Reed Switch Sensor Circuit

In its simplest and most common form it consists of a pair of ferromagnetic flexible metal contacts in a hermetically sealed glass envelope.

Reed switch sensor circuit.

The reed switch is an electrical switch operated by an applied magnetic field it was invented at bell telephone laboratories in 1936 by walter b. The contacts are usually normally open closing when a magnetic field is present or they may be. Capacitive loads as low as 50 pf which could even be caused by the wiring between the reed switch and the load could enough to reduce the life. Simply put it is a magnetic switch.

In case a capacitor is connected in series or in parallel with a reed switch in a closed circuit the inrush current which flows during charge and discharge of the capacitor will cause deterioration of the reed contacts. What problem do reed switches solve. However reed switches can be fragile to use directly hence this module can make it easier to handle and mount the sensor in various applications. A spring makes it pop back out again when you take your finger away.

A reed switch switches a current on the same way but a magnet provides the pushing pressure instead of your finger. Reed sensors can be used in many applications where contactless on off is required. A reed switch is a very basic 2 lead switch that is switched on by a magnet being brought into the vicinity of the switch. The pcb tracks can be designed in such a way that a full tank gives high resistance and an empty tank gives low resistance or vice versa.

Reed switches and reed sensors are used along with resistors or special reed sensors with integrated resistor to give out a potentiometric feed back across two outputs as a foamed magnetic float moves along the pcb s length. A push to make switch makes a connection and completes a circuit when you push it in. How to build a reed switch circuit.