Magnetic sensing in clothes dryers

Like many modern appliances, clothes dryer designed with microprocessor based controllers allow the use of a variety of sensors to ensure proper, safe, and energy efficient operation. Littelfuse’s magnetic sensor products help make these appliances as reliable as ever.

Reed sensors and Hall Effect sensors are both very reliable and will operate over millions of cycles with long term integrity when used with microprocessor electrical loads.

Both reed and Hall Effect devices are operated by a magnetic field.

Reed switches and sensors consume no power, while Hall Effect devices are semiconductors and will consume a small amount of current in both the activated and de-activated state.

Dryer door closure sensor
The typical dryer in past designs had used a mechanical pushbutton switch as the closure switch. However, these mechanical switches within this warm and humid dryer environment can encounter problems with oxidizing contacts at this low switching voltage. This can cause erratic switching continuity. A reed sensor or Hall Effect sensor will overcome this issue since the reed switch is hermetically sealed and the Hall is an IC.

The dryer door magnetic sensor sends a signal to the microcontroller that the door is closed or open. The non-contacting sensor can either be a reed or Hall Effect digital signal device.

The reed sensor or Hall Effect is fixed on the outer frame while the actuator/magnet would be placed within the dryer door.

Find out more here.