Introduction

Some top loading clothes washers have the drum rotating perpendicular to the door and some have the drum rotating in the same plane as the top.  In the former of the two rotating directions, opening the top can be very dangerous if the drum continues to rotate.  In the case of the latter rotating drum is less dangerous, but trouble may still occur.  To avoid law suits, appliance designers are using a reed sensor...

Full application write-up: Reed Sensor Detects Open/Closed Lid in Washing Machines

Features

• Magnet and Reed Sensor are isolated and have no physical contact by typically having the magnet mounted to the top lid of the washing machine, and the Reed Sensor is mounted on the chassis of the washing machine strategically placed such that the magnetic field of magnet will be sensed when the top is opened and closed.
• The reed switch used in the Reed Sensor is hermetically sealed and is therefore not sensitive to rough, wet, moist, high temperature environments
• The magnet is not affected by its environment
• Tens of millions of reliable operations
• Cylindrical hole and screw fastening mounting
• Contacts dynamically tested