How to Use Signal-Relais, 5 V DC, 3 A, 2 CO: Examples, Pinouts, and Specs

The Signal-Relais AZ832-2C-5DE by Zettler is a compact, high-performance electromechanical relay designed for low-power signal switching applications. It operates on a 5 V DC control signal and can handle currents of up to 3 A. This relay features 2 changeover (CO) contacts, making it suitable for versatile switching configurations. Its small size and reliable performance make it ideal for applications in telecommunications, industrial control systems, home automation, and more.

• Signal switching in telecommunications equipment
• Industrial automation and control systems
• Home automation circuits
• Low-power motor control
• Audio and video equipment switching

The AZ832-2C-5DE relay has a total of 8 pins. The pinout is as follows:

1. Power the Coil: Connect the relay's coil terminals (pins 1 and 2) to a 5 V DC power source. Ensure the polarity is correct: pin 1 is positive, and pin 2 is negative.
2. Control the Circuit: Use the relay's contacts (pins 3–8) to control the desired circuit. The relay provides two independent changeover (CO) contacts:
   • When the coil is not energized, the common (COM) pins are connected to the normally closed (NC) pins.
   • When the coil is energized, the common (COM) pins are connected to the normally open (NO) pins.
3. Load Connection: Connect the load to the appropriate contact pins (NO or NC) based on your application requirements.

• Diode Protection: Always connect a flyback diode across the coil terminals to protect the driving circuit from voltage spikes when the relay is de-energized.
• Current Ratings: Ensure the load current does not exceed the relay's maximum switching current of 3 A.
• Isolation: Maintain proper isolation between the coil and contact circuits to prevent interference or damage.
• Mounting: Secure the relay on a PCB or socket to ensure stable operation and avoid mechanical stress.

The AZ832-2C-5DE relay can be controlled using an Arduino UNO. Below is an example circuit and code to toggle the relay:

1. Connect pin 1 of the relay to a digital output pin on the Arduino (e.g., pin 7) through a transistor and a 1 kΩ base resistor.
2. Connect pin 2 of the relay to the Arduino's GND.
3. Add a flyback diode (e.g., 1N4007) across the relay coil terminals (pin 1 and pin 2) with the cathode connected to pin 1.

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

void setup() {
  // Set the relay pin as an output
  pinMode(relayPin, OUTPUT);
}

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

  // Turn the relay OFF
  digitalWrite(relayPin, LOW);
  delay(1000); // Keep the relay OFF for 1 second
}

1. Relay Not Switching

   • Cause: Insufficient voltage or current to the coil.
   • Solution: Verify that the coil is receiving 5 V DC and sufficient current. Check the power supply and connections.

2. Contacts Not Conducting

   • Cause: Incorrect wiring or damaged contacts.
   • Solution: Double-check the wiring and ensure the load is connected to the correct pins (NO or NC). Inspect the relay for physical damage.

3. Voltage Spikes Damaging the Circuit

   • Cause: Lack of a flyback diode across the coil.
   • Solution: Install a flyback diode (e.g., 1N4007) across the coil terminals to suppress voltage spikes.

4. Relay Heating Up

   • Cause: Exceeding the maximum current rating.
   • Solution: Ensure the load current does not exceed 3 A. Use a heat sink or cooling mechanism if necessary.

Q1: Can this relay switch AC loads?
A1: Yes, the relay can switch AC loads up to 250 V, provided the current does not exceed 3 A.

Q2: Can I use this relay with a 3.3 V microcontroller?
A2: Yes, but you will need a transistor or relay driver circuit to step up the control voltage to 5 V.

Q3: What is the lifespan of this relay?
A3: The relay has a mechanical lifespan of approximately 10 million operations and an electrical lifespan of around 100,000 operations under rated load conditions.

Q4: Is the relay polarity-sensitive?
A4: The coil terminals (pins 1 and 2) are polarity-sensitive. Ensure correct polarity when connecting the power supply.