Hi all. I have a simple cct that I want to simulate. Ltspice gives me strange behaviour , depending on values in the circuit.
here is the cct:
Version 4 SHEET 1 880 680 WIRE -128 448 -128 400 WIRE -32 320 -128 320 WIRE 80 176 80 144 WIRE 80 256 80 240 WIRE 80 320 48 320 WIRE 144 16 144 -16 WIRE 144 144 80 144 WIRE 144 144 144 96 WIRE 144 176 144 144 WIRE 144 256 80 256 WIRE 144 272 144 256 WIRE 144 448 -128 448 WIRE 144 448 144 368 WIRE 160 144 144 144 WIRE 224 448 144 448 WIRE 224 464 224 448 WIRE 288 -16 144 -16 WIRE 288 96 224 96 WIRE 288 96 288 -16 WIRE 352 192 224 192 WIRE 352 240 352 192 WIRE 352 448 224 448 WIRE 352 448 352 320 WIRE 448 192 352 192 WIRE 448 240 448 192 WIRE 448 448 352 448 WIRE 448 448 448 304 WIRE 592 -16 288 -16 WIRE 592 160 592 -16 WIRE 592 448 448 448 WIRE 592 448 592 240 FLAG 224 464 0 SYMBOL res 128 160 R0 SYMATTR InstName R1 SYMATTR Value 2k2 SYMBOL res 128 0 R0 SYMATTR InstName R2 SYMATTR Value 10k SYMBOL res 64 304 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R3 SYMATTR Value 1k SYMBOL res 336 224 R0 SYMATTR InstName R4 SYMATTR Value 500 SYMBOL cap 432 240 R0 SYMATTR InstName C1 SYMATTR Value 100=B5 SYMBOL voltage 592 144 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 5 SYMBOL voltage -128 304 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value PULSE(0 5 100u 100n) SYMBOL cap 64 176 R0 SYMATTR InstName C2 SYMATTR Value 10=B5 SYMBOL npn 80 272 R0 SYMATTR InstName Q1 SYMATTR Value 2N2222 SYMBOL pnp 160 192 M180 SYMATTR InstName Q2 SYMATTR Value 2N2907 TEXT -162 506 Left 0 !.tran 2m
If I make C2 1 , 2 ,3 ,4 or 5uF the circuit simulates quickly. If I make C2 6u or 10u the cct simulates very slowly up to 100uS , then runs quickly.If I make it 22u it goes quickly again. Why is this happening. I am using the default settings in the control panel. Cheers Rob