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

Started by RobertMacy October 16, 2013
On Monday, October 21, 2013 11:14:10 AM UTC-4, John S wrote:
> On 10/21/2013 9:53 AM, George Herold wrote: > > > On Monday, October 21, 2013 8:57:43 AM UTC-4, John S wrote: > > >> On 10/20/2013 7:53 PM, George Herold wrote: > > >> > > >>> On Sunday, October 20, 2013 9:05:15 AM UTC-4, John S wrote: > > >> > > >>>> On 10/19/2013 4:50 PM, Jasen Betts wrote: > > >> > > > <snip> > > > > > >>> I was going to say it looked a bit like what I drew for a current boost. But I had the diode and inductor switched around. > > >> > > >>> > > >> > > >>> +----+--FET--+-LLL--+ > > >>> | | | | > > >>> ^ C _ R > > >>> I C ^ R > > >>> | | | | > > >>> +----+-------+------+ > > >> > > >>> > > >> > > >>> Something like that, > > >> > > >>> > > >> > > >>> George H. > > >> > > >> > > >> > > >> Thanks, George. It believe this is a standard buck switcher without the > > >> > > >> output filter capacitor. > > > > > > Hi John, Here's the current to current buck that I drew... from upstream > > > https://www.dropbox.com/s/h2a8dyz0vzoovev/DSCF0031.JPG > > > I guess I could try simulating these, if I ever get 'free' time. > > > > > > George H. > > > > Yes, thank you, George. I saw it. But your image and your ASCII drawing > > above do not agree. Your ASCII drawing is a standard buck without an > > output filter capacitor. I agree with your ASCII (with, possibly, the > > requirement for an output filter capacitor) for a scheme which could work.
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" http://uspas.fnal.gov/programs/1998/Stanford/courses/magneticsystems.shtml (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.
On Mon, 21 Oct 2013 08:57:07 -0700, George Herold <gherold@teachspin.com>  
wrote:

>> ...gotta snip, else AIOE won't post... > 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" > http://uspas.fnal.gov/programs/1998/Stanford/courses/magneticsystems.shtml > (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.
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?
On Mon, 21 Oct 2013 09:22:37 -0700, RobertMacy <robert.a.macy@gmail.com> wrote:

>On Mon, 21 Oct 2013 08:57:07 -0700, George Herold <gherold@teachspin.com> >wrote: > >>> ...gotta snip, else AIOE won't post... >> 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" >> http://uspas.fnal.gov/programs/1998/Stanford/courses/magneticsystems.shtml >> (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. > >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?
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. -- 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 10/21/2013 09:52 AM, Joerg wrote:
> krw@attt.bizz wrote: >> On Sun, 20 Oct 2013 12:51:26 -0700, Joerg <invalid@invalid.invalid> >> wrote: >> >>> krw@attt.bizz wrote: >>>> On Sun, 20 Oct 2013 09:33:54 -0700, Joerg <invalid@invalid.invalid> >>>> wrote: >>>> >>>>> krw@attt.bizz wrote: >>>>>> On Sun, 20 Oct 2013 07:21:15 -0700, Joerg <invalid@invalid.invalid> >>>>>> wrote: >>>>>> >>>>>>> krw@attt.bizz wrote: >>>>>>>> On Sat, 19 Oct 2013 16:36:45 -0700, Joerg <invalid@invalid.invalid> >>>>>>>> wrote: >>>>>>>> > > > [...] > >>> Oops, I probably mixed you up with someone else. I thought it was stage >>> electronics for rock bands and stuff. >> >> That was the last job. ;-) I've done a few career changes in the >> last 10 years. Before that, one employer, oneish (perhaps two) >> markets, but very different jobs every five to eight years. >> > > 5-8 years would be a bit much for me. > > >>>>> I work for numerous clients who are all in very different >>>>> markets. This keeps our jobs interesting. But after talking to >>>>> automotive designers I'd be bored stiff if I had to do their job for >>>>> more than a year. >>>> Perhaps but I think you have a pretty small view of that world. >>> >>> Nope. Medical devices for hospitals, low cost medical devices for >>> consumers (over-the-counter), aircraft electronics, spacecraft stuff, >>> chemical pump controllers, power generation, oil/gas exploration >>> electronics, NDT, commercial automotive (trucks), and so on. >> >> You have a very small view of the automotive market. That is for >> sure. >> > > I see it from two view points. One is the actual product and that often > doesn't look very good, both from a quality point of view and sometimes > also from an engineering point of view (flickering LED backlights > anyone?). Then from a people perspective and here talking to folks who > actually work in that field helps. Pretty much all of them reported > extreme pressure to keep NRE and R&D schedules down, which explains a > lot of the quality issues. To the point I wouldn't want to work there. > As a consultant maybe but niot if they'd demansd unrealistic timelines > like they often do from their employees. > > There are automotive electronics that work quite well, mostly in > Japanese cars. In the end it boils down to the reliability ratings of > the various entities in the know. > > >>>> However, I've been involved in many different markets at many >>>> different levels, over the years. It's a *big* field. There is no >>>> reason to do the same thing for forty years. Impossible, actually. >>>> >>> Not impossible. I met people who worked in one particular field such as >>> engine control units for over 30 years. I'd have a hard time doing that, >>> after being a consultant for this long. >> >> ECUs have changed more than a little in 30 years. They will change >> drastically, again, over the next ten. ... > > > Sure, incremental change. Same in medical ultrasound which is my home > turf. But ... after we built a flagship product in the late 80's and the > satellite R&D location was closed afterwards I wasn't too unhappy that I > could jump into consulting for the first time, and do something else. > > >> ... Hell, you'd have a hard time >> showing up for work with your pants on, after being a consultant that >> long. ;-) > > > As a consultant I get to wear shorts all summer long. When a web > conference with bigshots is coming up I have a "dress shirt on duty" > hanging in the lab closet :-) >
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 -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
Phil Hobbs wrote:
> On 10/21/2013 09:52 AM, Joerg wrote: >> krw@attt.bizz wrote:
[...]
>>> ... Hell, you'd have a hard time >>> showing up for work with your pants on, after being a consultant that >>> long. ;-) >> >> >> As a consultant I get to wear shorts all summer long. When a web >> conference with bigshots is coming up I have a "dress shirt on duty" >> hanging in the lab closet :-) >> > > 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. ;) >
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. -- Regards, Joerg http://www.analogconsultants.com/
On Mon, 21 Oct 2013 09:39:38 -0700, Joerg <invalid@invalid.invalid> wrote:

