Yup. I posted the Spice model three days ago. "Bubble Converter."
I'm using a dual comparator, one Schmitt buffer, and a SOT23 mosfet, instead of a store-bought chip.
Seems to work.
The 2N7000 is just a hack, because I don't have the right open-drain comparator yet.
-- 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
Is that blood on the lower left solder pad?
-- Regards, Joerg http://www.analogconsultants.com/
Some are remarkably quiet, for example on my Gammatech Durabook. But that's more like mil-spec laptop and has a proper gruond structure. On the Samsung NC-10 netbook, different story. Only two mains pins and lot of noise.
-- Regards, Joerg http://www.analogconsultants.com/
No, Sharpie. Red is +5.
I cleaned up all the blood. The burns heal by themselves.
-- 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
Metglas do. For boost PFC correction circuits.
-- "For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." (Richard Feynman)
Thanks, Lasse, that's an interesting approach.
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
But use a better chip that doesn't do subharmonic stuff and shield at least the inductor.
-- Regards, Joerg http://www.analogconsultants.com/
t
In RM and pot cores manufactured with a build-in air gap, only the central face is relieved - the outside layer of ferrite is continuous, which does h elp the shielding.
much higher (for a given current) and it's that much closer to saturation. (Maybe a lot closer!) So I guess I can believe that for a gapped inductor you can get more energy storage... you just have to run it at a higher cur rent. (I'll have to try putting in some numbers.)
oThere are books, and E.C. Snelling of Mullard, which got taken over by Phil ips, wrote several of them. They were horrible - Snelling produced the most confusing and misleading technical expositions that I ever came across.
When I ran into the Siemens Magnetic Materials data book in the late 1970's , it was a revelation - the application notes were clear, concise, well org anised and informative. The late great Tony Williams shared my enthusiasm a nd was known to forward several mega-bytes of .pdf files to interested part ies.
When Siemens became EPCOS, and the magnetic business was eventually sold of f to TDK the situation got a bit confused, and I've lost touch with the rel evant web-sites.
If Winfield Hill ever does get around to releasing the third edition of "Th e Art of Electronics" it may include a decent section on magnetics - I cert ainly put in a personal plea for one a few years ago.
At the time I laid a fair bit of emphasis on the transformer equation
V1 = L1. dI1/dt + M. dI2/dt
V2 = M. dI1/dt + L2. dI2/dt
where M = k.(L1.L2)^0.5
and k is around 0.99 for a well-coupled transformer. L1 and L2 are the indu ctances of the coupled windings and M is the mutual inductance of the two w indings (in Henries).
Snelling never seems to have used it, and it came as a revelation to me whe n I found it in the Siemens application notes.
For advanced stuff, look for the John Chan model of hysteritic inductors in the LTSpice help files where they do include the reference "John Chan et l a. in IEEE Transactions On Computer-Aided Design, Vol. 10. No. 4, April 199
1".-- Bill Sloman, Sydney
On 7/17/2013 5:46 PM, Joerg 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
Version 4 SHEET 1 880 900 WIRE -528 48 -656 48 WIRE -336 48 -528 48 WIRE -256 48 -336 48 WIRE -112 48 -160 48 WIRE -64 48 -112 48 WIRE 80 48 -64 48 WIRE 96 48 80 48 WIRE 256 48 240 48 WIRE 304 48 256 48 WIRE 464 48 368 48 WIRE 576 48 464 48 WIRE 592 48 576 48 WIRE 256 80 256 48 WIRE -656 96 -656 48 WIRE 464 112 464 48 WIRE 592 112 592 48 WIRE -336 128 -336 48 WIRE -240 128 -240 96 WIRE -64 144 -64 112 WIRE 256 144 -64 144 WIRE 80 192 80 48 WIRE 208 192 144 192 WIRE -240 208 -336 208 WIRE 208 224 208 192 WIRE 464 224 464 176 WIRE 592 224 592 192 WIRE -656 240 -656 176 WIRE 80 240 80 192 WIRE -64 272 -64 144 WIRE -64 336 -64 272 WIRE 0 336 -64 336 WIRE 80 336 80 320 WIRE 80 336 64 336 WIRE -64 352 -64 336 WIRE -64 352 -128 352 WIRE 208 352 208 304 WIRE 272 352 208 352 WIRE 288 352 272 352 WIRE 480 352 352 352 WIRE 592 352 480 352 WIRE 640 352 592 352 WIRE 80 368 80 336 WIRE -128 400 -128 352 WIRE -64 400 -64 352 WIRE 640 400 640 352 WIRE 272 416 272 352 WIRE 480 416 480 352 WIRE -128 512 -128 464 WIRE -64 512 -64 480 WIRE -64 512 -128 512 WIRE -64 528 -64 512 WIRE 480 528 480 480 WIRE 640 528 640 480 WIRE -528 560 -528 48 WIRE 272 560 272 480 WIRE 272 560 -528 560 FLAG 464 224 0 FLAG -656 240 0 FLAG 576 48 Out- FLAG 480 528 0 FLAG 592 352 Out+ FLAG 80 368 0 FLAG -64 528 0 FLAG -112 48 Switch FLAG -64 272 -15 FLAG 640 528 0 FLAG 592 224 0 SYMBOL ind2 64 224 R0 WINDOW 0 50 51 Left 2 WINDOW 3 60 86 Left 2 SYMATTR InstName L1 SYMATTR Value 150u SYMATTR Type ind SYMBOL cap 448 112 R0 SYMATTR InstName C1 SYMATTR Value 10u SYMBOL schottky 368 64 M270 WINDOW 0 32 32 VTop 2 WINDOW 3 -3 -7 VBottom 2 SYMATTR InstName D1 SYMATTR Value MBRS1100 SYMATTR Description Diode SYMATTR