5V 2 Channel Relay Module
5V 2 Channel Relay Module
Dual-channel optically isolated relay board with independent control for Arduino/Raspberry Pi projects
Introduction
The 5V 2 Channel Relay Module allows you to control two separate high-voltage/high-current circuits (up to 250VAC/10A each) using low-voltage 5V signals. This module features optocoupler isolation, status LEDs, and both normally open (NO) and normally closed (NC) contacts for each relay.
Key Features
Dual Independent Relays
Control two circuits separately
High Power Handling
10A @ 250VAC or 30VDC per channel
Optoisolation
PC817 optocouplers protect control circuit
Status Indicators
Power + Relay activation LEDs
Jumper Selectable
Choose between HIGH/LOW level trigger
Screw Terminals
Secure connections for high-power wiring
Technical Specifications
| Number of Channels | 2 (independent control) |
|---|---|
| Trigger Voltage | 5V DC (HIGH or LOW level selectable) |
| Trigger Current | 15-20mA per channel |
| Max Switching Current | 10A @ 250VAC or 30VDC per channel |
| Contact Type | SPDT (1 Form C) – NO + NC contacts |
| Default State | Normally Open (NO) |
| Optocoupler | PC817 (or equivalent) per channel |
| Operating Voltage | 5V ±10% |
| Operating Temperature | -40°C to +70°C |
| Module Dimensions | 70mm x 53mm x 19mm (L×W×H) |
Pin Configuration
| Pin Label | Description | Connection |
|---|---|---|
| VCC | 5V Power Input | Connect to 5V supply |
| GND | Ground | Connect to system ground |
| IN1 | Channel 1 Control | Microcontroller pin 1 |
| IN2 | Channel 2 Control | Microcontroller pin 2 |
| NO1/NC1/COM1 | Channel 1 Contacts | Load connections |
| NO2/NC2/COM2 | Channel 2 Contacts | Load connections |
| JD-VCC Jumper | Opto-isolator power | See setup instructions |
Wiring with Arduino
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 |
// Arduino Dual Relay Control const int relay1Pin = 8; // Channel 1 control const int relay2Pin = 9; // Channel 2 control void setup() { pinMode(relay1Pin, OUTPUT); pinMode(relay2Pin, OUTPUT); digitalWrite(relay1Pin, HIGH); // Start with relay OFF (active LOW) digitalWrite(relay2Pin, HIGH); // Start with relay OFF (active LOW) } void loop() { // Alternate relay activation digitalWrite(relay1Pin, LOW); // Activate relay 1 digitalWrite(relay2Pin, HIGH); delay(2000); digitalWrite(relay1Pin, HIGH); digitalWrite(relay2Pin, LOW); // Activate relay 2 delay(2000); } |
Jumper Configuration
Trigger Mode Selection
HIGH Level Trigger: Relay activates when IN pin is HIGH (5V)
LOW Level Trigger: Relay activates when IN pin is LOW (0V)
Configure via jumper near each IN pin
Power Isolation
JD-VCC Jumper ON: Optocouplers use board VCC
JD-VCC Jumper OFF: Use separate power for optocouplers
Required when controlling circuits with different grounds
Application Examples
Smart Home Control
Independent control of lights and appliances
HVAC Systems
Control both heating and cooling units
Automotive Projects
Dual accessory control (lights, fans, etc.)
Industrial Automation
Machine start/stop and safety interlocks
Safety Precautions
- ⚠️ High Voltage Warning: Treat all mains voltage connections as potentially lethal
- 🔧 Use proper insulated tools when working with live circuits
- 📏 Maintain at least 8mm clearance between low and high voltage sections
- 🔌 Secure all high-voltage connections with screw terminals
- 🔥 Never exceed 10A current rating per channel
- 💧 Keep module away from moisture and conductive debris
