"Peter" <nospam@nospam9876.com> wrote in message news:52bef176$0$1157$5b6aafb4@news.zen.co.uk...> Guys, is it physically possible to transfer energy with just > capacitors for isolation?Signals anyway, http://www.ti.com/lit/ds/symlink/iso103.pdf Nothing wrong with it for power, but the capacitances will be small to ensure galvanic isolation (~nF), suggesting very high frequencies or inductive reactances to cancel it. The inductive case looks like coupled resonators, which might be achieved accidentally by proximity of the coils (in which case you have "wireless energy", which is a slowly rising fad these days). At that point, isolation distance is only a matter of having sufficiently high Q factors (and closely matched resonators). Tim -- Seven Transistor Labs Electrical Engineering Consultation Website: http://seventransistorlabs.com
new 30MHz to 300MHz switcher - worlds smallest laptop adapter
Started by ●December 25, 2013
Reply by ●December 28, 20132013-12-28
Reply by ●December 28, 20132013-12-28
On 2013-12-28, Peter <nospam@nospam9876.com> wrote:> I know you can send data that way (because it can be encoded with just > edges, and providing there isn't too much common mode noise, the edges > can be decoded) but I can't see any way to transfer *power* that way.use a higher frequency. _ _ _ ......... / \_/ \_/ \ --||--:~ +:-- _ _ : -|>|- : \_/ \_/ \_/ --||--:~ -:-- :.......:> Inductive components are needed if you want isolation - as in most > consumer appliances.It's usually more practical to do it that way. there's rules about the size and type of capacitors that are allowed accross an isolation barrier.> LED lamps don't need isolation and there is a huge amount of work > being done in that area.Yes, it's the same for any other double-insulated appliance. -- For a good time: install ntp --- news://freenews.netfront.net/ - complaints: news@netfront.net ---
Reply by ●December 28, 20132013-12-28
dagmargoodboat@yahoo.com wrote:> Without patents it wouldn't make sense to do all that work--make all > that investment--only to have it ripped off the nanosecond you ship.A patent makes it even easier... People's Shining Switching Power Supply Factories 1 through 37 can start working on it as soon as they can get a copy of the patent! For an extra penny per unit, PSSPSF will even use the good fake UL marking, rather than the standard one they did in Microsoft Paint. Matt Roberds
Reply by ●December 28, 20132013-12-28
On Saturday, December 28, 2013 10:14:31 PM UTC-5, mrob...@att.net wrote:> dagmarg...@yahoo.com wrote: > > > Without patents it wouldn't make sense to do all that work--make all > > that investment--only to have it ripped off the nanosecond you ship. > > A patent makes it even easier... People's Shining Switching Power Supply > > Factories 1 through 37 can start working on it as soon as they can get a > copy of the patent! For an extra penny per unit, PSSPSF will even use > the good fake UL marking, rather than the standard one they did in > Microsoft Paint.True, but you can sue. That's all a patent really boils down to-- the right to sue someone for copying your <gadget>. Trade secrets are better, if possible. But much hardware--esp. a topology, like this--is so easily reverse-engineered, that trade secrets are useless. Cheers, James Arthur
Reply by ●December 29, 20132013-12-29
This was promoted as having a size advantage but has no line isolation that would pass safety standards. One hint is that they never mentioned line isolation which would be an obvious problem. By the time they add line isolation this design won't be so very small, will it?
Reply by ●December 29, 20132013-12-29
On Saturday, December 28, 2013 11:33:59 PM UTC-5, Greegor wrote:> This was promoted as having a size > advantage but has no line isolation that > would pass safety standards. > > One hint is that they never mentioned > line isolation which would be an > obvious problem. > > By the time they add line isolation > this design won't be so very small, > will it?Dunno. Inserting a transformer after the switched-cap stage would do it. At many MHz it could be pretty small. Crudely suggested below, Fig. X. ======== FIG. 6 (from patent) ======== |<------- Charge pump --------->| . |<--- Synch. Buck --->| (~1MHz) . (5-300MHz) . / . .-----------o o-----------. . | / | . | .----o o----+ . Vin | C1 | C2 | . Lbuck >---o<-o-+--||-+--o<-o-+-||-+-o<-o-+-----+----o\ ====== | | . | o--' '--+---> Vout o o . --- o | \ \ . --- | --- o o . | === --- | | . === | === === === - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ======== FIG. X ======== / . .-----------o o-----------. . | / | . | .----o o----+ . | C1 | C2 | . >---o<-o-+--||-+--o<-o-+-||-+-o<-o-+-----+---. .--o\ ====== | | . | )|( o--' '--+---> Vout o o . --- )|( o | \ \ . --- )|( | --- o o . | | | --- | | . === | === === . === The patent talks about low-voltage uses too. In col. 8, lines 38-45 it mentions inputs of 1.5-5vdc, 6-12vdc, and 10-14vdc. The darn thing rambles all over the hills and into a few creeks--in lawyerese--so it's kind of hard to know where they're really going. It sounds like they didn't know either. The picture showed a line-operated "plug," which suggests they've got galvanic isolation. Cheers. James Arthur
Reply by ●December 29, 20132013-12-29
On Fri, 27 Dec 2013 08:42:46 -0800 (PST), dagmargoodboat@yahoo.com wrote:> >> Oh I see lots of problems, this cap switcher, when in series with the =buck,>> may charge smoothly, but then putting those caps in parallel >> on the next step, would require precise equal caps (so they were =charged to the same voltage),>> else you get big spikes (at that 1MHz) in the switching FETS to =equalize the cap voltages,> >Agreed--any cap mismatch produces dV(c), making spikey spikes when >switching from series to parallel configuration, same as a >conventional charge-pump. > >> If on chip caps then they could be equal, in any case what would aging=do with external caps?> >I haven't bothered with any numbers, but I rather doubt they could >use on-chip caps. The capacitances and voltages needed are too high. >So says my gut, anyhow. > >Let's see...if we wanted 60w (input) worth of charge packets at >1MHz at 170VDC input, >c=3D60W/(.5*v^2*1Mhz)=3D 4nF for the series string, or 12nF each for >a string of 3, at 57 volts each. > >That would be quite a chip.I would hope to shout. Dang, that would be massive caps on chip. Mebbe one of our IC design capable persons could enlighten us on the kind of area needed. These would have to be relatively good quality (for on = chip) caps as well. ?-)
Reply by ●December 29, 20132013-12-29
On Sun, 29 Dec 2013 20:13:00 -0800, josephkk <joseph_barrett@sbcglobal.net> wrote:>On Fri, 27 Dec 2013 08:42:46 -0800 (PST), dagmargoodboat@yahoo.com wrote: > >> >>> Oh I see lots of problems, this cap switcher, when in series with the buck, >>> may charge smoothly, but then putting those caps in parallel >>> on the next step, would require precise equal caps (so they were charged to the same voltage), >>> else you get big spikes (at that 1MHz) in the switching FETS to equalize the cap voltages, >> >>Agreed--any cap mismatch produces dV(c), making spikey spikes when >>switching from series to parallel configuration, same as a >>conventional charge-pump. >> >>> If on chip caps then they could be equal, in any case what would aging do with external caps? >> >>I haven't bothered with any numbers, but I rather doubt they could >>use on-chip caps. The capacitances and voltages needed are too high. >>So says my gut, anyhow. >> >>Let's see...if we wanted 60w (input) worth of charge packets at >>1MHz at 170VDC input, >>c=60W/(.5*v^2*1Mhz)= 4nF for the series string, or 12nF each for >>a string of 3, at 57 volts each. >> >>That would be quite a chip. > >I would hope to shout. Dang, that would be massive caps on chip. Mebbe >one of our IC design capable persons could enlighten us on the kind of >area needed. These would have to be relatively good quality (for on chip) >caps as well. > >?-)Realistically, the max easily obtainable is about 1pF/um^2 ...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.
Reply by ●December 30, 20132013-12-30
dagmargoodboat@yahoo.com wrote:> On Saturday, December 28, 2013 10:14:31 PM UTC-5, mrob...@att.net wrote: >> >> A patent makes it even easier... People's Shining Switching Power >> Supply Factories 1 through 37 can start working on it as soon as they >> can get a copy of the patent! > > True, but you can sue.Let me know how that lawsuit against People's Shining Switching Power Supply Factories 1 through 37 works out. Step 1: Figure out whom to sue and which court to do it in... :)> That's all a patent really boils down to-- the right to sue someone > for copying your <gadget>.Yeah, I understand why the money people like patents. To me it just seems like a road to spending a lot of money on activities that do not tend to make cool new things appear in the world, which seems like a moderately silly road to take. Matt Roberds
Reply by ●December 30, 20132013-12-30
JA > The picture showed a line-operated JA > "plug," which suggests they've JA > got galvanic isolation. They're taking PRE-ORDERS on their website.. This 65W laptop adapter is to be out in mid 2014. At CES 2014 in Las Vegas Jan 7-10 Venetian Level 1 Booth #74113 Anybody here going to CES? FINsix is supposedly based in Menlo Park, CA ASIC work is to be at: 27 Drydock Avenue, Boston, MA 02210 Venture capital backed. http://www.finsix.com/products/adapter.html http://www.finsix.com/company/team.html (Impressive) Their other product: http://www.finsix.com/products/led.html LED Driver (In Development) I just hope it's not another vaporware..
