1-Channel Relay Module DC 3.3V–24V Optocoupler for Arduino

1-Channel Relay Module with Optocoupler Isolation – DC 3.3V / 5V / 12V / 24V

Take full control of high-power circuits with this versatile 1-Channel Electromagnetic Relay Module. Designed for makers, engineers, and hobbyists, it integrates seamlessly with Arduino, Raspberry Pi, and other microcontrollers. Dual optocoupler isolation keeps your sensitive control circuitry safe while switching loads up to AC 250V/10A or DC 30V/10A. Wide input voltage compatibility (3.3V, 5V, 12V, 24V DC) means it works right out of the box with virtually any development platform.

Made in Mainland China.

Key Features

• Wide Voltage Range: Compatible with DC 3.3V, 5V, 12V, and 24V power supplies — no extra regulator needed.
• Double Optocoupler Isolation: Strong drive capability, stable performance, and reliable signal separation; trigger current just 5mA.
• High & Low Level Trigger: Jumper-selectable HIGH or LOW level trigger per channel for maximum flexibility.
• Fault-Tolerant Design: Relay remains inactive even if the control line is disconnected, preventing accidental switching.
• Maximum Load Capacity: Normally open interface handles AC 250V/10A and DC 30V/10A — suitable for high-power applications.
• LED Status Indicators: Green power LED and red relay-status LED for instant visual feedback.
• Screw Terminal Connectors: All interfaces are accessible via easy-connect screw terminals — no soldering required for basic setups.

Module Interface Guide

• DC+: Connect to positive pole of power supply (match relay voltage: 5V, 12V, or 24V)
• DC–: Connect to negative pole of power supply
• IN: Control signal input — accepts high or low logic level

Relay Output Terminals

• NO (Normally Open): Open circuit at rest; shorts to COM when relay is energised
• COM (Common): Common relay terminal
• NC (Normally Closed): Shorted to COM at rest; opens when relay is energised

High / Low Level Trigger Selection

Jumper S1 selects the trigger level for the relay channel. Short COM to LOW for low-level trigger; short COM to HIGH for high-level trigger. This makes the module compatible with both active-high and active-low microcontroller outputs.

Specifications

Compatible With

Arduino Uno, Mega, Nano, ESP8266, ESP32, Raspberry Pi, and any microcontroller with a 3.3V–24V logic output.

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Further Reading

For electrical safety guidelines when working with relay-switched mains-voltage circuits, refer to OSHA Electrical Safety Standards.

Frequently Asked Questions

Q: What voltages can I use to power this 1-channel relay module?

A: The module supports DC 3.3V, 5V, 12V, and 24V input voltages, making it compatible with a wide range of microcontrollers and power supplies — including 3.3V boards like ESP32 and standard 5V Arduino boards.

Q: Can I use this relay module with both high-level and low-level trigger microcontrollers?

A: Yes. The onboard jumper (S1) lets you select either high-level or low-level trigger mode, so the module works with virtually any microcontroller output regardless of its active logic state.

Q: What is the maximum load this relay module can switch?

A: The normally open (NO) contacts are rated for AC 250V/10A and DC 30V/10A, making this module suitable for controlling lights, motors, pumps, and other high-power devices from a low-voltage microcontroller signal.

Q: What does the optocoupler isolation do?

A: The dual optocoupler isolation electrically separates the low-voltage control side (your Arduino or microcontroller) from the high-voltage load side. This protects your development board from voltage spikes and noise generated by the switched load.