https://www.dropbox.com/scl/fi/3hyvmc3mkvhrk6rc8dt72/P970_DC-DC.jpg?rlkey=npgerceq4t191hnjfd0907v6u&raw=1That makes two isolated 56-volt power supplies. But the problem ishow to start it up.I could just slam on the square wave drives and let the TIchipcurrent limit until the caps charge up. That might work.I was thiking I could start the two half-bridges with in-phase squarewaves and then slowly slide them out to 180 degrees. My FPGA kidscould do that. That would be a nuisance to Spice.We did a
john larkin <JL@gct.com> Wrote in message:rchipcurrent limit until the caps charge up. That might work.I was thiking I could start the two half-bridges with in-phase squarewaves and then slowly slide them out to 180 degrees. My FPGA kidscould do that. That would be a nuisance to Spice.We did a
https://www.dropbox.com/scl/fi/3hyvmc3mkvhrk6rc8dt72/P970_DC-DC.jpg?rlkey=npgerceq4t191hnjfd0907v6u&raw=1That makes two isolated 56-volt power supplies. But the problem ishow to start it up.I could just slam on the square wave drives and let the TI
Yea, software softstart.
Cheers
On Tue, 14 Jan 2025 10:19:01 -0500 (EST), Martin Rid <martin_riddle@verison.net> wrote:chipcurrent limit until the caps charge up. That might work.I was thiking I could start the two half-bridges with in-phase squarewaves and then slowly slide them out to 180 degrees. My FPGA kidscould do that. That would be a nuisance to Spice.We did a
john larkin <JL@gct.com> Wrote in message:r
https://www.dropbox.com/scl/fi/3hyvmc3mkvhrk6rc8dt72/P970_DC-DC.jpg?rlkey=npgerceq4t191hnjfd0907v6u&raw=1That makes two isolated 56-volt power supplies. But the problem ishow to start it up.I could just slam on the square wave drives and let the TI
Yea, software softstart.
Cheers
I think the sliding square wave thing will work, but I have sceptics.
So how can I Spice two 200 KHz square waves that start in phase and
slowly crawl to 180 degrees apart? Over a second maybe.
Am 14.01.2025 um 17:10 schrieb john larkin:
So how can I Spice two 200 KHz square waves that start in phase and
slowly crawl to 180 degrees apart? Over a second maybe.
Let the one have 199.9995 (or 200.0005) kHz.
Tilmann
So how can I Spice two 200 KHz square waves that start in phase and
slowly crawl to 180 degrees apart? Over a second maybe.
https://www.dropbox.com/scl/fi/3hyvmc3mkvhrk6rc8dt72/P970_DC-DC.jpg?rlkey=npgerceq4t191hnjfd0907v6u&raw=1
That makes two isolated 56-volt power supplies. But the problem is
how to start it up.
I could just slam on the square wave drives and let the TI chip
current limit until the caps charge up. That might work.
I was thiking I could start the two half-bridges with in-phase square
waves and then slowly slide them out to 180 degrees. My FPGA kids
could do that. That would be a nuisance to Spice.
We did a similar supply a while back with discrete fets, no current
limits. Startup made 300 amp spikes that made all sorts of problems.
On 1/14/25 17:10, john larkin wrote:chipcurrent limit until the caps charge up. That might work.I was thiking I could start the two half-bridges with in-phase squarewaves and then slowly slide them out to 180 degrees. My FPGA kidscould do that. That would be a nuisance to Spice.We did a
On Tue, 14 Jan 2025 10:19:01 -0500 (EST), Martin Rid
<martin_riddle@verison.net> wrote:
john larkin <JL@gct.com> Wrote in message:r
https://www.dropbox.com/scl/fi/3hyvmc3mkvhrk6rc8dt72/P970_DC-DC.jpg?rlkey=npgerceq4t191hnjfd0907v6u&raw=1That makes two isolated 56-volt power supplies. But the problem ishow to start it up.I could just slam on the square wave drives and let the TI
Yea, software softstart.
Cheers
I think the sliding square wave thing will work, but I have sceptics.
So how can I Spice two 200 KHz square waves that start in phase and
slowly crawl to 180 degrees apart? Over a second maybe.
Something like below? The squares start off in phase and
one of them is shifted by V3 to end up in opposition after
50us. Scale to taste.
You can control the rise and fall times of the squares by
adjusting the amplitudes of the sines in the expressions
for B1 and B2.
Jeroen Belleman
==============================================================
Version 4
SHEET 1 1116 680
WIRE 128 48 128 16
WIRE 128 80 128 48
WIRE -128 96 -192 96
WIRE -80 96 -128 96
WIRE -192 160 -192 96
WIRE 128 192 128 160
WIRE -192 272 -192 240
WIRE 128 272 128 240
WIRE 128 304 128 272
WIRE 128 416 128 384
FLAG 128 192 0
FLAG 128 48 out1
FLAG -192 272 0
FLAG -128 96 p
FLAG 128 416 0
FLAG 128 272 out2
SYMBOL voltage -192 144 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V3
SYMATTR Value PWL(0 0 50u {pi})
SYMBOL bv 128 64 R0
SYMATTR InstName B1
SYMATTR Value V=tanh(10*sin(time*2*pi*200k+v(p)))
SYMBOL bv 128 288 R0
SYMATTR InstName B2
SYMATTR Value V=tanh(10*sin(time*2*pi*200k))
TEXT 272 104 Left 2 !.tran 100u
TEXT 272 32 Left 2 ;Square waves with controlled phase.
TEXT 272 64 Left 2 ;Jeroen Belleman - 20250114
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