Inductor current can't be suddenly cutoff if no freewheel diode is attached

I expect to sell several thousand of them.

How much crap you sell is immaterial.

You're supposed to "educate" us. Bwahahahahahahahaha! ...Jim Thompson

Got a message ID? I'm not finding a schematic. ...Jim Thompson

Found it. You fixed it by adding current trip rather than the oscillator-only in your first post. (As I posted in several versions right after your original post.) ...Jim Thompson

I've posted many switcher circuits over the years, and some were open-loop oscillators. But in this case, I did post a Spice model of the full circuit, adaptive peak current limiting, boost-doubler, and capacitor pre-charge.

I put this up on July 13

I made only a couple of minor tweaks for the real thing.

"Pretty Dumb Boost" from late June

worked fine, but the customer load current, during charge, wasn't as constant as I'd like it, so I went to a single-winding boost/doubler added the adaptive peak current thing.

So, where are the "problems." ?

That's the one I remember that lacked a current trip.

My unease was with that original version, with no current control.

If you're happy, I'm happy ;-) ...Jim Thompson

No, I believe his mandate actually is "to sell stuff and make money". Educating us is a sideline, and I would be surprised if your priorities were any different.

I don't expect anybody here to buy anything, and I give a lot away, for free. Besides, selling stuff and making money are just side effects of designing cool electronics.

Very few people here post schematics of actual stuff that they have designed recently. I suppose most people aren't allowed.

Must be a small set of people here who

- design interesting stuff

- are not afraid of ridicule, potentially making their mistakes public

- have the inclination and authority to publish their designs in the first place (in the case of professionals)

I like the D4 LED driver.

igned

And those that are might be more inclined to post the schematic in a higher prestige forum.

Sloman A.W., Buggs P., Molloy J., and Stewart D. ?A microcontroller-based driver to stabilise the temperature of an optical stage to 1mK in the rang e 4C to 38C, using a Peltier heat pump and a thermistor sensor? Measureme nt Science and Technology, 7 1653-64 (1996).

Sloman, A.W. and Swords, M.D. "A fast and economical gated discriminator", Journal of Physics E: Scientific Instruments, 11, 521-524 (1978).

Ghiggino, K.P., Phillips, D., and Sloman, A.W. "Nanosecond pulse stretcher" ,Journal of Physics E: Scientific Instruments, 12, 686-687 (1979).

It takes work to describe the schematic and set it in context. John Larkin posts pencil sketches, which takes less effort.

As I've mentioned here before, I've now got what I find to be an interestin g schematic of a low-distortion sine-wave oscillator, which I still haven't got around to testing as a working circuit, despite having spent quite a b it on buying all the parts for it.

If I posted it here, the sort of journal that might publish it could object that it had already been posted here and knock it back. The Review Scienti fic Instruments wasn't too fussed a year or so ago when I'd posted the cont ent of a comment of one their papers here before I submitted it for peer-re viewed publication.

Sloman A. W. ?Comment on ?A versatile thermoelectric temperature contro ller with 10 mK reproducibility and 100 mK absolute accuracy? [Rev. Sci. Instrum. 80, 126107 (2009)] ?, Review of Scientific Instruments 82, 27101 - 027101-2 (2011).

but that wasn't about self-advertisement - aka helping to move the field fo rward - as it was about giggling at a drop-off.

Judging from what I hear from colleagues both academic and industrial, it's not at all clear that RSI and JoP E are "higher prestige." In academic circles, instruments papers are very much the poor relative, whereas here you can see the "peer review" process in action. (Open-source software has raised the bar on peer review for everybody. IME professional journals are far behind.)

Certainly I get a lot more consulting inquiries that cite SED than cite about 80% of my publications. Anyway, if it's a question of doing good work and making a contribution, who cares about _prestige_? Does anybody really get up in the morning and go off to the lab for _prestige_? Life is a lot better when one isn't looking at oneself all the time. You get a lot more done, and have a much better time.

In the immortal words of your far-famed fellow-traveller Andrei Gromyko, "My personal life doesn't interest me." ;)

Cheers

Phil Hobbs

Most people won't even post a pic or a link to a product that they designed, even when those things are public, on web sites.

