• dc/dc soft start

    From john larkin@21:1/5 to All on Wed Jan 15 16:12:31 2025
    Here's my soft start circuit. Thanks for suggestions from Tilmann and
    Jeroen.

    The idea is to drive the ends of the transformer with in-phase square
    waves and then slowly walk them to 180 degrees, to achieve a soft
    start. An FPGA can do that easily. We might take a second... but that
    would simulate forever.

    What works well is to use two spice "modulator" elements and FM the
    frequency of one of them for 50 ms, until they are 180 degrees out of
    phase.

    Spice BV elements with sin(time*freq) type expressions seemed to
    overload or something.

    Version 4
    SHEET 1 2568 1220
    WIRE -512 -944 -576 -944
    WIRE -400 -944 -512 -944
    WIRE 16 -944 -32 -944
    WIRE 48 -944 16 -944
    WIRE 256 -944 192 -944
    WIRE 304 -944 256 -944
    WIRE -1104 -912 -1136 -912
    WIRE -1040 -912 -1104 -912
    WIRE -400 -912 -400 -944
    WIRE -32 -912 -32 -944
    WIRE 192 -912 192 -944
    WIRE -128 -896 -144 -896
    WIRE -80 -896 -128 -896
    WIRE -848 -880 -896 -880
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    WIRE -576 -816 -576 -944
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    WIRE -720 -800 -784 -800
    WIRE -624 -800 -720 -800
    WIRE -400 -800 -400 -832
    WIRE -32 -800 -32 -832
    WIRE 192 -800 192 -832
    WIRE -848 -768 -848 -800
    WIRE -624 -752 -656 -752
    WIRE -576 -688 -576 -736
    WIRE -448 -688 -576 -688
    WIRE -368 -688 -448 -688
    WIRE -208 -688 -304 -688
    WIRE 160 -688 -32 -688
    WIRE 208 -688 160 -688
    WIRE 416 -688 272 -688
    WIRE 480 -688 416 -688
    WIRE 544 -688 480 -688
    WIRE 656 -688 544 -688
    WIRE -848 -656 -848 -688
    WIRE -576 -640 -576 -688
    WIRE -656 -624 -656 -752
    WIRE -624 -624 -656 -624
    WIRE -720 -576 -720 -800
    WIRE -624 -576 -720 -576
    WIRE 208 -576 112 -576
    WIRE 416 -576 416 -688
    WIRE 416 -576 272 -576
    WIRE -1024 -560 -1104 -560
    WIRE -880 -560 -944 -560
    WIRE -848 -560 -880 -560
    WIRE -1104 -544 -1104 -560
    WIRE -848 -544 -848 -560
    WIRE -656 -528 -656 -624
    WIRE -576 -528 -576 -560
    WIRE -208 -528 -208 -688
    WIRE -32 -528 -32 -688
    WIRE 416 -512 416 -576
    WIRE 544 -512 544 -688
    WIRE 656 -512 656 -688
    WIRE -1104 -448 -1104 -464
    WIRE -848 -448 -848 -480
    WIRE -528 -400 -576 -400
    WIRE -480 -400 -528 -400
    WIRE -576 -368 -576 -400
    WIRE 160 -368 160 -688
    WIRE 208 -368 160 -368
    WIRE 416 -368 416 -448
    WIRE 416 -368 272 -368
    WIRE -784 -352 -848 -352
    WIRE -720 -352 -784 -352
    WIRE -624 -352 -720 -352
    WIRE -848 -320 -848 -352
    WIRE -624 -304 -656 -304
    WIRE -576 -240 -576 -288
    WIRE -448 -240 -576 -240
    WIRE -368 -240 -448 -240
    WIRE -208 -240 -208 -448
    WIRE -208 -240 -304 -240
    WIRE -32 -240 -32 -448
    WIRE 112 -240 112 -576
    WIRE 112 -240 -32 -240
    WIRE 208 -240 112 -240
    WIRE 416 -240 416 -368
    WIRE 416 -240 272 -240
    WIRE 544 -240 544 -432
    WIRE 544 -240 416 -240
    WIRE 656 -240 656 -432
    WIRE 656 -240 544 -240
    WIRE -848 -208 -848 -240
    WIRE -576 -192 -576 -240
    WIRE 416 -192 416 -240
    WIRE -656 -176 -656 -304
    WIRE -624 -176 -656 -176
    WIRE -1072 -160 -1152 -160
    WIRE -880 -128 -928 -128
    WIRE -848 -128 -880 -128
    WIRE -720 -128 -720 -352
    WIRE -624 -128 -720 -128
    WIRE -1152 -112 -1152 -160
    WIRE -656 -80 -656 -176
    WIRE -576 -80 -576 -112
    FLAG -400 -800 0
    FLAG -512 -944 +48
    FLAG -32 -800 0
    FLAG -128 -896 HA
    FLAG -128 -848 HB
    FLAG 16 -944 BRO
    FLAG -448 -688 HA
    FLAG -448 -240 HB
    FLAG -576 -528 0
    FLAG -656 -528 0
    FLAG -576 -80 0
    FLAG -528 -400 +48
    FLAG -656 -80 0
    FLAG 416 -192 0
    FLAG 480 -688 OUT
    FLAG -784 -800 A
    FLAG 256 -944 SS
    FLAG 192 -800 0
    FLAG -1104 -912 SS
    FLAG -1152 -112 0
    FLAG -784 -352 B
    FLAG -1104 -448 0
    FLAG -880 -560 AB
    FLAG -848 -448 0
    FLAG -848 -208 0
    FLAG -880 -128 K
    FLAG -848 -656 0
    FLAG -848 -880 J
    SYMBOL voltage -400 -928 R0
    WINDOW 0 53 46 Left 2
    WINDOW 3 53 78 Left 2
    SYMATTR InstName V3
    SYMATTR Value 48
    SYMBOL e -32 -928 R0
    WINDOW 0 45 50 Left 2
    WINDOW 3 49 78 Left 2
    SYMATTR InstName E5
    SYMATTR Value 1
    SYMBOL sw -576 -720 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S2
    SYMATTR Value Sj
    SYMBOL sw -576 -544 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S3
    SYMATTR Value Sj
    SYMBOL sw -576 -272 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S4
    SYMATTR Value Sj
    SYMBOL sw -576 -96 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S5
    SYMATTR Value Sj
    SYMBOL cap -304 -704 R90
    WINDOW 0 79 30 VBottom 2
    WINDOW 3 86 29 VTop 2
    SYMATTR InstName C1
    SYMATTR Value 20µ
    SYMBOL FerriteBead -336 -240 R90
    WINDOW 0 -37 -1 VBottom 2
    SYMATTR InstName L1
    SYMATTR Value 2.5µ
    SYMATTR SpiceLine Ipk=3 Rser=0.0023 Rpar=475 Cpar=1.75p
    SYMBOL ind2 -224 -544 R0
    WINDOW 0 -49 37 Left 2
    WINDOW 3 -61 76 Left 2
    SYMATTR InstName L2
    SYMATTR Value 72µ
    SYMATTR Type ind
    SYMBOL ind2 -48 -544 R0
    WINDOW 0 61 40 Left 2
    WINDOW 3 50 76 Left 2
    SYMATTR InstName L3
    SYMATTR Value 112µ
    SYMATTR Type ind
    SYMBOL schottky 208 -672 R270
    WINDOW 0 42 40 VTop 2
    WINDOW 3 -14 54 VBottom 2
    SYMATTR InstName D1
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL cap 400 -512 R0
    WINDOW 0 -58 36 Left 2
    WINDOW 3 -70 67 Left 2
    SYMATTR InstName C6
    SYMATTR Value 100µ
    SYMBOL res 528 -528 R0
    WINDOW 0 -63 51 Left 2
    WINDOW 3 -61 83 Left 2
    SYMATTR InstName R5
    SYMATTR Value 5K
    SYMBOL schottky 208 -560 R270
    WINDOW 0 39 33 VTop 2
    WINDOW 3 -14 55 VBottom 2
    SYMATTR InstName D2
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -384 R90
    WINDOW 0 -10 31 VBottom 2
    WINDOW 3 45 28 VTop 2
    SYMATTR InstName D3
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -256 R90
    WINDOW 0 -16 31 VBottom 2
    WINDOW 3 43 32 VTop 2
    SYMATTR InstName D4
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL current 656 -512 R0
    WINDOW 0 54 63 Left 2
    WINDOW 3 19 107 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName I1
    SYMATTR Value PULSE(0 0.5 75m 1m 0 9)
    SYMBOL voltage 192 -928 R0
    WINDOW 0 58 36 Left 2
    WINDOW 3 41 74 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V1
    SYMATTR Value PULSE(0 1 0 1u 1u 50m)
    SYMBOL SpecialFunctions\\modulate -1040 -912 R0
    WINDOW 0 56 29 Left 2
    SYMATTR InstName A1
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250.01K
    SYMBOL SpecialFunctions\\modulate -1072 -160 R0
    WINDOW 0 56 31 Left 2
    SYMATTR InstName A2
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250K
    SYMBOL bv -1104 -560 R0
    WINDOW 0 46 98 Left 2
    WINDOW 3 30 135 Left 2
    SYMATTR InstName B1
    SYMATTR Value V=V(A) * V(B)
    SYMBOL res -928 -576 R90
    WINDOW 0 66 56 VBottom 2
    WINDOW 3 65 57 VTop 2
    SYMATTR InstName R1
    SYMATTR Value 1K
    SYMBOL bv -848 -336 R0
    WINDOW 0 -89 48 Left 2
    WINDOW 3 -185 94 Left 2
    SYMATTR InstName B2
    SYMATTR Value V=sgn(V(K))
    SYMBOL bv -848 -784 R0
    WINDOW 0 -89 59 Left 2
    WINDOW 3 -183 96 Left 2
    SYMATTR InstName B3
    SYMATTR Value V=sgn(V(J))
    SYMBOL cap -864 -544 R0
    WINDOW 0 -53 40 Left 2
    WINDOW 3 -66 68 Left 2
    SYMATTR InstName C2
    SYMATTR Value 100n
    TEXT 216 -136 Left 4 ;P970 DC-DC Converter
    TEXT 288 -88 Left 3 ;JL Jan 15 2025
    TEXT -200 -80 Left 2 !.model Sj SW(Ron=50m Roff=1g)
    TEXT -200 -128 Left 2 !.tran 0 100m 0 20n
    TEXT -192 -568 Left 2 ;PL300-101L
    TEXT -160 -488 Left 2 ;4T
    TEXT -96 -488 Left 2 ;5T
    TEXT -200 -720 Left 2 !K1 L2 L3 0.999
    TEXT -392 -192 Left 2 ;163-5001
    TEXT -392 -152 Left 2 ;2.7 uH 5A
    TEXT -168 -600 Left 2 ;Coilcraft
    TEXT 232 -816 Left 2 ;50 ms soft start

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Klaus Kragelund@21:1/5 to john larkin on Mon Jan 20 22:09:05 2025
    On 16-01-2025 01:12, john larkin wrote:

    Here's my soft start circuit. Thanks for suggestions from Tilmann and
    Jeroen.

