AC THREE PHASE ANALOG INPUTS DETECTOR C CODE

[Dhananjaya]

Dear Sir/Madam please give any idea/concept for AC Phase detecting either Present/Absent (Logic 1/0)without converting DC volt to detect TTL PIC16F676 microcontroller someone already implemented this products but know i am also implementing  this concept on same circuits but I have dont know the logic/ C code for this know I am tried as follows but still i cant  able to detecting phase

 

three phase (RY & AC analog inputs directly connected microcontroller pin without converting DC volts / reduced the voltage by using resistor divider circuit  series with of 2.2Mohm 0.5watt+5Mohm 0.25watt connected to microcontroller(PIC16F676 pins RA0,RA1 & RA2). and internal oscillator like

 

#define _XTAl_FREQ 4000000

__CONFIG(0x3FF4)

#define R_phase RA0

#define Y_phase RA1

#define B_phase RA2

 

#define Three_phase_LED RC0

#define Two_phase_LED RC1

#define Single_phase_LED RC2

#define NO_phase_LED RC3

 

char phaseRflag = 0;  // flag variables for each phase

char phaseYflag = 0;

char phaseBflag = 0;

 

char single_phase_flag = 0;  // used for single phase detection test

 

unsigned int sample = 0; // used to set "for loop" duration

 

void main()

{

  CMCON=0x07;

  ANSEL=0x00; 

  TRISA =0b001111;

  PORTA=0b001111;

  TRISC=0b000000;

  PORTC=0b00000;

 

  while(1) // while loop to test phases continously

    {

    phaseRflag = 0;  // phase flags are set to zero

    phaseYflag = 0;

    phaseBflag = 0;

   

   // a "for loop" tests the inputs for 20 milliseconds, setting a flag if a logic 1 is read

 

    for(sample = 16000; sample > 0; sample–)  // test all phases for at least 20 milliseconds

        {

        if(R_phase)        // if a 1 is detected on a phase set a flag to 1;

           phaseRflag = 1;

        if(Y_phase)

           phaseYflag = 1;   

        if(B_phase)

           phaseBflag = 1; 

        }                          // end of the  for loop   

 

    // phase tests running as before, except now looking at the flag settings

    // test for all phases on

---

  

    if(phaseRflag && phaseYflag && phaseBflag) 

       Three_phase_LED = 1;  // RC0 pin connected(Three_phase) LED will Glow ON

    else

       Three_phase_LED = 0;

 

    // test for phase R and B on

---

 

    if(phaseRflag && phaseBflag && !phaseYflag)

        Two_phase_LED = 1;    // RC1 pin connected(Two_phase) LED will Glow ON

    else

        Two_phase_LED = 0; 

 

    // test for a single phase on

---

 

 

    single_phase_flag = 0;  // set if only a single phase was detected

 

    if(phaseRflag || !phaseYflag || !phaseBflag)  // only R_phase is on

         single_phase_flag = 1;  

   

    if(!phaseRflag || phaseYflag || !phaseBflag)  // only Y_phase is on

         single_phase_flag = 1; 

   

    if(!phaseRflag || !phaseYflag || phaseBflag)  // only B_phase is on

         single_phase_flag = 1; 

   

    if(single_phase_flag == 1)   // if  a single phase was detected

         Single_phase_LED = 1;   // RC2 pin connected(Single_phase) LED will Glow ON

    else

         Single_phase_LED = 0;   // single phase LED off

    

    // test for no phases on

---

   

    if(!phaseRflag && !phaseYflag && !phaseBflag)

       NO_phase_LED = 1;    // RC3 pin connected(No_phase) LED will Glow On    

    else

       NO_phase_LED = 0;

   }   // end of while loop

}      // end of main

 

 

In this pregame only  

       NO_phase_LED = 1;    LED is On  always….  

[Prabakaran P M]

Hi Dhananjaya,

                    For giving you idea in this topic i need the circuit diagram of the voltage divider circuit you used. coding logic is correct. Use diodes and voltage divider to ac voltage to dc voltage. Because Pic microcontroller can only read the dc voltage logics.

http://www.engineersgarage.com/contribution/transformerless-power-supply-circuit?page=1

you can refer to this page for transformerless ac to dc convertion.

 

Note: Ac live Voltage will be found all over the circuit so be safe while doing these type of projects.

[Author]

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