Keyes SR1y Relay module circuit

 

Keyes SR1y Relay module photo with labels

The Keyes SR1y relay module is an active high relay module with an SPDT relay.
Maximum 10A 250V AC
Maximum 10A 30V DC

Keyes-SR1y circuit diagram

The + pin is connected to a +5V DC power supply.
The – pin is connected to the power supply ground.
The S pin connection is the input.

The relay and led will operate when a high signal is present on the S input.

The diode across the relay coil is there to prevent back emf from the coil.

The transistor provides current gain and a small input current can switch the relatively large current required to operate the relay coil.

Keyes SR1y relay module input connection to an Arduino Uno

Keyes SR1y relay connection with Arduino Uno

The S input of the relay board can be connected to any of the Arduino Uno digital outputs. in this case, it is connected to pin 13, which is turned on and off (along with the Uno onboard led) by the blink sketch example.

Keyes SR1y arduino blink sketch

// Keyes SR1y relay blink sketch

#define RELAY_ON 1			// Define relay on pin state
#define RELAY_OFF 0			// Define relay off pin state

#define Relay  13  			// Arduino pin where the relay connects

void setup()  
{
  digitalWrite(Relay, RELAY_OFF);      // initialise the relay to off
  pinMode(Relay, OUTPUT);   
  delay(1000); 
}

void loop() 				// Turn the relay on and off in sequence
{
  digitalWrite(Relay, RELAY_ON);	// turn the relay on
  delay(1000);               		// wait
 
  digitalWrite(Relay, RELAY_OFF);	// turn the relay off
  delay(1000);              		// wait
}

Relay Load connections

Flashing Led light strip

A 12v led light strip and a 12v battery are connected in series to the COM (common) and NO (normally open) contacts on the relay module.

The relay will operate when the output from the Arduino is high and turn on the led strip.

Keyes SR1y with Arduino LED strip circuit diagram

Arduino relay led strip flashing

Dual alternate flashing LED light strips

Adding another led light strip to the NC (normally connected) contact of the relay creates alternate flashing led strips.

Keyes SR1y Arduino dual led strip

Keyes Sr1y relay arduino dual flashing led strip

How does an Electric Relay work?

Opto isolated dual relay module (Arduino)

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