On 7/18/2013 7:19 PM, Jim Thompson wrote:> On Thu, 18 Jul 2013 17:47:24 -0400, Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> On 7/18/2013 2:24 PM, Jim Thompson wrote: >>> On Thu, 18 Jul 2013 10:06:17 -0700, Jim Thompson >>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>> On Thu, 18 Jul 2013 10:53:53 -0400, Phil Hobbs >>>> <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>> >>>>> On 07/18/2013 10:49 AM, Jim Thompson wrote: >>>>>> On Thu, 18 Jul 2013 10:39:22 -0400, Phil Hobbs >>>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>> >>>>>>> On 07/18/2013 10:32 AM, Jim Thompson wrote: >>>>>>>> On Thu, 18 Jul 2013 08:32:13 -0400, Phil Hobbs >>>>>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>>> >>>>>>>>> On 07/17/2013 11:01 PM, John K wrote: >>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>>>>> >>>>>>>>>>> Okay, thanks all--I think I've got it figured out. I'm already using >>>>>>>>>>> a Simple Switcher buck to make -15 from +16-20, and I'll piggyback off >>>>>>>>>>> the free AC and then use regulated cap multipliers to make a nice >>>>>>>>>>> quiet +-40ish volts. >>>>>>>>>>> >>>>>>>>>>> Cartoon attached. >>>>>>>>>>> >>>>>>>>>>> Cheers >>>>>>>>>>> >>>>>>>>>>> Phil Hobbs >>>>>>>>>> >>>>>>>>>> Very nice. You got rid of the horrible ringing at the drain on most of >>>>>>>>>> the other versions posted here. That is very nice. >>>>>>>>>> >>>>>>>>>> I was wondering why you want to dump 2.25 watts into R2, the 100 ohm >>>>>>>>>> going from -15V to ground. >>>>>>>>>> >>>>>>>>> >>>>>>>>> That's the load, i.e. it represents the circuit that needs the -15V. >>>>>>>>> >>>>>>>>>> I couldn't see why it was needed, so I removed it. Circuit works fine. >>>>>>>>>> >>>>>>>>>> There may be some loading effect on either or both supplies that require >>>>>>>>>> it, but as currently shown, the reason is not apparent. >>>>>>>>>> >>>>>>>>>> Similarly, D6 which was in parallel with R2 doesn't seem to be needed >>>>>>>>>> either. Removed it also. Circuit works fine. >>>>>>>>> >>>>>>>>> That was there to get rid of a weird polarity reversal at power-on. The >>>>>>>>> power-on transient isn't representative of what the real circuit will >>>>>>>>> do--the chip has built-in current limiting, whereas this version goes up >>>>>>>>> to like 7A on power-up--but putting +3V on a -15V rail isn't usually >>>>>>>>> considered too healthy for the rest of the circuitry. >>>>>>>> >>>>>>>> Running it on LTspice: The current thru M1 goes up to 12A, with a half >>>>>>>> sinusoidal envelope, base width of nearly a millisecond. What is the >>>>>>>> actual schematic/chip that "has built-in current limiting"? >>>>>>>> >>>>>>>> [snip] >>>>>>>> >>>>>>>> ...Jim Thompson >>>>>>>> >>>>>>> >>>>>>> I'll probably hang it on the output of an LM2594. >>>>>>> >>>>>>> >>>>>>> Cheers >>>>>>> >>>>>>> Phil Hobbs >>>>>> >>>>>> 0.5A Limit, or is there a way to set it lower? >>>>>> >>>>>> ...Jim Thompson >>>>>> >>>>> >>>>> No, there isn't, but half an amp isn't awful. The current limit on that >>>>> chip is a bit squishy, as well--the datasheet limits are pretty wide, >>>>> but it's guaranteed to be less than 1.25A iirc. >>>>> >>>>> Cheers >>>>> >>>>> Phil Hobbs >>>> >>>> That's what I was noticing... it's a switch current limit, not an >>>> output current limit. But probably safe. >>>> >>>> ...Jim Thompson >>> >>> You might want to reconsider and add soft-start to your "cartoon".... >>> >>> Subject: Hobb's Cartoon (SED) - HobbsCartoon-with_CL.png >>> Date: Thu, 18 Jul 2013 11:19:26 -0700 >>> Message-ID: <abcgu89uf09kt8l0n55pvm5su9c7ct6li6@4ax.com> >>> >>> Using the LM2594, you're sort of caught between a rock and a >>> hard-place... large load (on LM2594) capacitor, huge peak currents on >>> your add-on inverter, smaller capacitor... sag your 16V. >>> >>> ...Jim Thompson >>> >> >> Okay, here's the slightly revised cartoon, with a JL efficiency meter in >> the lower left corner. (Handy, like a scope trace.) >> >> It'll probably need a preregulator to avoid having the outputs go above >> 60V if somebody attaches the wrong wall wart. >> >> Fun stuff. >> >> Cheers >> >> Phil Hobbs >> >> Version 4 >> SHEET 1 1656 900 >> WIRE -784 48 -832 48 >> WIRE -656 48 -704 48 >> WIRE -624 48 -656 48 >> WIRE -576 48 -624 48 >> WIRE -368 48 -576 48 >> WIRE -288 48 -368 48 >> WIRE -64 48 -192 48 >> WIRE 80 48 -64 48 >> WIRE 176 48 80 48 >> WIRE 256 48 176 48 >> WIRE 272 48 256 48 >> WIRE 368 48 352 48 >> WIRE 448 48 432 48 >> WIRE 496 48 448 48 >> WIRE 656 48 560 48 >> WIRE 784 48 656 48 >> WIRE 800 48 784 48 >> WIRE 448 80 448 48 >> WIRE -832 96 -832 48 >> WIRE 656 96 656 48 >> WIRE 800 112 800 48 >> WIRE -368 128 -368 48 >> WIRE -272 128 -272 96 >> WIRE -656 144 -656 112 >> WIRE -64 144 -64 112 >> WIRE 160 144 -64 144 >> WIRE 336 144 160 144 >> WIRE 448 144 416 144 >> WIRE 80 176 80 48 >> WIRE 656 208 656 160 >> WIRE -368 224 -368 208 >> WIRE -272 224 -272 208 >> WIRE -272 224 -368 224 >> WIRE 800 224 800 192 >> WIRE -832 240 -832 176 >> WIRE 256 240 256 48 >> WIRE 272 240 256 240 >> WIRE 400 240 336 240 >> WIRE 400 256 400 240 >> WIRE -64 272 -64 144 >> WIRE 0 272 -64 272 >> WIRE 80 272 80 256 >> WIRE 80 272 64 272 >> WIRE 80 304 80 272 >> WIRE -64 352 -64 272 >> WIRE -64 352 -128 352 >> WIRE 400 352 400 336 >> WIRE 464 352 400 352 >> WIRE 544 352 464 352 >> WIRE 656 352 608 352 >> WIRE 800 352 656 352 >> WIRE 464 368 464 352 >> WIRE -128 384 -128 352 >> WIRE -64 384 -64 352 >> WIRE 656 400 656 352 >> WIRE 800 400 800 352 >> WIRE -800 416 -864 416 >> WIRE -672 416 -720 416 >> WIRE -864 432 -864 416 >> WIRE -672 448 -672 416 >> WIRE 464 448 464 432 >> WIRE -128 496 -128 448 >> WIRE -64 496 -64 464 >> WIRE -64 496 -128 496 >> WIRE -64 512 -64 496 >> WIRE 656 512 656 464 >> WIRE 800 528 800 480 >> WIRE -864 544 -864 512 >> WIRE -672 544 -672 512 >> WIRE -576 560 -576 48 >> WIRE 176 560 -576 560 >> WIRE 464 560 464 528 >> WIRE 464 560 176 560 >> FLAG 656 208 0 >> FLAG -832 240 0 >> FLAG 784 48 Out- >> FLAG 656 512 0 >> FLAG 800 352 Out+ >> FLAG 80 304 0 >> FLAG -64 512 0 >> FLAG 176 48 Switch >> FLAG 160 144 -15 >> FLAG 800 528 0 >> FLAG 800 224 0 >> FLAG -656 144 0 >> FLAG 176 560 Vin >> FLAG -832 48 Vwart >> FLAG -624 48 Vin >> FLAG -864 544 0 >> FLAG -672 544 0 >> FLAG -672 416 Eff >> SYMBOL ind2 64 160 R0 >> WINDOW 0 50 51 Left 2 >> WINDOW 