>> ...snip... > 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. >
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.
On 10/21/2013 12:39 PM, Joerg wrote:
> Phil Hobbs wrote: >> On 10/21/2013 09:52 AM, Joerg wrote: >>> krw@attt.bizz wrote: > > [...] > > >>>> ... Hell, you'd have a hard time >>>> showing up for work with your pants on, after being a consultant that >>>> long. ;-) >>> >>> >>> As a consultant I get to wear shorts all summer long. When a web >>> conference with bigshots is coming up I have a "dress shirt on duty" >>> hanging in the lab closet :-) >>> >> >> 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. ;) >> > > 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. >
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 -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
On Mon, 21 Oct 2013 06:52:46 -0700, Joerg <invalid@invalid.invalid>
wrote:

>krw@attt.bizz wrote: >> On Sun, 20 Oct 2013 12:51:26 -0700, Joerg <invalid@invalid.invalid> >> wrote: >> >>> krw@attt.bizz wrote: >>>> On Sun, 20 Oct 2013 09:33:54 -0700, Joerg <invalid@invalid.invalid> >>>> wrote: >>>> >>>>> krw@attt.bizz wrote: >>>>>> On Sun, 20 Oct 2013 07:21:15 -0700, Joerg <invalid@invalid.invalid> >>>>>> wrote: >>>>>> >>>>>>> krw@attt.bizz wrote: >>>>>>>> On Sat, 19 Oct 2013 16:36:45 -0700, Joerg <invalid@invalid.invalid> >>>>>>>> wrote: >>>>>>>> > > >[...] > >>> Oops, I probably mixed you up with someone else. I thought it was stage >>> electronics for rock bands and stuff. >> >> That was the last job. ;-) I've done a few career changes in the >> last 10 years. Before that, one employer, oneish (perhaps two) >> markets, but very different jobs every five to eight years. >> > >5-8 years would be a bit much for me.
Takes that long to get a couple of generations of product out the door.
>>>>> I work for numerous clients who are all in very different >>>>> markets. This keeps our jobs interesting. But after talking to >>>>> automotive designers I'd be bored stiff if I had to do their job for >>>>> more than a year. >>>> Perhaps but I think you have a pretty small view of that world. >>> >>> Nope. Medical devices for hospitals, low cost medical devices for >>> consumers (over-the-counter), aircraft electronics, spacecraft stuff, >>> chemical pump controllers, power generation, oil/gas exploration >>> electronics, NDT, commercial automotive (trucks), and so on. >> >> You have a very small view of the automotive market. That is for >> sure. >> > >I see it from two view points. One is the actual product and that often >doesn't look very good, both from a quality point of view and sometimes >also from an engineering point of view (flickering LED backlights >anyone?). Then from a people perspective and here talking to folks who >actually work in that field helps. Pretty much all of them reported >extreme pressure to keep NRE and R&D schedules down, which explains a >lot of the quality issues. To the point I wouldn't want to work there. >As a consultant maybe but niot if they'd demansd unrealistic timelines >like they often do from their employees.
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.
>There are automotive electronics that work quite well, mostly in >Japanese cars. In the end it boils down to the reliability ratings of >the various entities in the know.
Things change. A lot!
>>>> However, I've been involved in many different markets at many >>>> different levels, over the years. It's a *big* field. There is no >>>> reason to do the same thing for forty years. Impossible, actually. >>>> >>> Not impossible. I met people who worked in one particular field such as >>> engine control units for over 30 years. I'd have a hard time doing that, >>> after being a consultant for this long. >> >> ECUs have changed more than a little in 30 years. They will change >> drastically, again, over the next ten. ... > > >Sure, incremental change. Same in medical ultrasound which is my home >turf. But ... after we built a flagship product in the late 80's and the >satellite R&D location was closed afterwards I wasn't too unhappy that I >could jump into consulting for the first time, and do something else. > > >> ... Hell, you'd have a hard time >> showing up for work with your pants on, after being a consultant that >> long. ;-) > > >As a consultant I get to wear shorts all summer long. When a web >conference with bigshots is coming up I have a "dress shirt on duty" >hanging in the lab closet :-)
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.
On Mon, 21 Oct 2013 10:19:11 -0700, Phil Hobbs  
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>> ...snip.... > 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 >
A table? A wall of books? I didn't know you were into 'antiques'. :)
On 10/21/2013 01:24 PM, RobertMacy wrote:
> On Mon, 21 Oct 2013 10:19:11 -0700, Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >>> ...snip.... >> 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 >> > > A table? A wall of books? I didn't know you were into 'antiques'. :)
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, http://electrooptical.net/www/EOILab/EOILab.html . 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 -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net