S.E.D is disappearing

te:

te:

em.

ched.

should get you the help you need.

ach one, but you probably don't want to lose the efficiency. FETs can do th e job more efficiently but require more control. Another option is 2 windin gs one driving each LED. Another is to split the switcher. And sometimes it may be an option for the switcher to just limit i of the higher i led.

ing.

your job for you. And 2nd you call me an idiot AND demand I do your design . Get lost.

too much time wasted on this troll

Just another hacker. Ill-defined problem, then gets his knickers all in a twist when someone asks questions. Killfile. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 

             I'm looking for work... see my website. 

Thinking outside the box...producing elegant & economic solutions.

Yes, do go away. The discussion has always been way above your understanding.

It's only ill-defined to those who won't, or can't, read. ...and the senile, of course.

That's the general idea but the "dump" has to be constant current.

50-100V is probably too high (12-16 ought to be enough) and will cost.

Why would anyone want to help you? You have been coy and obnoxious most of the way through.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

There are some interesting, and economical, possibilities, but the OP doesn't invite open discussion.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

Coy? The problem is completely stated. I'm not looking for a total solution. I'll do that. It was an answer to someone whining about the group dying because of politics and little ED in SED. OK, there's a challenge but, as expected, people were more interested in throwing stones than electronics. I thought it was an interesting problem and had a few twists that are only seen when a layer or two of the onion is peeled. It's obvious that people just want to whine.

Rubbish.

Certainly true in the political threads! But not in this one IMO.

In any case I would be interested, and others too I'm sure.

--

John Devereux

I'm done wasting time with him. It's just trolling.

NT

If it happens again I'll just ask you for your killfile :)

NT

So, you are saying the input is unregulated and may be less than 7 volts and less than 250mA but never more than that? Your output seems to be a constant

1.2 watts and the LEDs must be driven with PWM? Why does the duty cycle have to be 2 percent? I would imagine a 20 percent duty cycle would require less critical parts? I doubt you can hold an accurate 2 percent duty cycle with ordinary LRC parts? What sort of power supply does this thing use? .

Mine is Agent-specific, but you can probably adapt/edit it to another reader. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 

             I'm looking for work... see my website. 

Thinking outside the box...producing elegant & economic solutions.

Poor baby.

Because you can't answer and have been called on it? Again, knock yourself out.

I'm definitely bearing it in mind. I know I give some people too much time.

NT

No, I'm saying that it won't be any less than 7V but can never be more than 250mA.

That's the only way it works, I think. Efficiency is an issue.

This is an illuminator for a global shutter camera sensor. The integration time works out to about 2% of the frame. I think the numbers I gave for an example was 200us out of 10ms (it's really ~350us out of 1/60Hz but it makes the arithmetic messy).

The power may be delivered over something like an Ethernet interface, with long, thin, wires. What's left after all the wiring may be as low as 7V. The budget for this part of the circuit is 250mA.

On Thu, 14 Sep 2017 17:33:25 -0700, tabbypurr wrote: [...]

I can thoroughly recommend Jim's killfile list. I probably see less than half the posts & posters that 'contribute' here now. I see only a small residual amount of garbage these days and it takes far, far less time to read the group as a result. You won't regret it!

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