ARDUINO AC sensor proudu SCT-013.030 do 30A AC, neinvazivní

30A AC = 1V DC.

Arduino demo:

/* Single CT Arduino based PV load dump controller
 
 Uses an AC voltage input to determine in which diretion the current is flowing
 
 Measures current 20 times per half cycle for 10 seconds totalising readings.
 If below threshold decrements counter driving outputs
 If above threshold increments counter.
 Built in LED lights when input is between thresholds
 Currents much above or below threshold just hit the end stops
 
 Outputs are controlled by LSB of state_
 counter
 
 Status messages are sent to Serial port
 A off line calibration run with a known test load is need to set thresholds
 
 Enable appropriate code section near end depending on number and type of outputs
 
 Original version  Eric Ward Jan 2011
 
 */
#define LED 13       // Built in LED
/***************************************************
 * Define pin connections actually used
 * Only restriction is that CT must be an analog pin
 ******************************************************/
#define CT A1
#define PHASE 3
#define SSR1 A2      // first output
#define SSR2 A3      // second output (if used)

/*************************************************************
 ***** EDIT THIS VALUE AFTER A CALIBRATION RUN   ****************/
#define TEST_TOTAL  3755000   // Edit after calibration run
// Values for thresholds as percentage of test load
#define MAX_EXPORT  120
#define MIN_EXPORT  10
/************************************************************/
void setup()
{
  // set pin directions
  pinMode(CT,INPUT);
  pinMode(PHASE,INPUT);
  pinMode(LED,OUTPUT);
  pinMode(SSR1,OUTPUT);
  pinMode(SSR2,OUTPUT);
  pinMode(A4,OUTPUT);// Turn  outputs off
  digitalWrite(LED,LOW);
  digitalWrite(SSR1,HIGH);
  digitalWrite(SSR2,HIGH);
  Serial.begin(9600);
}
int state_counter;
void loop()

{
  unsigned long total;
  int current;

  // Calculate threshold values
  unsigned long max_total = MAX_EXPORT*TEST_TOTAL/100;
  unsigned long min_total = MIN_EXPORT*TEST_TOTAL/100;

  total = 0;
  // take average over 500 cycles (10 secs)
  for( int cycle_loop = 0; cycle_loop < 500 ; cycle_loop++)
  {
    /*******  Detect +ve edge on PHASE    ***/
    // wait for PHASE input to go low
    while( digitalRead(PHASE) == 1)
    {
      ;
    }
    // Wait for phase to go high again
    while( digitalRead(PHASE) == 0)
    {
      ;
    }
    // Measure 20 times per half cycle
    for(int slice_loop = 0; slice_loop < 20; slice_loop++)
    {
      digitalWrite(A4,HIGH);  //DEBUG
      current = analogRead(CT);
      total += current;
      digitalWrite(A4,LOW);  //DEBUG
      delayMicroseconds(300);
    }
    delay(5);
  } // end of # cycles

  Serial.print("Total ");
  Serial.print(total);
  Serial.print(" max ");
  Serial.print(max_total);
  Serial.print(" min ");
  Serial.print(min_total);
  Serial.print("  state ");
  Serial.print(state_counter);

  // setup output drives
  digitalWrite(LED,HIGH);  //Turn on LED
  // Turn LED off if change needed
  if(total < min_total)
  {
    if(state_counter != 0)
    {
      Serial.print(" Reducing load");
    }
    state_counter--;

    /* When appliance heating elements are switched on the is a sudden increase 3kW? in consumption
     to avoid a short burst of consumption is it better to switch off all our loads
     and then let it step back on again ??
     state_counter = 0;
     */
    digitalWrite(LED,LOW);
  }
  if(total > max_total)
  {
    state_counter++;
    digitalWrite(LED,LOW);

  }

  // uncomment this block for single output
  if(state_counter ==1)
  {
    Serial.print(" Increasing load");
  }
  state_counter = constrain(state_counter,0,1);
  // Set output (HIGH is off)
  digitalWrite(SSR1,!(state_counter & 1));


  /******************************
   * // *** Uncomment this block for two equal outputs ***
   * if(state_counter < 3)
   * {
   * Serial.print(" Increasing load");
   * }
   * state_counter = constrain(state_counter,0,2);
   * // Set outputs (HIGH is off)
   * if(State_counter == 0)
   * {
   * digitalWrite(SSR1,HIGH);
   * }
   * else
   * {
   * digitalWrite(SSR1,LOW);
   * } 
   * digitalWrite(SSR2,!(state_counter & 2));
   **********************************/

  /********************************
   * // *** Uncomment this block for two binary weighted outputs ***
   * if(state_counter < 4)
   * {
   * Serial.print(" Increasing load");
   * }
   * state_counter = constrain(state_counter,0,3);
   * // Set outputs (HIGH is off)
   * digitalWrite(SSR1,!(state_counter & 1));
   * digitalWrite(SSR2,!(state_counter & 2));
   ***********************************************/
  Serial.println();
}