The simulation is correct. The voltage is always one voltage drop lower than the input voltage. If you want negative pulses, you have to use a switch (transistor) instead of the diode. Please try the test circuit below..
You should use the standard unit multipliers. Instead of 0.00000001 you should write 10n or 10e-9 for better readability. Example: PULSE(10 0 0 10n 10n 1m 2.5m)
We are talking about LTspice.
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The user group is here.
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Best regards, Helmut
Save the text in a file named "test.asc"
Version 4 SHEET 1 880 868 WIRE -272 192 -320 192 WIRE -80 192 -272 192 WIRE 96 192 -16 192 WIRE 160 192 96 192 WIRE 160 240 160 192 WIRE -320 256 -320 192 WIRE 160 368 160 320 WIRE -320 384 -320 336 WIRE -288 496 -336 496 WIRE -80 496 -288 496 WIRE 144 496 16 496 WIRE 208 496 144 496 WIRE 272 496 208 496 WIRE 480 496 336 496 WIRE 560 496 480 496 WIRE 208 544 208 496 WIRE 480 544 480 496 WIRE 560 544 560 496 WIRE -144 560 -192 560 WIRE -64 560 -64 544 WIRE -64 560 -144 560 WIRE -336 576 -336 496 WIRE -192 592 -192 560 WIRE 208 672 208 624 WIRE 480 672 480 624 WIRE 560 672 560 608 WIRE -336 704 -336 656 WIRE -192 704 -192 672 FLAG -320 384 0 FLAG 160 368 0 FLAG 96 192 out FLAG -272 192 in FLAG -192 704 0 FLAG 208 672 0 FLAG 144 496 out1 FLAG -144 560 ctrl1 FLAG -336 704 0 FLAG -288 496 in1 FLAG 560 672 0 FLAG 480 672 0 SYMBOL ind2 144 224 R0 SYMATTR InstName L1 SYMATTR Value 0.1 SYMATTR SpiceLine Rser=1 Cpar=100p SYMBOL voltage -320 240 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value PULSE(0 10 0 10n 10n 1m 2.5m 4) SYMBOL schottky -80 208 R270 WINDOW 0 32 32 VTop 0 WINDOW 3 0 32 VBottom 0 SYMATTR InstName D1 SYMATTR Value MBRS360 SYMATTR Description Diode SYMATTR Type diode SYMBOL ind2 192 528 R0 SYMATTR InstName L2 SYMATTR Value 0.1 SYMATTR SpiceLine Rser=1 Cpar=100p SYMBOL voltage -192 576 R0 WINDOW 123 0 0 Left 0 WINDOW 39 24 132 Left 0 SYMATTR SpiceLine Rser=10 SYMATTR InstName V2 SYMATTR Value PULSE(10 0 0 10n 10n 1m 2.5m) SYMBOL pmos 16 544 M270 WINDOW 0 96 80 VLeft 0 WINDOW 3 73 81 VLeft 0 SYMATTR InstName M1 SYMATTR Value Si7465DP SYMBOL voltage -336 560 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V3 SYMATTR Value 10 SYMBOL cap 544 544 R0 SYMATTR InstName C1 SYMATTR Value 100n SYMBOL res 464 528 R0 SYMATTR InstName R1 SYMATTR Value 1k SYMBOL schottky 336 480 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName D2 SYMATTR Value MBRS360 SYMATTR Description Diode SYMATTR Type diode TEXT -320 96 Left 0 !.tran 0 20ms 0 TEXT 448 440 Left 0 ;external load RECTANGLE Normal 640 736 400 416
"PierreJ" schrieb im Newsbeitrag news: snipped-for-privacy@11g2000cwr.googlegroups.com...
At a philosophical level spice behaves the way things behave in the real world. They don't, you have to work out why.
Snipped LTSpice File.
Because you are French?
I ran your circuit and it went negative by about 300mV, which is what I might expect from one of those Schottky diode things. Not only did it go negative, as the current increased in your inductor it went more negative, which is sort of what I would expect.
I have use too many I's. LTspice was just telling you what it knew.
Doesn't sound like a well rounded person to me. However life can do that to you, it helps if you are a self opinionated thick cunt with problems about the size of your penis.
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