Detailed explanation of light spot switch technology

1、 Overview of Light Point Switch

Optical Switch is an electronic component based on the principle of photoelectric effect, which triggers the circuit on and off through optical signals to achieve non-contact detection and control. Its core function is to convert optical signals into electrical signals or control circuit states through optical path changes, widely used in industrial automation, communication, medical equipment and other fields.

2、 Technical characteristics

1. Working principle

Photoelectric conversion: using photosensitive elements (such as photodiodes, photoresistors) to receive light signals and trigger internal circuits.

Optical path control: By blocking or reflecting to change the optical path, trigger the switch action.

Signal processing: Built in amplifier or logic circuit to enhance signal stability.

2. Core parameters

Detection distance: 0.1mm to 50m (varies by type).

Response time: 0.1ms to 10ms, high-speed models can reach microsecond level.

Output type: NPN/PNP transistor, relay, analog signal (4-20mA/0-10V).

Working voltage: DC 5-240V， Partially supports AC 100-240V.

Protection level: IP67/IP68 (dustproof and waterproof), suitable for harsh environments.

3. Optical characteristics

Light source types: infrared (850nm), visible light (red/green), laser.

Beam mode: focused beam (high precision), diffused beam (wide range detection).

Anti interference capability: Modulation optical frequency technology (to avoid environmental light interference).

3、 Product type

1. Classify by testing method

Type, principle, characteristics, typical applications

The separation and detection distance between the transmitter and receiver are long, and the accuracy of object counting on the conveyor belt is high

Reflective transmission and reception integrated, reflector plate reflection installation is simple, low cost, automatic door sensing

Diffuse reflection utilizes the reflected light on the surface of an object without the need for a reflection plate, adapting to complex shaped robot grasping and positioning

Fiber optic transmission of optical signals through optical fibers, resistant to electromagnetic interference, high temperature and strong electromagnetic environment/narrow space

2. Classify by output form

Digital switch type: ON/OFF signal.

Analog output type: continuous distance/light intensity signal.

Logic programming type: can set parameters such as threshold and delay.

4、 Product Material and Structure

1. Shell material

Material Characteristics Applicable Scenarios

Engineering plastic ABS/PC, lightweight, corrosion-resistant for conventional industrial environments

Metal shell made of aluminum alloy/stainless steel, resistant to impact, high temperature, and high vibration environments

Ceramic packaging with high temperature resistance and good insulation for high-frequency communication equipment

2. Optical components

Lens: Glass or polycarbonate, determining the beam focusing characteristics.

Filter: Suppresses stray light and improves signal-to-noise ratio.

Fiber optic materials: quartz (high temperature resistance), plastic (low-cost short distance).

3. Internal circuit

Photosensitive chip: Si based/PIN photodiode.

Signal processing IC: integrates amplification, filtering, and logic control functions.

Protection design: TVS diode (anti surge), EMI shielding layer.

5、 Performance indicators

1. Environmental adaptability

Temperature range: -40 ℃ to+85 ℃ (industrial grade), -20 ℃ to+70 ℃ (commercial grade).

Humidity tolerance: 95% RH (non condensing).

Anti vibration: 10-55Hz, amplitude 1.5mm.

2. Electrical performance

Repetition accuracy: ± 0.1mm (high-precision type).

Insulation resistance: ≥ 100M Ω (500V DC).

Life cycle: Mechanical components ≥ 10 ^ 7 times, electronic components ≥ 50000 hours.

6、 Application Fields

1. Industrial automation

Production line inspection: Check for the presence of parts and correct their position.

Packaging machinery: film correction, bottle cap inspection.

AGV navigation: path recognition, obstacle avoidance.

2. Smart devices

Consumer electronics: smartphone proximity sensing, printer paper detection.

Medical equipment: infusion pump liquid level monitoring, surgical robot positioning.

3. Special environment

Energy industry: Oil tank level monitoring (explosion-proof type).

Rail transit: door safety inspection (anti vibration design).

7、 Welding and installation parameters

1. PCB soldering requirements

Precautions for Recommended Parameter Values

Soldering temperature 260 ± 5 ℃ (lead-free solder paste) to avoid damaging components beyond 300 ℃

Welding time 3-5 seconds (reflow soldering) preheating rate ≤ 3 ℃/second

Pin spacing ≥ 0.5mm (anti bridging), use nitrogen protection to reduce oxidation

2. Mechanical Installation Guide

Shooting type: The optical axis deviation of the transmitter/receiver is ≤ 1 °.

Reflective: The parallelism error between the reflective plate and the detection surface is less than 2 °.

Protective measures: Install a light shield (in strong light environment) and ground it (anti-static).

8、 Selection suggestions

Environmental factors: Choose metal casing and fiber optic type for high temperature environment.

Detection requirement: Laser aiming type (0.1mm accuracy) for detecting small objects.

Cost control: Short distance detection can choose diffuse reflection (eliminating the cost of reflection plates).