fredag den 5. januar 2024 kl. 05.15.37 UTC+1 skrev Anthony William Sloman:> On Thursday, January 4, 2024 at 8:16:06 PM UTC+11, Lasse Langwadt Christensen wrote: > > torsdag den 4. januar 2024 kl. 03.10.48 UTC+1 skrev Anthony William Sloman: > > > On Thursday, January 4, 2024 at 10:57:28 AM UTC+11, Lasse Langwadt Christensen wrote: > > > > torsdag den 4. januar 2024 kl. 00.42.02 UTC+1 skrev john larkin: > > > > > On Wed, 3 Jan 2024 12:44:24 -0800 (PST), Lasse Langwadt Christensen > > > > > <lang...@fonz.dk> wrote: onsdag den 3. januar 2024 kl. 20.29.19 UTC+1 skrev john larkin: > > > > > >> There is a new-to-me power supply architecture, an H-bridge driving a > > > > > >> load, but with the phases on the two sides slid around to control > > > > > >> delivered power. TI does that in some chips, like UCC2895. I may have > > > > > >> seen the architecture first in this ng. > > > > > >> > > > > > >> Anyhow, I was thinking about a high-voltage power supply with the > > > > > >> phase-shifted bridge driving a series-resonant transformer. > > > > > >> > > > > > >> https://www.dropbox.com/scl/fi/tbiioti0gt2emknjc61p7/Res_HV_Supply.jpg?rlkey=f1gryr8vr4jdu2y46wsz6ch2k&raw=1 > > > > > >> > > > > > >> I wonder if one of the cores of an RP2040 could do this without an > > > > > >> FPGA. It would of course need a voltage feedback loop in software too. > > > > > > > > > > > >should easily do that with the PIOs > > > > > If I did a 2-channel HV supply, that would need, I guess, three square > > > > > waves. On as the "reference" side of both supplies, and then a phase > > > > > shiftable square wave for each supply. > > > > > > > > > > The frequency might be, say, 50 to 100 KHz and I'd want to shift the > > > > > phases with 10s of ns resolution. Probably needs an FPGA. > > > > PIOs run at the full up to 133MHz pico clock > > > https://www.onsemi.com/pdf/datasheet/mc100ep196-d.pdf > > > > > > offers up to 10.6nsec digitally tunable in steps of 10ps and is analog fine tunable below that. Similar parts from Motorola date back to about the early 1990's. The delay has some temperature drift, but if you are fine tuning for a specific output voltage the feedback loop can take that out. > > > > > and what would you use that for? > Fine control of the male-to-space ratio. I did think that was obvious.you must be joking, not even Rube Goldberg would think that was a good idea
HV power supply maybe
Started by ●January 3, 2024
Reply by ●January 5, 20242024-01-05
Reply by ●January 5, 20242024-01-05
On Wednesday, January 3, 2024 at 2:29:19 PM UTC-5, john larkin wrote:> There is a new-to-me power supply architecture, an H-bridge driving a > load, but with the phases on the two sides slid around to control > delivered power. TI does that in some chips, like UCC2895. I may have > seen the architecture first in this ng. > > Anyhow, I was thinking about a high-voltage power supply with the > phase-shifted bridge driving a series-resonant transformer. > > https://www.dropbox.com/scl/fi/tbiioti0gt2emknjc61p7/Res_HV_Supply.jpg?rlkey=f1gryr8vr4jdu2y46wsz6ch2k&raw=1 > > I wonder if one of the cores of an RP2040 could do this without an > FPGA. It would of course need a voltage feedback loop in software too.May I ask how much power is being consumed in the 500 V circuit? Since your step-up is ~ 20:1, that would be a reduction of load resistance by a factor of 400 in the primary circuit, in parallel with the resonant inductance. It doesn't look like a hopeful candidate for high Q, which is usually expected when people say resonance. It does have the advantage of a single ended power supply delivering the same power as a bipolar, which could be a big simplification. And if it had any Q, it does eliminate a lot of broadband spikey stuff that creates radiated emi. So the circuit is not a total dud.
Reply by ●January 5, 20242024-01-05
On Fri, 5 Jan 2024 08:47:50 -0800 (PST), Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:>fredag den 5. januar 2024 kl. 05.15.37 UTC+1 skrev Anthony William Sloman: >> On Thursday, January 4, 2024 at 8:16:06?PM UTC+11, Lasse Langwadt Christensen wrote: >> > torsdag den 4. januar 2024 kl. 03.10.48 UTC+1 skrev Anthony William Sloman: >> > > On Thursday, January 4, 2024 at 10:57:28?AM UTC+11, Lasse Langwadt Christensen wrote: >> > > > torsdag den 4. januar 2024 kl. 00.42.02 UTC+1 skrev john larkin: >> > > > > On Wed, 3 Jan 2024 12:44:24 -0800 (PST), Lasse Langwadt Christensen >> > > > > <lang...@fonz.dk> wrote: onsdag den 3. januar 2024 kl. 20.29.19 UTC+1 skrev john larkin: >> > > > > >> There is a new-to-me power supply architecture, an H-bridge driving a >> > > > > >> load, but with the phases on the two sides slid around to control >> > > > > >> delivered power. TI does that in some chips, like UCC2895. I may have >> > > > > >> seen the architecture first in this ng. >> > > > > >> >> > > > > >> Anyhow, I was thinking about a high-voltage power supply with the >> > > > > >> phase-shifted bridge driving a series-resonant transformer. >> > > > > >> >> > > > > >> https://www.dropbox.com/scl/fi/tbiioti0gt2emknjc61p7/Res_HV_Supply.jpg?rlkey=f1gryr8vr4jdu2y46wsz6ch2k&raw=1 >> > > > > >> >> > > > > >> I wonder if one of the cores of an RP2040 could do this without an >> > > > > >> FPGA. It would of course need a voltage feedback loop in software too. >> > > > > > >> > > > > >should easily do that with the PIOs >> > > > > If I did a 2-channel HV supply, that would need, I guess, three square >> > > > > waves. On as the "reference" side of both supplies, and then a phase >> > > > > shiftable square wave for each supply. >> > > > > >> > > > > The frequency might be, say, 50 to 100 KHz and I'd want to shift the >> > > > > phases with 10s of ns resolution. Probably needs an FPGA. >> > > > PIOs run at the full up to 133MHz pico clock >> > > https://www.onsemi.com/pdf/datasheet/mc100ep196-d.pdf >> > > >> > > offers up to 10.6nsec digitally tunable in steps of 10ps and is analog fine tunable below that. Similar parts from Motorola date back to about the early 1990's. The delay has some temperature drift, but if you are fine tuning for a specific output voltage the feedback loop can take that out. >> > > >> > and what would you use that for? >> Fine control of the male-to-space ratio. I did think that was obvious. > >you must be joking, not even Rube Goldberg would think that was a good ideaSloman never jokes. Never. If a timer channel can run at 125 MHz, and my resonant drive is, say, 50 KHz, that ratio is 2500:1, which gives me pretty good resolution to control the HV output. Some cute tricks could improve that too, like some delta-sigma twiddling with the quantized phase shifts. Should work. With feedack from the HV out and some luck on time constants, it might just dither itself to better resolution.
Reply by ●January 5, 20242024-01-05
On Fri, 05 Jan 2024 08:47:03 GMT, Jan Panteltje <alien@comet.invalid> wrote:>On a sunny day (Thu, 04 Jan 2024 20:59:16 -0800) it happened John Larkin ><jl@997PotHill.com> wrote in <in2fpitju1b2163tpb5qhmhs97qeufvu4m@4ax.com>: > >>On Fri, 05 Jan 2024 04:18:40 GMT, Jan Panteltje >><pNaonStpealmtje@yahoo.com> wrote: >> >>>On a sunny day (Wed, 03 Jan 2024 11:29:02 -0800) it happened john larkin >>><jl@650pot.com> wrote in <olcbpihia58uugpv9g3ptumif14qru2007@4ax.com>: >>> >>>> >>>>There is a new-to-me power supply architecture, an H-bridge driving a >>>>load, but with the phases on the two sides slid around to control >>>>delivered power. TI does that in some chips, like UCC2895. I may have >>>>seen the architecture first in this ng. >>>> >>>>Anyhow, I was thinking about a high-voltage power supply with the >>>>phase-shifted bridge driving a series-resonant transformer. >>>> >>>>https://www.dropbox.com/scl/fi/tbiioti0gt2emknjc61p7/Res_HV_Supply.jpg?rlkey=f1gryr8vr4jdu2y46wsz6ch2k&raw=1 >>> >>>Is it not much simpler to drive a capacitor with L to ground from a complementary output stage? >>> >>> + >>> | >>> T1 >>> | C1 D1 >>> |------||-------|>|---------- >>> | | | >>> T2 L1 === >>> | | --- C2 >>> : | | >>>/// /// /// >>> >>>Now Q of C1 L1 and load sets the voltage, no transformer needed. >>>Simple PIC micro can drive that. >> >>The transformer provides step-up and isolation. > >That circuit has both sides connected to ground? >Or is that not a ground on V1 negative supply?My 24 volt supply will be grounded, but I want the HV output channels to float. Are you commenting on the quality of my hand-drawn schematic?> >>I kind of like the >>full-bridge drive, to put 48 volts p-p into the transformer primary >>circuit. > >Yes, all depends on the amount of power needed...Not a lot, so I may be able to use that cute little IXYS driver.> > >>> >>>>I wonder if one of the cores of an RP2040 could do this without an >>>>FPGA. It would of course need a voltage feedback loop in software too. >>> >>>PIC micro. >>>Has hardware PWM generator and comparators that can directly switch the PWM off. >>>Used many times. >> >>I'm plannng to use RP2040 in this product line. > >If more tasks are needed and that RP2040 has a hardware facility to make PWM yes >If not using a PIC is simple, interrupt increments a counter, sets a pin, again counter resets a pin. >Or use the build in PWM generator. >Main routine reads ADCs sets counter values. drives an LCD, etc... >The 18F14K22 has 4 ADCs, a hardware comparator (for cycle by cycle current liming for example), 64 MHz internal PLL clock.. >This uses the PIC's PWM generator: > https://panteltje.online/panteltje/pic/pwr_pic/power_box_diagram_img_1817.jpg >use ctrl+ in browser to enlarge and read circuit diagram. >I use a current transformer to sense transistor current and trigger the PIC hardware comparator >making the cycle by cycle urrent protection. >The PIC ADCs read current and voltage and display it on an LCD, no interrupst anywhere needed. > http://panteltje.online/panteltje/pic/pwr_pic/ > >You could reduce diode voltage drop, think I got the idea here in this group? > https://panteltje.online/pub/power_pic/power_pic_synchronous_rectifier_diagram_img_0968.jpg > https://panteltje.online/pub/power_pic/power_pic_synchronous_rectifier_working_img_0965.jpgIt will probably need a C-W voltage multiplier after the transformer, depending on the transformer I can find. I'm thinking 1500 volts out per channel, maybe 2KV. Diode drops won't matter at HV, low current. A C-W multiplier lets me use cheap SOT-23 diodes and reasonable caps, to. I'm planning a new product line and was just toying with possible boxes. A dual HV supply might be fun.
Reply by ●January 5, 20242024-01-05
On Fri, 5 Jan 2024 13:04:59 -0800 (PST), Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:>On Wednesday, January 3, 2024 at 2:29:19?PM UTC-5, john larkin wrote: >> There is a new-to-me power supply architecture, an H-bridge driving a >> load, but with the phases on the two sides slid around to control >> delivered power. TI does that in some chips, like UCC2895. I may have >> seen the architecture first in this ng. >> >> Anyhow, I was thinking about a high-voltage power supply with the >> phase-shifted bridge driving a series-resonant transformer. >> >> https://www.dropbox.com/scl/fi/tbiioti0gt2emknjc61p7/Res_HV_Supply.jpg?rlkey=f1gryr8vr4jdu2y46wsz6ch2k&raw=1 >> >> I wonder if one of the cores of an RP2040 could do this without an >> FPGA. It would of course need a voltage feedback loop in software too. > > >May I ask how much power is being consumed in the 500 V circuit? Since your step-up is ~ 20:1, that would be a reduction of load resistance by a factor of 400 in the primary circuit, in parallel with the resonant inductance. It doesn't look like a hopeful candidate for high Q, which is usually expected when people say resonance.I'm thinking maybe 1.5 or 2 KV at a couple of watts, per isolated channel.> >It does have the advantage of a single ended power supply delivering the same power as a bipolar, which could be a big simplification. And if it had any Q, it does eliminate a lot of broadband spikey stuff that creates radiated emi. So the circuit is not a total dud.High praise!
Reply by ●January 5, 20242024-01-05
On 6/01/2024 8:45 am, john larkin wrote:> On Fri, 5 Jan 2024 08:47:50 -0800 (PST), Lasse Langwadt Christensen > <langwadt@fonz.dk> wrote: > >> fredag den 5. januar 2024 kl. 05.15.37 UTC+1 skrev Anthony William Sloman: >>> On Thursday, January 4, 2024 at 8:16:06?PM UTC+11, Lasse Langwadt Christensen wrote: >>>> torsdag den 4. januar 2024 kl. 03.10.48 UTC+1 skrev Anthony William Sloman: >>>>> On Thursday, January 4, 2024 at 10:57:28?AM UTC+11, Lasse Langwadt Christensen wrote: >>>>>> torsdag den 4. januar 2024 kl. 00.42.02 UTC+1 skrev john larkin: >>>>>>> On Wed, 3 Jan 2024 12:44:24 -0800 (PST), Lasse Langwadt Christensen >>>>>>> <lang...@fonz.dk> wrote: onsdag den 3. januar 2024 kl. 20.29.19 UTC+1 skrev john larkin: >>>>>>>>> There is a new-to-me power supply architecture, an H-bridge driving a >>>>>>>>> load, but with the phases on the two sides slid around to control >>>>>>>>> delivered power. TI does that in some chips, like UCC2895. I may have >>>>>>>>> seen the architecture first in this ng. >>>>>>>>> >>>>>>>>> Anyhow, I was thinking about a high-voltage power supply with the >>>>>>>>> phase-shifted bridge driving a series-resonant transformer. >>>>>>>>> >>>>>>>>> https://www.dropbox.com/scl/fi/tbiioti0gt2emknjc61p7/Res_HV_Supply.jpg?rlkey=f1gryr8vr4jdu2y46wsz6ch2k&raw=1 >>>>>>>>> >>>>>>>>> I wonder if one of the cores of an RP2040 could do this without an >>>>>>>>> FPGA. It would of course need a voltage feedback loop in software too. >>>>>>>> >>>>>>>> should easily do that with the PIOs >>>>>>> If I did a 2-channel HV supply, that would need, I guess, three square >>>>>>> waves. On as the "reference" side of both supplies, and then a phase >>>>>>> shiftable square wave for each supply. >>>>>>> >>>>>>> The frequency might be, say, 50 to 100 KHz and I'd want to shift the >>>>>>> phases with 10s of ns resolution. Probably needs an FPGA. >>>>>> PIOs run at the full up to 133MHz pico clock >>>>> https://www.onsemi.com/pdf/datasheet/mc100ep196-d.pdf >>>>> >>>>> offers up to 10.6nsec digitally tunable in steps of 10ps and is analog fine tunable below that. Similar parts from Motorola date back to about the early 1990's. The delay has some temperature drift, but if you are fine tuning for a specific output voltage the feedback loop can take that out. >>>>> >>>> and what would you use that for? >>> Fine control of the male-to-space ratio. I did think that was obvious. >> >> you must be joking, not even Rube Goldberg would think that was a good ideaRube Goldberg and Heath Robinson were cartoonists, not electronic engineers.> Sloman never jokes. Never.John Larkin never gets my jokes, even the unsubtle ones,> > If a timer channel can run at 125 MHz, and my resonant drive is, say, > 50 KHz, that ratio is 2500:1, which gives me pretty good resolution to > control the HV output.You keep telling us about exotic switching transistors (SiC etc) where the switching losses don't catch up with dissipation in the on state below a couple of MHz. Why limit yourself to 50kHz?> Some cute tricks could improve that too, like > some delta-sigma twiddling with the quantized phase shifts. > > Should work.Sigma-delta relies on the digital filtering to move most of the switching noise up to the high frequency end. You can do it systematically, as I discussed in my 1996 paper. Sloman A.W., Buggs P., Molloy J., and Stewart D. “A microcontroller-based driver to stabilise the temperature of an optical stage to 1mK in the range 4C to 38C, using a Peltier heat pump and a thermistor sensor” Measurement Science and Technology, 7 1653-64 (1996)> With feedack from the HV out and some luck on time constants, it might > just dither itself to better resolution.Circuits don't dither themselves. You have to design it in, as also discussed in my 1996 paper. -- Bill Sloman, Sydney
Reply by ●January 5, 20242024-01-05
On 6/01/2024 9:09 am, john larkin wrote:> On Fri, 05 Jan 2024 08:47:03 GMT, Jan Panteltje <alien@comet.invalid> > wrote: > >> On a sunny day (Thu, 04 Jan 2024 20:59:16 -0800) it happened John Larkin >> <jl@997PotHill.com> wrote in <in2fpitju1b2163tpb5qhmhs97qeufvu4m@4ax.com>: >> >>> On Fri, 05 Jan 2024 04:18:40 GMT, Jan Panteltje >>> <pNaonStpealmtje@yahoo.com> wrote:<snip>> It will probably need a C-W voltage multiplier after the transformer, > depending on the transformer I can find.Be adventurous. Get one wound, or printed, these days.> I'm thinking 1500 volts out. > per channel, maybe 2KV. Diode drops won't matter at HV, low current.And it's going to float? That much insulation will be rare in an off-the shelf high-frequency transformer.> A C-W multiplier lets me use cheap SOT-23 diodes and reasonable caps, > too. > > I'm planning a new product line and was just toying with possible > boxes. A dual HV supply might be fun.We always bought them in. The woods were full of photomultiplier power supply specialists. They have probably branched out into providing power supplies for high-voltage electro-optic modulators as well these days. -- Bill Sloman, Sydney
Reply by ●January 6, 20242024-01-06
On a sunny day (Fri, 05 Jan 2024 14:09:56 -0800) it happened john larkin <jl@650pot.com> wrote in <t5ugpilo3r4tg912oif2av49872u0ej8ob@4ax.com>:>On Fri, 05 Jan 2024 08:47:03 GMT, Jan Panteltje <alien@comet.invalid> >wrote: > >>On a sunny day (Thu, 04 Jan 2024 20:59:16 -0800) it happened John Larkin >><jl@997PotHill.com> wrote in <in2fpitju1b2163tpb5qhmhs97qeufvu4m@4ax.com>: >> >>>On Fri, 05 Jan 2024 04:18:40 GMT, Jan Panteltje >>><pNaonStpealmtje@yahoo.com> wrote: >>> >>>>On a sunny day (Wed, 03 Jan 2024 11:29:02 -0800) it happened john larkin >>>><jl@650pot.com> wrote in <olcbpihia58uugpv9g3ptumif14qru2007@4ax.com>: >>>> >>>>> >>>>>There is a new-to-me power supply architecture, an H-bridge driving a >>>>>load, but with the phases on the two sides slid around to control >>>>>delivered power. TI does that in some chips, like UCC2895. I may have >>>>>seen the architecture first in this ng. >>>>> >>>>>Anyhow, I was thinking about a high-voltage power supply with the >>>>>phase-shifted bridge driving a series-resonant transformer. >>>>> >>>>>https://www.dropbox.com/scl/fi/tbiioti0gt2emknjc61p7/Res_HV_Supply.jpg?rlkey=f1gryr8vr4jdu2y46wsz6ch2k&raw=1 >>>> >>>>Is it not much simpler to drive a capacitor with L to ground from a complementary output stage? >>>> >>>> + >>>> | >>>> T1 >>>> | C1 D1 >>>> |------||-------|>|---------- >>>> | | | >>>> T2 L1 === >>>> | | --- C2 >>>> : | | >>>>/// /// /// >>>> >>>>Now Q of C1 L1 and load sets the voltage, no transformer needed. >>>>Simple PIC micro can drive that. >>> >>>The transformer provides step-up and isolation. >> >>That circuit has both sides connected to ground? >>Or is that not a ground on V1 negative supply? > >My 24 volt supply will be grounded, but I want the HV output channels >to float. > >Are you commenting on the quality of my hand-drawn schematic? > > >> >>>I kind of like the >>>full-bridge drive, to put 48 volts p-p into the transformer primary >>>circuit. >> >>Yes, all depends on the amount of power needed... > >Not a lot, so I may be able to use that cute little IXYS driver. > >> >> >>>> >>>>>I wonder if one of the cores of an RP2040 could do this without an >>>>>FPGA. It would of course need a voltage feedback loop in software too. >>>> >>>>PIC micro. >>>>Has hardware PWM generator and comparators that can directly switch the PWM off. >>>>Used many times. >>> >>>I'm plannng to use RP2040 in this product line. >> >>If more tasks are needed and that RP2040 has a hardware facility to make PWM yes >>If not using a PIC is simple, interrupt increments a counter, sets a pin, again counter resets a pin. >>Or use the build in PWM generator. >>Main routine reads ADCs sets counter values. drives an LCD, etc... >>The 18F14K22 has 4 ADCs, a hardware comparator (for cycle by cycle current liming for example), 64 MHz internal PLL clock.. >>This uses the PIC's PWM generator: >> https://panteltje.online/panteltje/pic/pwr_pic/power_box_diagram_img_1817.jpg >>use ctrl+ in browser to enlarge and read circuit diagram. >>I use a current transformer to sense transistor current and trigger the PIC hardware comparator >>making the cycle by cycle urrent protection. >>The PIC ADCs read current and voltage and display it on an LCD, no interrupst anywhere needed. >> http://panteltje.online/panteltje/pic/pwr_pic/ >> >>You could reduce diode voltage drop, think I got the idea here in this group? >> https://panteltje.online/pub/power_pic/power_pic_synchronous_rectifier_diagram_img_0968.jpg >> https://panteltje.online/pub/power_pic/power_pic_synchronous_rectifier_working_img_0965.jpg > >It will probably need a C-W voltage multiplier after the transformer, >depending on the transformer I can find. I'm thinking 1500 volts out >per channel, maybe 2KV. Diode drops won't matter at HV, low current.Dunno what he power requirement is, this worked for me for my PMT: https://panteltje.online/pub/PMT_regulated_power_supply_diagram_img_3182.jpg https://panteltje.online/pub/PMT_HV_supply_with_regulator_img_3175.jpg https://panteltje.online/pub/PMT_HV_generator_solder_side_img_3172.jpg Or just get an old TV voltage multiplier: https://panteltje.nl/panteltje/pic/sc_pic/sc_pic_pcb_test_in_box_img_2452.jpg>A C-W multiplier lets me use cheap SOT-23 diodes and reasonable caps, >to. > >I'm planning a new product line and was just toying with possible >boxes. A dual HV supply might be fun.There are likely many possibilities, I usually just use what I find laying about.. Or get cheap stuff from ebay... Old CRT monitors had nice transformers, rectifiers, 15625 kHz 25 kV Must be millions still available... I keep am old CRT color monitor in the attic as my own personal particle accelerator :-) Tried all sorts of things: https://panteltje.online/pub/multi_transformer_2_kV_PMT_supply_img_3126.jpg And there is the very high voltage ebay thing: https://www.ebay.com/b/High-Voltage-Generator/117000/bn_7023272732 cannot beat the price, I have one :-)
Reply by ●January 6, 20242024-01-06
On Friday, January 5, 2024 at 5:13:11 PM UTC-5, john larkin wrote:> On Fri, 5 Jan 2024 13:04:59 -0800 (PST), Fred Bloggs > <bloggs.fred...@gmail.com> wrote: > >On Wednesday, January 3, 2024 at 2:29:19?PM UTC-5, john larkin wrote: > >> There is a new-to-me power supply architecture, an H-bridge driving a > >> load, but with the phases on the two sides slid around to control > >> delivered power. TI does that in some chips, like UCC2895. I may have > >> seen the architecture first in this ng. > >> > >> Anyhow, I was thinking about a high-voltage power supply with the > >> phase-shifted bridge driving a series-resonant transformer. > >> > >> https://www.dropbox.com/scl/fi/tbiioti0gt2emknjc61p7/Res_HV_Supply.jpg?rlkey=f1gryr8vr4jdu2y46wsz6ch2k&raw=1 > >> > >> I wonder if one of the cores of an RP2040 could do this without an > >> FPGA. It would of course need a voltage feedback loop in software too. > > > > > >May I ask how much power is being consumed in the 500 V circuit? Since your step-up is ~ 20:1, that would be a reduction of load resistance by a factor of 400 in the primary circuit, in parallel with the resonant inductance. It doesn't look like a hopeful candidate for high Q, which is usually expected when people say resonance. > I'm thinking maybe 1.5 or 2 KV at a couple of watts, per isolated > channel. > > > >It does have the advantage of a single ended power supply delivering the same power as a bipolar, which could be a big simplification. And if it had any Q, it does eliminate a lot of broadband spikey stuff that creates radiated emi. So the circuit is not a total dud. > High praise!I'm pretty sure you're going to have insert inductance in the secondary. My first cut/ guess/ wish/ ( no idea iow ) would be to make the L/Requivalent be about 10/w_resonant to achieve a Q of about 10. Doing that should allow your series C + transformer L to actually be resonant and not pulled too much if not totally extinguished by the secondary load. And that spikey capacitor voltage doubler isn't helping the situation. Those hv capacitors won't be cheap, might as well go with the transformer all the way. As you're probably aware, the transformer primary voltage will be Q x Vinput at resonance. That could be a good thing if it's reliable, as less step-up is required, or it can be a bad thing if it blows something. Does your switching controller sense the resonance condition and modify its frequency to track it?
Reply by ●January 6, 20242024-01-06
On Friday, January 5, 2024 at 5:13:11 PM UTC-5, john larkin wrote:> On Fri, 5 Jan 2024 13:04:59 -0800 (PST), Fred Bloggs > <bloggs.fred...@gmail.com> wrote: > >On Wednesday, January 3, 2024 at 2:29:19?PM UTC-5, john larkin wrote: > >> There is a new-to-me power supply architecture, an H-bridge driving a > >> load, but with the phases on the two sides slid around to control > >> delivered power. TI does that in some chips, like UCC2895. I may have > >> seen the architecture first in this ng. > >> > >> Anyhow, I was thinking about a high-voltage power supply with the > >> phase-shifted bridge driving a series-resonant transformer. > >> > >> https://www.dropbox.com/scl/fi/tbiioti0gt2emknjc61p7/Res_HV_Supply.jpg?rlkey=f1gryr8vr4jdu2y46wsz6ch2k&raw=1 > >> > >> I wonder if one of the cores of an RP2040 could do this without an > >> FPGA. It would of course need a voltage feedback loop in software too. > > > > > >May I ask how much power is being consumed in the 500 V circuit? Since your step-up is ~ 20:1, that would be a reduction of load resistance by a factor of 400 in the primary circuit, in parallel with the resonant inductance. It doesn't look like a hopeful candidate for high Q, which is usually expected when people say resonance. > I'm thinking maybe 1.5 or 2 KV at a couple of watts, per isolated > channel. > > > >It does have the advantage of a single ended power supply delivering the same power as a bipolar, which could be a big simplification. And if it had any Q, it does eliminate a lot of broadband spikey stuff that creates radiated emi. So the circuit is not a total dud. > High praise!I should have added your primary magnetizing current alone will Vinput/Rc, with Rc = equivalent core and winding loss. That could be a lot of Amps, but that's resonance for you.
