YJJ LTH-1550-01 Photoelectric Sensor Photoelectric Switch Reflective Photoelectric Switch

Product Description:

YJJ LTH-1550-01 Photoelectric Sensor - Photoelectric Switch - Reflective Photoelectric Switch - Used in Automated Equipment

Features:

I. Basic Product Information
Brand: LITEON (Taiwan original factory)
Model: LTH-1550-01
Type: Reflective Photoelectric Sensor (Reflective Photoelectric Interrupter)
Package: DIP4 Surface Mount 4-pin, standard 2.54mm pitch
Standard Sensing Distance: 3.81mm (Optimal Detection Range)
Certification: Compliant with RoHS environmental standards, suitable for industrial/ consumer electronics
II. Internal Structure Principle
Integrated of two components in one unit:
940nm Infrared Emitting LED (Emit Infrared Light)
NPN Phototransistor (Receive Reflected Infrared Light)
The emission and reception windows are arranged in the same direction and side by side. When an object enters the 3.81mm detection range, the infrared light is reflected to the receiving tube, the transistor conducts, the level changes, achieving non-contact presence detection. The black shell comes with a shading structure, resisting environmental stray light interference.
III. Core Electrical Parameters
Limiting Rated Values
Table
Parameter Specification
LED Forward Current If Maximum 60mA
LED Reverse Voltage Vr 5V
LED Forward Drop Vf Typical 1.2V
Phototransistor Collector Current Ic Maximum 20mA
Collector-Emitter Voltage Vceo 30V
Operating Temperature -25℃ ~ +85℃
Storage Temperature -55℃ ~ +110℃
Electrical Characteristics
Current Transfer Ratio CTR: 50% ~ 600%
Fast response speed, suitable for high-speed counting, position detection
NPN Collector Open-Loop Output, can be directly paired with single-chip microcontroller IO
IV. 4-Pin Definition (Printed Characters Viewed from Below, Pins from Left to Right)
Pin 1: LED Anode (LED+)
Pin 2: LED Cathode (LED- / GND)
Pin 3: Phototransistor Emitter (E, Common Ground GND)
Pin 4: Phototransistor Collector (C, Signal Output)
Simple Wiring Scheme (ESP32 / Single-Chip Microcontroller General)
LED + Connected to 220Ω Current Limiting Resistor to 3.3V/5V; LED - Connected to GND
Phototransistor E Connected to GND; Collector C Connected to IO with 10K Resistor Pull-Up
When an object approaches, IO outputs a low level; no object is high level
V. Product Core Advantages
Integrated factory calibration, no need for manual adjustment of light path, plug-and-play
No mechanical contacts, lifespan far exceeds mechanical microswitches
Compact size, surface mount to PCB, suitable for internal installation in small devices
Black shading shell, does not trigger in indoor lighting, weak natural light
Wide temperature range operation, compatible with industrial equipment, office equipment, small appliances
VI. Typical Application Scenarios
Office Equipment: Paper detection, paper counting, paper jam detection in printers / copiers
Automation Equipment: Presence and absence detection, limit position detection of small assembly lines
Smart Hardware: Door detection of storage bins, lid opening detection of trash cans, simple liquid level detection
Financial Equipment: ATM, cash register paper currency recognition, bill counting

Specifications: