5v Single Channel Relay module (Without Optocoupler)

A 5V Single Channel Relay Module is a widely used component in electronics, particularly in microcontroller-based projects such as Arduino or Raspberry Pi. It allows you to control high-voltage or high-current devices (like motors, lights, and other electrical appliances) using low-voltage signals (e.g., from an Arduino or other microcontroller). Here's a detailed breakdown of what the 5V Single Channel Relay Module is, how it works, and its typical applications:

Key Features of a 5V Single Channel Relay Module:

1. Relay:

• A relay is an electromechanical switch that allows you to control a high-voltage device (like a 110V/220V appliance) with a low-voltage signal (like 3.3V or 5V from a microcontroller).
• The relay inside the module is typically rated for 5V on the coil side and can control higher voltage and current on the switched side (AC or DC load).

1. Operating Voltage:

• The module operates on 5V DC (this is the voltage used to power the relay coil and the control circuitry).
• The control pin, which comes from a microcontroller or other control device, also needs to be a 5V signal (typically high for turning the relay on and low for turning it off).

1. Single Channel:

• This module has one relay channel, meaning it can control a single device (like a light, fan, or motor).
• For projects needing multiple control channels, you can use multi-channel relay modules, like 2, 4, or 8-channel versions.

1. Relay Contacts:

• The relay has three contacts:
• NO (Normally Open): The contact is open (disconnected) when the relay is off. When the relay is triggered, the NO pin closes and connects the circuit.
• NC (Normally Closed): The contact is closed (connected) when the relay is off. When the relay is triggered, the NC pin opens, disconnecting the circuit.
• COM (Common): This is the shared connection. You use COM to connect to either the NO or NC pin, depending on whether you want the circuit to be open or closed when the relay is off.

1. Indication LED:

• Many modules have an LED indicator that lights up when the relay is activated (i.e., the controlled device is turned on). This can help with debugging and indicate that the relay is working.

1. Optocoupler Isolation:

• Some 5V relay modules include an optocoupler between the microcontroller's control pin and the relay's coil. This helps protect the microcontroller from voltage spikes and noise generated by the high-voltage side of the circuit.

1. Current/Voltage Rating:

• The typical relay found in a single-channel 5V module can control devices with the following approximate ratings:
• AC: 10A @ 120V AC or 7A @ 240V AC
• DC: 10A @ 28V DC
• Be sure to check the specific relay module's datasheet for the exact ratings for your application.

Pinout of a 5V Single Channel Relay Module:

Here’s the typical pin configuration you’ll find on the module:

1. VCC (Power Supply):

• This pin connects to a 5V power supply to power the module and the relay coil.

1. GND (Ground):

• Connect this pin to the ground (GND) of your power supply or microcontroller.

1. IN (Control Pin):

• This pin is used to control the relay. It should be connected to a GPIO pin on your microcontroller (like Arduino or Raspberry Pi).
• When you apply a high signal (5V) to this pin, the relay will activate and close the NO contact to COM. When the signal is low (0V), the relay will turn off, and the NO contact will open.

1. NO (Normally Open):

• This is the terminal that connects to the load (e.g., an appliance, light, or motor) when the relay is triggered. This contact is normally open (disconnected) and closes when the relay is energized.

1. NC (Normally Closed):

• This terminal connects to the load when the relay is in its default (off) state. When the relay is energized, the NC contact opens and disconnects the load from the circuit.

1. COM (Common):

• This is the common contact that is used to connect the load. It is either connected to NO or NC depending on the relay's state (on or off).

How It Works:

When you send a signal (usually a 5V HIGH signal) to the IN pin, the relay coil is energized, causing the internal switch to change its state:

• NO (Normally Open) and COM will be connected, completing the circuit and turning on the connected device.
• When the signal is turned LOW, the relay is de-energized, and the NO contact will disconnect from COM, turning off the device.

Applications of a 5V Single Channel Relay Module:

1. Home Automation:

• Control household devices (lights, fans, etc.) remotely using microcontrollers like Arduino or Raspberry Pi.

1. Automated Systems:

• Turn on/off motors, pumps, or other electrical devices automatically in industrial or home automation systems.

1. IoT Projects:

• Use it to create Internet of Things (IoT) projects that control devices via the internet or a mobile app.

1. Arduino Projects:

• In Arduino-based systems, you can use a relay to control home appliances or other high-power devices based on inputs from sensors or user commands.

1. Timing Applications:

• Use relays to create timers that automatically turn devices on/off after a set period.

Sample Code for Controlling a Relay with Arduino:

Here's a simple example of how to control a 5V relay with an Arduino:

#define RELAY_PIN 7  // Define the relay control pin

void setup() {
  pinMode(RELAY_PIN, OUTPUT);  // Set the relay control pin as an output
  Serial.begin(9600);          // Start serial communication
}

void loop() {
  Serial.println("Relay On");
  digitalWrite(RELAY_PIN, HIGH);  // Turn the relay ON (device connected to NO will be powered)
  delay(1000);                    // Wait for 1 second

  Serial.println("Relay Off");
  digitalWrite(RELAY_PIN, LOW);   // Turn the relay OFF (disconnect device)
  delay(1000);                    // Wait for 1 second
}

Brand:- Generic

Origin:- China