Version 4 SHEET 1 880 680 WIRE 624 16 624 0 WIRE 704 16 624 16 WIRE 272 32 272 16 WIRE 624 32 624 16 WIRE 704 32 704 16 WIRE -176 96 -176 80 WIRE -112 96 -176 96 WIRE 112 96 -32 96 WIRE 704 112 704 96 WIRE 112 128 112 96 WIRE 160 128 112 128 WIRE 400 128 160 128 WIRE 112 160 112 128 WIRE 112 160 32 160 WIRE 272 160 272 112 WIRE -176 176 -176 96 WIRE -112 176 -176 176 WIRE -32 176 -112 176 WIRE 112 176 112 160 WIRE 400 176 400 128 WIRE 432 176 400 176 WIRE 48 192 32 192 WIRE 528 192 528 160 WIRE 528 192 496 192 WIRE 560 192 528 192 WIRE 384 208 320 208 WIRE 432 208 384 208 WIRE -176 224 -176 176 WIRE 272 272 272 240 WIRE 384 272 384 208 WIRE 400 272 384 272 WIRE -256 320 -256 304 WIRE -176 320 -176 304 WIRE -176 320 -256 320 WIRE 48 320 48 192 WIRE 48 320 -176 320 WIRE -176 336 -176 320 WIRE 480 336 416 336 WIRE 416 352 416 336 WIRE 272 368 272 352 WIRE -176 432 -176 416 FLAG 624 112 0 FLAG 624 0 V+ FLAG 464 224 0 FLAG 464 160 V+ FLAG 560 192 PWM IOPIN 560 192 Out FLAG 704 112 0 FLAG 272 368 0 FLAG 272 16 V+ FLAG 112 240 0 FLAG -176 432 0 FLAG 0 208 0 FLAG -176 0 V+ FLAG -256 224 V+ FLAG 160 128 Tri FLAG 528 80 V+ FLAG 0 144 V+ FLAG -112 176 Sq FLAG 400 272 Mod_In IOPIN 400 272 In FLAG 416 432 0 FLAG 480 336 Mod_In SYMBOL battery 624 16 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value 12V SYMBOL cap 688 32 R0 WINDOW 3 49 35 Left 2 SYMATTR Value 0.1µF SYMATTR InstName C5 SYMBOL pot 256 144 R0 WINDOW 3 -21 3 VRight 2 SYMATTR Value Rtot=10K wiper=W SYMATTR InstName U4 SYMBOL Comparators\\LM339 464 192 R0 SYMATTR InstName U2 SYMBOL Comparators\\LM339 0 176 M0 SYMATTR InstName U1 SYMBOL res -160 -16 M0 SYMATTR InstName R2 SYMATTR Value 3k SYMBOL res -128 80 M90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R1 SYMATTR Value 100k SYMBOL res -192 320 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R3 SYMATTR Value 100k SYMBOL res -192 432 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R4 SYMATTR Value 100k SYMBOL res -272 320 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R5 SYMATTR Value 100k SYMBOL cap 128 176 M0 WINDOW 3 -47 9 Left 2 SYMATTR Value 6.8nF SYMATTR InstName C1 SYMBOL res 512 64 R0 SYMATTR InstName R6 SYMATTR Value 3k SYMBOL res 256 16 R0 SYMATTR InstName R7 SYMATTR Value 10k SYMBOL res 256 256 R0 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL voltage 416 336 R0 WINDOW 0 35 56 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V_Mod SYMATTR Value PULSE(3.9 8.1 2ms 30ms) TEXT 168 352 Right 2 !.tran 0 33ms 1ms startup TEXT 528 296 Left 2 ;.step param W list .05 .95 TEXT 552 264 Left 2 !.param W=.5 TEXT 280 232 Left 2 ;Duty\nCycle TEXT -144 32 Left 2 ;Frequency ~ 1/(1.5 * R1 * C1) TEXT 224 -32 Left 2 ;Optional TEXT 584 360 Left 2 ;Simulation\nOnly RECTANGLE Normal 352 400 192 -48 1 RECTANGLE Normal 720 448 368 320 1