OPTOISOLATED DC-DC
in [Design]
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From: Jan Panteltje on 30 Apr 2010 07:52 On a sunny day (Thu, 29 Apr 2010 20:21:12 -0400) it happened Spehro Pefhany <speffSNIP(a)interlogDOTyou.knowwhat> wrote in <hi8kt5l10h4m7kddomecemnf6a8b1g4dmn(a)4ax.com>: >>Well, been thinking: >>Motor, belt, generator. >>It is not optical, but OK, if the belt is isolating you get a very good efficiency :-) > >Just spray some charge on the belt and you might not need the >generator. Yes, wanted to mention vd Graaf, but was not sure if any charge would build.
From: Jan Panteltje on 30 Apr 2010 07:53 On a sunny day (Fri, 30 Apr 2010 01:55:23 +0200) it happened Sjouke Burry <burrynulnulfour(a)ppllaanneett.nnll> wrote in <4bda1c6d$0$14123$703f8584(a)textnews.kpn.nl>: >Jan Panteltje wrote: >> On a sunny day (Thu, 29 Apr 2010 13:27:16 -0700) it happened John Larkin >> <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in >> <dqqjt5tded693q7b3oifcq9hm92volte6e(a)4ax.com>: >> >>> On Thu, 29 Apr 2010 11:58:40 -0700, Joerg <invalid(a)invalid.invalid> >>> wrote: >>> >>>> hamilton wrote: >>>>> On 4/29/2010 12:09 PM, Joerg wrote: >>>>>> Spehro Pefhany wrote: >>>>>>> On Thu, 29 Apr 2010 07:37:08 -0700 (PDT), Johnny5 >>>>>>> <dirtylogicdesigns(a)gmail.com> wrote: >>>>>>> >>>>>>>> Gentlemen, I was curious on any ideas of an opto dc-dc converter >>>>>>>> providing 20mA. Small footprint and heighth.. >>>>>>>> Any ideas? Please and Thank You. >>>>>>>> >>>>>>>> VIN-8-16VDC >>>>>>>> VOUT 5VDC 20mA, >>>>>>> It's certainly possible (since you don't specify efficiency), but it >>>>>>> probably would cost in the thousands of dollars. JDS Uniphase might be >>>>>>> a place to start. It could well be a practical solution for such >>>>>>> challenging problems as powering instrumentation that's at 100's of kV >>>>>>> potential relative to ground. >>>>>> Even that I'd try to power magnetically through some porcelain or glass >>>>>> insulation. >>>>>> >>>>> That's not opto isolation, its magnetic, right ?? >>>>> >>>> Yes, just meant as a hint that you can do this stuff at high isolation >>>> voltages. >>>> >>>> >>>>> So the OPs request is not feasible. >>>>> >>>> Maybe feasible but it gets expensive. >>>> >>>>> hamilton >>>>> >>>>> PS: OK, solar cells maybe. >>>> >>>> With small footprint and height that can become a challenge. >>> >>> Motor. Long fiberglass rod. Generator. Megavolts of isolation. >>> >>> John >> >> Well, been thinking: >> Motor, belt, generator. >> It is not optical, but OK, if the belt is isolating you get a very good efficiency :-) > >An isolating belt is how they make a de Graaf generator, to produce high >voltage. >It would produce a very nasty leak to ground. >a plastic rod with motor/dynamo attached would be better. Genius! Nice solution :-)
From: Jure Newsgroups on 30 Apr 2010 09:53 "Jan Panteltje" <pNaonStpealmtje(a)yahoo.com> wrote in message news:hrd4h2$3kv$1(a)news.albasani.net... > On a sunny day (Thu, 29 Apr 2010 13:27:16 -0700) it happened John Larkin > <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in > <dqqjt5tded693q7b3oifcq9hm92volte6e(a)4ax.com>: > >>On Thu, 29 Apr 2010 11:58:40 -0700, Joerg <invalid(a)invalid.invalid> >>wrote: >> >>>hamilton wrote: >>>> On 4/29/2010 12:09 PM, Joerg wrote: >>>>> Spehro Pefhany wrote: >>>>>> On Thu, 29 Apr 2010 07:37:08 -0700 (PDT), Johnny5 >>>>>> <dirtylogicdesigns(a)gmail.com> wrote: >>>>>> >>>>>>> Gentlemen, I was curious on any ideas of an opto dc-dc converter >>>>>>> providing 20mA. Small footprint and heighth.. >>>>>>> Any ideas? Please and Thank You. >>>>>>> >>>>>>> VIN-8-16VDC >>>>>>> VOUT 5VDC 20mA, >>>>>> >>>>>> It's certainly possible (since you don't specify efficiency), but it >>>>>> probably would cost in the thousands