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#include <stdio.h>
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2
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#include <time.h>
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3
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#include <termios.h>
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4
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#include <errno.h>
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5
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#include <fcntl.h>
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6
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#include <QList>
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7
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8
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9
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float E12[]
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11
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{
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12
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100, 120, 150, 180, 220, 270, 330, 390, 470, 560, 680, 820,
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1000, 1200, 1500, 1800, 2200, 2700, 3300, 3900, 4700, 5600, 6800, 8200,
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10000, 12000, 15000, 18000, 22000, 27000, 33000, 39000, 47000, 56000, 68000, 82000,
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15
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};
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16
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float E24[]
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{
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100, 110, 120, 130, 150, 160, 180, 200, 220, 240, 270, 300, 330, 360, 390, 430, 470, 510, 560, 620, 680, 750, 820, 910,
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20
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1000, 1100, 1200, 1300, 1500, 1600, 1800, 2000, 2200, 2400, 2700, 3000, 3300, 3600, 3900, 4300, 4700, 5100, 5600, 6200, 6800, 7500, 8200, 9100,
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10000, 11000, 12000, 13000, 15000, 16000, 18000, 20000, 22000, 24000, 27000, 30000, 33000, 36000, 39000, 43000, 47000, 51000, 56000, 62000, 68000, 75000, 82000, 91000
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};
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23
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24
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#define E E12
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27
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float r2( float target, float r1 )
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29
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{
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return( r1 * ( ( target / 1.23 ) - 1 ) );
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31
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};
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32
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33
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float voltage( float totalVoltage, float r1, float r2 )
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35
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{
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36
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//return(1.23 * ( 1 + ( r2 / r1 ) ) );
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return( ( totalVoltage / ( r1 + r2 ) ) * r2 );
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};
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39
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40
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float r_ges(float r1, float r2)
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42
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{
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// https://studyflix.de/elektrotechnik/parallelschaltung-widerstand-4533
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return( ( r1 * r2 ) / ( r1 + r2 ) );
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45
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}
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46
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47
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48
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int main()
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49
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{
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50
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float totalVoltage=48; // 48V
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float targetVoltage=totalVoltage-20;
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53
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54
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// Invalidate values
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int bestR1=-1;
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int bestR2=-1;
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int bestR3=-1;
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float bestVoltage=1000000;
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59
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float v;
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60
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int count=sizeof(E)/sizeof(E[0]);
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62
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printf("%g total Voltage\n", totalVoltage);
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printf("%g target Voltage\n", targetVoltage);
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//printf("%g Ohm\n", r2(target, 1000.0) );
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//for(int i1=0; i1<count; i1++)
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int i1=0;
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68
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{
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// if( ( E[i1] >= 1000 ) && ( E[i1] <= 5000 ) )
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//if( E[i1] == 1000 )
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{
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for(int i2=0; i2<count; i2++)
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{
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for(int i3=0; i3<count; i3++)
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{
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v=voltage( totalVoltage, E[i2], E[i3] );
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printf("%g V\n", v );
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if( ( v >= targetVoltage ) && ( v < bestVoltage ) )
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{
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bestR1=i1;
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bestR2=i2;
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bestR3=i3;
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bestVoltage=v;
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}
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}
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}
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}
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}
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89
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printf("%d/%d/%d\n", bestR1, bestR2, bestR3 );
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//printf("R1=%g\n", E[bestR1] );
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printf("R2=%g\n", E[bestR2] );
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printf("R3=%g\n", E[bestR3] );
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printf("[R2|R3]=%g\n", r_ges( E[bestR2], E[bestR3] ) );
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//v=voltage(E[bestR1], E[bestR2] );
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v = bestVoltage;
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printf("Result=%g; %g%%\n", v, (v-targetVoltage)*(100/targetVoltage) );
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98
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// References from TI:
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100
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// 3.3 V R2 = 1.7 k
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101
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// 5 V, R2 = 3.1 k
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102
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// 12 V, R2 = 8.84 k
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103
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// 15 V, R2 = 11.3 k
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104
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// For ADJ. Version R1 = Open, R2 = 0 Ω Patent Pending
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105
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//v=voltage(totalVoltage, 1000, 8840);
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106
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//v=voltage(totalVoltage, 1000, 3100);
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107
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//v=voltage(totalVoltage, 1000, 11300);
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printf(" 48V: Reference=%g\n", voltage(48.0, E[bestR2], E[bestR3])-48);
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printf(" 36V: Reference=%g\n", voltage(36.0, E[bestR2], E[bestR3])-36);
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110
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printf(" 15V: Reference=%g\n", voltage(15.0, E[bestR2], E[bestR3])-15);
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111
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112
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return 0;
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113
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}
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