Optional external adjustment. Efficiency 80-96%. Must always have a load connected.

MaxFlex. $32. Boost regulator, 2.5-20V in. User configurable constant current, 350-1200mA at up to 24V. >85% efficient, uController UI, status LED. 23mm diameter. Efficiency 83-93%.

Shark. $20. Boost regulator, 2.7-20V in. Regulates on voltage or current, output current adjustable from 50-980mA. Maximum input current 4A. Some questions are answered in this CPF thread.

If these are really just Boost regulators then your description are misleading (not your fault). The product descriptions on their website are also misleading / unclear. For a boost regulator the Vout has to be higher than the Vin. Conversely the Vin can't be higher than Vout. So, for example, you can't use these drivers with say 4 D cells 6.0V (4.8V on NiMH) and a single Q5 Cree because Vin is higher than Vout. IMHO, that's makes them not very useful for single LED applications.

Where are you getting the information that Vin can't be higher than Vout? I have just (for example) looked at the MaxFlex page and I don't see that stated at all.

What I read is that it is a constant current driver with a range of selectable currents. It will accept an input voltage from 2.5 V to 20 V, and it will boost the output voltage to 24 V if necessary. The clear implication is that if you only connect one LED, it will set the output voltage to just what is required to achieve the required current and not higher.

It seems to me to be a very flexible device, and it is misleading to say "Vin can't be higher than Vout" unless you have a reference for that in the technical data sheet.

 

[TorchBoy]

Re: Driver board list / regulator board list

The micropuck, powerpuck, etc is in post 2 - my to-do list. I'll get there eventually.

Where are you getting the information that Vin can't be higher than Vout? I have just (for example) looked at the MaxFlex page and I don't see that stated at all.
...
It seems to me to be a very flexible device, and it is misleading to say "Vin can't be higher than Vout" unless you have a reference for that in the technical data sheet.

Sure.

http://www.taskled.com/techfatman.html

Note, Fatman is a Boost regulator (step up), so input voltage must be less than the output voltage to ensure Fatman remains in regulation. If the input voltage exceeds the output voltage (at the dialed in drive current), Fatman will no longer regulate and the input voltage will go through the series inductor and schottky diode directly to the load. This will cause the output current to a LED to rise rapidly since LEDs have a very steep Current vs Voltage curve (Vf). Fatman must never be powered up without a load connected or it will be damaged.

http://www.taskled.com/techmaxflex.html

Note, MaxFlex2 is a Boost regulator (step up), so input voltage must be less than the output voltage to ensure MaxFlex2 remains in regulation. If the input voltage exceeds the output voltage (at the dialed in drive current), MaxFlex2 will no longer regulate and the input voltage will go through the series inductor and schottky diode directly to the load. This will cause the output current to a LED to rise rapidly since LEDs have a very steep Current vs Voltage curve (Vf).

And yes, they do sound quite flexible - just not as flexible as a buck/boost regulator. It should be clearly stated.

 

[TorchBoy]

Re: Driver board list / regulator board list

http://www.taskled.com/techcchipo.html

Note, CCHIPO is a Boost regulator (step up), so input voltage must be less than the output voltage to ensure CCHIPO remains in regulation. If the input voltage exceeds the output voltage (at the dialed in drive current), CCHIPO will no longer regulate and the input voltage will go through the series inductor and schottky diode directly to the load. This will cause the output current to a LED to rise rapidly since LEDs have a very steep Current vs Voltage curve (Vf). CCHIPO is open circuit protected. If powered up without a load connected it will NOT be damaged. Output voltage will limit to 39V - be careful to NOT connect a LED load until the output discharges otherwise the 39V pulse before CCHIPO can regulate may damage the LEDs.

39V through an LED would be worse than the 12V I tried.

 

[Mr Happy]

Re: Driver board list / regulator board list

Sure.

http://www.taskled.com/techfatman.html

http://www.taskled.com/techmaxflex.html

And yes, they do sound quite flexible - just not as flexible as a buck/boost regulator. It should be clearly stated.

Ah, thank you, I stand corrected then. I missed that technical reference page first time around.

I agree with you, it should be stated more clearly on the main page.

 

[Stereodude]

Re: Driver board list / regulator board list

Where are you getting the information that Vin can't be higher than Vout? I have just (for example) looked at the MaxFlex page and I don't see that stated at all.

It's common knowledge. The fact that it's not on the page is precisely why I said it's misleading. It should be stated.

What I read is that it is a constant current driver with a range of selectable currents. It will accept an input voltage from 2.5 V to 20 V, and it will boost the output voltage to 24 V if necessary. The clear implication is that if you only connect one LED, it will set the output voltage to just what is required to achieve the required current and not higher.

