Need the topology for a current to current SMPS, not voltage to voltage SMPS

Grin.. sure... the ascii is a current boost and the first dropbox scribble is a current buck. I'm not sure what you mean about the ascii drawing... It's being fed from a current source.. so how can it be a 'standard buck'. (The output is also a (DC) current.. so I can't really put a capacitor there.)

You should also note that the ascii has a current source feeding right into a capacitor! (But that really does seem analogous to the voltage boost where the voltage source feeds an inductor... both will 'rail out' if not part of the switching scheme.)

I'm having a lot of fun in my smps course. Maybe I'll have to build one someday and 'really' learn something :^) I've often thought there might be a niche vacation market for geeks. Instead of going to the the ocean or mountains, you go to 'school' and intensely learn a new subject. When I was at the FEL in Vanderbilt I went to "accelerator school"

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(I think that might be it.) It was great! Each night we'd sit around with a few beers and do the homework together.

George H.

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George Herold
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Sounds like a great learning experience.

One can't help compare the 'basic'ness of Maxwell's Equations to Newton's Laws of Physics in the sense that they work, and work well, but just as for Newton, there might be one more thing out there? Didn't real progress occur when observations that refuted Newton's Laws appear? Anybody know of any observations that refute Maxwell's Equations? Or, are those observations being swept under the carpet as erroneous or anomalies?

Reply to
RobertMacy

Good book, "The Maxwellians" by Hunt. Maxwell's original formulations were abtruse and wrong, and a motley bunch of rich and poor guys fixed it up and put the equations into their familiar forms.

Maxwell of course didn't anticipate quantum effects.

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John Larkin                  Highland Technology Inc 
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John Larkin

I just change into a new golf shirt. The good news about being a solo consultant is that it's up to you. The bad news is also that it's up to you. ;)

Cheers

Phil Hobbs

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Dr Philip C D Hobbs 
Principal Consultant 
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Phil Hobbs

[...]

Not always. For example, on Friday I had to wear a more formal attire including a tie. The CEO that picked me up from the airport down south also did. Well, I could have just not worn a tie but in that situation is was customary and probably expected.

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Regards, Joerg 

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Joerg

Noting the dangers of enemies and terrorists: I think the first 'important' people to stop wearing suits and ties were the leaders in Israel. It's carried over a bit now to "low profile, no suit" else get kidnapped etc. Plus, the allure of being SO rich that you can dress anyway you please. So those of us with little money can now emulate wealth, by dressing badly. Haberdashers everywhere have taken a hit.

Reply to
RobertMacy

Sure, when you're at their site. I wear a jacket when I'm doing video Skype interviews with clients, too--especially lawyers. (It's convenient that my drawing table is just across the room from a wall full of books.)

Cheers

Phil Hobbs

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Phil Hobbs

Takes that long to get a couple of generations of product out the door.

Cost is everything but it's still no excuse for designing junk. In that regard, it's not a lot different than what you've described that you do.

Things change. A lot!

In my last job I was the only one who wore long pants from April to October. Everyone else in Engineering wore T-shirts year 'round. I can't do that. I wear long-sleeved shirts (Oxfords, preferred) even for mowing the lawn.

Reply to
krw

A table? A wall of books? I didn't know you were into 'antiques'. :)

Reply to
RobertMacy

Since I turned 50 I'm entitled to wear a vintage plate myself. ;)

And I love books. I have thousands of them, and have chucked out or given away more thousands. I buy probably half a dozen a month, mostly fine or VG condition used hardbacks. This month I got a book on electromagnetic shock lines and one on hypersonic flow visualization. Fun stuff.

You can see the aforementioned table and bookshelf in my virtual lab tour,

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.

It looks pretty much like that, except that I have a bunch more furniture (two big lab benches and a table in the whiteboard/reception area, plus some more in the admin/layout space). I also have way more equipment. I've been meaning to replace the pictures, but the lab hasn't been that clean since 2011. ;)

Cheers

Phil Hobbs

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Phil Hobbs

Me too! I paint in a long sleeved Oxford shirt! even in AZ

My wife is still laughing about the time, on one of our sojourns including Santa Cruz Boardwalk; I went to get us hotdogs from the boardwalk vendors in a three piece suit, ...and was carrying my briefcase.

