Crowtail- Relay

Description¶

The Crowtail- Relay module is a digital normally-open switch. Through it, you can control circuit of high voltage with low voltage, say 5V on the controller.

Model: CT0008RE

Features¶

High Switching Current

Specification¶

Dimensions(mm):40.0(L)x20.0(W)x17.2(H)

Parameter	Description
Operating Voltage	5V
Operating Current	90mA
Relay Life	100,000 Cycle
Max Switching Voltage	120VAC/24VDC
Max Switching Current	3A

Usage¶

Intelligent Temperature Control Fan¶

1.Hardware Connection

2.Copy the demo code to your sketch, then upload to Arduino or Crowduino board.You can set a threshold temperature value to control the realy ON or OFF, then control the fan work or not.

/*
Temperature sensor connect to AO
Relay connetct to D5
*/

#include <math.h>
int a;
float temperature;
int B=3975;                  //B value of the thermistor
float resistance;
// Connect the Relay to digital pin D5.
// give it a name:
int Relay = 5;

void setup()
{
 // initialize the digital pin as an output.
 pinMode(Relay, OUTPUT);  
 Serial.begin(9600);  
}

void loop()
{
   a=analogRead(0);
   resistance=(float)(1023-a)*10000/a; //get the resistance of the sensor;
   temperature=1/(log(resistance/10000)/B+1/298.15)-273.15;//convert to temperature via datasheet ;
   delay(1000);
   Serial.print("Current temperature is ");
   Serial.println(temperature);
   if(temperature>20)
   {
         digitalWrite(Relay, HIGH);  //if temperature >20 degree,turn the Relay on,fan working
   }
   else
   {
        digitalWrite(Relay, LOW);//if temperature <=20 degree,turn the Relay off,fan not working
   }
}

3.When the temperature above 20 degrees,the fan will working.