Gravity 16A Relay Module 3.3-5V Logic Compatible

The Gravity 16A Relay Module from DFRobot switches loads up to 30 V with a relay via a digital output of an Arduino, ESP32 or Raspberry Pi. The relay has a changeover contact with COM, NO and NC on the screw terminal. A transistor drives the relay coil, the module works with 3.3 V and with 5 V. It is connected via the Gravity cable, a HIGH at input D switches the relay on.

Important: For safety reasons, the module is only intended for voltages up to 30 V and not for mains voltage. The DFRobot rating 16 A 277 V AC applies to the relay, not to the module. The module is therefore not suitable for switching the mains supply of devices such as a 3D printer.

Note: The connection cable can be converted to male pins with a Dupont cable M-M, so that it also fits an Arduino UNO.

Recommended Accessories:

• Gravity IO Expansion Shield for Arduino V7.1
• Dupont Cables M-M 10cm 20 Pieces

Features:

• 1 relay with changeover contact (COM, NO, NC) on screw terminal
• High level control: the relay switches when D is HIGH
• Coil via transistor and its own 3.3 V regulator, for 3.3 V and 5 V boards
• Input D with 100 kΩ to GND, the relay stays off at power-up
• LED shows the switching state
• Gravity connector PH2.0 3-pin
• Frame, base plate, screws and spacers included

Application Examples:

• Switching 12 V solenoid valves and pumps
• Switching LED strips with extra-low voltage on and off
• Controlling fans and motors with extra-low voltage

Connection to 5 V Logic (for example Arduino UNO):

• Gravity cable: red (+) to 5V, black (-) to GND
• Green (D) to a digital output, for example pin 8
• Output HIGH: relay on, NO connected to COM. Output LOW: relay off, NC connected to COM

Connection to 3.3 V Logic (for example ESP32, Raspberry Pi):

• Red (+) to 5 V (Raspberry Pi: pin 2) or to 3.3 V (Raspberry Pi: pin 1)
• Black (-) to GND (Raspberry Pi: pin 6)
• Green (D) to a GPIO (Raspberry Pi: GPIO17, pin 11)
• According to the schematic, D only leads via resistors to the base of the transistor and with 100 kΩ to GND, there are no 5 V at the GPIO
• GPIO HIGH: relay on. GPIO LOW: relay off

Documentation:

• Wiki DFRobot DFR0251
• Example relay on and off with Arduino (DFRobot)
• Schematic V2.0 (PDF)

Technical Data:

• Manufacturer: DFRobot
• Manufacturer SKU: DFR0251
• Marking: 16A Relay Module V2.0
• Relay: Hongfa HF152FD/3-1ZPS (DFRobot image)
• Permitted voltage on this module: up to 30 V
• Relay rating according to DFRobot: 16 A 277 V AC / 24 V DC between COM and NO, 7 A between COM and NC
• Supply (VCC): 3.3 V to 5.5 V
• Input D: HIGH from 3.0 V, LOW up to 0.9 V
• Switching time: max. 10 ms on, 5 ms off
• Service life: mechanical at least 10 million, electrical at least 50,000 operations
• Interface: Gravity digital PH2.0 3-pin
• Dimensions: 37 × 29 × 22 mm
• Weight: 27 g (module, according to the wiki)

Scope of Delivery:

• 1× Gravity 16A Relay Module
• 1× Gravity cable 3-pin, PH2.0 to socket
• 1× Black frame and 1× base plate
• 4× M3 screw
• 4× Nylon spacer