of dollars. JDS Uniphase might >>>>>> be >>>>>> a place to start. It could well be a practical solution for such >>>>>> challenging problems as powering instrumentation that's at 100's of >>>>>> kV >>>>>> potential relative to ground. >>>>> >>>>> Even that I'd try to power magnetically through some porcelain or >>>>> glass >>>>> insulation. >>>>> >>>> That's not opto isolation, its magnetic, right ?? >>>> >>> >>>Yes, just meant as a hint that you can do this stuff at high isolation >>>voltages. >>> >>> >>>> So the OPs request is not feasible. >>>> >>> >>>Maybe feasible but it gets expensive. >>> >>>> hamilton >>>> >>>> PS: OK, solar cells maybe. >>> >>> >>>With small footprint and height that can become a challenge. >> >> >>Motor. Long fiberglass rod. Generator. Megavolts of isolation. >> >>John > > Well, been thinking: > Motor, belt, generator. > It is not optical, but OK, if the belt is isolating you get a very good > efficiency :-) I seem to recall that his is called a Ward-Leonard arrangement, motor and generator on a common shaft. Many uses in electrical machinery / systems. Even as a frequency converter.
From: John Larkin on 30 Apr 2010 11:36 On Fri, 30 Apr 2010 06:53:41 -0700, "Jure Newsgroups" <jure(a)get_a_life.com> wrote: > >"Jan Panteltje" <pNaonStpealmtje(a)yahoo.com> wrote in message >news:hrd4h2$3kv$1(a)news.albasani.net... >> On a sunny day (Thu, 29 Apr 2010 13:27:16 -0700) it happened John Larkin >> <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in >> <dqqjt5tded693q7b3oifcq9hm92volte6e(a)4ax.com>: >> >>>On Thu, 29 Apr 2010 11:58:40 -0700, Joerg <invalid(a)invalid.invalid> >>>wrote: >>> >>>>hamilton wrote: >>>>> On 4/29/2010 12:09 PM, Joerg wrote: >>>>>> Spehro Pefhany wrote: >>>>>>> On Thu, 29 Apr 2010 07:37:08 -0700 (PDT), Johnny5 >>>>>>> <dirtylogicdesigns(a)gmail.com> wrote: >>>>>>> >>>>>>>> Gentlemen, I was curious on any ideas of an opto dc-dc converter >>>>>>>> providing 20mA. Small footprint and heighth.. >>>>>>>> Any ideas? Please and Thank You. >>>>>>>> >>>>>>>> VIN-8-16VDC >>>>>>>> VOUT 5VDC 20mA, >>>>>>> >>>>>>> It's certainly possible (since you don't specify efficiency), but it >>>>>>> probably would cost in the thousands of dollars. JDS Uniphase might >>>>>>> be >>>>>>> a place to start. It could well be a practical solution for such >>>>>>> challenging problems as powering instrumentation that's at 100's of >>>>>>> kV >>>>>>> potential relative to ground. >>>>>> >>>>>> Even that I'd try to power magnetically through some porcelain or >>>>>> glass >>>>>> insulation. >>>>>> >>>>> That's not opto isolation, its magnetic, right ?? >>>>> >>>> >>>>Yes, just meant as a hint that you can do this stuff at high isolation >>>>voltages. >>>> >>>> >>>>> So the OPs request is not feasible. >>>>> >>>> >>>>Maybe feasible but it gets expensive. >>>> >>>>> hamilton >>>>> >>>>> PS: OK, solar cells maybe. >>>> >>>> >>>>With small footprint and height that can become a challenge. >>> >>> >>>Motor. Long fiberglass rod. Generator. Megavolts of isolation. >>> >>>John >> >> Well, been thinking: >> Motor, belt, generator. >> It is not optical, but OK, if the belt is isolating you get a very good >> efficiency :-) > > I seem to recall that his is called a Ward-Leonard arrangement, motor and >generator on a common shaft. > Many uses in electrical machinery / systems. Even as a frequency >converter. > Old military electronics often used a "dynamotor" to make B+ voltages from low voltage DC. I think it was usually a shaft with a motor section and a generator section, spinning in a common field. All brushes of course. http://en.wikipedia.org/wiki/Dynamotor The version with separate fields could be used as a power amplifier. That was an "amplidyne" http://en.wikipedia.org/wiki/Amplidyne John
