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

Started by Patrick Chung September 2, 2013
On Sunday, 8 September 2013 02:53:43 UTC+10, John Larkin  wrote:
> On Sat, 07 Sep 2013 09:40:26 +0100, John Devereux <john@devereux.me.uk> wrote: > >John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> writes:
<snip>
> 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.
"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.
> 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.
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. -- Bill Sloman, Sydney
On Sat, 07 Sep 2013 12:39:18 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>On 9/7/2013 4:58 AM, Bill Sloman wrote: >> On Saturday, 7 September 2013 18:40:26 UTC+10, John Devereux wrote: >>> John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> writes: >> >> <snip> >> >>>> Very few people here post schematics of actual stuff that they >>>> have designed recently. I suppose most people aren't allowed. >> >> And those that are might be more inclined to post the schematic in a >> higher prestige forum. >> ><snip> > >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.)
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!
> >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. >
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.
>In the immortal words of your far-famed fellow-traveller Andrei Gromyko, >"My personal life doesn't interest me." ;)
Good one. -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
On Sat, 07 Sep 2013 09:53:43 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:


>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.
--- That profile seems to fit you well, in that when you've been found to be incontrovertibly wrong, here, you generally respond by trying to kill the messenger instead of simply admitting to the error. You also subscribe to "NIH" in that if someone comes up with a clever idea which trumps your clever idea you absolutely refuse to recognize the achievement, usually employing smoke and mirrors in an effort to discredit it. ---
>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.
--- Typical Larkinese attitude: "I'll post what I like, and if it doesn't help you, who cares? At least I got another post with my name on it out there, which is what's important." -- JF
On Sat, 07 Sep 2013 15:19:43 -0700, John Larkin
<jlarkin@highlandtechnology.com> wrote:


>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!
--- Since you pay your ISP and your usenet provider for allowing you to tell everyone that you're a legend in your own mind, how is that not different from what you ridicule? -- JF
On Sat, 07 Sep 2013 09:40:26 +0100, the renowned John Devereux
<john@devereux.me.uk> wrote:

>John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> writes: > >[...] > >>>>>>> What problems? >>>>>>> >>>>>>> This is essentially the same as the "bubbler" circuit I posted >>>>>>> previously. Here's the (censored) schematic of the real thing: >>>>>>> >>>>>>> https://dl.dropboxusercontent.com/u/53724080/Circuits/Power/Boost-Doubler.pdf >>>>>>> >>>>>>> It's tiny and it works great. It's simple, efficient, and very >>>>>>> tunable. The current pulled from the customer's supply, during >>>>>>> chargeup or recharge, is nearly flat and is easily settable. > >[...] > >> >> 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.
Somebody asked me the other day about current regulator diodes and why they were not used more frequently for LEDs (to make them work over a wide range of voltages). I explained they were basically JFETs with the gate tied to one end, and added that depletion mode MOSFETs could be used too, to much higher voltages, but I'd never seen one so used. Finish up, go to SED, and there it is. Showed him, and LOL'd. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
On Sat, 07 Sep 2013 17:56:23 -0500, the renowned John Fields
<jfields@austininstruments.com> wrote:

>On Sat, 07 Sep 2013 15:19:43 -0700, John Larkin ><jlarkin@highlandtechnology.com> wrote: > > >>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! > >--- >Since you pay your ISP and your usenet provider for allowing you to >tell everyone that you're a legend in your own mind, how is that not >different from what you ridicule?
FYI: http://rsi.aip.org/authors/publication_charges Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
On Sat, 07 Sep 2013 17:43:05 -0500, John Fields
<jfields@austininstruments.com> wrote:

>On Sat, 07 Sep 2013 09:53:43 -0700, John Larkin ><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: > > >>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. > >--- >That profile seems to fit you well, in that when you've been found to >be incontrovertibly wrong, here, you generally respond by trying to >kill the messenger instead of simply admitting to the error. > >You also subscribe to "NIH" in that if someone comes up with a clever >idea which trumps your clever idea you absolutely refuse to recognize >the achievement, usually employing smoke and mirrors in an effort to >discredit it. >--- > >>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. > >--- >Typical Larkinese attitude: "I'll post what I like, and if it doesn't >help you, who cares? > >At least I got another post with my name on it out there, which is >what's important."
Larkin is an unfortunate mixture of mental derangement and extraordinary rudeness. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
On Sat, 07 Sep 2013 19:23:45 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

>http://rsi.aip.org/authors/publication_charges
--- Interesting. Thanks. -- JF
On Sat, 07 Sep 2013 19:23:45 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

>On Sat, 07 Sep 2013 17:56:23 -0500, the renowned John Fields ><jfields@austininstruments.com> wrote: > >>On Sat, 07 Sep 2013 15:19:43 -0700, John Larkin >><jlarkin@highlandtechnology.com> wrote: >> >> >>>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! >> >>--- >>Since you pay your ISP and your usenet provider for allowing you to >>tell everyone that you're a legend in your own mind, how is that not >>different from what you ridicule? > >FYI: > >http://rsi.aip.org/authors/publication_charges > > > >Best regards, >Spehro Pefhany
There used to be page charges for these journals. Looks like they don't sell RSI in print any more, so they have that new pricing model. They charge either the subscribers and the occasional reader, or the author. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
On Monday, 9 September 2013 01:31:12 UTC+10, John Larkin  wrote:
> On Sat, 07 Sep 2013 19:23:45 -0400, Spehro Pefhany > <speffSNIP@interlogDOTyou.knowwhat> wrote:=20 > >On Sat, 07 Sep 2013 17:56:23 -0500, the renowned John Fields > ><jfields@austininstruments.com> wrote: =20 > >>On Sat, 07 Sep 2013 15:19:43 -0700, John Larkin > >><jlarkin@highlandtechnology.com> wrote:=20 > >>=20 > >>>RSI is notorious for horrendous circuit designs.
They do show up from time to time, but the peer review process misses other= errors as well. I've had comments published criticising circuit design, bu= t I've also published criticisms of authors' grasp of the literature, which= is a more serious fault in a scholarly journal. <snipped Larkin being sillier than usual>
> >>>And don't you have to pay *them* to get published in RSI? Fame for=20 > >>>sale!=20
In fact you don't have to, and never did. Paying the page charges got you r= eprints.
> >>Since you pay your ISP and your usenet provider for allowing you to=20 > >>tell everyone that you're a legend in your own mind, how is that not > >>different from what you ridicule? > > > >FYI:=20 > >=20 > >http://rsi.aip.org/authors/publication_charges=20 > =20 > There used to be page charges for these journals. Looks like they don't s=
ell > RSI in print any more, so they have that new pricing model. They char= ge=20
> either the subscribers and the occasional reader, or the author.
The pages charges were never obligatory. I never paid a cent to get any of = my comments published, and the first one was back in 1972. --=20 Bill Sloman, Sydney