1-Channel Relay Module 3.3V–24V Dual Optocoupler Isolation

1-Channel Relay Module – Dual Optocoupler Isolation, 3.3V / 5V / 12V / 24V Compatible

Take full control of your electronics projects with this versatile 1-Channel Relay Module Board. Compatible with 3.3V, 5V, 12V, and 24V systems, it works seamlessly with Arduino, Raspberry Pi, and a wide range of microcontrollers. Dual optocoupler isolation ensures robust signal separation, stable performance, and strong drive capability — making it an excellent choice for hobbyists, engineers, and makers alike. Made in Mainland China.

Key Features

• Wide Voltage Compatibility: Supports 3.3V, 5V, 12V, and 24V input — works with virtually any microcontroller or development board.
• High Load Capacity: Normally open (NO) interface supports up to AC 250V/10A or DC 30V/10A for switching high-power devices.
• Dual Optocoupler Isolation: Provides strong electrical isolation between control and load circuits, ensuring stable, interference-free operation.
• High & Low Level Trigger Selection: Each channel can be set to trigger on high or low logic level via onboard jumper (S1), giving you maximum flexibility.
• Fault-Tolerant Design: If the control signal line is disconnected, the relay remains in its current state — no accidental switching.
• Trigger Current: Only 5mA required — compatible with low-power microcontrollers without additional drivers.
• Status Indicators: Green LED for power-on confirmation; Red LED for relay status monitoring at a glance.
• Easy Wiring: All interfaces (DC+, DC−, IN, NO, COM, NC) are clearly labelled and accessible via screw terminals for quick, tool-friendly connections.

Module Interface Guide

• DC+: Connect to the positive terminal of the power supply.
• DC−: Connect to the negative terminal of the power supply.
• IN: Signal input — control the relay via high or low logic level.

Relay Output Terminals

• NO (Normally Open): Open circuit by default; shorts to COM when relay is energised.
• COM (Common): Common reference terminal for relay output.
• NC (Normally Closed): Short circuit to COM by default; opens when relay is energised.

Trigger Level Selection

• Use the S1 jumper to select trigger mode for Relay 1.
• COM shorted to LOW: Low-level trigger mode.
• COM shorted to HIGH: High-level trigger mode.

Specifications

Great for Use With

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Frequently Asked Questions

Q: What voltage levels does this relay module support?

A: This relay module board supports 3.3V, 5V, 12V, and 24V DC input signals, making it compatible with Arduino, Raspberry Pi, ESP8266, ESP32, and most other common microcontrollers and development platforms.

Q: Can I choose between high-level and low-level triggering?

A: Yes. The onboard S1 jumper lets you select between high-level and low-level trigger modes for the relay channel. Simply short the jumper to COM-HIGH for high-level triggering, or COM-LOW for low-level triggering — no soldering required.

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

A: The normally open (NO) output interface supports a maximum load of AC 250V/10A or DC 30V/10A, making it suitable for controlling lights, pumps, motors, solenoids, and other household or low-voltage industrial devices.

Q: Why does this relay module use dual optocoupler isolation?

A: Dual optocoupler isolation electrically separates the low-voltage control circuit (your microcontroller) from the high-voltage load circuit. This protects your controller board from voltage spikes or back-EMF, ensuring more stable and reliable operation over time.