51 lines
814 B
C
51 lines
814 B
C
/*
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Calculator for Bridge voltages given four resistance values
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A
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/ \
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R1 R2
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/ \
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B C
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\ /
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R3 R4
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\ /
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D
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5V on A
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0V on D
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voltage diff between B and C calculated
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*/
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#include <stdio.h>
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#include <stdlib.h>
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// compile on linux as
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// gcc -o br bridge_v.c
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//
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// run as
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// ./br 10 10 10 10.1
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//
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int main(int argc, char **argv)
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{
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double r1, r2, r3, r4;
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double v = 5.0;
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if (argc != 5) {
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printf(" usage: %s R1 R2 R3 R4 \n", argv[0]);
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printf(" usage: resistances in k Ohm\n" );
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} else {
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r1 = atof(argv[1])*1000.0;
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r2 = atof(argv[2])*1000.0;
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r3 = atof(argv[3])*1000.0;
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r4 = atof(argv[4])*1000.0;
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printf(" Voltage diff == %f\n", v * (r2 * r3 - r1 * r4) / ((r1 + r3) * (r2 + r4)));
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}
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}
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