3 60 86 Left 2 >> SYMATTR InstName L1 >> SYMATTR Value 150u >> SYMATTR Type ind >> SYMATTR SpiceLine Rser=0.2 Cpar=20p >> SYMBOL cap 640 96 R0 >> SYMATTR InstName C1 >> SYMATTR Value 1u >> SYMBOL diode 560 64 M270 >> WINDOW 0 42 32 VTop 2 >> WINDOW 3 -3 -7 VBottom 2 >> SYMATTR InstName D1 >> SYMATTR Value BAV99 >> SYMBOL voltage -832 80 R0 >> WINDOW 0 40 54 Left 2 >> WINDOW 3 -109 209 Left 2 >> WINDOW 123 0 0 Left 2 >> WINDOW 39 0 0 Left 2 >> SYMATTR InstName V1 >> SYMATTR Value PULSE(0 {Vraw} 100n 10n 10n 1) >> SYMBOL cap 640 400 R0 >> SYMATTR InstName C2 >> SYMATTR Value 1u >> SYMBOL diode 544 368 R270 >> WINDOW 0 32 62 VTop 2 >> WINDOW 3 -7 64 VBottom 2 >> SYMATTR InstName D2 >> SYMATTR Value BAV99 >> SYMBOL diode 448 432 M180 >> WINDOW 0 55 41 Left 2 >> WINDOW 3 39 0 Left 2 >> SYMATTR InstName D3 >> SYMATTR Value BAV99 >> SYMBOL diode 432 80 R0 >> SYMATTR InstName D4 >> SYMATTR Value BAV99 >> SYMBOL cap 432 32 R90 >> WINDOW 0 0 32 VBottom 2 >> WINDOW 3 32 32 VTop 2 >> SYMATTR InstName C5 >> SYMATTR Value 100n >> SYMBOL cap 336 224 R90 >> WINDOW 0 0 32 VBottom 2 >> WINDOW 3 32 32 VTop 2 >> SYMATTR InstName C6 >> SYMATTR Value 100n >> SYMBOL cap 0 256 M90 >> WINDOW 0 0 32 VBottom 2 >> WINDOW 3 32 32 VTop 2 >> SYMATTR InstName C4 >> SYMATTR Value 100u >> SYMBOL schottky -80 112 M180 >> WINDOW 0 47 33 Left 2 >> WINDOW 3 24 0 Left 2 >> SYMATTR InstName D5 >> SYMATTR Value 1N5819 >> SYMATTR Description Diode >> SYMATTR Type diode >> SYMBOL res -80 368 R0 >> WINDOW 3 53 81 Left 2 >> SYMATTR Value {Load15} >> SYMATTR InstName R2 >> SYMBOL pmos -192 96 M270 >> WINDOW 0 72 72 VLeft 2 >> WINDOW 3 -17 64 VLeft 2 >> SYMATTR InstName M1 >> SYMATTR Value Si9407AEY >> SYMBOL voltage -368 224 R180 >> WINDOW 123 0 0 Left 2 >> WINDOW 39 0 0 Left 2 >> WINDOW 3 -269 -26 Left 2 >> SYMATTR Value PULSE(0 -10 .5u 10n 10n {6.6u*10.3/(8+Vraw)} 6.6u) >> SYMATTR InstName V2 >> SYMBOL res -288 112 R0 >> SYMATTR InstName R4 >> SYMATTR Value 100 >> SYMBOL schottky -144 384 R0 >> WINDOW 0 -58 28 Left 2 >> WINDOW 3 -104 94 Left 2 >> SYMATTR InstName D6 >> SYMATTR Value 1N5819 >> SYMATTR Description Diode >> SYMATTR Type diode >> SYMBOL res 784 384 R0 >> SYMATTR InstName R1 >> SYMATTR Value 4k >> SYMBOL res 784 96 R0 >> SYMATTR InstName R5 >> SYMATTR Value {LoadM45} >> SYMBOL res 256 64 R270 >> WINDOW 0 32 56 VTop 2 >> WINDOW 3 0 56 VBottom 2 >> SYMATTR InstName R3 >> SYMATTR Value {Rsoft} >> SYMBOL res 384 240 R0 >> SYMATTR InstName R6 >> SYMATTR Value {Rsoft} >> SYMBOL res -800 64 R270 >> WINDOW 0 32 56 VTop 2 >> WINDOW 3 0 56 VBottom 2 >> SYMATTR InstName R7 >> SYMATTR Value 2 >> SYMBOL cap -672 48 R0 >> WINDOW 0 -26 61 Left 2 >> WINDOW 3 -19 87 Left 2 >> SYMATTR InstName C3 >> SYMATTR Value 47u >> SYMBOL res 448 432 R0 >> WINDOW 0 48 38 Left 2 >> SYMATTR InstName R8 >> SYMATTR Value {Rsoft} >> SYMBOL res 432 128 R90 >> WINDOW 0 0 56 VBottom 2 >> WINDOW 3 32 56 VTop 2 >> SYMATTR InstName R9 >> SYMATTR Value {Rsoft} >> SYMBOL bv -864 416 R0 >> WINDOW 3 -37 169 Left 2 >> SYMATTR Value V=(V(out+)*I(R1)+V(out-)*I(R5)+V(-15)*I(R2))/(-V(Vin)*I(V1)) >> SYMATTR InstName B1 >> SYMBOL res -816 432 R270 >> WINDOW 0 32 56 VTop 2 >> WINDOW 3 0 56 VBottom 2 >> SYMATTR InstName R10 >> SYMATTR Value 1 >> SYMBOL cap -688 448 R0 >> WINDOW 0 -45 34 Left 2 >> WINDOW 3 -57 70 Left 2 >> SYMATTR InstName C7 >> SYMATTR Value 100u >> TEXT 600 640 Left 2 !.tran 8mm >> TEXT -120 632 Left 2 !.param Load15=100 >> TEXT -120 600 Left 2 !.param LoadM45=2.2k >> TEXT 176 600 Left 2 !.MODEL BAV99 D IS=4.858E-9 N=2.038 RS=1.238 XTI=3 >> TEXT 280 -32 Left 2 ;Add this part to the -15V switcher >> TEXT -72 -48 Left 2 ;Switcher >> TEXT -72 -16 Left 2 ;External >> TEXT -80 16 Left 2 ;Components >> TEXT -272 360 Left 2 ;-15V Load >> TEXT -488 -24 Left 2 ;LM2594 -15V switcher chip >> TEXT -488 -64 Left 2 ;Toy model of the >> TEXT 736 0 Left 2 ;-43-47V >> TEXT 744 304 Left 2 ;+44-52V >> TEXT -304 -144 Left 2 ;ADDING +-40V UNREGULATED SUPPLIES TO THE -15V >> SWITCHER >> TEXT 608 -144 Left 2 ;7/18/13 PH >> TEXT 152 632 Left 2 !.param Rsoft=10 >> TEXT -504 632 Left 2 !.step param Vraw 16 22 2 >> RECTANGLE Normal 96 544 -288 336 2 >> RECTANGLE Normal 112 336 112 336 2 >> RECTANGLE Normal -96 -64 112 320 2 >> RECTANGLE Normal -544 -96 -96 272 2 >> RECTANGLE Normal 720 544 240 -64 2 > > I don't think a wall-wart is going to look like 2 Ohms... it's going > to be current limited... even if it is made in China ;-) > > ...Jim Thompson >The 2 ohms is the initial resistance of the polyswitch in the input protection network. Quite a lot of computer wall warts have a big cap at the output, leading to crackling sounds when you plug them into the back of the machine. Anyway, their current limits will be up in the 5A range, which is way above what my little switcher will allow through on a steady state basis. 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 USA +1 845 480 2058 hobbs at electrooptical dot net http://electrooptical.net
Flyback vs half-bridge
Started by ●July 16, 2013
Reply by ●July 18, 20132013-07-18
Reply by ●July 18, 20132013-07-18
On Friday, 19 July 2013 02:16:40 UTC+10, Joerg wrote:> Bill Sloman wrote:=20 > > On Friday, 19 July 2013 00:37:44 UTC+10, Phil Hobbs wrote: > >> On 07/18/2013 10:06 AM, Joerg wrote:=20 >=20 > [...] > =20 > >>> It's probably long gone. If you want to also learn about switcher=20 > >>> design you might want to take a look at a book by Pressman. I > >>> don't have it but heard it being lauded by lots of engineers. >=20 > >>> Maybe someone can shed light as to the exact title or ISBN. On=20 > >>> some online stores you can take a preview before buying.=20 > >> =20 > >> Pressman, Billings, & Morey, "Switching Power Supply Design" 3rd > >> Ed, McGraw Hill.=20 > >> =20 > >> I bought a copy the other day but haven't spent much time with it=20 > >> yet.=20 > > =20 > > I've got a copy of the second edition ISBN 0-07-052236-7 > >=20 > > The chapter on magnetics is comprehensive, and even covers the skin > > effect, and the "proximity effect" which I've never heard of before. > > Pedagogically, it's rubbish - almost as bad as Snelling. The author > > assumes that the reader understands the basics, and concentrates on > > the complicated detail. > =20 > That's what most books about advanced technologies do. If they didn't=20 > then