    The idea is to drive the ends of the transformer with in-phase square
    waves and then slowly walk them to 180 degrees, to achieve a soft
    start. An FPGA can do that easily. We might take a second... but that
    would simulate forever.

    What works well is to use two spice "modulator" elements and FM the
    frequency of one of them for 50 ms, until they are 180 degrees out of
    phase.

    Spice BV elements with sin(time*freq) type expressions seemed to
    overload or something.

    Version 4
    SHEET 1 2568 1220
    WIRE -512 -944 -576 -944
    WIRE -400 -944 -512 -944
    WIRE 16 -944 -32 -944
    WIRE 48 -944 16 -944
    WIRE 256 -944 192 -944
    WIRE 304 -944 256 -944
    WIRE -1104 -912 -1136 -912
    WIRE -1040 -912 -1104 -912
    WIRE -400 -912 -400 -944
    WIRE -32 -912 -32 -944
    WIRE 192 -912 192 -944
    WIRE -128 -896 -144 -896
    WIRE -80 -896 -128 -896
    WIRE -848 -880 -896 -880
    WIRE -800 -880 -848 -880
    WIRE -128 -848 -144 -848
    WIRE -80 -848 -128 -848
    WIRE -576 -816 -576 -944
    WIRE -784 -800 -848 -800
    WIRE -720 -800 -784 -800
    WIRE -624 -800 -720 -800
    WIRE -400 -800 -400 -832
    WIRE -32 -800 -32 -832
    WIRE 192 -800 192 -832
    WIRE -848 -768 -848 -800
    WIRE -624 -752 -656 -752
    WIRE -576 -688 -576 -736
    WIRE -448 -688 -576 -688
    WIRE -368 -688 -448 -688
    WIRE -208 -688 -304 -688
    WIRE 160 -688 -32 -688
    WIRE 208 -688 160 -688
    WIRE 416 -688 272 -688
    WIRE 480 -688 416 -688
    WIRE 544 -688 480 -688
    WIRE 656 -688 544 -688
    WIRE -848 -656 -848 -688
    WIRE -576 -640 -576 -688
    WIRE -656 -624 -656 -752
    WIRE -624 -624 -656 -624
    WIRE -720 -576 -720 -800
    WIRE -624 -576 -720 -576
    WIRE 208 -576 112 -576
    WIRE 416 -576 416 -688
    WIRE 416 -576 272 -576
    WIRE -1024 -560 -1104 -560
    WIRE -880 -560 -944 -560
    WIRE -848 -560 -880 -560
    WIRE -1104 -544 -1104 -560
    WIRE -848 -544 -848 -560
    WIRE -656 -528 -656 -624
    WIRE -576 -528 -576 -560
    WIRE -208 -528 -208 -688
    WIRE -32 -528 -32 -688
    WIRE 416 -512 416 -576
    WIRE 544 -512 544 -688
    WIRE 656 -512 656 -688
    WIRE -1104 -448 -1104 -464
    WIRE -848 -448 -848 -480
    WIRE -528 -400 -576 -400
    WIRE -480 -400 -528 -400
    WIRE -576 -368 -576 -400
    WIRE 160 -368 160 -688
    WIRE 208 -368 160 -368
    WIRE 416 -368 416 -448
    WIRE 416 -368 272 -368
    WIRE -784 -352 -848 -352
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    WIRE -624 -352 -720 -352
    WIRE -848 -320 -848 -352
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    WIRE -448 -240 -576 -240
    WIRE -368 -240 -448 -240
    WIRE -208 -240 -208 -448
    WIRE -208 -240 -304 -240
    WIRE -32 -240 -32 -448
    WIRE 112 -240 112 -576
    WIRE 112 -240 -32 -240
    WIRE 208 -240 112 -240
    WIRE 416 -240 416 -368
    WIRE 416 -240 272 -240
    WIRE 544 -240 544 -432
    WIRE 544 -240 416 -240
    WIRE 656 -240 656 -432
    WIRE 656 -240 544 -240
    WIRE -848 -208 -848 -240
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    WIRE 416 -192 416 -240
    WIRE -656 -176 -656 -304
    WIRE -624 -176 -656 -176
    WIRE -1072 -160 -1152 -160
    WIRE -880 -128 -928 -128
    WIRE -848 -128 -880 -128
    WIRE -720 -128 -720 -352
    WIRE -624 -128 -720 -128
    WIRE -1152 -112 -1152 -160
    WIRE -656 -80 -656 -176
    WIRE -576 -80 -576 -112
    FLAG -400 -800 0
    FLAG -512 -944 +48
    FLAG -32 -800 0
    FLAG -128 -896 HA
    FLAG -128 -848 HB
    FLAG 16 -944 BRO
    FLAG -448 -688 HA
    FLAG -448 -240 HB
    FLAG -576 -528 0
    FLAG -656 -528 0
    FLAG -576 -80 0
    FLAG -528 -400 +48
    FLAG -656 -80 0
    FLAG 416 -192 0
    FLAG 480 -688 OUT
    FLAG -784 -800 A
    FLAG 256 -944 SS
    FLAG 192 -800 0
    FLAG -1104 -912 SS
    FLAG -1152 -112 0
    FLAG -784 -352 B
    FLAG -1104 -448 0
    FLAG -880 -560 AB
    FLAG -848 -448 0
    FLAG -848 -208 0
    FLAG -880 -128 K
    FLAG -848 -656 0
    FLAG -848 -880 J
    SYMBOL voltage -400 -928 R0
    WINDOW 0 53 46 Left 2
    WINDOW 3 53 78 Left 2
    SYMATTR InstName V3
    SYMATTR Value 48
    SYMBOL e -32 -928 R0
    WINDOW 0 45 50 Left 2
    WINDOW 3 49 78 Left 2
    SYMATTR InstName E5
    SYMATTR Value 1
    SYMBOL sw -576 -720 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S2
    SYMATTR Value Sj
    SYMBOL sw -576 -544 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S3
    SYMATTR Value Sj
    SYMBOL sw -576 -272 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S4
    SYMATTR Value Sj
    SYMBOL sw -576 -96 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S5
    SYMATTR Value Sj
    SYMBOL cap -304 -704 R90
    WINDOW 0 79 30 VBottom 2
    WINDOW 3 86 29 VTop 2
    SYMATTR InstName C1
    SYMATTR Value 20µ
    SYMBOL FerriteBead -336 -240 R90
    WINDOW 0 -37 -1 VBottom 2
    SYMATTR InstName L1
    SYMATTR Value 2.5µ
    SYMATTR SpiceLine Ipk=3 Rser=0.0023 Rpar=475 Cpar=1.75p
    SYMBOL ind2 -224 -544 R0
    WINDOW 0 -49 37 Left 2
    WINDOW 3 -61 76 Left 2
    SYMATTR InstName L2
    SYMATTR Value 72µ
    SYMATTR Type ind
    SYMBOL ind2 -48 -544 R0
    WINDOW 0 61 40 Left 2
    WINDOW 3 50 76 Left 2
    SYMATTR InstName L3
    SYMATTR Value 112µ
    SYMATTR Type ind
    SYMBOL schottky 208 -672 R270
    WINDOW 0 42 40 VTop 2
    WINDOW 3 -14 54 VBottom 2
    SYMATTR InstName D1
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL cap 400 -512 R0
    WINDOW 0 -58 36 Left 2
    WINDOW 3 -70 67 Left 2
    SYMATTR InstName C6
    SYMATTR Value 100µ
    SYMBOL res 528 -528 R0
    WINDOW 0 -63 51 Left 2
    WINDOW 3 -61 83 Left 2
    SYMATTR InstName R5
    SYMATTR Value 5K
    SYMBOL schottky 208 -560 R270
    WINDOW 0 39 33 VTop 2
    WINDOW 3 -14 55 VBottom 2
    SYMATTR InstName D2
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -384 R90
    WINDOW 0 -10 31 VBottom 2
    WINDOW 3 45 28 VTop 2
    SYMATTR InstName D3
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -256 R90
    WINDOW 0 -16 31 VBottom 2
    WINDOW 3 43 32 VTop 2
    SYMATTR InstName D4
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL current 656 -512 R0
    WINDOW 0 54 63 Left 2
    WINDOW 3 19 107 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName I1
    SYMATTR Value PULSE(0 0.5 75m 1m 0 9)
    SYMBOL voltage 192 -928 R0
    WINDOW 0 58 36 Left 2
    WINDOW 3 41 74 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V1
    SYMATTR Value PULSE(0 1 0 1u 1u 50m)
    SYMBOL SpecialFunctions\\modulate -1040 -912 R0
    WINDOW 0 56 29 Left 2
    SYMATTR InstName A1
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250.01K
    SYMBOL SpecialFunctions\\modulate -1072 -160 R0
    WINDOW 0 56 31 Left 2
    SYMATTR InstName A2
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250K
    SYMBOL bv -1104 -560 R0
    WINDOW 0 46 98 Left 2
    WINDOW 3 30 135 Left 2
    SYMATTR InstName B1
    SYMATTR Value V=V(A) * V(B)
    SYMBOL res -928 -576 R90
    WINDOW 0 66 56 VBottom 2
    WINDOW 3 65 57 VTop 2
    SYMATTR InstName R1
    SYMATTR Value 1K
    SYMBOL bv -848 -336 R0
    WINDOW 0 -89 48 Left 2
    WINDOW 3 -185 94 Left 2
    SYMATTR InstName B2
    SYMATTR Value V=sgn(V(K))
    SYMBOL bv -848 -784 R0
    WINDOW 0 -89 59 Left 2
    WINDOW 3 -183 96 Left 2
    SYMATTR InstName B3
    SYMATTR Value V=sgn(V(J))
    SYMBOL cap -864 -544 R0
    WINDOW 0 -53 40 Left 2
    WINDOW 3 -66 68 Left 2
    SYMATTR InstName C2
    SYMATTR Value 100n
    TEXT 216 -136 Left 4 ;P970 DC-DC Converter
    TEXT 288 -88 Left 3 ;JL Jan 15 2025
    TEXT -200 -80 Left 2 !.model Sj SW(Ron=50m Roff=1g)
    TEXT -200 -128 Left 2 !.tran 0 100m 0 20n
    TEXT -192 -568 Left 2 ;PL300-101L
    TEXT -160 -488 Left 2 ;4T
    TEXT -96 -488 Left 2 ;5T
    TEXT -200 -720 Left 2 !K1 L2 L3 0.999
    TEXT -392 -192 Left 2 ;163-5001
    TEXT -392 -152 Left 2 ;2.7 uH 5A
    TEXT -168 -600 Left 2 ;Coilcraft
    TEXT 232 -816 Left 2 ;50 ms soft start

    Very nice simulation

    I did a digital SMPS +10 years ago, use the same softstart principle.
    Was based on a halfbridge converter, so if it did not have softstart
    inrush current was very large. I believe you can do the same with phase
    shifted controllers, but they are probably very expensive. I did it with
    a 30cent microcontroller.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to klauskvik@hotmail.com on Mon Jan 20 16:18:02 2025
    On Mon, 20 Jan 2025 22:09:05 +0100, Klaus Kragelund
    <klauskvik@hotmail.com> wrote:

    On 16-01-2025 01:12, john larkin wrote:

    Here's my soft start circuit. Thanks for suggestions from Tilmann and
    Jeroen.

    The idea is to drive the ends of the transformer with in-phase square
    waves and then slowly walk them to 180 degrees, to achieve a soft
    start. An FPGA can do that easily. We might take a second... but that
    would simulate forever.

    What works well is to use two spice "modulator" elements and FM the
    frequency of one of them for 50 ms, until they are 180 degrees out of
    phase.

    Spice BV elements with sin(time*freq) type expressions seemed to
    overload or something.

    Version 4
    SHEET 1 2568 1220
    WIRE -512 -944 -576 -944
    WIRE -400 -944 -512 -944
    WIRE 16 -944 -32 -944
    WIRE 48 -944 16 -944
    WIRE 256 -944 192 -944
    WIRE 304 -944 256 -944
    WIRE -1104 -912 -1136 -912
    WIRE -1040 -912 -1104 -912
    WIRE -400 -912 -400 -944
    WIRE -32 -912 -32 -944
    WIRE 192 -912 192 -944
    WIRE -128 -896 -144 -896
    WIRE -80 -896 -128 -896
    WIRE -848 -880 -896 -880
    WIRE -800 -880 -848 -880
    WIRE -128 -848 -144 -848
    WIRE -80 -848 -128 -848
    WIRE -576 -816 -576 -944
    WIRE -784 -800 -848 -800
    WIRE -720 -800 -784 -800
    WIRE -624 -800 -720 -800
    WIRE -400 -800 -400 -832
    WIRE -32 -800 -32 -832
    WIRE 192 -800 192 -832
    WIRE -848 -768 -848 -800
    WIRE -624 -752 -656 -752
    WIRE -576 -688 -576 -736
    WIRE -448 -688 -576 -688
    WIRE -368 -688 -448 -688
    WIRE -208 -688 -304 -688
    WIRE 160 -688 -32 -688
    WIRE 208 -688 160 -688
    WIRE 416 -688 272 -688
    WIRE 480 -688 416 -688
    WIRE 544 -688 480 -688
    WIRE 656 -688 544 -688
    WIRE -848 -656 -848 -688
    WIRE -576 -640 -576 -688
    WIRE -656 -624 -656 -752
    WIRE -624 -624 -656 -624
    WIRE -720 -576 -720 -800
    WIRE -624 -576 -720 -576
    WIRE 208 -576 112 -576
    WIRE 416 -576 416 -688
    WIRE 416 -576 272 -576
    WIRE -1024 -560 -1104 -560
    WIRE -880 -560 -944 -560
    WIRE -848 -560 -880 -560
    WIRE -1104 -544 -1104 -560
    WIRE -848 -544 -848 -560
    WIRE -656 -528 -656 -624
    WIRE -576 -528 -576 -560
    WIRE -208 -528 -208 -688
    WIRE -32 -528 -32 -688
    WIRE 416 -512 416 -576
    WIRE 544 -512 544 -688
    WIRE 656 -512 656 -688
    WIRE -1104 -448 -1104 -464
    WIRE -848 -448 -848 -480
    WIRE -528 -400 -576 -400
    WIRE -480 -400 -528 -400
    WIRE -576 -368 -576 -400
    WIRE 160 -368 160 -688
    WIRE 208 -368 160 -368
    WIRE 416 -368 416 -448
    WIRE 416 -368 272 -368
    WIRE -784 -352 -848 -352
    WIRE -720 -352 -784 -352
    WIRE -624 -352 -720 -352
    WIRE -848 -320 -848 -352
    WIRE -624 -304 -656 -304
    WIRE -576 -240 -576 -288
    WIRE -448 -240 -576 -240
    WIRE -368 -240 -448 -240
    WIRE -208 -240 -208 -448
    WIRE -208 -240 -304 -240
    WIRE -32 -240 -32 -448
    WIRE 112 -240 112 -576
    WIRE 112 -240 -32 -240
    WIRE 208 -240 112 -240
    WIRE 416 -240 416 -368
    WIRE 416 -240 272 -240
    WIRE 544 -240 544 -432
    WIRE 544 -240 416 -240
    WIRE 656 -240 656 -432
    WIRE 656 -240 544 -240
    WIRE -848 -208 -848 -240
    WIRE -576 -192 -576 -240
    WIRE 416 -192 416 -240
    WIRE -656 -176 -656 -304
    WIRE -624 -176 -656 -176
    WIRE -1072 -160 -1152 -160
    WIRE -880 -128 -928 -128
    WIRE -848 -128 -880 -128
    WIRE -720 -128 -720 -352
    WIRE -624 -128 -720 -128
    WIRE -1152 -112 -1152 -160
    WIRE -656 -80 -656 -176
    WIRE -576 -80 -576 -112
    FLAG -400 -800 0
    FLAG -512 -944 +48
    FLAG -32 -800 0
    FLAG -128 -896 HA
    FLAG -128 -848 HB
    FLAG 16 -944 BRO
    FLAG -448 -688 HA
    FLAG -448 -240 HB
    FLAG -576 -528 0
    FLAG -656 -528 0
    FLAG -576 -80 0
    FLAG -528 -400 +48
    FLAG -656 -80 0
    FLAG 416 -192 0
    FLAG 480 -688 OUT
    FLAG -784 -800 A
    FLAG 256 -944 SS
    FLAG 192 -800 0
    FLAG -1104 -912 SS
    FLAG -1152 -112 0
    FLAG -784 -352 B
    FLAG -1104 -448 0
    FLAG -880 -560 AB
    FLAG -848 -448 0
    FLAG -848 -208 0
    FLAG -880 -128 K
    FLAG -848 -656 0
    FLAG -848 -880 J
    SYMBOL voltage -400 -928 R0
    WINDOW 0 53 46 Left 2
    WINDOW 3 53 78 Left 2
    SYMATTR InstName V3
    SYMATTR Value 48
    SYMBOL e -32 -928 R0
    WINDOW 0 45 50 Left 2
    WINDOW 3 49 78 Left 2
    SYMATTR InstName E5
    SYMATTR Value 1
    SYMBOL sw -576 -720 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S2
    SYMATTR Value Sj
    SYMBOL sw -576 -544 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S3
    SYMATTR Value Sj
    SYMBOL sw -576 -272 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S4
    SYMATTR Value Sj
    SYMBOL sw -576 -96 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S5
    SYMATTR Value Sj
    SYMBOL cap -304 -704 R90
    WINDOW 0 79 30 VBottom 2
    WINDOW 3 86 29 VTop 2
    SYMATTR InstName C1
    SYMATTR Value 20µ
    SYMBOL FerriteBead -336 -240 R90
    WINDOW 0 -37 -1 VBottom 2
    SYMATTR InstName L1
    SYMATTR Value 2.5µ
    SYMATTR SpiceLine Ipk=3 Rser=0.0023 Rpar=475 Cpar=1.75p
    SYMBOL ind2 -224 -544 R0
    WINDOW 0 -49 37 Left 2
    WINDOW 3 -61 76 Left 2
    SYMATTR InstName L2
    SYMATTR Value 72µ
    SYMATTR Type ind
    SYMBOL ind2 -48 -544 R0
    WINDOW 0 61 40 Left 2
    WINDOW 3 50 76 Left 2
    SYMATTR InstName L3
    SYMATTR Value 112µ
    SYMATTR Type ind
    SYMBOL schottky 208 -672 R270
    WINDOW 0 42 40 VTop 2
    WINDOW 3 -14 54 VBottom 2
    SYMATTR InstName D1
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL cap 400 -512 R0
    WINDOW 0 -58 36 Left 2
    WINDOW 3 -70 67 Left 2
    SYMATTR InstName C6
    SYMATTR Value 100µ
    SYMBOL res 528 -528 R0
    WINDOW 0 -63 51 Left 2
    WINDOW 3 -61 83 Left 2
    SYMATTR InstName R5
    SYMATTR Value 5K
    SYMBOL schottky 208 -560 R270
    WINDOW 0 39 33 VTop 2
    WINDOW 3 -14 55 VBottom 2
    SYMATTR InstName D2
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -384 R90
    WINDOW 0 -10 31 VBottom 2
    WINDOW 3 45 28 VTop 2
    SYMATTR InstName D3
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -256 R90
    WINDOW 0 -16 31 VBottom 2
    WINDOW 3 43 32 VTop 2
    SYMATTR InstName D4
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL current 656 -512 R0
    WINDOW 0 54 63 Left 2
    WINDOW 3 19 107 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName I1
    SYMATTR Value PULSE(0 0.5 75m 1m 0 9)
    SYMBOL voltage 192 -928 R0
    WINDOW 0 58 36 Left 2
    WINDOW 3 41 74 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V1
    SYMATTR Value PULSE(0 1 0 1u 1u 50m)
    SYMBOL SpecialFunctions\\modulate -1040 -912 R0
    WINDOW 0 56 29 Left 2
    SYMATTR InstName A1
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250.01K
    SYMBOL SpecialFunctions\\modulate -1072 -160 R0
    WINDOW 0 56 31 Left 2
    SYMATTR InstName A2
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250K
    SYMBOL bv -1104 -560 R0
    WINDOW 0 46 98 Left 2
    WINDOW 3 30 135 Left 2
    SYMATTR InstName B1
    SYMATTR Value V=V(A) * V(B)
    SYMBOL res -928 -576 R90
    WINDOW 0 66 56 VBottom 2
    WINDOW 3 65 57 VTop 2
    SYMATTR InstName R1
    SYMATTR Value 1K
    SYMBOL bv -848 -336 R0
    WINDOW 0 -89 48 Left 2
    WINDOW 3 -185 94 Left 2
    SYMATTR InstName B2
    SYMATTR Value V=sgn(V(K))
    SYMBOL bv -848 -784 R0
    WINDOW 0 -89 59 Left 2
    WINDOW 3 -183 96 Left 2
    SYMATTR InstName B3
    SYMATTR Value V=sgn(V(J))
    SYMBOL cap -864 -544 R0
    WINDOW 0 -53 40 Left 2
    WINDOW 3 -66 68 Left 2
    SYMATTR InstName C2
    SYMATTR Value 100n
    TEXT 216 -136 Left 4 ;P970 DC-DC Converter
    TEXT 288 -88 Left 3 ;JL Jan 15 2025
    TEXT -200 -80 Left 2 !.model Sj SW(Ron=50m Roff=1g)
    TEXT -200 -128 Left 2 !.tran 0 100m 0 20n
    TEXT -192 -568 Left 2 ;PL300-101L
    TEXT -160 -488 Left 2 ;4T
    TEXT -96 -488 Left 2 ;5T
    TEXT -200 -720 Left 2 !K1 L2 L3 0.999
    TEXT -392 -192 Left 2 ;163-5001
    TEXT -392 -152 Left 2 ;2.7 uH 5A
    TEXT -168 -600 Left 2 ;Coilcraft
    TEXT 232 -816 Left 2 ;50 ms soft start

