Photodiode Relay Control Board – Light-Activated Switching Module (12VDC, 10A) for Automation Systems

Description

Description

The Photodiode Relay Control Board is a precision light-activated switching module designed for automation systems requiring reliable, threshold-based control of electrical loads. Unlike basic LDR-based modules that respond broadly to ambient light, this module utilizes a photodiode sensor that offers superior directionality and faster response times, making it ideal for applications where precise light detection from a specific direction is required.

The module operates on a 12V DC power supply and integrates a high-quality electromagnetic relay capable of switching loads up to 10A at 250V AC or 30V DC — sufficient for most industrial and residential applications including lighting systems, ventilation fans, pumps, and security equipment.

At the heart of the module is an LM393 comparator that processes the photodiode signal against an adjustable threshold set by the onboard blue potentiometer. This design provides clean, jitter-free switching without the need for a microcontroller. The module features both red power indicator and blue relay status LEDs, four 3mm mounting holes for secure installation, and screw terminal blocks for reliable load connections.

The photodiode sensor offers distinct advantages over traditional photoresistors: it responds primarily to light from a specific direction (narrow detection angle), is less affected by ambient light from the sides, and provides faster switching speeds. This makes the module particularly suitable for automotive lighting control, industrial automation, security systems, solar tracking, and any application where precise, directional light detection is required.

This module works in standalone mode — simply connect 12V power and your load, adjust the sensitivity threshold, and the module automatically switches your load based on ambient light levels. No programming or microcontroller is required for basic operation.

Features

• Photodiode sensor — superior directionality and faster response compared to LDR sensors

• 12V DC operation — compatible with automotive, marine, solar, and industrial 12V systems

• 10A relay output — SPDT contacts rated for 250V AC or 30V DC loads

• Adjustable light threshold — onboard blue potentiometer for precise sensitivity setting

• LM393 comparator — provides clean, stable switching without jitter

• Dual LED indicators — red for power, blue for relay status

• Standalone operation — no microcontroller required for basic light-activated switching

• Four mounting holes (3mm) — easy panel or enclosure installation

• Screw terminal blocks — secure wiring for power and loads

• Compact form factor — approx. 50mm × 26mm × 19mm

Technical Parameters