In 70's while at Stanford's Chapel for Christmas obaservance, one of my colleagues wearing a rather worn sweatsuit [it WAS post hippy era] leaned over and in attempting to ridicule my dress suit asked, "Why do you want to dress like everyone else?" My reply, "Look around. I'm the ONLY suit here. Look at you. Why do YOU want to dress like everyone else." And, yes. EVERYBODY else was in totally casual attire.

Reply to
RobertMacy

Nobody seems to have told the executives that are ultimately responsible for automotive electronics. Nearly all quality issues have their root cause in upper management.

Except I do not cut corners. Ever. If a client wants me to do that I politely decline the whole assignment. It does happen but very rarely, and those companies then do not even become clients of mine.

That's what Maxim kept telling people :-)

I am just the opposite. I wear shorts and T-shirts as long as I can. Only in really cold weather it's lumberjack shirts and jeans. For a winter coat or jacket it almost would have to drop to below 0F.

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

I have a voltmeter.

Reply to
RobertMacy

I raise you one: I have a megacycle meter 8-)

This one:

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Regards, Joerg 

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Reply to
Joerg

So, you cannot provide a short circuit for the current source? You are in deep trouble.

Reply to
John S

I CAN short circuit the current source, but I CANNOT afford to shunt off POWER. As in, 'unused' power removed to somewhere else.

Reply to
RobertMacy

I don't really care about the source. It's max voltage is specified at

100V, no? It' max (and constant) current is specified at .05A, no?

There is therefore a maximum power output capability of 5W. No?

It does not matter what topology you use, you cannot get more out than you put in. Where am I wrong here?

Who cares? You cannot amplify power (in this particular scenario). If the output is 5V, what is the current? I think maybe 1A. That's current amplification if you put 100V into a buck switcher at 50mA and regulate the output to 5V.

This is not what I am suggesting, so see my other post.

(snipped fun times)

Reply to
John S

The current source won't be 100% efficient. What Robert probably wants to avoid is having to shunt some of the current to ground. This will cause loss because another part of that current is used to make a different secondary current. That means there is going to be voltage drop. If you shunt past that -> wasted energy.

The ideal situation would be, for example, a flyback that regulates to an output current that has the desired ratio to the input current and at that point sets its input impedance in such a way that it uses up all the current coming in, wasting none. Sounds feasible.

Of course, with AC Robert would need a rectifier and, if AC is to be delivered at the output, a FET bridge.

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

That's too bad you won't be able to use it, since it measures megacycles and megacycles no longer exist. Unless you can find some equipment that produces megacycles, like...perhaps I can help, I have an original pair of WWII walkietalkies!

You have NO idea how long it took me to stop saying megacycles/kilocycles and start saying megaHertz/kiloHertz.

Reply to
RobertMacy

Ah, yes! Into every forest of test equipment, a little acorn (tube) must fall!

This really is an excellent piece of "kit". A few years ago I did a comparison of my Model 59, a Heathkit dipper, and the dipper coil accessory set for an MFJ 269 impedance meter.

The test fixture was a piece of Airdux coil, with an air variable capacitor soldered across the ends. Should have a nice high Q.

The MFJ-and-probe combination was... well, saying "pathetic" and "an absolute waste of money and effort" is about right. In order to get any readable dip in the meter I had to shove the probe to within a small fraction of an inch of the Airdux coil. Talk about a measurement, affecting the thing to be measured :-(

The Heathkit solid-state dipper did better. I could get a good reading by just barely bringing the coil to the center end of the Airdux... wouldn't have been much capacitive coupling to worry about.

The Measurements 59 - wow. Nice sharp high-Q narrow dip with the coil about 2" away from the center of the Airdux.

The best combination would probably be the 59 as a dipper, and the MJF in frequency-counter mode to give a more precise reading on the dip frequency, just as the article you pointed to suggests.

Reply to
David Platt

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