The diverse Allen-Bradley offering serves the full spectrum of customer needs, from light-duty packaging applications to the punishing environments on automotive welding equipment or the harsh washdowns in food processing plants.
Presence Sensors detect the location of objects or personnel near hazardous areas. The Types are …
Radio Frequency Identification Devices (RFID), Inductive Proximity Sensors, Capacitive Proximity Sensors, Ultrasonic Sensors, Photoelectric Sensors and Safety Devices.
Products include Reed Switches, Proximity Switches, Shock Sensors.
“The reed switch was invented by Dr. W. B. Ellwood at Bell Telephone Laboratories in 1936. The first application was made during 1938 when the reed switch was used as a selector switch in coaxial carrier equipment. Later, improvements of the reed switches were made in parallel with the development of the telecommunications technology.”
“Structure and Operating Principles As shown in Figure 3.1, the reed switches comprise two ferromagnetic reeds placed with a gap in between and hermetically sealed in a glass tube. The glass tube is filled with inert gas to prevent the activation of the contacts. The surfaces of the reed contacts are plated with rhodium.”
from The Oki Reed Catalog
OKI Introduces High Switching Current Reed Switch This device achieves industry-first 5 A maximum carry current and 2 A maximum switching current with glass tube length of 16.5 mm