8-channel relay module - 5 V, HIGH-LOW trigger, up to 250 V / 10 A

Product overview

• Relay board with 8 independent relays for switching mains-voltage loads
• Logic inputs with HIGH/LOW trigger, operates with 5 V control signals
• Each relay switches up to 250 V AC and 10 A load
• Can be mounted on common development boards via standardized connectors
• Optoisolation between control logic and switching contacts
• Built-in flyback diodes for protection against voltage spikes

Product description

This relay board adds eight switching outputs for mains-powered devices to microcontroller boards. Control is provided via LOW-active or HIGH-active inputs, depending on the jumper configuration. This means that the relays can respond either to a 5 V signal or to ground, allowing the board to be integrated flexibly into existing circuits.

The optoisolation galvanically separates the control side from the switching contacts. This prevents feedback from the high-voltage circuit to the control logic, increasing stability and protecting sensitive measurement electronics from interference. Each relay is equipped with a flyback diode that absorbs voltage spikes when inductive loads are switched off.

Practical applications include remote control of heaters, pumps, or lighting via web interfaces or mobile applications, automation of laboratory setups with multiple consumers that can be switched in parallel, and control of solenoid valves in prototypes for fluidics experiments. The board is also suitable for implementing safety circuits that reliably switch off devices under specific sensor conditions.

A microcontroller or board with digital outputs that provide 5 V logic levels is required. The switching load must not exceed 250 V AC and 10 A. A separate power supply is required to operate the relay module, as the control logic alone does not provide sufficient current.

Safety notice

This module is intended exclusively for prototyping, testing, and development purposes and is not intended for installation in household electrical circuits. Work on or near circuits carrying mains voltage may only be performed by a qualified electrician; consult a qualified electrician before commissioning if anything is unclear. Before connecting, check that the power supply is correct and that the jumper is set correctly for the trigger level.

Scope of delivery

• 1x HIGH-LOW-LEVEL Trigger - 8-channel, 5V