most of the forests on this planet would be depleted by now :-)They do it because they can get away with it. It takes more work to organis= e the information in a way that leads the reader through it, and if there's= not a lot of competition they don't have to bother. My impression is that = it doesn't take much - if any - extra text. Ralph Morrison's book "Grounding and Shielding Techniques" - I've now got t= he 4th edition, ISBN 0-471-24518-6 - was remarkably easy to read, and relat= ively slim. =20> But seriously, a person with lacking EE basics should not be designing > switchers without first becoming proficient enough, that's something the > pros should do.I've spent a career doing state of the art stuff in a couple of different a= reas. Getting proficient enough involved a lot of reading, and most of the = books I had to read were poorly organised and hard to plow through. William= s and Taylor's "Electronic Filter Design Handbook" 0-07-070430-9 is a fairl= y horrible example, which doesn't stop it from being an extremely useful bo= ok. Hell - at one point I read a Ph.D. thesis in German "Electronenstrahl Tests= ystem fur die funktionscontrolle und fehleranalyse hochstintegrieter schalt= kreise" by Eberhard Menzel (which is actually pretty well organised). I've = still got it - a two page thesis copied onto a hundred pages of A4 at the r= ate of two pages of thesis for one page of A4. Not an easy read. --=20 Bill Sloman, Sydney
Reply by ●July 18, 20132013-07-18
Bill Sloman wrote:> On Friday, 19 July 2013 02:16:40 UTC+10, Joerg wrote:[...]>> But seriously, a person with lacking EE basics should not be >> designing switchers without first becoming proficient enough, >> that's something the pros should do. > > I've spent a career doing state of the art stuff in a couple of > different areas. Getting proficient enough involved a lot of reading, > and most of the books I had to read were poorly organised and hard to > plow through. Williams and Taylor's "Electronic Filter Design > Handbook" 0-07-070430-9 is a fairly horrible example, which doesn't > stop it from being an extremely useful book. >That is actually one of the books I used the most in my career. Until affordable computer tools showed up, now I hardly use it anymore, thinking about donating it. IMHO it is a good book, and lots of engineers at clients thought so as well. Most already had it on the shelf and I probably triggered another half dozen book sales. Without getting a cut, hurumph ...> Hell - at one point I read a Ph.D. thesis in German "Electronenstrahl > Testsystem fur die funktionscontrolle und fehleranalyse > hochstintegrieter schaltkreise" by Eberhard Menzel (which is actually > pretty well organised). I've still got it - a two page thesis copied > onto a hundred pages of A4 at the rate of two pages of thesis for one > page of A4. Not an easy read. >I've had not-so-easy reads as well. Mostly in the form of source code that needed to be review where all comments were in Spanish, and then some Portuguese. Also Italian. Every time I got to a power supply section (they call that alimentazione) I became hungry. -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●July 18, 20132013-07-18
On Friday, 19 July 2013 09:21:47 UTC+10, Phil Hobbs wrote:> On 7/18/2013 7:15 PM, Harry D wrote: > >=20 > > oK, Here is a duh question, When in LTSPICE, how do you save that top==20> > level *.asc file you show above?=20 > > Thanks, Harry >=20 > There are a couple of methods. >=20 > (BTW you should get a real newsreader and a (free) Eternal September =20 > account--lots of people round here killfile anyone from Google Groups =20 > because of the spam and the zillions of blank lines.=20 >=20 > http://eternal-september.org ). > =20 > If you have an eternal-september.org account, you can just use your =20 > mailer and attach the .asc file as you would any other file. > =20 > Otherwise, open the .asc file in a text editor, and cut-n-paste it into ==20> your post. > =20 > Mike Engelhardt understands the goodness of human-readable files!He's not the first. The 1997 Linux gEDA project insisted on human-readable = files from the start. Back around 1988 I started on electronic CAD on a Uni= x-based Metheus system where you could use grep and awk to edit your design= files - great for shifting large blocks of circuit around quickly. http://en.wikipedia.org/wiki/GEDA --=20 Bill Sloman, Sydney
Reply by ●July 19, 20132013-07-19
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:> On 07/17/2013 11:01 PM, John K wrote: >> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>> Very nice. You got rid of the horrible ringing at the drain on most >> of the other versions posted here. That is very nice. >> >> I was wondering why you want to dump 2.25 watts into R2, the 100 ohm >> going from -15V to ground. >> > > That's the load, i.e. it represents the circuit that needs the -15V.Thanks, I was wondering if that was the case.>> Similarly, D6 which was in parallel with R2 doesn't seem to be needed >> either. Removed it also. Circuit works fine.> That was there to get rid of a weird polarity reversal at power-on.That is strange. Was that on the bench or in LTspice? It's not clear how that could happen.>The > power-on transient isn't representative of what the real circuit will > do--the chip has built-in current limiting, whereas this version goes > up to like 7A on power-up--but putting +3V on a -15V rail isn't > usually considered too healthy for the rest of the circuitry.To protect against polarity reversal, I add diodes at each voltage output to prevent damage in the event of an inadvertent short, for example when probing. All it takes is one incident.>> I think the reason R2 is not needed is because whatever charge is >> introduced into C4 via D5 is removed on the next half cycle via D4 >> and dumped into R5. So the load presented by R5 is all that is needed >> to keep -15V on C4. Good guess? >> >> I really have to congratulate you. Yours is the best circuit I've >> seen so far, especially for eliminating noise from the ringing. You >> truly have a gift for design that most others lack. > > Thanks. Blind luck and bloody ignorance this time round though!I think it's more than that:) I never paid much attention to switchers due to the RF noise they spew out. However, I started getting interested when you began posting your work on switching circuits. Knowing your sensitivity to nanovolts of noise in most of your circuits, I started thinking if you can make them work, then maybe there's some hope I might be able to get some success also. So you have definitely changed my direction. I should add that nobody else could have done that! Thanks,> Cheers > > Phil HobbsJK
Reply by ●July 19, 20132013-07-19
On a sunny day (Wed, 17 Jul 2013 20:47:22 -0400) it happened Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote in <51E73B1A.7060402@electrooptical.net>:>Okay, thanks all--I think I've got it figured out. I'm already using a >Simple Switcher buck to make -15 from +16-20, and I'll piggyback off the >free AC and then use regulated cap multipliers to make a nice quiet >+-40ish volts. > >Cartoon attached. > >Cheers > >Phil Hobbs > >Version 4 >SHEET 1 880 900That is completely insane. It is a worse design than Chim Pansee made after being told she could not go back to Affrica, and being fed Bananas in a cage in the zoo. This is how it SHOULD be done: http://panteltje.com/pub/simple_resonant_voltage_converter_IMG_3957.JPG only 10 components, better output regulation, better efficiency, less RFI, better reliability, better MTBF, less size, cheaper, etc etc. and as old as the world: http://panteltje.com/panteltje/z80/system14/diagrams/io-1.jpg 1985 EEPROM programmer programming volts generator. I have the same circuit in an other programmer I designed, still working after 30 years or more.
Reply by ●July 19, 20132013-07-19
On a sunny day (Thu, 18 Jul 2013 03:01:08 GMT) it happened John K <spam@me.not> wrote in <XnsA200EA29B73C5idtokenpost@69.16.179.20>:>Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> Okay, thanks all--I think I've got it figured out. I'm already using >> a Simple Switcher buck to make -15 from +16-20, and I'll piggyback off >> the free AC and then use regulated cap multipliers to make a nice >> quiet +-40ish volts. >> >> Cartoon attached. >> >> Cheers >> >> Phil Hobbs > >Very nice. You got rid of the horrible ringing at the drain on most of >the other versions posted here. That is very nice. > >I was wondering why you want to dump 2.25 watts into R2, the 100 ohm >going from -15V to ground. > >I couldn't see why it was needed, so I removed it. Circuit works fine. > >There may be some loading effect on either or both supplies that require >it, but as currently shown, the reason is not apparent. > >Similarly, D6 which was in parallel with R2 doesn't seem to be needed >either. Removed it also. Circuit works fine. > >I think the reason R2 is not needed is because whatever charge is >introduced into C4 via D5 is removed on the next half cycle via D4 and >dumped into R5. So the load presented by R5 is all that is needed to >keep -15V on C4. Good guess? > >I really have to congratulate you. Yours is the best circuit I've seen >so far, especially for eliminating noise from the ringing. You truly >have a gift for design that most others lack. > >Thanks, > >JKFor Gods sake stop feeding the man's ego, you know how dangerous bubbles can be.
