Magnetic Reed Switch Circuit

A switch with one magnetic reed and one non magnetic one.

Magnetic reed switch circuit.

Here is the circuit diagram of a magnetic proximity switch that finds a lot of applications in many fields the circuit is based on a magnetic reed switch s1 as the proximity sensor a monostable multivibrator based on ne555 ic1 and a toggle flip flop based on cd4013 ic2 does the rest of the circuit. However for an application such as a door security sensor the reed switch needs a protective shell housing for handling and mounting. Reed switch also called reed relay is a low current magnetic switch with a concealed pair of contacts that close and open in response to magnetic field near it. The circuit then starts oscillating and the loudspeaker convey a loud alarm sound.

Normally closed reed switch by anthony j. There are 2 basic types of reed switches. Sw1 opens whenever the magnet looses its contact with the reed switch. When this device exposed to the magnetic field then ferrous materials inside reed switch pull together and switch closes.

It takes negligible power to pulse the coils of latching reed relays. There are all sorts of creative applications for reed switches. Introduction to reed switches magnets and magnetic fields by stephen day. A bare reed switch can easily be mounted on circuit boards.

The contacts are concealed inside a glass tube and its ends terminated out of the glass tube for external connection. There are normally open reed switches and normally closed reed switches. Generally a 2 msec pulse supplied at the relay nominal voltage is enough to change the state of the relay contacts. The following magnetic reed switch alarm is made to be a home and handbag alarm that can be put on door on home windows or put it inside a bag a reed switch and a magnet form this circuit.

Describes various ways of making a normally closed switch. Simply put it is a magnetic switch. When a magnet is reached in proximity of s1 it closes to give a negative. This alarm circuit constructed by.

Wilkis october 17 1967. They re perfect for any projects that require non contact control. When there is no magnetic field then ferrous materials separate and switch open. 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.

Quite a neat summary of how reed switches are used in. The contacts are usually normally open closing when a magnetic field is present or they may be. The reed switch will remain in its closed state until another magnetic pulse with the opposite magnetic polarity is applied. These packages offer resistance to mechanical stress by protecting the bare glass of the reed switch.

How to build a reed switch circuit. In its simplest and most common form it consists of a pair of ferromagnetic flexible metal contacts in a hermetically sealed glass envelope.