4CH 12V Relay Module

A 4-channel 12 V relay module that allows any microcontroller to switch mains AC or high-current DC loads via optocoupled inputs — providing complete electrical isolation between your control circuit and the switched load. Each relay switches independently, and both normally-open and normally-closed contacts are available on each channel.

🔹 Key Applications

• Home automation switching (lights, fans, appliances)
• Arduino-controlled power outlet switching
• Industrial process control actuator switching
• Irrigation solenoid valve control
• Remote-controlled high-power load switching
• HVAC and thermostat control

🔹 Why Choose This Module?

• 4 independent channels — control 4 separate loads
• Optocoupler isolation — MCU fully protected from switched loads
• Both NO and NC contacts — flexible circuit design
• 12 V coil operation — powered from standard Arduino supply
• Status LED per channel — visual confirmation of relay state

🔹 Technical Specifications

• Channels: 4
• Coil Voltage: 12 V DC
• Contact Rating: 10 A / 250 V AC or 10 A / 30 V DC
• Isolation: Optocoupled inputs
• Trigger: Active LOW (configurable to HIGH)
• Indicators: LED per channel

🔹 What's Included

1 × 4-Channel 12V Relay Module

🔹 Pro Tip

💡 Connect your load between COM and NO for normally-open (load OFF by default) operation, or COM and NC for normally-closed. Use a flyback diode across inductive loads (motors, solenoids) to prevent relay contact damage from voltage spikes. Active-LOW trigger means the relay fires when the GPIO pin goes LOW.

⚠️ Note: Always ensure proper heat dissipation and correct voltage configuration before powering connected devices.