    Very nice simulation

    I did a digital SMPS +10 years ago, use the same softstart principle.
    Was based on a halfbridge converter, so if it did not have softstart
    inrush current was very large. I believe you can do the same with phase >shifted controllers, but they are probably very expensive. I did it with
    a 30cent microcontroller.

    Envision an FPGA. Spin up a 200 MHz clock and stick that into a 10 bit
    binary counter. The MSB is a 200 KHz square wave that drives one
    half-bridge.

    Now stick that into a 10-bit adder, add integer P to it. The sum is
    the counter phase shifted by P, so the MSB is similarly time shifted,
    driving the other half bridge. Start it all up and tick P up to 512 at
    the power supply ramp-up rate, maybe over a second.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Klaus Kragelund@21:1/5 to john larkin on Wed Jan 22 22:47:10 2025
    On 21-01-2025 01:18, john larkin wrote:
    On Mon, 20 Jan 2025 22:09:05 +0100, Klaus Kragelund
    <klauskvik@hotmail.com> wrote:

    On 16-01-2025 01:12, john larkin wrote:

    Here's my soft start circuit. Thanks for suggestions from Tilmann and
    Jeroen.

    The idea is to drive the ends of the transformer with in-phase square
    waves and then slowly walk them to 180 degrees, to achieve a soft
    start. An FPGA can do that easily. We might take a second... but that
    would simulate forever.

    What works well is to use two spice "modulator" elements and FM the
    frequency of one of them for 50 ms, until they are 180 degrees out of
    phase.

    Spice BV elements with sin(time*freq) type expressions seemed to
    overload or something.

    Version 4
    SHEET 1 2568 1220
    WIRE -512 -944 -576 -944
    WIRE -400 -944 -512 -944
    WIRE 16 -944 -32 -944
    WIRE 48 -944 16 -944
    WIRE 256 -944 192 -944
    WIRE 304 -944 256 -944
    WIRE -1104 -912 -1136 -912
    WIRE -1040 -912 -1104 -912
    WIRE -400 -912 -400 -944
    WIRE -32 -912 -32 -944
    WIRE 192 -912 192 -944
    WIRE -128 -896 -144 -896
    WIRE -80 -896 -128 -896
    WIRE -848 -880 -896 -880
    WIRE -800 -880 -848 -880
    WIRE -128 -848 -144 -848
    WIRE -80 -848 -128 -848
    WIRE -576 -816 -576 -944
    WIRE -784 -800 -848 -800
    WIRE -720 -800 -784 -800
    WIRE -624 -800 -720 -800
    WIRE -400 -800 -400 -832
    WIRE -32 -800 -32 -832
    WIRE 192 -800 192 -832
    WIRE -848 -768 -848 -800
    WIRE -624 -752 -656 -752
    WIRE -576 -688 -576 -736
    WIRE -448 -688 -576 -688
    WIRE -368 -688 -448 -688
    WIRE -208 -688 -304 -688
    WIRE 160 -688 -32 -688
    WIRE 208 -688 160 -688
    WIRE 416 -688 272 -688
    WIRE 480 -688 416 -688
    WIRE 544 -688 480 -688
    WIRE 656 -688 544 -688
    WIRE -848 -656 -848 -688
    WIRE -576 -640 -576 -688
    WIRE -656 -624 -656 -752
    WIRE -624 -624 -656 -624
    WIRE -720 -576 -720 -800
    WIRE -624 -576 -720 -576
    WIRE 208 -576 112 -576
    WIRE 416 -576 416 -688
    WIRE 416 -576 272 -576
    WIRE -1024 -560 -1104 -560
    WIRE -880 -560 -944 -560
    WIRE -848 -560 -880 -560
    WIRE -1104 -544 -1104 -560
    WIRE -848 -544 -848 -560
    WIRE -656 -528 -656 -624
    WIRE -576 -528 -576 -560
    WIRE -208 -528 -208 -688
    WIRE -32 -528 -32 -688
    WIRE 416 -512 416 -576
    WIRE 544 -512 544 -688
    WIRE 656 -512 656 -688
    WIRE -1104 -448 -1104 -464
    WIRE -848 -448 -848 -480
    WIRE -528 -400 -576 -400
    WIRE -480 -400 -528 -400
    WIRE -576 -368 -576 -400
    WIRE 160 -368 160 -688
    WIRE 208 -368 160 -368
    WIRE 416 -368 416 -448
    WIRE 416 -368 272 -368
    WIRE -784 -352 -848 -352
    WIRE -720 -352 -784 -352
    WIRE -624 -352 -720 -352
    WIRE -848 -320 -848 -352
    WIRE -624 -304 -656 -304
    WIRE -576 -240 -576 -288
    WIRE -448 -240 -576 -240
    WIRE -368 -240 -448 -240
    WIRE -208 -240 -208 -448
    WIRE -208 -240 -304 -240
    WIRE -32 -240 -32 -448
    WIRE 112 -240 112 -576
    WIRE 112 -240 -32 -240
    WIRE 208 -240 112 -240
    WIRE 416 -240 416 -368
    WIRE 416 -240 272 -240
    WIRE 544 -240 544 -432
    WIRE 544 -240 416 -240
    WIRE 656 -240 656 -432
    WIRE 656 -240 544 -240
    WIRE -848 -208 -848 -240
    WIRE -576 -192 -576 -240
    WIRE 416 -192 416 -240
    WIRE -656 -176 -656 -304
    WIRE -624 -176 -656 -176
    WIRE -1072 -160 -1152 -160
    WIRE -880 -128 -928 -128
    WIRE -848 -128 -880 -128
    WIRE -720 -128 -720 -352
    WIRE -624 -128 -720 -128
    WIRE -1152 -112 -1152 -160
    WIRE -656 -80 -656 -176
    WIRE -576 -80 -576 -112
    FLAG -400 -800 0
    FLAG -512 -944 +48
    FLAG -32 -800 0
    FLAG -128 -896 HA
    FLAG -128 -848 HB
    FLAG 16 -944 BRO
    FLAG -448 -688 HA
    FLAG -448 -240 HB
    FLAG -576 -528 0
    FLAG -656 -528 0
    FLAG -576 -80 0
    FLAG -528 -400 +48
    FLAG -656 -80 0
    FLAG 416 -192 0
    FLAG 480 -688 OUT
    FLAG -784 -800 A
    FLAG 256 -944 SS
    FLAG 192 -800 0
    FLAG -1104 -912 SS
    FLAG -1152 -112 0
    FLAG -784 -352 B
    FLAG -1104 -448 0
    FLAG -880 -560 AB
    FLAG -848 -448 0
    FLAG -848 -208 0
    FLAG -880 -128 K
    FLAG -848 -656 0
    FLAG -848 -880 J
    SYMBOL voltage -400 -928 R0
    WINDOW 0 53 46 Left 2
    WINDOW 3 53 78 Left 2
    SYMATTR InstName V3
    SYMATTR Value 48
    SYMBOL e -32 -928 R0
    WINDOW 0 45 50 Left 2
    WINDOW 3 49 78 Left 2
    SYMATTR InstName E5
    SYMATTR Value 1
    SYMBOL sw -576 -720 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S2
    SYMATTR Value Sj
    SYMBOL sw -576 -544 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S3
    SYMATTR Value Sj
    SYMBOL sw -576 -272 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S4
    SYMATTR Value Sj
    SYMBOL sw -576 -96 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S5
    SYMATTR Value Sj
    SYMBOL cap -304 -704 R90
    WINDOW 0 79 30 VBottom 2
    WINDOW 3 86 29 VTop 2
    SYMATTR InstName C1
    SYMATTR Value 20µ
    SYMBOL FerriteBead -336 -240 R90
    WINDOW 0 -37 -1 VBottom 2
    SYMATTR InstName L1
    SYMATTR Value 2.5µ
    SYMATTR SpiceLine Ipk=3 Rser=0.0023 Rpar=475 Cpar=1.75p
    SYMBOL ind2 -224 -544 R0
    WINDOW 0 -49 37 Left 2
    WINDOW 3 -61 76 Left 2
    SYMATTR InstName L2
    SYMATTR Value 72µ
    SYMATTR Type ind
    SYMBOL ind2 -48 -544 R0
    WINDOW 0 61 40 Left 2
    WINDOW 3 50 76 Left 2
    SYMATTR InstName L3
    SYMATTR Value 112µ
    SYMATTR Type ind
    SYMBOL schottky 208 -672 R270
    WINDOW 0 42 40 VTop 2
    WINDOW 3 -14 54 VBottom 2
    SYMATTR InstName D1
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL cap 400 -512 R0
    WINDOW 0 -58 36 Left 2
    WINDOW 3 -70 67 Left 2
    SYMATTR InstName C6
    SYMATTR Value 100µ
    SYMBOL res 528 -528 R0
    WINDOW 0 -63 51 Left 2
    WINDOW 3 -61 83 Left 2
    SYMATTR InstName R5
    SYMATTR Value 5K
    SYMBOL schottky 208 -560 R270
    WINDOW 0 39 33 VTop 2
    WINDOW 3 -14 55 VBottom 2
    SYMATTR InstName D2
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -384 R90
    WINDOW 0 -10 31 VBottom 2
    WINDOW 3 45 28 VTop 2
    SYMATTR InstName D3
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -256 R90
    WINDOW 0 -16 31 VBottom 2
    WINDOW 3 43 32 VTop 2
    SYMATTR InstName D4
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL current 656 -512 R0
    WINDOW 0 54 63 Left 2
    WINDOW 3 19 107 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName I1
    SYMATTR Value PULSE(0 0.5 75m 1m 0 9)
    SYMBOL voltage 192 -928 R0
    WINDOW 0 58 36 Left 2
    WINDOW 3 41 74 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V1
    SYMATTR Value PULSE(0 1 0 1u 1u 50m)
    SYMBOL SpecialFunctions\\modulate -1040 -912 R0
    WINDOW 0 56 29 Left 2
    SYMATTR InstName A1
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250.01K
    SYMBOL SpecialFunctions\\modulate -1072 -160 R0
    WINDOW 0 56 31 Left 2
    SYMATTR InstName A2
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250K
    SYMBOL bv -1104 -560 R0
    WINDOW 0 46 98 Left 2
    WINDOW 3 30 135 Left 2
    SYMATTR InstName B1
    SYMATTR Value V=V(A) * V(B)
    SYMBOL res -928 -576 R90
    WINDOW 0 66 56 VBottom 2
    WINDOW 3 65 57 VTop 2
    SYMATTR InstName R1
    SYMATTR Value 1K
    SYMBOL bv -848 -336 R0
    WINDOW 0 -89 48 Left 2
    WINDOW 3 -185 94 Left 2
    SYMATTR InstName B2
    SYMATTR Value V=sgn(V(K))
    SYMBOL bv -848 -784 R0
    WINDOW 0 -89 59 Left 2
    WINDOW 3 -183 96 Left 2
    SYMATTR InstName B3
    SYMATTR Value V=sgn(V(J))
    SYMBOL cap -864 -544 R0
    WINDOW 0 -53 40 Left 2
    WINDOW 3 -66 68 Left 2
    SYMATTR InstName C2
    SYMATTR Value 100n
    TEXT 216 -136 Left 4 ;P970 DC-DC Converter
    TEXT 288 -88 Left 3 ;JL Jan 15 2025
    TEXT -200 -80 Left 2 !.model Sj SW(Ron=50m Roff=1g)
    TEXT -200 -128 Left 2 !.tran 0 100m 0 20n
    TEXT -192 -568 Left 2 ;PL300-101L
    TEXT -160 -488 Left 2 ;4T
    TEXT -96 -488 Left 2 ;5T
    TEXT -200 -720 Left 2 !K1 L2 L3 0.999
    TEXT -392 -192 Left 2 ;163-5001
    TEXT -392 -152 Left 2 ;2.7 uH 5A
    TEXT -168 -600 Left 2 ;Coilcraft
    TEXT 232 -816 Left 2 ;50 ms soft start

    Very nice simulation

    I did a digital SMPS +10 years ago, use the same softstart principle.
    Was based on a halfbridge converter, so if it did not have softstart
    inrush current was very large. I believe you can do the same with phase
    shifted controllers, but they are probably very expensive. I did it with
    a 30cent microcontroller.

    Envision an FPGA. Spin up a 200 MHz clock and stick that into a 10 bit
    binary counter. The MSB is a 200 KHz square wave that drives one
    half-bridge.

    Now stick that into a 10-bit adder, add integer P to it. The sum is
    the counter phase shifted by P, so the MSB is similarly time shifted,
    driving the other half bridge. Start it all up and tick P up to 512 at
    the power supply ramp-up rate, maybe over a second.

    Yeah, the idea is nice.

    But I not that much of a fan of FPGAs. Very expensive compared to microcontrollers. In some applications they are trusted more than Class
    B embedded SW, and have more performance than microcontrollers. But for
    the price of that FPGA, you can probably buy 100 cortex microcontrollers.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to klauskvik@hotmail.com on Wed Jan 22 15:25:41 2025
    On Wed, 22 Jan 2025 22:47:10 +0100, Klaus Kragelund
    <klauskvik@hotmail.com> wrote:

    On 21-01-2025 01:18, john larkin wrote:
    On Mon, 20 Jan 2025 22:09:05 +0100, Klaus Kragelund
    <klauskvik@hotmail.com> wrote:

    On 16-01-2025 01:12, john larkin wrote:

    Here's my soft start circuit. Thanks for suggestions from Tilmann and
    Jeroen.

    The idea is to drive the ends of the transformer with in-phase square
    waves and then slowly walk them to 180 degrees, to achieve a soft
    start. An FPGA can do that easily. We might take a second... but that
    would simulate forever.

    What works well is to use two spice "modulator" elements and FM the
    frequency of one of them for 50 ms, until they are 180 degrees out of
    phase.

    Spice BV elements with sin(time*freq) type expressions seemed to
    overload or something.

    Version 4
    SHEET 1 2568 1220
    WIRE -512 -944 -576 -944
    WIRE -400 -944 -512 -944
    WIRE 16 -944 -32 -944
    WIRE 48 -944 16 -944
    WIRE 256 -944 192 -944
    WIRE 304 -944 256 -944
    WIRE -1104 -912 -1136 -912
    WIRE -1040 -912 -1104 -912
    WIRE -400 -912 -400 -944
    WIRE -32 -912 -32 -944
    WIRE 192 -912 192 -944
    WIRE -128 -896 -144 -896
    WIRE -80 -896 -128 -896
    WIRE -848 -880 -896 -880
    WIRE -800 -880 -848 -880
    WIRE -128 -848 -144 -848
    WIRE -80 -848 -128 -848
    WIRE -576 -816 -576 -944
    WIRE -784 -800 -848 -800
    WIRE -720 -800 -784 -800
    WIRE -624 -800 -720 -800
    WIRE -400 -800 -400 -832
    WIRE -32 -800 -32 -832
    WIRE 192 -800 192 -832
    WIRE -848 -768 -848 -800
    WIRE -624 -752 -656 -752
    WIRE -576 -688 -576 -736
    WIRE -448 -688 -576 -688
    WIRE -368 -688 -448 -688
    WIRE -208 -688 -304 -688
    WIRE 160 -688 -32 -688
    WIRE 208 -688 160 -688
    WIRE 416 -688 272 -688
    WIRE 480 -688 416 -688
    WIRE 544 -688 480 -688
    WIRE 656 -688 544 -688
    WIRE -848 -656 -848 -688
    WIRE -576 -640 -576 -688
    WIRE -656 -624 -656 -752
    WIRE -624 -624 -656 -624
    WIRE -720 -576 -720 -800
    WIRE -624 -576 -720 -576
    WIRE 208 -576 112 -576
    WIRE 416 -576 416 -688
    WIRE 416 -576 272 -576
    WIRE -1024 -560 -1104 -560
    WIRE -880 -560 -944 -560
    WIRE -848 -560 -880 -560
    WIRE -1104 -544 -1104 -560
    WIRE -848 -544 -848 -560
    WIRE -656 -528 -656 -624
    WIRE -576 -528 -576 -560
    WIRE -208 -528 -208 -688
    WIRE -32 -528 -32 -688
    WIRE 416 -512 416 -576
    WIRE 544 -512 544 -688
    WIRE 656 -512 656 -688
    WIRE -1104 -448 -1104 -464
    WIRE -848 -448 -848 -480
    WIRE -528 -400 -576 -400
    WIRE -480 -400 -528 -400
    WIRE -576 -368 -576 -400
    WIRE 160 -368 160 -688
    WIRE 208 -368 160 -368
    WIRE 416 -368 416 -448
    WIRE 416 -368 272 -368
    WIRE -784 -352 -848 -352
    WIRE -720 -352 -784 -352
    WIRE -624 -352 -720 -352
    WIRE -848 -320 -848 -352
    WIRE -624 -304 -656 -304
    WIRE -576 -240 -576 -288
    WIRE -448 -240 -576 -240
    WIRE -368 -240 -448 -240
    WIRE -208 -240 -208 -448
    WIRE -208 -240 -304 -240
    WIRE -32 -240 -32 -448
    WIRE 112 -240 112 -576
    WIRE 112 -240 -32 -240
    WIRE 208 -240 112 -240
    WIRE 416 -240 416 -368
    WIRE 416 -240 272 -240
    WIRE 544 -240 544 -432
    WIRE 544 -240 416 -240
    WIRE 656 -240 656 -432
    WIRE 656 -240 544 -240
    WIRE -848 -208 -848 -240
    WIRE -576 -192 -576 -240
    WIRE 416 -192 416 -240
    WIRE -656 -176 -656 -304
    WIRE -624 -176 -656 -176
    WIRE -1072 -160 -1152 -160
    WIRE -880 -128 -928 -128
    WIRE -848 -128 -880 -128
    WIRE -720 -128 -720 -352
    WIRE -624 -128 -720 -128
    WIRE -1152 -112 -1152 -160
    WIRE -656 -80 -656 -176
    WIRE -576 -80 -576 -112
    FLAG -400 -800 0
    FLAG -512 -944 +48
    FLAG -32 -800 0
    FLAG -128 -896 HA
    FLAG -128 -848 HB
    FLAG 16 -944 BRO
    FLAG -448 -688 HA
    FLAG -448 -240 HB
    FLAG -576 -528 0
    FLAG -656 -528 0
    FLAG -576 -80 0
    FLAG -528 -400 +48
    FLAG -656 -80 0
    FLAG 416 -192 0
    FLAG 480 -688 OUT
    FLAG -784 -800 A
    FLAG 256 -944 SS
    FLAG 192 -800 0
    FLAG -1104 -912 SS
    FLAG -1152 -112 0
    FLAG -784 -352 B
    FLAG -1104 -448 0
    FLAG -880 -560 AB
    FLAG -848 -448 0
    FLAG -848 -208 0
    FLAG -880 -128 K
    FLAG -848 -656 0
    FLAG -848 -880 J
    SYMBOL voltage -400 -928 R0
    WINDOW 0 53 46 Left 2
    WINDOW 3 53 78 Left 2
    SYMATTR InstName V3
    SYMATTR Value 48
    SYMBOL e -32 -928 R0
    WINDOW 0 45 50 Left 2
    WINDOW 3 49 78 Left 2
    SYMATTR InstName E5
    SYMATTR Value 1
    SYMBOL sw -576 -720 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S2
    SYMATTR Value Sj
    SYMBOL sw -576 -544 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S3
    SYMATTR Value Sj
    SYMBOL sw -576 -272 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S4
    SYMATTR Value Sj
    SYMBOL sw -576 -96 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S5
    SYMATTR Value Sj
    SYMBOL cap -304 -704 R90
    WINDOW 0 79 30 VBottom 2
    WINDOW 3 86 29 VTop 2
    SYMATTR InstName C1
    SYMATTR Value 20µ
    SYMBOL FerriteBead -336 -240 R90
    WINDOW 0 -37 -1 VBottom 2
    SYMATTR InstName L1
    SYMATTR Value 2.5µ
    SYMATTR SpiceLine Ipk=3 Rser=0.0023 Rpar=475 Cpar=1.75p
    SYMBOL ind2 -224 -544 R0
    WINDOW 0 -49 37 Left 2
    WINDOW 3 -61 76 Left 2
    SYMATTR InstName L2
    SYMATTR Value 72µ
    SYMATTR Type ind
    SYMBOL ind2 -48 -544 R0
    WINDOW 0 61 40 Left 2
    WINDOW 3 50 76 Left 2
    SYMATTR InstName L3
    SYMATTR Value 112µ
    SYMATTR Type ind
    SYMBOL schottky 208 -672 R270
    WINDOW 0 42 40 VTop 2
    WINDOW 3 -14 54 VBottom 2
    SYMATTR InstName D1
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL cap 400 -512 R0
    WINDOW 0 -58 36 Left 2
    WINDOW 3 -70 67 Left 2
    SYMATTR InstName C6
    SYMATTR Value 100µ
    SYMBOL res 528 -528 R0
    WINDOW 0 -63 51 Left 2
    WINDOW 3 -61 83 Left 2
    SYMATTR InstName R5
    SYMATTR Value 5K
    SYMBOL schottky 208 -560 R270
    WINDOW 0 39 33 VTop 2
    WINDOW 3 -14 55 VBottom 2
    SYMATTR InstName D2
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -384 R90
    WINDOW 0 -10 31 VBottom 2
    WINDOW 3 45 28 VTop 2
    SYMATTR InstName D3
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -256 R90
    WINDOW 0 -16 31 VBottom 2
    WINDOW 3 43 32 VTop 2
    SYMATTR InstName D4
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL current 656 -512 R0
    WINDOW 0 54 63 Left 2
    WINDOW 3 19 107 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName I1
    SYMATTR Value PULSE(0 0.5 75m 1m 0 9)
    SYMBOL voltage 192 -928 R0
    WINDOW 0 58 36 Left 2
    WINDOW 3 41 74 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V1
    SYMATTR Value PULSE(0 1 0 1u 1u 50m)
    SYMBOL SpecialFunctions\\modulate -1040 -912 R0
    WINDOW 0 56 29 Left 2
    SYMATTR InstName A1
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250.01K
    SYMBOL SpecialFunctions\\modulate -1072 -160 R0
    WINDOW 0 56 31 Left 2
    SYMATTR InstName A2
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250K
    SYMBOL bv -1104 -560 R0
    WINDOW 0 46 98 Left 2
    WINDOW 3 30 135 Left 2
    SYMATTR InstName B1
    SYMATTR Value V=V(A) * V(B)
    SYMBOL res -928 -576 R90
    WINDOW 0 66 56 VBottom 2
    WINDOW 3 65 57 VTop 2
    SYMATTR InstName R1
    SYMATTR Value 1K
    SYMBOL bv -848 -336 R0
    WINDOW 0 -89 48 Left 2
    WINDOW 3 -185 94 Left 2
    SYMATTR InstName B2
    SYMATTR Value V=sgn(V(K))
    SYMBOL bv -848 -784 R0
    WINDOW 0 -89 59 Left 2
    WINDOW 3 -183 96 Left 2
    SYMATTR InstName B3
    SYMATTR Value V=sgn(V(J))
    SYMBOL cap -864 -544 R0
    WINDOW 0 -53 40 Left 2
    WINDOW 3 -66 68 Left 2
    SYMATTR InstName C2
    SYMATTR Value 100n
    TEXT 216 -136 Left 4 ;P970 DC-DC Converter
    TEXT 288 -88 Left 3 ;JL Jan 15 2025
    TEXT -200 -80 Left 2 !.model Sj SW(Ron=50m Roff=1g)
    TEXT -200 -128 Left 2 !.tran 0 100m 0 20n
    TEXT -192 -568 Left 2 ;PL300-101L
    TEXT -160 -488 Left 2 ;4T
    TEXT -96 -488 Left 2 ;5T
    TEXT -200 -720 Left 2 !K1 L2 L3 0.999
    TEXT -392 -192 Left 2 ;163-5001
    TEXT -392 -152 Left 2 ;2.7 uH 5A
    TEXT -168 -600 Left 2 ;Coilcraft
    TEXT 232 -816 Left 2 ;50 ms soft start

    Very nice simulation

    I did a digital SMPS +10 years ago, use the same softstart principle.
    Was based on a halfbridge converter, so if it did not have softstart
    inrush current was very large. I believe you can do the same with phase
    shifted controllers, but they are probably very expensive. I did it with >>> a 30cent microcontroller.

    Envision an FPGA. Spin up a 200 MHz clock and stick that into a 10 bit
    binary counter. The MSB is a 200 KHz square wave that drives one
    half-bridge.

    Now stick that into a 10-bit adder, add integer P to it. The sum is
    the counter phase shifted by P, so the MSB is similarly time shifted,
    driving the other half bridge. Start it all up and tick P up to 512 at
    the power supply ramp-up rate, maybe over a second.

    Yeah, the idea is nice.

    But I not that much of a fan of FPGAs. Very expensive compared to >microcontrollers. In some applications they are trusted more than Class
    B embedded SW, and have more performance than microcontrollers. But for
    the price of that FPGA, you can probably buy 100 cortex microcontrollers.

    We have a modular power system with plugin boards, and every board has
    an FPGA, so the function is incrementally free. The FPGA is an Efinix
    T20, about $10.

    Here's the system:

    https://highlandtechnology.com/Category/MPS

    We really need an FPGA on these boards. There are three 50 MBPS data
    streams to and from the motherboard, and fast PWM generation and
    stuff.

    I'm designing a 4-channel dummy load board that simulates programmable resistance+inductance, like a solenoid or something. It needs four
    isolated power supplies.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Klaus Kragelund@21:1/5 to john larkin on Fri Jan 24 13:09:16 2025
    On 23-01-2025 00:25, john larkin wrote:
    On Wed, 22 Jan 2025 22:47:10 +0100, Klaus Kragelund
    <klauskvik@hotmail.com> wrote:

    On 21-01-2025 01:18, john larkin wrote:
    On Mon, 20 Jan 2025 22:09:05 +0100, Klaus Kragelund
    <klauskvik@hotmail.com> wrote:

    On 16-01-2025 01:12, john larkin wrote:

    Here's my soft start circuit. Thanks for suggestions from Tilmann and >>>>> Jeroen.

    The idea is to drive the ends of the transformer with in-phase square >>>>> waves and then slowly walk them to 180 degrees, to achieve a soft
    start. An FPGA can do that easily. We might take a second... but that >>>>> would simulate forever.

    What works well is to use two spice "modulator" elements and FM the
    frequency of one of them for 50 ms, until they are 180 degrees out of >>>>> phase.

    Spice BV elements with sin(time*freq) type expressions seemed to
    overload or something.

    Version 4
    SHEET 1 2568 1220
    WIRE -512 -944 -576 -944
    WIRE -400 -944 -512 -944
    WIRE 16 -944 -32 -944
    WIRE 48 -944 16 -944
    WIRE 256 -944 192 -944
    WIRE 304 -944 256 -944
    WIRE -1104 -912 -1136 -912
    WIRE -1040 -912 -1104 -912
    WIRE -400 -912 -400 -944
    WIRE -32 -912 -32 -944
    WIRE 192 -912 192 -944
    WIRE -128 -896 -144 -896
    WIRE -80 -896 -128 -896
    WIRE -848 -880 -896 -880
    WIRE -800 -880 -848 -880
    WIRE -128 -848 -144 -848
    WIRE -80 -848 -128 -848
    WIRE -576 -816 -576 -944
    WIRE -784 -800 -848 -800
    WIRE -720 -800 -784 -800
    WIRE -624 -800 -720 -800
    WIRE -400 -800 -400 -832
    WIRE -32 -800 -32 -832
    WIRE 192 -800 192 -832
    WIRE -848 -768 -848 -800
    WIRE -624 -752 -656 -752
    WIRE -576 -688 -576 -736
    WIRE -448 -688 -576 -688
    WIRE -368 -688 -448 -688
    WIRE -208 -688 -304 -688
    WIRE 160 -688 -32 -688
    WIRE 208 -688 160 -688
    WIRE 416 -688 272 -688
    WIRE 480 -688 416 -688
    WIRE 544 -688 480 -688
    WIRE 656 -688 544 -688
    WIRE -848 -656 -848 -688
    WIRE -576 -640 -576 -688
    WIRE -656 -624 -656 -752
    WIRE -624 -624 -656 -624
    WIRE -720 -576 -720 -800
    WIRE -624 -576 -720 -576
    WIRE 208 -576 112 -576
    WIRE 416 -576 416 -688
    WIRE 416 -576 272 -576
    WIRE -1024 -560 -1104 -560
    WIRE -880 -560 -944 -560
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    WIRE -848 -544 -848 -560
    WIRE -656 -528 -656 -624
    WIRE -576 -528 -576 -560
    WIRE -208 -528 -208 -688
    WIRE -32 -528 -32 -688
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    WIRE 544 -512 544 -688
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    WIRE -1104 -448 -1104 -464
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    WIRE -528 -400 -576 -400
    WIRE -480 -400 -528 -400
    WIRE -576 -368 -576 -400
    WIRE 160 -368 160 -688
    WIRE 208 -368 160 -368
    WIRE 416 -368 416 -448
    WIRE 416 -368 272 -368
    WIRE -784 -352 -848 -352
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    WIRE -624 -352 -720 -352
    WIRE -848 -320 -848 -352
    WIRE -624 -304 -656 -304
    WIRE -576 -240 -576 -288
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    WIRE -368 -240 -448 -240
    WIRE -208 -240 -208 -448
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    WIRE -32 -240 -32 -448
    WIRE 112 -240 112 -576
    WIRE 112 -240 -32 -240
    WIRE 208 -240 112 -240
    WIRE 416 -240 416 -368
    WIRE 416 -240 272 -240
    WIRE 544 -240 544 -432
    WIRE 544 -240 416 -240
    WIRE 656 -240 656 -432
    WIRE 656 -240 544 -240
    WIRE -848 -208 -848 -240
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    WIRE 416 -192 416 -240
    WIRE -656 -176 -656 -304
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    WIRE -1072 -160 -1152 -160
    WIRE -880 -128 -928 -128
    WIRE -848 -128 -880 -128
    WIRE -720 -128 -720 -352
    WIRE -624 -128 -720 -128
    WIRE -1152 -112 -1152 -160
    WIRE -656 -80 -656 -176
    WIRE -576 -80 -576 -112
    FLAG -400 -800 0
    FLAG -512 -944 +48
    FLAG -32 -800 0
    FLAG -128 -896 HA
    FLAG -128 -848 HB
    FLAG 16 -944 BRO
    FLAG -448 -688 HA
    FLAG -448 -240 HB
    FLAG -576 -528 0
    FLAG -656 -528 0
    FLAG -576 -80 0
    FLAG -528 -400 +48
    FLAG -656 -80 0
    FLAG 416 -192 0
    FLAG 480 -688 OUT
    FLAG -784 -800 A
    FLAG 256 -944 SS
    FLAG 192 -800 0
    FLAG -1104 -912 SS
    FLAG -1152 -112 0
    FLAG -784 -352 B
    FLAG -1104 -448 0
    FLAG -880 -560 AB
    FLAG -848 -448 0
    FLAG -848 -208 0
    FLAG -880 -128 K
    FLAG -848 -656 0
    FLAG -848 -880 J
    SYMBOL voltage -400 -928 R0
    WINDOW 0 53 46 Left 2
    WINDOW 3 53 78 Left 2
    SYMATTR InstName V3
    SYMATTR Value 48
    SYMBOL e -32 -928 R0
    WINDOW 0 45 50 Left 2
    WINDOW 3 49 78 Left 2
    SYMATTR InstName E5
    SYMATTR Value 1
    SYMBOL sw -576 -720 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S2
    SYMATTR Value Sj
    SYMBOL sw -576 -544 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S3
    SYMATTR Value Sj
    SYMBOL sw -576 -272 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S4
    SYMATTR Value Sj
    SYMBOL sw -576 -96 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S5
    SYMATTR Value Sj
    SYMBOL cap -304 -704 R90
    WINDOW 0 79 30 VBottom 2
    WINDOW 3 86 29 VTop 2
    SYMATTR InstName C1
    SYMATTR Value 20µ
    SYMBOL FerriteBead -336 -240 R90
    WINDOW 0 -37 -1 VBottom 2
    SYMATTR InstName L1
    SYMATTR Value 2.5µ
    SYMATTR SpiceLine Ipk=3 Rser=0.0023 Rpar=475 Cpar=1.75p
    SYMBOL ind2 -224 -544 R0
    WINDOW 0 -49 37 Left 2
    WINDOW 3 -61 76 Left 2
    SYMATTR InstName L2
    SYMATTR Value 72µ
    SYMATTR Type ind
    SYMBOL ind2 -48 -544 R0
    WINDOW 0 61 40 Left 2
    WINDOW 3 50 76 Left 2
    SYMATTR InstName L3
    SYMATTR Value 112µ
    SYMATTR Type ind
    SYMBOL schottky 208 -672 R270
    WINDOW 0 42 40 VTop 2
    WINDOW 3 -14 54 VBottom 2
    SYMATTR InstName D1
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL cap 400 -512 R0
    WINDOW 0 -58 36 Left 2
    WINDOW 3 -70 67 Left 2
    SYMATTR InstName C6
    SYMATTR Value 100µ
    SYMBOL res 528 -528 R0
    WINDOW 0 -63 51 Left 2
    WINDOW 3 -61 83 Left 2
    SYMATTR InstName R5
    SYMATTR Value 5K
    SYMBOL schottky 208 -560 R270
    WINDOW 0 39 33 VTop 2
    WINDOW 3 -14 55 VBottom 2
    SYMATTR InstName D2
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -384 R90
    WINDOW 0 -10 31 VBottom 2
    WINDOW 3 45 28 VTop 2
    SYMATTR InstName D3
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -256 R90
    WINDOW 0 -16 31 VBottom 2
    WINDOW 3 43 32 VTop 2
    SYMATTR InstName D4
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL current 656 -512 R0
    WINDOW 0 54 63 Left 2
    WINDOW 3 19 107 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName I1
    SYMATTR Value PULSE(0 0.5 75m 1m 0 9)
    SYMBOL voltage 192 -928 R0
    WINDOW 0 58 36 Left 2
    WINDOW 3 41 74 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V1
    SYMATTR Value PULSE(0 1 0 1u 1u 50m)
    SYMBOL SpecialFunctions\\modulate -1040 -912 R0
    WINDOW 0 56 29 Left 2
    SYMATTR InstName A1
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250.01K
    SYMBOL SpecialFunctions\\modulate -1072 -160 R0
    WINDOW 0 56 31 Left 2
    SYMATTR InstName A2
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250K
    SYMBOL bv -1104 -560 R0
    WINDOW 0 46 98 Left 2
    WINDOW 3 30 135 Left 2
    SYMATTR InstName B1
    SYMATTR Value V=V(A) * V(B)
    SYMBOL res -928 -576 R90
    WINDOW 0 66 56 VBottom 2
    WINDOW 3 65 57 VTop 2
    SYMATTR InstName R1
    SYMATTR Value 1K
    SYMBOL bv -848 -336 R0
    WINDOW 0 -89 48 Left 2
    WINDOW 3 -185 94 Left 2
    SYMATTR InstName B2
    SYMATTR Value V=sgn(V(K))
    SYMBOL bv -848 -784 R0
    WINDOW 0 -89 59 Left 2
    WINDOW 3 -183 96 Left 2
    SYMATTR InstName B3
    SYMATTR Value V=sgn(V(J))
    SYMBOL cap -864 -544 R0
    WINDOW 0 -53 40 Left 2
    WINDOW 3 -66 68 Left 2
    SYMATTR InstName C2
    SYMATTR Value 100n
    TEXT 216 -136 Left 4 ;P970 DC-DC Converter
    TEXT 288 -88 Left 3 ;JL Jan 15 2025
    TEXT -200 -80 Left 2 !.model Sj SW(Ron=50m Roff=1g)
    TEXT -200 -128 Left 2 !.tran 0 100m 0 20n
    TEXT -192 -568 Left 2 ;PL300-101L
    TEXT -160 -488 Left 2 ;4T
    TEXT -96 -488 Left 2 ;5T
    TEXT -200 -720 Left 2 !K1 L2 L3 0.999
    TEXT -392 -192 Left 2 ;163-5001
    TEXT -392 -152 Left 2 ;2.7 uH 5A
    TEXT -168 -600 Left 2 ;Coilcraft
    TEXT 232 -816 Left 2 ;50 ms soft start

    Very nice simulation

    I did a digital SMPS +10 years ago, use the same softstart principle.
    Was based on a halfbridge converter, so if it did not have softstart
    inrush current was very large. I believe you can do the same with phase >>>> shifted controllers, but they are probably very expensive. I did it with >>>> a 30cent microcontroller.

    Envision an FPGA. Spin up a 200 MHz clock and stick that into a 10 bit
    binary counter. The MSB is a 200 KHz square wave that drives one
    half-bridge.

    Now stick that into a 10-bit adder, add integer P to it. The sum is
    the counter phase shifted by P, so the MSB is similarly time shifted,
    driving the other half bridge. Start it all up and tick P up to 512 at
    the power supply ramp-up rate, maybe over a second.

    Yeah, the idea is nice.

    But I not that much of a fan of FPGAs. Very expensive compared to
    microcontrollers. In some applications they are trusted more than Class
    B embedded SW, and have more performance than microcontrollers. But for
    the price of that FPGA, you can probably buy 100 cortex microcontrollers.

    We have a modular power system with plugin boards, and every board has
    an FPGA, so the function is incrementally free. The FPGA is an Efinix
    T20, about $10.


    Here's the system:

    https://highlandtechnology.com/Category/MPS


    The web page shows and then is blank. Tried on several browser.

    The other pages on the site are ok

    We really need an FPGA on these boards. There are three 50 MBPS data
    streams to and from the motherboard, and fast PWM generation and
    stuff.


    Makes good sense then :-)


    I'm designing a 4-channel dummy load board that simulates programmable resistance+inductance, like a solenoid or something. It needs four
    isolated power supplies.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to klauskvik@hotmail.com on Mon Jan 27 14:02:10 2025
    On Fri, 24 Jan 2025 13:09:16 +0100, Klaus Kragelund
    <klauskvik@hotmail.com> wrote:

    On 23-01-2025 00:25, john larkin wrote:
    On Wed, 22 Jan 2025 22:47:10 +0100, Klaus Kragelund
    <klauskvik@hotmail.com> wrote:

    On 21-01-2025 01:18, john larkin wrote:
    On Mon, 20 Jan 2025 22:09:05 +0100, Klaus Kragelund
    <klauskvik@hotmail.com> wrote:

    On 16-01-2025 01:12, john larkin wrote:

    Here's my soft start circuit. Thanks for suggestions from Tilmann and >>>>>> Jeroen.

    The idea is to drive the ends of the transformer with in-phase square >>>>>> waves and then slowly walk them to 180 degrees, to achieve a soft
    start. An FPGA can do that easily. We might take a second... but that >>>>>> would simulate forever.

    What works well is to use two spice "modulator" elements and FM the >>>>>> frequency of one of them for 50 ms, until they are 180 degrees out of >>>>>> phase.

    Spice BV elements with sin(time*freq) type expressions seemed to
    overload or something.

    Version 4
    SHEET 1 2568 1220
    WIRE -512 -944 -576 -944
    WIRE -400 -944 -512 -944
    WIRE 16 -944 -32 -944
    WIRE 48 -944 16 -944
    WIRE 256 -944 192 -944
    WIRE 304 -944 256 -944
    WIRE -1104 -912 -1136 -912
    WIRE -1040 -912 -1104 -912
    WIRE -400 -912 -400 -944
    WIRE -32 -912 -32 -944
    WIRE 192 -912 192 -944
    WIRE -128 -896 -144 -896
    WIRE -80 -896 -128 -896
    WIRE -848 -880 -896 -880
    WIRE -800 -880 -848 -880
    WIRE -128 -848 -144 -848
    WIRE -80 -848 -128 -848
    WIRE -576 -816 -576 -944
    WIRE -784 -800 -848 -800
    WIRE -720 -800 -784 -800
    WIRE -624 -800 -720 -800
    WIRE -400 -800 -400 -832
    WIRE -32 -800 -32 -832
    WIRE 192 -800 192 -832
    WIRE -848 -768 -848 -800
    WIRE -624 -752 -656 -752
    WIRE -576 -688 -576 -736
    WIRE -448 -688 -576 -688
    WIRE -368 -688 -448 -688
    WIRE -208 -688 -304 -688
    WIRE 160 -688 -32 -688
    WIRE 208 -688 160 -688
    WIRE 416 -688 272 -688
    WIRE 480 -688 416 -688
    WIRE 544 -688 480 -688
    WIRE 656 -688 544 -688
    WIRE -848 -656 -848 -688
    WIRE -576 -640 -576 -688
    WIRE -656 -624 -656 -752
    WIRE -624 -624 -656 -624
    WIRE -720 -576 -720 -800
    WIRE -624 -576 -720 -576
    WIRE 208 -576 112 -576
    WIRE 416 -576 416 -688
    WIRE 416 -576 272 -576
    WIRE -1024 -560 -1104 -560
    WIRE -880 -560 -944 -560
    WIRE -848 -560 -880 -560
    WIRE -1104 -544 -1104 -560
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    WIRE -656 -528 -656 -624
    WIRE -576 -528 -576 -560
    WIRE -208 -528 -208 -688
    WIRE -32 -528 -32 -688
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    WIRE 656 -512 656 -688
    WIRE -1104 -448 -1104 -464
    WIRE -848 -448 -848 -480
    WIRE -528 -400 -576 -400
    WIRE -480 -400 -528 -400
    WIRE -576 -368 -576 -400
    WIRE 160 -368 160 -688
    WIRE 208 -368 160 -368
    WIRE 416 -368 416 -448
    WIRE 416 -368 272 -368
    WIRE -784 -352 -848 -352
    WIRE -720 -352 -784 -352
    WIRE -624 -352 -720 -352
    WIRE -848 -320 -848 -352
    WIRE -624 -304 -656 -304
    WIRE -576 -240 -576 -288
    WIRE -448 -240 -576 -240
    WIRE -368 -240 -448 -240
    WIRE -208 -240 -208 -448
    WIRE -208 -240 -304 -240
    WIRE -32 -240 -32 -448
    WIRE 112 -240 112 -576
    WIRE 112 -240 -32 -240
    WIRE 208 -240 112 -240
    WIRE 416 -240 416 -368
    WIRE 416 -240 272 -240
    WIRE 544 -240 544 -432
    WIRE 544 -240 416 -240
    WIRE 656 -240 656 -432
    WIRE 656 -240 544 -240
    WIRE -848 -208 -848 -240
    WIRE -576 -192 -576 -240
    WIRE 416 -192 416 -240
    WIRE -656 -176 -656 -304
    WIRE -624 -176 -656 -176
    WIRE -1072 -160 -1152 -160
    WIRE -880 -128 -928 -128
    WIRE -848 -128 -880 -128
    WIRE -720 -128 -720 -352
    WIRE -624 -128 -720 -128
    WIRE -1152 -112 -1152 -160
    WIRE -656 -80 -656 -176
    WIRE -576 -80 -576 -112
    FLAG -400 -800 0
    FLAG -512 -944 +48
    FLAG -32 -800 0
    FLAG -128 -896 HA
    FLAG -128 -848 HB
    FLAG 16 -944 BRO
    FLAG -448 -688 HA
    FLAG -448 -240 HB
    FLAG -576 -528 0
    FLAG -656 -528 0
    FLAG -576 -80 0
    FLAG -528 -400 +48
    FLAG -656 -80 0
    FLAG 416 -192 0
    FLAG 480 -688 OUT
    FLAG -784 -800 A
    FLAG 256 -944 SS
    FLAG 192 -800 0
    FLAG -1104 -912 SS
    FLAG -1152 -112 0
    FLAG -784 -352 B
    FLAG -1104 -448 0
    FLAG -880 -560 AB
    FLAG -848 -448 0
    FLAG -848 -208 0
    FLAG -880 -128 K
    FLAG -848 -656 0
    FLAG -848 -880 J
    SYMBOL voltage -400 -928 R0
    WINDOW 0 53 46 Left 2
    WINDOW 3 53 78 Left 2
    SYMATTR InstName V3
    SYMATTR Value 48
    SYMBOL e -32 -928 R0
    WINDOW 0 45 50 Left 2
    WINDOW 3 49 78 Left 2
    SYMATTR InstName E5
    SYMATTR Value 1
    SYMBOL sw -576 -720 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S2
    SYMATTR Value Sj
    SYMBOL sw -576 -544 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S3
    SYMATTR Value Sj
    SYMBOL sw -576 -272 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S4
    SYMATTR Value Sj
    SYMBOL sw -576 -96 M180
    WINDOW 0 58 74 Left 2
    WINDOW 3 61 47 Left 2
    SYMATTR InstName S5
    SYMATTR Value Sj
    SYMBOL cap -304 -704 R90
    WINDOW 0 79 30 VBottom 2
    WINDOW 3 86 29 VTop 2
    SYMATTR InstName C1
    SYMATTR Value 20µ
    SYMBOL FerriteBead -336 -240 R90
    WINDOW 0 -37 -1 VBottom 2
    SYMATTR InstName L1
    SYMATTR Value 2.5µ
    SYMATTR SpiceLine Ipk=3 Rser=0.0023 Rpar=475 Cpar=1.75p
    SYMBOL ind2 -224 -544 R0
    WINDOW 0 -49 37 Left 2
    WINDOW 3 -61 76 Left 2
    SYMATTR InstName L2
    SYMATTR Value 72µ
    SYMATTR Type ind
    SYMBOL ind2 -48 -544 R0
    WINDOW 0 61 40 Left 2
    WINDOW 3 50 76 Left 2
    SYMATTR InstName L3
    SYMATTR Value 112µ
    SYMATTR Type ind
    SYMBOL schottky 208 -672 R270
    WINDOW 0 42 40 VTop 2
    WINDOW 3 -14 54 VBottom 2
    SYMATTR InstName D1
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL cap 400 -512 R0
    WINDOW 0 -58 36 Left 2
    WINDOW 3 -70 67 Left 2
    SYMATTR InstName C6
    SYMATTR Value 100µ
    SYMBOL res 528 -528 R0
    WINDOW 0 -63 51 Left 2
    WINDOW 3 -61 83 Left 2
    SYMATTR InstName R5
    SYMATTR Value 5K
    SYMBOL schottky 208 -560 R270
    WINDOW 0 39 33 VTop 2
    WINDOW 3 -14 55 VBottom 2
    SYMATTR InstName D2
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -384 R90
    WINDOW 0 -10 31 VBottom 2
    WINDOW 3 45 28 VTop 2
    SYMATTR InstName D3
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL schottky 272 -256 R90
    WINDOW 0 -16 31 VBottom 2
    WINDOW 3 43 32 VTop 2
    SYMATTR InstName D4
    SYMATTR Value RB168VAM150
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL current 656 -512 R0
    WINDOW 0 54 63 Left 2
    WINDOW 3 19 107 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName I1
    SYMATTR Value PULSE(0 0.5 75m 1m 0 9)
    SYMBOL voltage 192 -928 R0
    WINDOW 0 58 36 Left 2
    WINDOW 3 41 74 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V1
    SYMATTR Value PULSE(0 1 0 1u 1u 50m)
    SYMBOL SpecialFunctions\\modulate -1040 -912 R0
    WINDOW 0 56 29 Left 2
    SYMATTR InstName A1
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250.01K
    SYMBOL SpecialFunctions\\modulate -1072 -160 R0
    WINDOW 0 56 31 Left 2
    SYMATTR InstName A2
    SYMATTR SpiceLine space=250K
    SYMATTR SpiceLine2 mark=250K
    SYMBOL bv -1104 -560 R0
    WINDOW 0 46 98 Left 2
    WINDOW 3 30 135 Left 2
    SYMATTR InstName B1
    SYMATTR Value V=V(A) * V(B)
    SYMBOL res -928 -576 R90
    WINDOW 0 66 56 VBottom 2
    WINDOW 3 65 57 VTop 2
    SYMATTR InstName R1
    SYMATTR Value 1K
    SYMBOL bv -848 -336 R0
    WINDOW 0 -89 48 Left 2
    WINDOW 3 -185 94 Left 2
    SYMATTR InstName B2
    SYMATTR Value V=sgn(V(K))
    SYMBOL bv -848 -784 R0
    WINDOW 0 -89 59 Left 2
    WINDOW 3 -183 96 Left 2
    SYMATTR InstName B3
    SYMATTR Value V=sgn(V(J))
    SYMBOL cap -864 -544 R0
    WINDOW 0 -53 40 Left 2
    WINDOW 3 -66 68 Left 2
    SYMATTR InstName C2
    SYMATTR Value 100n
    TEXT 216 -136 Left 4 ;P970 DC-DC Converter
    TEXT 288 -88 Left 3 ;JL Jan 15 2025
    TEXT -200 -80 Left 2 !.model Sj SW(Ron=50m Roff=1g)
    TEXT -200 -128 Left 2 !.tran 0 100m 0 20n
    TEXT -192 -568 Left 2 ;PL300-101L
    TEXT -160 -488 Left 2 ;4T
    TEXT -96 -488 Left 2 ;5T
    TEXT -200 -720 Left 2 !K1 L2 L3 0.999
    TEXT -392 -192 Left 2 ;163-5001
    TEXT -392 -152 Left 2 ;2.7 uH 5A
    TEXT -168 -600 Left 2 ;Coilcraft
    TEXT 232 -816 Left 2 ;50 ms soft start

    Very nice simulation

    I did a digital SMPS +10 years ago, use the same softstart principle. >>>>> Was based on a halfbridge converter, so if it did not have softstart >>>>> inrush current was very large. I believe you can do the same with phase >>>>> shifted controllers, but they are probably very expensive. I did it with >>>>> a 30cent microcontroller.

    Envision an FPGA. Spin up a 200 MHz clock and stick that into a 10 bit >>>> binary counter. The MSB is a 200 KHz square wave that drives one
    half-bridge.

    Now stick that into a 10-bit adder, add integer P to it. The sum is
    the counter phase shifted by P, so the MSB is similarly time shifted,
    driving the other half bridge. Start it all up and tick P up to 512 at >>>> the power supply ramp-up rate, maybe over a second.

    Yeah, the idea is nice.

    But I not that much of a fan of FPGAs. Very expensive compared to
    microcontrollers. In some applications they are trusted more than Class
    B embedded SW, and have more performance than microcontrollers. But for
    the price of that FPGA, you can probably buy 100 cortex microcontrollers. >>
    We have a modular power system with plugin boards, and every board has
    an FPGA, so the function is incrementally free. The FPGA is an Efinix
    T20, about $10.


    Here's the system:

    https://highlandtechnology.com/Category/MPS


    The web page shows and then is blank. Tried on several browser.

    The other pages on the site are ok

    Something was broken last week for a while. Does it work now?

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