Type diode SYMBOL voltage -656 80 R0 SYMATTR InstName V1 SYMATTR Value 16 SYMBOL cap 464 416 R0 SYMATTR InstName C2 SYMATTR Value 10u SYMBOL schottky 288 368 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D2 SYMATTR Value MBRS1100 SYMATTR Description Diode SYMATTR Type diode SYMBOL schottky 256 480 M180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D3 SYMATTR Value MBRS1100 SYMATTR Description Diode SYMATTR Type diode SYMBOL schottky 240 80 R0 SYMATTR InstName D4 SYMATTR Value MBRS1100 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 240 32 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C5 SYMATTR Value 1u SYMBOL cap 144 176 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C6 SYMATTR Value 1u SYMBOL cap 0 320 M90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C4 SYMATTR Value 10u SYMBOL schottky -80 112 M180 WINDOW 0 47 33 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D5 SYMATTR Value MBRS1100 SYMATTR Description Diode SYMATTR Type diode SYMBOL res -80 384 R0 WINDOW 3 25 4 Left 2 SYMATTR InstName R2 SYMATTR Value 100 SYMBOL pmos -160 96 M270 SYMATTR InstName M1 SYMATTR Value Si9407AEY SYMBOL voltage -336 224 R180 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 WINDOW 3 -236 -15 Left 2 SYMATTR InstName V2 SYMATTR Value PULSE(0 -10 100n 10n 10n 2.75u 6.6u) SYMBOL res -256 112 R0 SYMATTR InstName R4 SYMATTR Value 100 SYMBOL schottky -144 400 R0 WINDOW 0 -58 28 Left 2 WINDOW 3 -104 94 Left 2 SYMATTR InstName D6 SYMATTR Value MBRS1100 SYMATTR Description Diode SYMATTR Type diode SYMBOL res 624 384 R0 SYMATTR InstName R1 SYMATTR Value 2k SYMBOL res 576 96 R0 SYMATTR InstName R5 SYMATTR Value 4k SYMBOL res 80 64 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R3 SYMATTR Value 5 SYMBOL res 192 208 R0 SYMATTR InstName R6 SYMATTR Value 5 TEXT 360 624 Left 2 !.tran 12m
-- 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
On further examination it has 100A peaks. Can the LT1071HV handle that? ...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.
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,
JK
OK, I see it now. I let the analysis run further out, and with R2 removed the -15V tends to drift down towards -20V. So that part depends on the balance between the load on the -15V and -45V supplies.
However, putting R2 back in the circuit and increasing it to 1k seems to solve the problem. An alternative might be to increase the load on the -45V supply, or simply keep the -15V heavily loaded.
Altogether not bad at all. You have +/-15v and +/-45V supplies with a remarkably small bunch of parts. And no ringing!
Thanks,
JK
That's the load, i.e. it represents the circuit that needs the -15V.
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.
Thanks. Blind luck and bloody ignorance this time round though!
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
n't
l face is relieved - the outside layer of ferrite is continuous, which does help the shielding.
To
ilips, wrote several of them. They were horrible - Snelling produced the mo st confusing and misleading technical expositions that I ever came across.
's, it was a revelation - the application notes were clear, concise, well o rganised and informative. The late great Tony Williams shared my enthusiasm and was known to forward several mega-bytes of .pdf files to interested pa rties.
off to TDK the situation got a bit confused, and I've lost touch with the r elevant web-sites.
The Art of Electronics" it may include a decent section on magnetics - I ce rtainly put in a personal plea for one a few years ago.
ductances of the coupled windings and M is the mutual inductance of the two windings (in Henries).
hen I found it in the Siemens application notes.
in the LTSpice help files where they do include the reference "John Chan et la. in IEEE Transactions On Computer-Aided Design, Vol. 10. No. 4, April 1
991".OK thanks Bill, So I should go looking for the Siemens book. I'll see wha t the web has to offer.
George H.
It's probably long gone. If you want to also learn about switcher design you might want to take a look at a book by Pressman. I don't have i but heard it being lauded by lots of engineers. Maybe someone can shed light as to the exact title or ISBN. On some online stores you can take a preview before buying.
-- Regards, Joerg http://www.analogconsultants.com/
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
--
| 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.
Pressman, Billings, & Morey, "Switching Power Supply Design" 3rd Ed, McGraw Hill.
I bought a copy the other day but haven't spent much time with it yet.
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
I'll probably hang it on the output of an LM2594.
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
0.5A Limit, or is there a way to set it lower? ...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.
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
-- 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
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