I'm a fan of brainstorming, part of which consists of presenting, to a professional audience, half-baked, defective, and downright goofy ideas. In the right environment, some of those ideas, even ones that are plainly wrong, can shake things up and evolve into new, useful stuff. We've developed a lot of cool circuits and products through that process. Most people can't play the game, because they can't stand to be seen as "wrong" or because they are locked into accepted practices sanctioned by authority. Or because they have no ideas, or are insecure.

Some people in this ng are outraged by posts that are not fully worked out circuits, with parts values, that are ready for them to simulate or use. Too bad.

My chip design customers are almost always on the leading edge of their particular technology.

As such, publishing the design I did for them would divulge their proprietary information to competitors; and, of course, I am bound by NDA's to keep that information confidential.

But here is an eleven year old design that can now be freely published... typical of my designs in an advanced BiCMOS technology...

As you can see, I don't deal in the simple stuff >:-} ...Jim Thompson

Making things that actually work is more fun.

I published a couple of papers in the late '60's and early '70's...

(1) Never made me any particularly notable amount of money.

(2) The glazed look of the audience, who were completely lost, was annoying... why bother trying to educate the plebes >:-} ...Jim Thompson

The peer review process consists of asking for an opinion from people who a re known to know what they are talking about, and interested enough to be w illing to go to the trouble of writing such an opinion.

What we get here are opinions from everybody who is motivated to comment. S ome of them know what they are talking about. It's not quite the same.

For a long time the Review of Scientific Instruments didn't have a pool of referees who knew anything about electronics, and they published some total nonsense.

Sloman A. W. ?Comment on ?A versatile thermoelectric temperature contro ller with 10 mK reproducibility and 100 mK absolute accuracy? [Rev. Sci. Instrum. 80, 126107 (2009)] ?, Review of Scientific Instruments 82, 27101 - 027101-2 (2011).

is a fair example. I don't know JoP E - unless it is what used to be the Br itish "Journal of Scientific Instruments" which metamorphosed through Journ al of Physics E: Scientific Instruments" to "Measurement Science and Techno logy" which is where I've published most of my stuff. They do have access t o referees who know electronics - I've refereed for them from time to time, but not that often.

Good to hear. I had that in mind when I started posting here in 1996, but d idn't get anything like enough business out of it to justify giving up the day job.

More people read "high prestige" journals, and cite the articles they find. That's what defines a high prestige journal.

Too true. But once you've done the work, you owe it to the field to write i t up and publish it, and reputation, as well as academic appointments and p romotion do tend to be influenced by the number of papers that you've publi shed, and how often they get cited.

My wife has fairly impressive list of publications, and she worries if her graduate students and post-docs aren't getting enough publications into the right journals.

Gromyko was famous for his "complete identification with the interest of th e state and his faithful service to it". His is probably an extreme positio n. And do note that I'm a socialist, not a communist - if you were as well edu cated about politics as you are about physics, you'd be aware that socialis ts believe in democracy, and communists favour oligarchy. Since the US is c urrently more like an oligarchy of the wealthy than a democracy, this disti nction may escape you, but it shouldn't.

People who have less important jobs than Gromyko had probably need to worry more about their personal life, at least to the extent that that they both er to get out of bed in the morning and eat enough to maintain their weight at a body mass index of over 20.

Much more fun.

That's not the point. Good papers are supposed to attract the attention of people who may hire you to carry out more fun work. The money follows the work, not the papers.

You need to work out how to dumb down the story to a level that the audience can follow. In industry this is called telling management the story in a form that they can makes sense of.

It's definitely a skill that any good engineer needs to cultivate. Some audiences can't follow calculus, which can be a nuisance.

"Brainstorming" is weird but can be useful. As John says, not everybody can do it, and some of the people that can't or won't have to be excluded from brainstorming sessions.

It's easier to make sense of a circuit diagram with parts values than it is to make sense of a purely topological diagram. Sometimes I know enough about what you are doing that I can make sense of your scribbles, but there are exceptions. And you have been known to post LTSpice simulations that only run long enough that they look as if they are working, when a longer run shows up odder behaviour.

Some of that outrage is well-founded.

RSI is notorious for horrendous circuit designs. The FoD, Figure of Demerit, for a circuit is the number of unnecessary differential pairs multiplied by the number of trimpots.

And don't you have to pay *them* to get published in RSI? Fame for sale!

Right. Building cool stuff that works for people, solving difficult real-life problems, is a lot better than being published in some peer-reviewed journal.

Good one.