Reply by ●July 19, 20132013-07-19
On 7/19/2013 2:44 AM, Jan Panteltje wrote:> On a sunny day (Wed, 17 Jul 2013 20:47:22 -0400) it happened Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote in > <51E73B1A.7060402@electrooptical.net>: > >> Okay, thanks all--I think I've got it figured out. I'm already using a >> Simple Switcher buck to make -15 from +16-20, and I'll piggyback off the >> free AC and then use regulated cap multipliers to make a nice quiet >> +-40ish volts. >> >> Cartoon attached. >> >> Cheers >> >> Phil Hobbs >> >> Version 4 >> SHEET 1 880 900 > > That is completely insane. > It is a worse design than Chim Pansee made after being told > she could not go back to Affrica, and being fed Bananas in a cage > in the zoo. > > This is how it SHOULD be done: > http://panteltje.com/pub/simple_resonant_voltage_converter_IMG_3957.JPG > > only 10 components, > better output regulation, > better efficiency, > less RFI, > better reliability, > better MTBF, > less size, > cheaper, > etc etc. > and as old as the world: > http://panteltje.com/panteltje/z80/system14/diagrams/io-1.jpg > 1985 > EEPROM programmer programming volts generator. > > I have the same circuit in an other programmer I designed, still working after > 30 years or more.Glad to see that your ego remains unimpaired as well. ;) Having grown up as a discrete-circuit designer, I like the resonant converter, and if I didn't need a higher-current negative supply as well, I might well do it that way, if I could find a standard part that would work for the transformer. My gizmo piggybacks on an existing -15V supply, and requires two dual diodes, one quad resistor pack, and four cheap caps. Yours requires a custom transformer, four caps, one resistor, and one transistor, and a dual diode. I'd need the -15V switcher anyway, so my scheme is considerably simpler and cheaper than yours. What's insane about that? 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 USA +1 845 480 2058 hobbs at electrooptical dot net http://electrooptical.net
Reply by ●July 19, 20132013-07-19
On a sunny day (Fri, 19 Jul 2013 08:34:08 -0400) it happened Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote in <ksbbch$s7i$1@dont-email.me>:>> This is how it SHOULD be done: >> http://panteltje.com/pub/simple_resonant_voltage_converter_IMG_3957.JPG >> >> only 10 components, >> better output regulation, >> better efficiency, >> less RFI, >> better reliability, >> better MTBF, >> less size, >> cheaper, >> etc etc. >> and as old as the world: >> http://panteltje.com/panteltje/z80/system14/diagrams/io-1.jpg >> 1985 >> EEPROM programmer programming volts generator. >> >> I have the same circuit in an other programmer I designed, still working after >> 30 years or more. > >Glad to see that your ego remains unimpaired as well. ;)Yes I am glad too:-)>Having grown up as a discrete-circuit designer, I like the resonant >converter, and if I didn't need a higher-current negative supply as >well, I might well do it that way, if I could find a standard part that >would work for the transformer.If your designs require 'standard parts', well in short, US would never have made it to the moon. Poeple have fobia for coils and transformers, especially winding a wire around some former it seems. Should be a training requirement.>My gizmo piggybacks on an existing -15V supply, and requires two dual >diodes, one quad resistor pack, and four cheap caps.Your load regulation sucks, always does with R3 R6 C5 C6 and diodes in series. Your efficiency sucks for the same reason, you waste power in resistors and diode drops. Where does V2 come from, it is floating? You are driving R5 and R1 as load I presume, hardly any current at all. This type of resonant converter I did draw can easily power some relais, a very big industrial plant has boards with it I designed with that converter to isolate relays... Probably no switcher needed, just an extra diode and capacitor (depends on how stable supply is). Anyways now I know you have a fetish for Schotkeys on top of one for Ferry High value resistors.. No problem for me.>Yours requires a custom transformer, four caps, one resistor, and one >transistor, and a dual diode.10 parts, numbers are in the diagram.>I'd need the -15V switcher anyway, so my scheme is considerably simpler >and cheaper than yours. What's insane about that?What is 'simpler?' ??????????????>Cheers > >Phil Hobbs
Reply by ●July 19, 20132013-07-19
On a sunny day (Fri, 19 Jul 2013 12:57:30 GMT) it happened Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote in <ksbd53$ckp$1@news.albasani.net>:>>Yours requires a custom transformer, four caps, one resistor, and one >>transistor, and a dual diode. > >10 parts, numbers are in the diagram. > > >>I'd need the -15V switcher anyway, so my scheme is considerably simpler >>and cheaper than yours. What's insane about that? > >What is 'simpler?' > >??????????????And CHEAPER? ???????????????????????????? Not even in one of, or in milions. Last night, even before seeing that LT spice thing, I was remembering a watch I won at a fair. It had a potcore in it the size of a pin-head (the type you get when you buy a new shirt). I think the watch price was around 3 $ (new including battery). The potcore was part of a resonant circuit to drive the alarm beeper.
