All Proximity sensors

1. PROXIMITY SENSORS
• Sensor jarak mengesan objek apabila objek mendekati julat
pengesanan dan sempadan sensor.
• Sensor jarak merangkumi semua sensor yang melakukan pengesanan
bukan hubungan berbanding dengan sensor seperti suis had, yang
mengesan objek dengan secara fizikal mengendalikannya.
• Sensor jarak digunakan dalam pelbagai aspek pembuatan untuk
mengesan pendekatan objek logam dan bukan logam.

2. Types of Proximity Sensors
Proximity
Sensors
Inductive
Capacitive
Ultrasonic
Optical
Reflective
Direct
Retro
Reflective
Polarized
Reflection with
reflector
Thru Beam

3. Proximity Sensors in smartphones
• Sensor jarak adalah biasa pada kebanyakan telefon pintar, yang
mempunyai skrin sentuhan. Ini adalah kerana fungsi utama sensor
jarak adalah untuk melumpuhkan acara sentuh secara tidak sengaja.
Senario yang paling biasa ialah- Telinga datang bersentuhan dengan
skrin dan menjana peristiwa sentuhan, semasa dalam panggilan.
• Jika penderia jarak dekat dengan pembesar suara, maka ia akan
mengesan sebarang objek di sekitar pembesar suara. Sekiranya ada
objek (telinga pengguna), maka peristiwa sentuhan boleh dianggap
sebagai tidak sengaja & diabaikan.

4. Inductive Proximity Sensors
• Detects Metallic objects without physical contact
• A coil and high frequency oscillator is used
• Operating distance depends on
• Coil’s size
• Target’s shape, size, material

5. Capacitive Proximity Sensors
• Detects metallic objects as well as non-metallic objects(liquid, plastic,
wooden material etc)
• Uses variation of capacitance between sensor and object
• Distance down to 1 micro inch can be measured
• All targets having dielectric constant more than air can be detected

6. Ultrasonic Proximity Sensors
• Uses ultrasonic sound wave for detection
• Used frequency is higher than audible range
• Can measure distances very accurately
• Provides good sensing for large objects with hard surface

7. Optical Proximity Sensors
• Senses any object within 10 meters range
• Uses an LED in either infrared or visible light spectrum to transmit
• Photodiode detects the light generated
• Generally light sources pulse the infra-red light on and off at a fixed
frequency.
• Sensor detects object when it disrupts light beam
• Two types- Reflective type And Thru beam type

8. CONCLUSON
• The global market for these proximity sensors is expected to grow at a
steady rate. Major industries using proximity sensors are machine
tools, woodworking machines, packaging machines and other types
of machinery.
• Further applications of are automatic door units such as garage doors
or doors inside buildings, elevator doors or doors inside railway
coaches.
• The building and automotive sector are further industries using high
volumes of proximity sensors.