Overview

This Slot Sensor Module is a compact and reliable photoelectric sensor that uses infrared technology along with an LM393 comparator to detect object presence or movement within its 15mm-wide slot. It is ideal for applications like speed counting, motor encoders, and general object detection.

Features

• 15mm wide sensing slot for larger encoder wheels or object detection.

• Built-in LM393 dual comparator provides clean digital output signals.

• Infrared emitter and phototransistor are positioned facing each other inside the slot.

• Digital output changes when the IR beam is interrupted.

• Sensitivity can be adjusted using the onboard potentiometer.

• Includes power LED and signal status LED indicators.

• Compatible with 3.3V and 5V systems.

Technical Details

• Operating voltage: 3.3V to 5V DC

• Output type: Digital (0 or 1)

• Sensor type: Infrared with LM393 comparator

• Slot width: 15mm

• Typical size: 32mm x 14mm x 18mm

Pin Descriptions

• VCC: Connect to 3.3V or 5V supply

• GND: Connect to ground

• OUT: Digital signal output pin

Working Principle

An infrared LED emits light across the slot. If no object is blocking the light, the output remains high. When an object enters the slot and interrupts the beam, the phototransistor detects the absence of light and triggers the comparator, changing the output to low. The onboard potentiometer allows you to adjust the detection sensitivity.

Common Applications

• Wheel encoder for motors

• Object counter on conveyor systems

• Robotic arm limit detection

• CNC or 3D printer endstop sensors

• DIY automation projects

Tutorials:

• How to measure speed of gear motor (teachmemicro)