How to Use Relay Omron MY2N: Examples, Pinouts, and Specs

The Omron MY2N is a general-purpose electromagnetic relay with a Double Pole Double Throw (DPDT) configuration. It is designed to switch high currents and voltages while maintaining a compact and reliable form factor. This relay is widely used in automation, industrial control systems, and general-purpose switching applications. Its high durability and dependable performance make it a popular choice for engineers and hobbyists alike.

• Industrial automation and control systems
• Motor control circuits
• Signal switching in electronic devices
• Home automation projects
• Power distribution and load management

Below are the key technical details of the Omron MY2N relay:

The Omron MY2N relay has 8 pins, which are configured as follows:

1. Power the Coil: Connect the relay's coil terminals (pins 1 and 2) to a DC or AC voltage source that matches the relay's rated coil voltage. Ensure the power supply can provide sufficient current to energize the coil.
2. Connect the Load:
   • For Pole 1: Connect the load to the common terminal (pin 3) and either the normally open (pin 4) or normally closed (pin 5) contact, depending on the desired switching behavior.
   • For Pole 2: Similarly, connect the load to the common terminal (pin 6) and either the normally open (pin 7) or normally closed (pin 8) contact.
3. Switching Behavior: When the coil is energized, the normally open (NO) contacts close, and the normally closed (NC) contacts open. When the coil is de-energized, the contacts return to their default state.

• Flyback Diode: When using the relay with a DC coil, always connect a flyback diode across the coil terminals to protect the driving circuit from voltage spikes caused by the collapsing magnetic field.
• Driving the Relay: Use a transistor or MOSFET to drive the relay if the control signal cannot provide sufficient current. A base resistor is required when using a BJT transistor.
• Isolation: Ensure proper electrical isolation between the control circuit and the load circuit to prevent damage to sensitive components.
• Contact Ratings: Do not exceed the relay's contact ratings to avoid overheating or damage.

Below is an example of how to control the Omron MY2N relay using an Arduino UNO:

• Connect pin 1 of the relay coil to the collector of an NPN transistor (e.g., 2N2222).
• Connect pin 2 of the relay coil to the Arduino's GND.
• Place a flyback diode (e.g., 1N4007) across the coil terminals, with the cathode connected to pin 1.
• Connect the emitter of the transistor to GND.
• Connect the base of the transistor to an Arduino digital pin (e.g., pin 7) through a 1kΩ resistor.
• Connect the load to the relay's common and normally open contacts.

// Define the relay control pin
const int relayPin = 7;

void setup() {
  pinMode(relayPin, OUTPUT); // Set the relay pin as an output
  digitalWrite(relayPin, LOW); // Ensure the relay is off at startup
}

void loop() {
  digitalWrite(relayPin, HIGH); // Turn the relay on
  delay(1000); // Keep the relay on for 1 second
  digitalWrite(relayPin, LOW); // Turn the relay off
  delay(1000); // Keep the relay off for 1 second
}

1. Relay Not Switching:

   • Cause: Insufficient voltage or current to the coil.
   • Solution: Verify the power supply voltage and current match the relay's specifications.

2. Chattering or Unstable Operation:

   • Cause: Noise or insufficient drive current.
   • Solution: Use a decoupling capacitor near the relay coil and ensure the driving circuit provides adequate current.

3. Contacts Not Conducting Properly:

   • Cause: Contacts may be worn or damaged.
   • Solution: Check the contact surfaces and replace the relay if necessary.

4. Arduino Not Controlling the Relay:

   • Cause: Incorrect wiring or missing flyback diode.
   • Solution: Double-check the wiring and ensure a flyback diode is installed.

Q: Can the Omron MY2N relay handle AC loads?
A: Yes, the relay can handle AC loads up to 250VAC, provided the current does not exceed 5A.

Q: Is the relay suitable for high-frequency switching?
A: No, the Omron MY2N is not designed for high-frequency switching. It is best suited for low to moderate switching frequencies.

Q: Can I use the relay without a transistor driver?
A: Only if the control signal can provide sufficient current to energize the coil. Otherwise, a transistor or MOSFET driver is recommended.

Q: What is the purpose of the flyback diode?
A: The flyback diode protects the driving circuit from voltage spikes generated when the relay coil is de-energized.