DFRobot - Gravity: Digital 5A Relay Module for Arduino

Simple, Reliable Switching for High-Power Devices.The Gravity: Digital Relay Module provides safe and stable ON/OFF control for high-power AC and DC loads through a standard low-voltage digital signal. It is widely used in automation systems, Arduino-based projects, smart home devices, and industrial prototypes.

Designed for plug-and-play integration, the module eliminates the need for external driver circuits while offering clear status feedback through a built-in indicator LED.

Features of Gravity: Digital Relay Module

• High-current switching capability up to 10A (NO) / 5A (NC)
• Wide load support: up to 250VAC / 30VDC switching voltage
• Direct digital control via standard TTL signal (3.3V/5V logic compatible in typical use cases)
• Built-in status LED for real-time relay state indication
• Opto-isolated design for improved electrical safety and signal separation
• Gravity interface for fast hardware integration
• Compact single-channel design suitable for embedded systems

Operating Principle

The relay functions as an electrically controlled mechanical switch. A low-power digital signal activates an internal electromagnetic coil, which mechanically opens or closes the high-power circuit.

• Digital HIGH → Relay ON (Load connected)
• Digital LOW → Relay OFF (Load disconnected)

Switching is suitable for low-frequency control applications such as ON/OFF automation.

Quick Start (Arduino Example)

A standard Arduino setup enables relay toggling within minutes using a digital output pin.

Wiring Overview

• Relay VCC → 5V
• Relay GND → GND
• Relay Signal → Digital Pin (e.g., D3)

Behavior

The relay switches ON and OFF every 2 seconds, demonstrating basic functional control and system responsiveness.

Example Code

Compatibility Notes

• Compatible with most 5V microcontroller systems
• For 3.3V systems (ESP32, Raspberry Pi Pico), a 3.3V-trigger compatible relay module is recommended
• Not suitable for PWM-based power regulation or dimming applications
• For speed control or brightness adjustment, a MOSFET power controller is recommended instead

Important Usage Guidance

• Suitable for low-frequency ON/OFF switching only
• Not designed for analog power control or high-frequency PWM operation
• Ensure load specifications remain within rated limits for safe operation
• Inductive loads (motors, solenoids) may require additional protection depending on application
• What This Module Is Best For

This relay module is optimized for simple, reliable switching tasks where electrical isolation and safe high-voltage control are required. It serves as a fundamental building block in embedded control systems and automation projects.

• Smart home lighting control systems
• Water pump and irrigation automation
• Solenoid valve switching systems
• Industrial relay control prototypes
• Arduino / ESP32 / Raspberry Pi based automation projects
• High-power device ON/OFF control modules

• Single relay board
• Rated through-current: 10A (NO) 5A (NC)
• Maximum switching voltage: 150VAC 24VDC
• Interface: Digital
• Control signal: TTL level (0~0.4V: OFF; 2.4~5V: ON)
• Contact Rating (Res. Load): 10A 250VAC / 24VDC
• Max. switching voltage 250VAC / 30VDC
• Max. switching current 15A
• Max. switching power 250VA 240W 
• UL Rating: 10A 120VAC / 10A 250VAC
• Operate time (at nomi. Vot.): 10ms
• Release time (at nomi. Vot.): 5ms
• High quality connector
• Immersion gold surface

• Gravity Relay Module V3.1 x1
• Digital  Cable  x1
• Acrylic Board x 1