A 5V relay is an electromechanical switch that uses an electromagnetic coil to open or close contacts. It allows a low voltage signal (5V) to control high voltage or high current circuits, making it an essential component in automation, home appliances, and industrial control systems.
This circuit uses an Arduino UNO to control a 5V relay. The relay is powered by the Arduino's Vin and GND pins, and its control input is connected to digital pin D9 on the Arduino. The provided code is a basic template with no specific functionality implemented.
Open Project in Cirkit Designer
This circuit uses a pushbutton to control a 5V relay, which in turn powers a red LED. The MAHIR 1.mini module provides the necessary 3.7V power supply, and the relay switches the LED on and off based on the pushbutton input.
Open Project in Cirkit Designer
This circuit uses a WeMos D1 R2 microcontroller to control a 5V 2-relay module, which in turn controls the power to an AC bulb and a cellphone charger. The microcontroller also interfaces with a line tracking sensor, which likely provides input to control the relay states. The AC bulb and cellphone charger are powered by an AC wire connection, with the relay acting as a switch for the bulb.
Open Project in Cirkit Designer
This circuit consists of a 5V battery powering a 4-channel relay module, which controls four LEDs (red, yellow, green, and blue) through individual resistors. Each relay channel is activated by a corresponding SPST toggle switch, allowing manual control of the LEDs.
Open Project in Cirkit DesignerBelow are the key technical details for a standard 5V relay:
| Parameter | Value |
|---|---|
| Operating Voltage | 5V DC |
| Trigger Voltage | 3.75V to 5V DC |
| Coil Resistance | ~70Ω to 100Ω |
| Switching Voltage (Max) | 250V AC / 30V DC |
| Switching Current (Max) | 10A |
| Contact Type | SPDT (Single Pole Double Throw) |
| Isolation | Electrical isolation between coil and contacts |
| Dimensions | Varies by model (e.g., 28mm x 10mm x 15mm) |
The 5V relay typically has 5 pins. Below is the pin configuration:
| Pin Name | Description |
|---|---|
| Coil+ | Positive terminal of the relay coil (connect to 5V DC) |
| Coil- | Negative terminal of the relay coil (connect to ground) |
| Common (COM) | Common terminal for the relay switch |
| Normally Open (NO) | Open circuit when the relay is inactive; closes when the relay is activated |
| Normally Closed (NC) | Closed circuit when the relay is inactive; opens when the relay is activated |
Coil+ pin to a 5V DC power source and the Coil- pin to ground. This energizes the relay coil.COM and NO or NC pins, depending on the desired behavior:
NO if the load should be off by default and turn on when the relay is activated.NC if the load should be on by default and turn off when the relay is activated.Below is an example of how to control a 5V relay using an Arduino UNO:
// Define the relay control pin
const int relayPin = 7; // Connect this pin to the relay's Coil+ via a transistor
void setup() {
pinMode(relayPin, OUTPUT); // Set the relay pin as an output
digitalWrite(relayPin, LOW); // Ensure the relay is off initially
}
void loop() {
digitalWrite(relayPin, HIGH); // Activate the relay
delay(1000); // Keep the relay on for 1 second
digitalWrite(relayPin, LOW); // Deactivate the relay
delay(1000); // Keep the relay off for 1 second
}
Circuit Notes:
Relay Not Activating:
Relay Chattering or Flickering:
Load Not Switching:
COM, NO, or NC pins.Burnt Relay or Circuit Damage:
COM, NO, NC) when the relay is activated or deactivated.Coil+ and Coil- pins to ensure it is functional.By following this documentation, you can effectively integrate and troubleshoot a 5V relay in your electronic projects.