Here is a simple a program written in MatLab and C programming to transform Resistance from Delta to Star and vice versa.
The C program can also find the equivalent resistance of resistors in series and parallel.

### MATLAB

#### .m file for delta2star

 function[soln]=delta2star(R_ab,R_bc,R_ac) R_a=(R_ab*R_ac)/(R_ab+R_bc+R_ac); R_b=(R_ab*R_bc)/(R_ab+R_bc+R_ac); R_c=(R_bc*R_ac)/(R_ab+R_bc+R_ac); fprintf('delta values \t Star values\n ') fprintf('R_ab=%.2f \t R_a=%.2f \n',R_ab,R_a); fprintf('R_bc=%.2f \t R_b=%.2f \n',R_bc,R_b); fprintf('R_ac=%.2f \t R_c=%.2f \n',R_ac,R_c); soln=[R_a;R_b;R_c]; end

#### .m file for star2delta

 function [Soln] = star2delta(R_a,R_b,R_c) R_ab = R_a + R_b + (R_a*R_b)/R_c; R_bc = R_b + R_c + (R_b*R_c)/R_a; R_ac = R_a + R_c + (R_a*R_c)/R_b; fprintf('delta values \t Star values \n') fprintf('R_a=%.2f \t R_ab=%.2f \n',R_a,R_ab) fprintf('R_b=%.2f \t R_bc=%.2f \n',R_b,R_bc) fprintf('R_c=%.2f \t R_ac=%.2f \n',R_c,R_ac) Soln=[R_ab;R_bc;R_ac]; end

#### output

Browse to where your m files are located in the current directory you can use cd command, in my case it was saved at the directory "c:\users\Zakaria\Documents\Matlab\blog" .

### C PROGRAM

Also included in the c program, can  calculate Resistors in series and parallel

 #include #include #include void Parallel_Series();     //declare series and parallel conversion function void Star_Delta_xform();    //declare series and parallel conversion function int input; int main() {     do     {         printf("__________________________\n");         printf("Select Conversion:\n");         printf("__________________________\n");         printf("1. Equivalent resistance of Parallel connection\n");         printf("2. Equivalent resistance of Series connection\n");         printf("3. Star Delta Transformation\n");         printf("4. Exit\n");         printf("Select: ");         scanf("%d",&input);         if (input == 1 || input == 2)         {             Parallel_Series();         }         else if(input == 3)         {             Star_Delta_xform();         }         else         {             printf("Wrong Selection! Try Again\n");         }     }     while(input != 4);     return 0; } void Parallel_Series() {     int num,cnt;     float R,R_t,result=0;     char str1="Parallel";     char str2="Series";     if (input==2)     {         //copy string 2 to 1 to display series instead of parallel         strcpy(str1,str2);     }     printf("How many number of Resistors are in %s: ",str1);     scanf("%d",&num);     printf("Enter Value for: \n");     for(cnt=0; cnt!=num; cnt++)     {         printf("%s R_%d=",str1,cnt+1);         scanf("%f",&R[cnt]);         //for parallel         if (input==1)         {             result +=  1/R[cnt];             R_t = 1/result;         }         else         {             R_t +=  R[cnt];         }     }     printf("Equivalent resistance of %d resistors in %s is %.2f Ohms\n",num,str1,R_t); } void Star_Delta_xform() {     float R_a=0,R_b=0,R_c=0,R_ab,R_bc,R_ac;     int select;     printf("Select transformation\n----------------------\n");     printf("1. Star --> Delta\n");     printf("2. Delta --> Star\n");     printf("Select: ");     scanf("%d",&select);     switch(select)     {     case 1:     {         printf("1. enter the value of the Star connected resistors:\n");         printf("R_a = ");         scanf("%f",&R_a);         printf("R_b = ");         scanf("%f",&R_b);         printf("R_c = ");         scanf("%f",&R_c);         R_ab=R_a+R_b+(R_a*R_b)/R_c;         R_bc=R_b+R_c+(R_b*R_c)/R_a;         R_ac=R_a+R_c+(R_a*R_c)/R_b;         printf("the equivalent Delta config. is: \n");         printf("R_ab = %.2f Ohms\n",R_ab);         printf("R_bc = %.2f Ohms\n",R_bc);         printf("R_ac = %.2f Ohms\n",R_ac);         break;     }     case 2:     {         printf("1. enter the values of the Delta connected resistors:\n");         printf("R_ab = ");         scanf("%f",&R_ab);         printf("R_bc = ");         scanf("%f",&R_bc);         printf("R_ac = ");         scanf("%f",&R_ac);         R_a = (R_ab*R_ac)/(R_ab + R_bc + R_ac);         R_b = (R_ab*R_bc)/(R_ab + R_bc + R_ac);         R_c = (R_ac*R_bc)/(R_ab + R_bc + R_ac);         printf("the equivalent Star config. is: \n");         printf("R_a = %.2f Ohms\n",R_a);         printf("R_b = %.2f Ohms\n",R_b);         printf("R_c = %.2f Ohms\n",R_c);         break;     }     } }

### output

STAR-DELTA TRANSFORMATION IN MATLAB AND C PROGRAMMING Reviewed by Zakaria Mohammed on October 10, 2015 Rating: 5