3-Channel Relay Board for Raspberry Pi 4B, 3B+ and 3B

Switch separate project circuits from a compatible Raspberry Pi using a three-channel relay board. This expansion accessory connects through the 40-pin GPIO interface on Raspberry Pi 4B, 3B+ and 3B. For makers building projects that need relay-controlled outputs.

Add three relay-controlled outputs to a Pi project

• ✅ Control separate circuits — Three onboard relays provide individual switching channels for your project.
• ✅ Check states during testing — Indicator LEDs give you a visible reference when checking relay operation.
• ✅ Work around other GPIO connections — Jumper selection lets you choose the control-pin arrangement for your build.
• ✅ Connect external wiring neatly — Screw terminals provide connection points for the circuits being switched.

The board is an expansion accessory rather than a complete computer. A Raspberry Pi is not included; check your exact model and allow room for the board and connected wiring.

The relay contact ratings describe the marked switching components, not a guarantee for every complete installation. External loads need an appropriate power supply and wiring arrangement. Use suitable professional installation for mains-voltage work.

Technical details

• Product: relay expansion board
• Relay channels: three
• Compatible computers: Raspberry Pi 4B, 3B+ and 3B
• Interface: 40-pin GPIO
• Optocouplers: PC817
• Control-pin selection: jumper configurable
• Relay contact markings: 5 A at 250 V AC or 5 A at 30 V DC
• Approximate board dimensions: 65.15 × 56.21 mm
• Package: one relay board and one screw set
• Raspberry Pi: not included

The labelled layout identifies the relays, terminals and control connections for planning your project.

The lamp demonstration illustrates a separately assembled project, rather than an included lamp or ready-made phone-control system.

Check the approximately 65.15 × 56.21 mm board outline when planning space in your build.

The package contains a relay board and screw set, so you can plan the remaining project parts separately.

The underside connector is for the compatible Raspberry Pi's 40-pin GPIO interface.

The jumpers let you select the control-pin arrangement to suit your project connections.

The mounted view shows the board alongside a Raspberry Pi; the computer is not included.

Project reference: www.waveshare.com/wiki/RPi_Relay_Board

Add the relay board to a compatible Pi project when you need three individually switched outputs.

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