Desperatly looking for driver (updated kennan driver?)

jtr1962

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Re: Desperately looking for driver (updated Kennan driver?)

Would a zener diode do that job? :thinking:
It would in theory but it would have to be capable of absorbing the full LED current times the zener voltage. In other words, in theory yes, in practice no. A better solution is to feed back the output voltage via a resistor divider, and limit the duty cycle when it gets too high. Many step-up drivers have inputs for doing this.
 

zega

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How bout this one?
http://cgi.ebay.com/3W-LED-Driver-f...36323QQcmdZViewItemQQ_trksidZp1713.m153.l1262
In the menatime i have designed some discrete SMPS drivers (1 BJT and 1 MOSFET 1coil few res and caps) 90% eff in LTC cad in efficiency report (eff report is done wit a help of some tricks, cannot be done with discrete design), pricing of the parts is well under 1 $...
Ok i scrap coils from wasted PC PSU-s but it works great on small scale...
I have done 4,5W 54 10mm LED submersible LED drop in that work on 60V (boost) to drive 4x14LED in series in pulse mode and i am very satisfied with results!
I plan to work on that drivers a little more because they perform great for the price and lately i have fetish on simple as possible designs (no PWM controller or PIC used)...
z
 

romroro

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Hello all, I have a question about Kennan drivers.
I received it from KD, it works fine ( approximately 1A Vin=7.4V Vout=3.5V)
But I would like put two in a parallel design for an hight current design.
But importunately it doesn't works ( it works but at 800 mA :( in place of 2000mA expected).

Is someone have design idea for do that works fine ?
Tks
Rom
PS: please excuse my bad English.
 

TorchBoy

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Hello all, I have a question about Kennan drivers.
I received it from KD, it works fine ( approximately 1A Vin=7.4V Vout=3.5V)
But I would like put two in a parallel design for an hight current design.
But importunately it doesn't works ( it works but at 800 mA :( in place of 2000mA expected).
I don't know about using the Kennan in parallel, but I see that the datasheet for the PT4105 regulator chip (used in the Kennan) indicates that 1A current output should only be used with at least 9V in, and it doesn't recommend anything over 750mA output at any input voltage. Perhaps the Kennan isn't the best driver for the job?
 

romroro

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Maybe you right, i'll look at effect with a bigger tension source ( 12 or 14 V ) and look at the result.

If someone one have an idea, i still looking for solutions.
 

zzonbi

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I've got exactly the same driver as MikePL, after a similar delay too, but mine doesn't work nowhere near 1A, as I'd like, but around 700mA, creeping under 600mA as things heat up. I also noticed an annoying hiss, probably the inductor. Any suggestions for sollutions?

Be careful when connecting this board to a PSU over 12V as ringing may damage the IC. They skipped the RC snubber originally recommended. It's true this isn't required with batteries, though. But the long wiring in a car may be an issue.

OT: Is expecting an other free replacement realistic and do you guys get those packets at your door, or do you have to collect them from the post office?
 
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mike2g

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I recently got a few of the updated Kennan boards and am having trouble connecting to it. I followed the second diagram from MikePL's directions for (+) and (-) (which agrees with Jerry from KD). However my flashlight won't light up and I can't get any reading when disconnected on my multimeter. Poking around with the multimeter I found power as shown below. It seems that the negative contact is the same but the positive moved. From playing with the multimeter it seems as though the old positive is also negative (after positioning the positive probe as shown I moved the negative probe to the ? and got the same reading as when on the negative contact) :shrug:

I know nothing about what the pieces on the board are doing but I know where the multimeter says that there's power. Is my board configured properly? Will the board operate as designed as I've made the the connection and if not what should I do?

just a little background, maybe relevant:

This board is connected to 6AA eneloops in a 2D maglite. I have a quad SSC (2 parallel, 2 series) setup. The emitters are H-bin so I was expecting each emitter to receive around 350-375ma at approximately 3-3.25V. (6-6.5V in series). My multimeter shows that the batteries are supply approximately 7.8V right now on the board contacts so I'm assuming that there is sufficient voltage for the board (at least 1.3V over what I need). As I've shown it the flashlight lights up but I am disappointed in the output. The brightness is comparable to a single SSC being driven by 4AA at 800ma this driver, which should be around 200 emitter lumens. I had expected the quad scc setup to be putting out approximately twice that, 400 lumens (350ma per emitter = ~100lumens X 4 emitters = ~400 lumens).

Resize-1.jpg
 

R290

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Re: Desperately looking for driver (updated Kennan driver?)

So the extra IC would be for PWM dimming?

Why do some of these photos have a 22µH inductor and some a 47µH one? (I think those units are right.) I noticed that for the first version too. What difference does more than doubling the value of the inductor make?


I found this thread, as I too order these drivers for auto app.

The difference in the inductor has to do with the efficiency of the driver.
If you go to webbench you can select different efficiency ratings and see the values change. Another reason is size, and cost, less copper is cheaper.

1695d1210005055-led-tech-4x4s-4105-driver.jpg


From there web site
633408028544335328.jpg
 
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uk_caver

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...This board is connected to 6AA eneloops in a 2D maglite. I have a quad SSC (2 parallel, 2 series) setup. The emitters are H-bin so I was expecting each emitter to receive around 350-375ma at approximately 3-3.25V. (6-6.5V in series). My multimeter shows that the batteries are supply approximately 7.8V right now on the board contacts so I'm assuming that there is sufficient voltage for the board (at least 1.3V over what I need). As I've shown it the flashlight lights up but I am disappointed in the output...
I'm not sure if there's quite enough headroom if the input voltage is 7.8V. At the very least, it'd be fairly borderline
I'd suggest trying to temporarily connect an extra cell or two into your setup and see if you get a brighter output.
 

TorchBoy

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I'm not sure if there's quite enough headroom if the input voltage is 7.8V. At the very least, it'd be fairly borderline
KD's information said it needed 1V headroom for each LED being run, so the supply would need greater than 8.5V.
 

zzonbi

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"Is my board configured properly?"

Your board is either a new design, either in error, as it has a condensor instead of a resistor (R5). I would resolder the led wires on the round pads, short circuit R6 and then try again.

What are these H bins SSCs?
 

TorchBoy

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FYI "condensers" are normally called capacitors in English.
Capacitors are occasionally referred to as condensers. This is considered an antiquated term in English, but most other languages use an equivalent, like "Kondensator" in German, "condensador" in Spanish, or "Kondensa" in Japanese.
 

spun

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in answer to mike2g i also have one of these new kennan's with what appears to be another of the capacitors in place of the old R5. well it works fine for me running two rebels in series. i read positive at both where you show positive in your pic as well as at the normal round positive pad that my led's are attached to. however i'm getting a 12v reading of my source at the pin you show and the proper 6+v for the rebels at the normal pad. make sure your soldering doesn't bridge the round positive pad to the smd part to the left of it. i've also had a couple of these drivers arrive doa.
 

TorchBoy

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zzonbi - when synonyms are reasonably well known they aren't normally a problem, but the use of antiquated terms (in English, at least) may be a problem, for example because meanings change. I'm sure some people still like to use it, and it seems there are several non-English languages that still use a variant, but most people just won't understand what you're talking about, even if they know what a capacitor is. And I'd like to think that I did more than try to be informative - we now all know what you were talking about. QED.
 

Brownstone

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Not only is "condenser" no longer used in English to designate a capacitor, electrical engineers have reused the word "condenser" to designate a device used to manage reactive load in power systems.

"Condenser" still exists as a fossilized word in "condenser microphone", but that no more means "condenser" is a current word for "capacitor" than the phrase "spick and span" means "spick" is a current word for "nails".

P.S. - I did understand you though. Just don't start talking about Leyden jars, animal electric fluid, and the aether.
 
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moonfish

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On motors, they are called condensers, as far as I know. But as far as the weird acronyms you guys use here that don't make sense, this seems trivial and a bit preachy.
 

TorchBoy

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Re: Desperately looking for driver (updated kennan driver?)

But as far as the weird acronyms you guys use here that don't make sense, ...
I've seen this angle before and I don't see the issue - I'm under the impression that forums and abbreviations go together, as it's a handy way to not have to type as much. You would do well to learn a few. (Whenever I see one I can't guess from context I look it up.)
... this seems trivial and a bit preachy.
And it's now off topic as well. :D If we all typed in our native language, understanding would drop considerably as there are a lot of people on CPF from non-English speaking countries. Your call on how important you think it is that we all understand what we mean by certain words. It doesn't need to be made into a big issue.
 

zzonbi

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"because meanings change... people just won't understand"
QED
I like the last part. It hasn't changed much last thousands of years.
 

TorchBoy

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Re: Desperately looking for driver (updated Kennan driver?)

"because meanings change... people just won't understand"
That quoting is a tad disingenuous. I said "people just won't understand" because they don't have a clue what a condenser was, which was a separate point from the meaning of words changing. But as I've said, people now know what a condenser was. Shall we get over it and move on? :kiss:
 

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