It seems to me to be a very flexible device, and it is misleading to say "Vin can't be higher than Vout" unless you have a reference for that in the technical data sheet.

Uh... It's common knowledge to those of us with Electrical Engineering Degrees. A boost regulator has to be boosting to regulate. If Vin is higher than Vout there is no regulation. You will just get unregulated current flow from Vin to Vout.

Lets look at following schematic of the boost mode regulator.



When Vin goes above Vout (by more than the forward voltage drop of the diode) you will get current flow through the inductor, through the Schottky diode, through the feedback resistor, and straight into the LEDs. It doesn't matter if any of the pages of those boost regulators say it or not. That's just how they work. Vout has to be higher than Vin.

 

[Stereodude]

Re: Driver board list / regulator board list

By the same merit the buck regulators need a warning that Vout has to be less than Vin. :wave:

 

[Mr Happy]

Re: Driver board list / regulator board list

It's common knowledge to those of us with Electrical Engineering Degrees.

Which of course includes everyone reading CPF, and everyone reading the product pages on the TaskLED web site... :duh2:

Without TaskLED giving clear information on the description page, the device might possibly have had a more complex circuit with a bucking capability too.

But thanks for the circuit diagram, that does make the reasoning clear.

 

[Stereodude]

Re: Driver board list / regulator board list

Which of course includes everyone reading CPF, and everyone reading the product pages on the TaskLED web site... :duh2:

That's exactly why I said it should be put on the page because it's misleading without it.

Without TaskLED giving clear information on the description page, the device might possibly have had a more complex circuit with a bucking capability too.

Which is exactly why I said in my first post, "If these are really just Boost regulators..."

But thanks for the circuit diagram, that does make the reasoning clear.

No problem.

 

[TorchBoy]

Re: Driver board list / regulator board list

Nice diagram Stereodude - even I understand that.

By the same merit the buck regulators need a warning that Vout has to be less than Vin. :wave:

Funny you should mention that. I think I said that for at least the Kennan board. It strikes me that many of the people who may benefit from this list would appreciate clear details like that.

 

[TorchBoy]

Re: Driver board list / regulator board list

Added Badboy range.

 

[Stereodude]

Re: Driver board list / regulator board list

The Shark is also only a boost converter. You can get that from reading this thread.

 

[TorchBoy]

Re: Driver board list / regulator board list

Thanks Stereodude. I've updated the Shark blurb.

 

[Wok]

Re: Driver board list / regulator board list

Found this manufacturer awhile back but their distribution seems to be Germany only. One of their distributers has some neat low current stuff. Haven't tried them due to logistics
http://www.constant-current.com/html/products.html

 

[Flipside]

This is fantastic!

Thank you for taking the initative to put this together. :goodjob:

While it may not be practical, I would love to see pro's and con's for the devices as well. For example, I have read [posts] about the Shark getting hot and faulting out, the wires on the pucks being very easy to work with, some sandwiches can be rigged with a dimmer, or output selected by hardware (changing or adding / removing a resistor), etc.

Oooh, on second thought... That could get crazy complicated

 

[Stereodude]

Re: Driver board list / regulator board list

Here is the datasheet for the infamous 7135 regulator. You can see that it is a linear regulator, so once the battery drops below about .15V more than Vf, you lose the constant current output. And because it's a regulator, too much Vin, and you'll fry it because the power difference between Vin and Vf has to be dissipated in the 7135 chip.

 

[TorchBoy]

Re: Driver board list / regulator board list

Why do you say "infamous"? (In italics, no less!) As I've mentioned in post 1, once the voltage gets too high, you've very nearly got enough to run an extra LED in series - neatly gets rid of the extra voltage problem, as long as you can cope with having an extra LED. I had mentioned that it's a linear regulator, along with the voltage requirement. I've seen people knocking it simply because they apparently didn't remember/realise before installing it that it needed enough volts. I figure they should blame themselves, not the regulator. Anyway, with three suitably matched AA NiMH cells and LED Vf they're going to be more efficient than any buck regulator I've seen, and can easily be about the same even without that matching. When the cells are empty and it drops out of regulation, thanks to the LED operating voltage requirements it ends up throttling back to very low current, thereby helping protect the cells from overdischarge (assuming the user notices the light's not bright any more). It's a true constant current regulator(!), is also a fraction of the price of certain buck regulators and comes with multimode setups OEM. Like any of the boards in this list, it has its uses - for some it's great - and it has its limitations.

End of rant. I've added a link to the datasheet, thanks.

I had a look through the Sure Electronics datasheet. 78% efficiency for the example given is almost exactly what I'd expect if using a resistor in that situation instead. It does appear to be a constant current regulator, though.