Version 4
SHEET 1 1992 3388
WIRE -448 368 -624 368
WIRE -288 368 -448 368
WIRE -448 400 -448 368
WIRE -288 400 -288 368
WIRE -288 512 -288 480
WIRE -240 512 -288 512
WIRE -288 528 -288 512
WIRE -624 544 -624 368
WIRE -448 560 -448 480
WIRE -384 560 -448 560
WIRE -352 560 -384 560
WIRE -448 624 -448 560
WIRE -288 640 -288 624
WIRE -240 640 -288 640
WIRE -288 672 -288 640
WIRE -624 784 -624 624
WIRE -448 784 -448 688
WIRE -448 784 -624 784
WIRE -288 784 -288 752
WIRE -288 784 -448 784
WIRE -624 816 -624 784
FLAG -624 816 0
FLAG -384 560 E1
FLAG -240 640 B1
FLAG -240 512 B2
SYMBOL voltage -624 528 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 10
SYMBOL nujt -336 528 R0
SYMATTR InstName U2
SYMATTR Value 2N2646
SYMATTR Description N-Channel Unijunction Transistor
SYMBOL res -304 384 R0
SYMATTR InstName R1
SYMATTR Value 100
SYMBOL res -304 656 R0
SYMATTR InstName R2
SYMATTR Value 20
SYMBOL res -464 384 R0
SYMATTR InstName R3
SYMATTR Value 10k
SYMBOL cap -464 624 R0
SYMATTR InstName C2
SYMATTR Value .1µ
TEXT -640 248 Left 0 !.tran 0 100m 0 .01m
TEXT -640 280 Left 0 !.options plotwinsize=0
TEXT -640 312 Left 0 ;.options trtol=1e-1
TEXT -640 -200 Left 0 ;Unijunction Transistor 2N2646\n \nUse the Alternate-solver.\nControl Panel -> SPICE -> Solver:Alternate\n \nThe discharge slope is too steep at the end and thus a very small\ntime step would be required to improve the simulation accuracy\nof the lower peaks. This is a model issue!
TEXT -640 48 Left 0 ;A small modification of the model has been required for LTspice.\nhttp://www.duncanamps.com/spice/miscsemi/2n2646.sub\n***RB1 7 2 38.15 RMOD\n***RB2 3 5 2.518K RMOD \nRB1 7 2 RMOD 38.15 \nRB2 3 5 RMOD 2.518K