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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 10/19/2013 3:11 PM, Joerg wrote:
> John S wrote: >> On 10/19/2013 1:41 PM, Joerg wrote: >>> John S wrote: >>>> On 10/19/2013 10:03 AM, Joerg wrote: >>>>> John S wrote: >>>>>> On 10/19/2013 2:26 AM, Jasen Betts wrote: >>>>>>> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>>>>>>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold >>>>>>>> <gherold@teachspin.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>>>> ...snip... >>>>>>>>> OK... We haven't done many AC circuit yet.. but I'm guessing the >>>>>>>>> same >>>>>>>>> sort of thing can be done. >>>>>>>>> For completeness here's the way a current source buck-boost should >>>>>>>>> look. >>>>>>>>> >>>>>>>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>>>>>>> (I figured out in the shower that the capacitor was in wrong.) >>>>>>>>> >>>>>>>>> George H. >>>>>>>> >>>>>>>> Thanks again for the images, surprisingly this time dropbox let me >>>>>>>> view >>>>>>>> them - usually doesn't. >>>>>>>> >>>>>>>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>>>>>>> OUT: approx 5Vdc, with variable current, adjusted with time envelope >>>>>>>> from >>>>>>>> 0.8A down to 50uA. >>>>>>> >>>>>>> current buck-boost converter. >>>>>>> >>>>>>> +--+-FET--+--|<------- >>>>>>> | | >>>>>>> === 3|| >>>>>>> | 3|| >>>>>>> | | >>>>>>> +--+------+----------- >>>>>>> >>>>>>> the more time the switch (FET in the diagram) >>>>>>> spends off the larger the current output >>>>>>> >>>>>> >>>>>> I don't understand how you can get more current out of the inductor >>>>>> than >>>>>> it had when the switch opened. >>>>> >>>>> >>>>> Ask a politician, they can do that :-) >>>>> >>>> >>>> So, I should have studied politics rather than engineering. I guess >>>> Momma was right. >>> >>> >>> If you and I had done that we'd be rich. But probably not too happy. If >>> I were 18 again I'd veer towards a brewmaster's degree and keep EE as a >>> hobby. No kidding. >>> >> >> It very hard to resist your true calling, I learned. > > > The problem is to figure out what your true calling is. Some people > realize that late in life. For example, a top chemical scientist in our > area who some day when he was well in his 50's quit his well-paying job > at Monsanto and started a winery. He said he'd found his true calling. > Or a sccessful surgeon who, late in his 50's, became a pilot (after an > expensive trek through commercial pilot flight schooling) and hired on > with an airline. His income probably went down by 10-15dB but he was happy. >
Of course, Joerg. Not everyone has a calling at birth, graduation, or any other special time in his life. However, when it comes, it is very hard to resist. If you are enjoying your calling, how much happier can you be? (Let's not get into salary)
On Sat, 19 Oct 2013 15:28:13 -0500, John S <Sophi.2@invalid.org>
wrote:

>On 10/19/2013 3:11 PM, Joerg wrote: >> John S wrote: >>> On 10/19/2013 1:41 PM, Joerg wrote: >>>> John S wrote: >>>>> On 10/19/2013 10:03 AM, Joerg wrote: >>>>>> John S wrote: >>>>>>> On 10/19/2013 2:26 AM, Jasen Betts wrote: >>>>>>>> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>>>>>>>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold >>>>>>>>> <gherold@teachspin.com> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>>> ...snip... >>>>>>>>>> OK... We haven't done many AC circuit yet.. but I'm guessing the >>>>>>>>>> same >>>>>>>>>> sort of thing can be done. >>>>>>>>>> For completeness here's the way a current source buck-boost should >>>>>>>>>> look. >>>>>>>>>> >>>>>>>>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>>>>>>>> (I figured out in the shower that the capacitor was in wrong.) >>>>>>>>>> >>>>>>>>>> George H. >>>>>>>>> >>>>>>>>> Thanks again for the images, surprisingly this time dropbox let me >>>>>>>>> view >>>>>>>>> them - usually doesn't. >>>>>>>>> >>>>>>>>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>>>>>>>> OUT: approx 5Vdc, with variable current, adjusted with time envelope >>>>>>>>> from >>>>>>>>> 0.8A down to 50uA. >>>>>>>> >>>>>>>> current buck-boost converter. >>>>>>>> >>>>>>>> +--+-FET--+--|<------- >>>>>>>> | | >>>>>>>> === 3|| >>>>>>>> | 3|| >>>>>>>> | | >>>>>>>> +--+------+----------- >>>>>>>> >>>>>>>> the more time the switch (FET in the diagram) >>>>>>>> spends off the larger the current output >>>>>>>> >>>>>>> >>>>>>> I don't understand how you can get more current out of the inductor >>>>>>> than >>>>>>> it had when the switch opened. >>>>>> >>>>>> >>>>>> Ask a politician, they can do that :-) >>>>>> >>>>> >>>>> So, I should have studied politics rather than engineering. I guess >>>>> Momma was right. >>>> >>>> >>>> If you and I had done that we'd be rich. But probably not too happy. If >>>> I were 18 again I'd veer towards a brewmaster's degree and keep EE as a >>>> hobby. No kidding. >>>> >>> >>> It very hard to resist your true calling, I learned. >> >> >> The problem is to figure out what your true calling is. Some people >> realize that late in life. For example, a top chemical scientist in our >> area who some day when he was well in his 50's quit his well-paying job >> at Monsanto and started a winery. He said he'd found his true calling. >> Or a sccessful surgeon who, late in his 50's, became a pilot (after an >> expensive trek through commercial pilot flight schooling) and hired on >> with an airline. His income probably went down by 10-15dB but he was happy. >> > >Of course, Joerg. Not everyone has a calling at birth, graduation, or >any other special time in his life. However, when it comes, it is very >hard to resist. If you are enjoying your calling, how much happier can >you be? (Let's not get into salary)
I'm confused. Why would anyone want to do anything but design electronics? -- 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 10/19/2013 4:01 PM, John Larkin wrote:
> On Sat, 19 Oct 2013 15:28:13 -0500, John S <Sophi.2@invalid.org> > wrote: > >> On 10/19/2013 3:11 PM, Joerg wrote: >>> John S wrote: >>>> On 10/19/2013 1:41 PM, Joerg wrote: >>>>> John S wrote: >>>>>> On 10/19/2013 10:03 AM, Joerg wrote: >>>>>>> John S wrote: >>>>>>>> On 10/19/2013 2:26 AM, Jasen Betts wrote: >>>>>>>>> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>>>>>>>>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold >>>>>>>>>> <gherold@teachspin.com> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>>> ...snip... >>>>>>>>>>> OK... We haven't done many AC circuit yet.. but I'm guessing the >>>>>>>>>>> same >>>>>>>>>>> sort of thing can be done. >>>>>>>>>>> For completeness here's the way a current source buck-boost should >>>>>>>>>>> look. >>>>>>>>>>> >>>>>>>>>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>>>>>>>>> (I figured out in the shower that the capacitor was in wrong.) >>>>>>>>>>> >>>>>>>>>>> George H. >>>>>>>>>> >>>>>>>>>> Thanks again for the images, surprisingly this time dropbox let me >>>>>>>>>> view >>>>>>>>>> them - usually doesn't. >>>>>>>>>> >>>>>>>>>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>>>>>>>>> OUT: approx 5Vdc, with variable current, adjusted with time envelope >>>>>>>>>> from >>>>>>>>>> 0.8A down to 50uA. >>>>>>>>> >>>>>>>>> current buck-boost converter. >>>>>>>>> >>>>>>>>> +--+-FET--+--|<------- >>>>>>>>> | | >>>>>>>>> === 3|| >>>>>>>>> | 3|| >>>>>>>>> | | >>>>>>>>> +--+------+----------- >>>>>>>>> >>>>>>>>> the more time the switch (FET in the diagram) >>>>>>>>> spends off the larger the current output >>>>>>>>> >>>>>>>> >>>>>>>> I don't understand how you can get more current out of the inductor >>>>>>>> than >>>>>>>> it had when the switch opened. >>>>>>> >>>>>>> >>>>>>> Ask a politician, they can do that :-) >>>>>>> >>>>>> >>>>>> So, I should have studied politics rather than engineering. I guess >>>>>> Momma was right. >>>>> >>>>> >>>>> If you and I had done that we'd be rich. But probably not too happy. If >>>>> I were 18 again I'd veer towards a brewmaster's degree and keep EE as a >>>>> hobby. No kidding. >>>>> >>>> >>>> It very hard to resist your true calling, I learned. >>> >>> >>> The problem is to figure out what your true calling is. Some people >>> realize that late in life. For example, a top chemical scientist in our >>> area who some day when he was well in his 50's quit his well-paying job >>> at Monsanto and started a winery. He said he'd found his true calling. >>> Or a sccessful surgeon who, late in his 50's, became a pilot (after an >>> expensive trek through commercial pilot flight schooling) and hired on >>> with an airline. His income probably went down by 10-15dB but he was happy. >>> >> >> Of course, Joerg. Not everyone has a calling at birth, graduation, or >> any other special time in his life. However, when it comes, it is very >> hard to resist. If you are enjoying your calling, how much happier can >> you be? (Let's not get into salary) > > I'm confused. Why would anyone want to do anything but design > electronics?
It is unimaginable. It has been my calling since 1951. It will never let go.
On 2013-10-19, John S <Sophi.2@invalid.org> wrote:
> On 10/19/2013 2:26 AM, Jasen Betts wrote: >> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold <gherold@teachspin.com> >>> wrote: >>> >>>>> ...snip... >>>> OK... We haven't done many AC circuit yet.. but I'm guessing the same >>>> sort of thing can be done. >>>> For completeness here's the way a current source buck-boost should look. >>>> >>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>> (I figured out in the shower that the capacitor was in wrong.) >>>> >>>> George H. >>> >>> Thanks again for the images, surprisingly this time dropbox let me view >>> them - usually doesn't. >>> >>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>> OUT: approx 5Vdc, with variable current, adjusted with time envelope from >>> 0.8A down to 50uA. >> >> current buck-boost converter. >> >> +--+-FET--+--|<------- >> | | >> === 3|| >> | 3|| >> | | >> +--+------+----------- >> >> the more time the switch (FET in the diagram) >> spends off the larger the current output >> > > I don't understand how you can get more current out of the inductor than > it had when the switch opened.
You can't, that's why decreasing the on-time increses the current. That capacitor on the left that looks like it's doing nothing is actually essential, you turn on the switch briefly and the capacitor supplies the bulk of the current to wind the inductor up. if you want to simulate this arrange the simulation to start with the switch closed. -- &#9858;&#9859; 100% natural --- news://freenews.netfront.net/ - complaints: news@netfront.net ---
On Sat, 19 Oct 2013 13:11:30 -0700, Joerg <invalid@invalid.invalid>
wrote:

>John S wrote: >> On 10/19/2013 1:41 PM, Joerg wrote: >>> John S wrote: >>>> On 10/19/2013 10:03 AM, Joerg wrote: >>>>> John S wrote: >>>>>> On 10/19/2013 2:26 AM, Jasen Betts wrote: >>>>>>> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>>>>>>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold >>>>>>>> <gherold@teachspin.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>>>> ...snip... >>>>>>>>> OK... We haven't done many AC circuit yet.. but I'm guessing the >>>>>>>>> same >>>>>>>>> sort of thing can be done. >>>>>>>>> For completeness here's the way a current source buck-boost should >>>>>>>>> look. >>>>>>>>> >>>>>>>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>>>>>>> (I figured out in the shower that the capacitor was in wrong.) >>>>>>>>> >>>>>>>>> George H. >>>>>>>> >>>>>>>> Thanks again for the images, surprisingly this time dropbox let me >>>>>>>> view >>>>>>>> them - usually doesn't. >>>>>>>> >>>>>>>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>>>>>>> OUT: approx 5Vdc, with variable current, adjusted with time envelope >>>>>>>> from >>>>>>>> 0.8A down to 50uA. >>>>>>> >>>>>>> current buck-boost converter. >>>>>>> >>>>>>> +--+-FET--+--|<------- >>>>>>> | | >>>>>>> === 3|| >>>>>>> | 3|| >>>>>>> | | >>>>>>> +--+------+----------- >>>>>>> >>>>>>> the more time the switch (FET in the diagram) >>>>>>> spends off the larger the current output >>>>>>> >>>>>> >>>>>> I don't understand how you can get more current out of the inductor >>>>>> than >>>>>> it had when the switch opened. >>>>> >>>>> >>>>> Ask a politician, they can do that :-) >>>>> >>>> >>>> So, I should have studied politics rather than engineering. I guess >>>> Momma was right. >>> >>> >>> If you and I had done that we'd be rich. But probably not too happy. If >>> I were 18 again I'd veer towards a brewmaster's degree and keep EE as a >>> hobby. No kidding. >>> >> >> It very hard to resist your true calling, I learned. > > >The problem is to figure out what your true calling is. Some people >realize that late in life. For example, a top chemical scientist in our >area who some day when he was well in his 50's quit his well-paying job >at Monsanto and started a winery. He said he'd found his true calling. >Or a sccessful surgeon who, late in his 50's, became a pilot (after an >expensive trek through commercial pilot flight schooling) and hired on >with an airline. His income probably went down by 10-15dB but he was happy.
David Stare, MIT EE, Class of 1962 (my class), founded Dry Creek Winery. I believe his daughter now runs it. ...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.
John Larkin wrote:
> On Sat, 19 Oct 2013 15:28:13 -0500, John S <Sophi.2@invalid.org> > wrote: > >> On 10/19/2013 3:11 PM, Joerg wrote: >>> John S wrote: >>>> On 10/19/2013 1:41 PM, Joerg wrote: >>>>> John S wrote: >>>>>> On 10/19/2013 10:03 AM, Joerg wrote: >>>>>>> John S wrote: >>>>>>>> On 10/19/2013 2:26 AM, Jasen Betts wrote: >>>>>>>>> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>>>>>>>>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold >>>>>>>>>> <gherold@teachspin.com> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>>> ...snip... >>>>>>>>>>> OK... We haven't done many AC circuit yet.. but I'm guessing the >>>>>>>>>>> same >>>>>>>>>>> sort of thing can be done. >>>>>>>>>>> For completeness here's the way a current source buck-boost should >>>>>>>>>>> look. >>>>>>>>>>> >>>>>>>>>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>>>>>>>>> (I figured out in the shower that the capacitor was in wrong.) >>>>>>>>>>> >>>>>>>>>>> George H. >>>>>>>>>> Thanks again for the images, surprisingly this time dropbox let me >>>>>>>>>> view >>>>>>>>>> them - usually doesn't. >>>>>>>>>> >>>>>>>>>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>>>>>>>>> OUT: approx 5Vdc, with variable current, adjusted with time envelope >>>>>>>>>> from >>>>>>>>>> 0.8A down to 50uA. >>>>>>>>> current buck-boost converter. >>>>>>>>> >>>>>>>>> +--+-FET--+--|<------- >>>>>>>>> | | >>>>>>>>> === 3|| >>>>>>>>> | 3|| >>>>>>>>> | | >>>>>>>>> +--+------+----------- >>>>>>>>> >>>>>>>>> the more time the switch (FET in the diagram) >>>>>>>>> spends off the larger the current output >>>>>>>>> >>>>>>>> I don't understand how you can get more current out of the inductor >>>>>>>> than >>>>>>>> it had when the switch opened. >>>>>>> >>>>>>> Ask a politician, they can do that :-) >>>>>>> >>>>>> So, I should have studied politics rather than engineering. I guess >>>>>> Momma was right. >>>>> >>>>> If you and I had done that we'd be rich. But probably not too happy. If >>>>> I were 18 again I'd veer towards a brewmaster's degree and keep EE as a >>>>> hobby. No kidding. >>>>> >>>> It very hard to resist your true calling, I learned. >>> >>> The problem is to figure out what your true calling is. Some people >>> realize that late in life. For example, a top chemical scientist in our >>> area who some day when he was well in his 50's quit his well-paying job >>> at Monsanto and started a winery. He said he'd found his true calling. >>> Or a sccessful surgeon who, late in his 50's, became a pilot (after an >>> expensive trek through commercial pilot flight schooling) and hired on >>> with an airline. His income probably went down by 10-15dB but he was happy. >>> >> Of course, Joerg. Not everyone has a calling at birth, graduation, or >> any other special time in his life. However, when it comes, it is very >> hard to resist. If you are enjoying your calling, how much happier can >> you be? (Let's not get into salary) > > I'm confused. Why would anyone want to do anything but design > electronics? >
<raises hand> I'd like to get into beer brewing some day. When I did that last time as a student in Germany I almost had more fun that when designing electronics (which I did a lot while studying for my masters). Nowadays, after designing the umpteenth switch mode converter that can get a bit old. It's only fun if there is something in the mix where people have said "it can't be done". That's when my fun level meter goes to 120%. -- Regards, Joerg http://www.analogconsultants.com/
On Sat, 19 Oct 2013 16:36:45 -0700, Joerg <invalid@invalid.invalid>
wrote:

>John Larkin wrote: >> On Sat, 19 Oct 2013 15:28:13 -0500, John S <Sophi.2@invalid.org> >> wrote: >> >>> On 10/19/2013 3:11 PM, Joerg wrote: >>>> John S wrote: >>>>> On 10/19/2013 1:41 PM, Joerg wrote: >>>>>> John S wrote: >>>>>>> On 10/19/2013 10:03 AM, Joerg wrote: >>>>>>>> John S wrote: >>>>>>>>> On 10/19/2013 2:26 AM, Jasen Betts wrote: >>>>>>>>>> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>>>>>>>>>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold >>>>>>>>>>> <gherold@teachspin.com> >>>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>>>> ...snip... >>>>>>>>>>>> OK... We haven't done many AC circuit yet.. but I'm guessing the >>>>>>>>>>>> same >>>>>>>>>>>> sort of thing can be done. >>>>>>>>>>>> For completeness here's the way a current source buck-boost should >>>>>>>>>>>> look. >>>>>>>>>>>> >>>>>>>>>>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>>>>>>>>>> (I figured out in the shower that the capacitor was in wrong.) >>>>>>>>>>>> >>>>>>>>>>>> George H. >>>>>>>>>>> Thanks again for the images, surprisingly this time dropbox let me >>>>>>>>>>> view >>>>>>>>>>> them - usually doesn't. >>>>>>>>>>> >>>>>>>>>>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>>>>>>>>>> OUT: approx 5Vdc, with variable current, adjusted with time envelope >>>>>>>>>>> from >>>>>>>>>>> 0.8A down to 50uA. >>>>>>>>>> current buck-boost converter. >>>>>>>>>> >>>>>>>>>> +--+-FET--+--|<------- >>>>>>>>>> | | >>>>>>>>>> === 3|| >>>>>>>>>> | 3|| >>>>>>>>>> | | >>>>>>>>>> +--+------+----------- >>>>>>>>>> >>>>>>>>>> the more time the switch (FET in the diagram) >>>>>>>>>> spends off the larger the current output >>>>>>>>>> >>>>>>>>> I don't understand how you can get more current out of the inductor >>>>>>>>> than >>>>>>>>> it had when the switch opened. >>>>>>>> >>>>>>>> Ask a politician, they can do that :-) >>>>>>>> >>>>>>> So, I should have studied politics rather than engineering. I guess >>>>>>> Momma was right. >>>>>> >>>>>> If you and I had done that we'd be rich. But probably not too happy. If >>>>>> I were 18 again I'd veer towards a brewmaster's degree and keep EE as a >>>>>> hobby. No kidding. >>>>>> >>>>> It very hard to resist your true calling, I learned. >>>> >>>> The problem is to figure out what your true calling is. Some people >>>> realize that late in life. For example, a top chemical scientist in our >>>> area who some day when he was well in his 50's quit his well-paying job >>>> at Monsanto and started a winery. He said he'd found his true calling. >>>> Or a sccessful surgeon who, late in his 50's, became a pilot (after an >>>> expensive trek through commercial pilot flight schooling) and hired on >>>> with an airline. His income probably went down by 10-15dB but he was happy. >>>> >>> Of course, Joerg. Not everyone has a calling at birth, graduation, or >>> any other special time in his life. However, when it comes, it is very >>> hard to resist. If you are enjoying your calling, how much happier can >>> you be? (Let's not get into salary) >> >> I'm confused. Why would anyone want to do anything but design >> electronics? >> > ><raises hand> > >I'd like to get into beer brewing some day. When I did that last time as >a student in Germany I almost had more fun that when designing >electronics (which I did a lot while studying for my masters). Nowadays, >after designing the umpteenth switch mode converter that can get a bit >old. It's only fun if there is something in the mix where people have >said "it can't be done". That's when my fun level meter goes to 120%.
I can imagine that brewing the billionth barrel of beer wouldn't be as much fun as the first, either. Perhaps you have the hobby and business right, after all.
On 10/19/2013 4:50 PM, Jasen Betts wrote:
> On 2013-10-19, John S <Sophi.2@invalid.org> wrote: >> On 10/19/2013 2:26 AM, Jasen Betts wrote: >>> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold <gherold@teachspin.com> >>>> wrote: >>>> >>>>>> ...snip... >>>>> OK... We haven't done many AC circuit yet.. but I'm guessing the same >>>>> sort of thing can be done. >>>>> For completeness here's the way a current source buck-boost should look. >>>>> >>>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>>> (I figured out in the shower that the capacitor was in wrong.) >>>>> >>>>> George H. >>>> >>>> Thanks again for the images, surprisingly this time dropbox let me view >>>> them - usually doesn't. >>>> >>>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>>> OUT: approx 5Vdc, with variable current, adjusted with time envelope from >>>> 0.8A down to 50uA. >>> >>> current buck-boost converter. >>> >>> +--+-FET--+--|<------- >>> | | >>> === 3|| >>> | 3|| >>> | | >>> +--+------+----------- >>> >>> the more time the switch (FET in the diagram) >>> spends off the larger the current output >>> >> >> I don't understand how you can get more current out of the inductor than >> it had when the switch opened. > > You can't, that's why decreasing the on-time increses the current. > > That capacitor on the left that looks like it's doing nothing > is actually essential, you turn on the switch briefly and > the capacitor supplies the bulk of the current to wind the inductor up. > > if you want to simulate this arrange the simulation to start with the > switch closed. >
Do you have a simulation you can share with us?
krw@attt.bizz wrote:
> On Sat, 19 Oct 2013 16:36:45 -0700, Joerg <invalid@invalid.invalid> > wrote: > >> John Larkin wrote: >>> On Sat, 19 Oct 2013 15:28:13 -0500, John S <Sophi.2@invalid.org> >>> wrote: >>> >>>> On 10/19/2013 3:11 PM, Joerg wrote: >>>>> John S wrote: >>>>>> On 10/19/2013 1:41 PM, Joerg wrote: >>>>>>> John S wrote: >>>>>>>> On 10/19/2013 10:03 AM, Joerg wrote: >>>>>>>>> John S wrote: >>>>>>>>>> On 10/19/2013 2:26 AM, Jasen Betts wrote: >>>>>>>>>>> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>>>>>>>>>>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold >>>>>>>>>>>> <gherold@teachspin.com> >>>>>>>>>>>> wrote: >>>>>>>>>>>> >>>>>>>>>>>>>> ...snip... >>>>>>>>>>>>> OK... We haven't done many AC circuit yet.. but I'm guessing the >>>>>>>>>>>>> same >>>>>>>>>>>>> sort of thing can be done. >>>>>>>>>>>>> For completeness here's the way a current source buck-boost should >>>>>>>>>>>>> look. >>>>>>>>>>>>> >>>>>>>>>>>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>>>>>>>>>>> (I figured out in the shower that the capacitor was in wrong.) >>>>>>>>>>>>> >>>>>>>>>>>>> George H. >>>>>>>>>>>> Thanks again for the images, surprisingly this time dropbox let me >>>>>>>>>>>> view >>>>>>>>>>>> them - usually doesn't. >>>>>>>>>>>> >>>>>>>>>>>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>>>>>>>>>>> OUT: approx 5Vdc, with variable current, adjusted with time envelope >>>>>>>>>>>> from >>>>>>>>>>>> 0.8A down to 50uA. >>>>>>>>>>> current buck-boost converter. >>>>>>>>>>> >>>>>>>>>>> +--+-FET--+--|<------- >>>>>>>>>>> | | >>>>>>>>>>> === 3|| >>>>>>>>>>> | 3|| >>>>>>>>>>> | | >>>>>>>>>>> +--+------+----------- >>>>>>>>>>> >>>>>>>>>>> the more time the switch (FET in the diagram) >>>>>>>>>>> spends off the larger the current output >>>>>>>>>>> >>>>>>>>>> I don't understand how you can get more current out of the inductor >>>>>>>>>> than >>>>>>>>>> it had when the switch opened. >>>>>>>>> Ask a politician, they can do that :-) >>>>>>>>> >>>>>>>> So, I should have studied politics rather than engineering. I guess >>>>>>>> Momma was right. >>>>>>> If you and I had done that we'd be rich. But probably not too happy. If >>>>>>> I were 18 again I'd veer towards a brewmaster's degree and keep EE as a >>>>>>> hobby. No kidding. >>>>>>> >>>>>> It very hard to resist your true calling, I learned. >>>>> The problem is to figure out what your true calling is. Some people >>>>> realize that late in life. For example, a top chemical scientist in our >>>>> area who some day when he was well in his 50's quit his well-paying job >>>>> at Monsanto and started a winery. He said he'd found his true calling. >>>>> Or a sccessful surgeon who, late in his 50's, became a pilot (after an >>>>> expensive trek through commercial pilot flight schooling) and hired on >>>>> with an airline. His income probably went down by 10-15dB but he was happy. >>>>> >>>> Of course, Joerg. Not everyone has a calling at birth, graduation, or >>>> any other special time in his life. However, when it comes, it is very >>>> hard to resist. If you are enjoying your calling, how much happier can >>>> you be? (Let's not get into salary) >>> I'm confused. Why would anyone want to do anything but design >>> electronics? >>> >> <raises hand> >> >> I'd like to get into beer brewing some day. When I did that last time as >> a student in Germany I almost had more fun that when designing >> electronics (which I did a lot while studying for my masters). Nowadays, >> after designing the umpteenth switch mode converter that can get a bit >> old. It's only fun if there is something in the mix where people have >> said "it can't be done". That's when my fun level meter goes to 120%. > > I can imagine that brewing the billionth barrel of beer wouldn't be as > much fun as the first, either. Perhaps you have the hobby and > business right, after all.
Hobby brewers and even the small commercial micro brewers don't run a bland same old same old scheme. They come up with variants and try out new recipes all the time. Like the chef in a fancy restaurant that is not tied to a chain, I was told by several that such a job never gets old. It's just hard not to gain weight (same with brewing). -- Regards, Joerg http://www.analogconsultants.com/
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: >> >>> John Larkin wrote: >>>> On Sat, 19 Oct 2013 15:28:13 -0500, John S <Sophi.2@invalid.org> >>>> wrote: >>>> >>>>> On 10/19/2013 3:11 PM, Joerg wrote: >>>>>> John S wrote: >>>>>>> On 10/19/2013 1:41 PM, Joerg wrote: >>>>>>>> John S wrote: >>>>>>>>> On 10/19/2013 10:03 AM, Joerg wrote: >>>>>>>>>> John S wrote: >>>>>>>>>>> On 10/19/2013 2:26 AM, Jasen Betts wrote: >>>>>>>>>>>> On 2013-10-17, RobertMacy <robert.a.macy@gmail.com> wrote: >>>>>>>>>>>>> On Thu, 17 Oct 2013 06:01:01 -0700, George Herold >>>>>>>>>>>>> <gherold@teachspin.com> >>>>>>>>>>>>> wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>>> ...snip... >>>>>>>>>>>>>> OK... We haven't done many AC circuit yet.. but I'm guessing the >>>>>>>>>>>>>> same >>>>>>>>>>>>>> sort of thing can be done. >>>>>>>>>>>>>> For completeness here's the way a current source buck-boost should >>>>>>>>>>>>>> look. >>>>>>>>>>>>>> >>>>>>>>>>>>>> https://www.dropbox.com/s/eey79dkci1sqpp0/DSCF0034.JPG >>>>>>>>>>>>>> (I figured out in the shower that the capacitor was in wrong.) >>>>>>>>>>>>>> >>>>>>>>>>>>>> George H. >>>>>>>>>>>>> Thanks again for the images, surprisingly this time dropbox let me >>>>>>>>>>>>> view >>>>>>>>>>>>> them - usually doesn't. >>>>>>>>>>>>> >>>>>>>>>>>>> IN: AC with source current maybe 30-50mA, compliance to 1kV >>>>>>>>>>>>> OUT: approx 5Vdc, with variable current, adjusted with time envelope >>>>>>>>>>>>> from >>>>>>>>>>>>> 0.8A down to 50uA. >>>>>>>>>>>> current buck-boost converter. >>>>>>>>>>>> >>>>>>>>>>>> +--+-FET--+--|<------- >>>>>>>>>>>> | | >>>>>>>>>>>> === 3|| >>>>>>>>>>>> | 3|| >>>>>>>>>>>> | | >>>>>>>>>>>> +--+------+----------- >>>>>>>>>>>> >>>>>>>>>>>> the more time the switch (FET in the diagram) >>>>>>>>>>>> spends off the larger the current output >>>>>>>>>>>> >>>>>>>>>>> I don't understand how you can get more current out of the inductor >>>>>>>>>>> than >>>>>>>>>>> it had when the switch opened. >>>>>>>>>> Ask a politician, they can do that :-) >>>>>>>>>> >>>>>>>>> So, I should have studied politics rather than engineering. I guess >>>>>>>>> Momma was right. >>>>>>>> If you and I had done that we'd be rich. But probably not too happy. If >>>>>>>> I were 18 again I'd veer towards a brewmaster's degree and keep EE as a >>>>>>>> hobby. No kidding. >>>>>>>> >>>>>>> It very hard to resist your true calling, I learned. >>>>>> The problem is to figure out what your true calling is. Some people >>>>>> realize that late in life. For example, a top chemical scientist in our >>>>>> area who some day when he was well in his 50's quit his well-paying job >>>>>> at Monsanto and started a winery. He said he'd found his true calling. >>>>>> Or a sccessful surgeon who, late in his 50's, became a pilot (after an >>>>>> expensive trek through commercial pilot flight schooling) and hired on >>>>>> with an airline. His income probably went down by 10-15dB but he was happy. >>>>>> >>>>> Of course, Joerg. Not everyone has a calling at birth, graduation, or >>>>> any other special time in his life. However, when it comes, it is very >>>>> hard to resist. If you are enjoying your calling, how much happier can >>>>> you be? (Let's not get into salary) >>>> I'm confused. Why would anyone want to do anything but design >>>> electronics? >>>> >>> <raises hand> >>> >>> I'd like to get into beer brewing some day. When I did that last time as >>> a student in Germany I almost had more fun that when designing >>> electronics (which I did a lot while studying for my masters). Nowadays, >>> after designing the umpteenth switch mode converter that can get a bit >>> old. It's only fun if there is something in the mix where people have >>> said "it can't be done". That's when my fun level meter goes to 120%. >> >> I can imagine that brewing the billionth barrel of beer wouldn't be as >> much fun as the first, either. Perhaps you have the hobby and >> business right, after all. > > >Hobby brewers and even the small commercial micro brewers don't run a >bland same old same old scheme. They come up with variants and try out >new recipes all the time. Like the chef in a fancy restaurant that is >not tied to a chain, I was told by several that such a job never gets >old. It's just hard not to gain weight (same with brewing).
I think the same can be said for design engineers. I rarely design complicated systems with unit logic anymore. ;-)