1.2-channel relay module with optocoupler — 2-way relay expansion board with high/low trigger selection and LED indicator Key benefits Provides isolated switching between low-voltage control circuitry and high-voltage loads, protecting your controller from noise and voltage spikes. High load capacity for reliable control of AC or DC devices: normally open contact rated AC 250V / 10A, DC 30V / 10A. Flexible trigger logic: jumper-selectable high or low trigger lets you integrate the module into different control systems without extra wiring or level shifting. Visual status with LED warning lamp for quick diagnostics and safe operation. Fault-tolerant design: if the control line is interrupted, the relay will not switch unexpectedly, reducing the risk of unintended operation. Features and specifications Channel count: 1.2-channel relay module (2-way relay expansion board). Relay quality: uses a real high-quality relay for durable switching performance. Contact rating (normally open): AC 250V / 10A, DC 30V / 10A. Isolation: patch optocoupler insulation for strong driving capability and stable performance. Trigger current: 5 mA. Operating voltage: 5 V supply available for module operation. Trigger mode: jumper-selectable high-level or low-level trigger. Indicator: LED warning lamp for each relay channel. Safety behavior: designed so the relay will not actuate if the control line is interrupted. How it solves common problems Protects sensitive controllers: optocoupler isolation prevents control-side interference from load-side transients. Simplifies integration: compatible with 5 V control signals and low trigger current makes it easy to drive from microcontrollers and logic circuits. Reduces troubleshooting time: LED indicators show relay state at a glance. Prevents accidental switching: the fault-tolerant trigger design minimizes unintended relay movement when control connections fail. Practical use scenarios Home automation: control lighting circuits, fans or other household appliances (within the stated AC/DC ratings) from a 5 V controller or expansion bus. Microcontroller projects: safely switch external devices from Arduino, Raspberry Pi or other 5 V logic systems while keeping the control electronics isolated. Prototyping and small automation tasks: use as a compact 2-way expansion board to add isolated relay outputs for sensors, alarms or auxiliary actuators. Notes and compatibility Ensure connected loads do not exceed the relay’s maximum rated current and voltage (AC 250V / 10A, DC 30V / 10A). Requires a 5 V supply for module operation; trigger current is approximately 5 mA. Use the jumper to select high or low trigger behavior according to your control signal logic. The module’s optocoupler isolation and fault-tolerant design improve system reliability without additional external isolation components.