Step Resistor in Spice

[Aubrey McIntosh]

I want to step a resistor value in SwitcherCAD. A hint of what I want
to do is in the following circuit. What are my choices?


Version 4
SHEET 1 880 680
WIRE 80 400 80 320
WIRE 80 320 176 320
WIRE 176 320 176 256
WIRE 80 320 -32 320
WIRE -32 320 -32 144
WIRE 176 80 176 160
WIRE 368 80 176 80
WIRE 240 208 368 208
WIRE 368 208 368 160
WIRE 176 0 176 -48
WIRE 176 -48 -32 -48
WIRE -32 -48 -32 64
FLAG 80 400 0
SYMBOL npn 240 160 M0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL res 160 -16 R0
SYMATTR InstName R1
SYMATTR Value 510
SYMBOL res 352 64 R0
SYMATTR InstName R2
SYMATTR Value 100K
SYMBOL voltage -32 48 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 1
TEXT -120 -88 Left 0 !.step oct V1 24 1 2
TEXT -122 424 Left 0 !.op
TEXT 248 -80 Left 0 !.step R2 list 100 200 500

 

[Mike Engelhardt]

Aubrey,

I want to step a resistor value in SwitcherCAD. A hint of what I want
to do is in the following circuit. What are my choices?

The idea is to step a parameter and make the
give the resistor the parameter as a value.
You have to enclose the parameter in curly
braces where you want the value of the
parameter substituted. You might want to
look over the examples with the word,
"step" in the name in the directory
../examples/Educational. Below is the
method applied to your circuit.

--Mike

Version 4
SHEET 1 880 680
WIRE 80 320 80 288
WIRE 80 288 176 288
WIRE 176 288 176 256
WIRE 80 288 -32 288
WIRE -32 288 -32 176
WIRE 176 64 176 80
WIRE 240 208 304 208
WIRE 304 208 304 192
WIRE 176 -16 176 -32
WIRE 176 -32 -32 -32
WIRE -32 -32 -32 96
WIRE 176 80 176 160
WIRE 304 112 304 80
WIRE 304 80 176 80
FLAG 80 320 0
SYMBOL npn 240 160 M0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL res 160 -32 R0
SYMATTR InstName R1
SYMATTR Value 510
SYMBOL res 288 96 R0
SYMATTR InstName R2
SYMATTR Value {R2}
SYMBOL voltage -32 80 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 1
TEXT 352 288 Left 0 !.step oct V1 24 1 2
TEXT 358 224 Left 0 !.op
TEXT 352 256 Left 0 !.step PARAM R2 list 100 200 500