From: Joerg on 30 Apr 2010 11:43
John Larkin wrote: > On Thu, 29 Apr 2010 17:17:53 -0700, Joerg <invalid(a)invalid.invalid> > wrote: > >> John Larkin wrote: >>> On Thu, 29 Apr 2010 13:33:03 -0700, Joerg <invalid(a)invalid.invalid> >>> wrote: >>> >>>> John Larkin wrote: >>>>> On Thu, 29 Apr 2010 11:58:40 -0700, Joerg <invalid(a)invalid.invalid> >>>>> wrote: >>>>> >>>>>> hamilton wrote: >>>>>>> On 4/29/2010 12:09 PM, Joerg wrote: >>>>>>>> Spehro Pefhany wrote: >>>>>>>>> On Thu, 29 Apr 2010 07:37:08 -0700 (PDT), Johnny5 >>>>>>>>> <dirtylogicdesigns(a)gmail.com> wrote: >>>>>>>>> >>>>>>>>>> Gentlemen, I was curious on any ideas of an opto dc-dc converter >>>>>>>>>> providing 20mA. Small footprint and heighth.. >>>>>>>>>> Any ideas? Please and Thank You. >>>>>>>>>> >>>>>>>>>> VIN-8-16VDC >>>>>>>>>> VOUT 5VDC 20mA, >>>>>>>>> It's certainly possible (since you don't specify efficiency), but it >>>>>>>>> probably would cost in the thousands of dollars. JDS Uniphase might be >>>>>>>>> a place to start. It could well be a practical solution for such >>>>>>>>> challenging problems as powering instrumentation that's at 100's of kV >>>>>>>>> potential relative to ground. >>>>>>>> Even that I'd try to power magnetically through some porcelain or glass >>>>>>>> insulation. >>>>>>>> >>>>>>> That's not opto isolation, its magnetic, right ?? >>>>>>> >>>>>> Yes, just meant as a hint that you can do this stuff at high isolation >>>>>> voltages. >>>>>> >>>>>> >>>>>>> So the OPs request is not feasible. >>>>>>> >>>>>> Maybe feasible but it gets expensive. >>>>>> >>>>>>> hamilton >>>>>>> >>>>>>> PS: OK, solar cells maybe. >>>>>> With small footprint and height that can become a challenge. >>>>> Motor. Long fiberglass rod. Generator. Megavolts of isolation. >>>>> >>>> ... minor imbalance, some rumbling is heard, bigger imbalance, snapping >>>> noise, stuff flying about, hissing, amperage stench develops, siren >>>> begins to wail, the captain from engine company 89 hollers something, >>>> his guys hurriedly don their helmets ... >>>> >>>> :-) >>> You would enjoy that, wouldn't you? >>> >> No joke, I have personally seen an aircraft go down because of it. New >> design, prototype was ready to go. Engine up front, prop in the rear, >> long shaft going through the fiber fuselage. I did some EMI fixing >> because that arrangement was causing static in the NAV/COM and this was >> a bear to debug because there was no ground to speak of. But I got it >> quiet. Then I wondered aloud whether the long shaft in a somewhat >> compliant fiber fuselage would not get out of whack at some rpm. "Nah, >> it was always fine in the run-ups and vibration tests" ... "What if >> there's g-load on the frame, like in a turn?" ... "Nah, it'll be fine". >> >> Test pilot donned his leather helmet, fired her up. At first it all >> sounded ok but then somehow the rpms dropped during the takeoff roll and >> the engine sounded very labored. From then on the flight was doomed. Due >> to the proximity of the fence the pilot had no choice but to continue >> the take-off. It all ended in a potato field half a mile away and >> luckily the pilot was fine. The aircraft did not fare so well, suffered >> a serious prop strike which I guess meant a mandatory engine teardown. >> Later I inquired as to what went wrong. "Strong vibrations" ... > > The drive shaft on the F35 JSF transmits 32,000 horsepower to the > forward lift fan. I understand there was some concern about stability. > In fact, we sold some waveform generators to help out with the > simulation. I think it's a tube, not a solid rod. > Shafts are pretty much always tubes but in my case it wasn't steel. Just from the gut feeling it didn't look kosher to me. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |