What Is a Magnetic Switch?

A bit of judiciously applied solder is helpful when making a magnetic switch.
••• soldering image by Bube from Fotolia.com

A magnetic switch is just like a light switch: it turns a circuit on or off depending on what position the arm of the switch is in. The only difference is that a magnetic switch is operated by a magnet, rather than your fingers.

Parts

A magnetic switch has an arm of conductive metal that is fixed on one end, two switch contacts that are near the free end of the arm, and a movable magnet. Some also have two magnetic clamps.

Types

There are three types of magnetic switch. Normally open monostable switches remain connected only when the movable magnet is near the arm. Normally closed monostable switches remain disconnected only when the magnet is near the arm. Bistable switches change position from open to closed whenever the magnet moves, but remain in their last position even when the magnet moves away.

How They Work

When the movable magnet comes close enough to the free end of the arm it attracts the metal arm to it. This brings the end of the arm into contact with (or away from contact with) the switch contacts. Bistable switches have magnetic clamps that hold the arm in place after the magnet moves.

Related Articles

Uses for Permanent Magnets
What Is an Electric Relay?
How to Build an Electromagnet
Parts of a Motor
How to Create a Powerful Magnetic Field
How Does a Latching Relay Work?
The Uses of Different Shaped Magnets
How to Make an Electromagnet From a 9V Battery
What Are the Functions of a Magnetic Contactor?
Uses for Permanent Magnets
How to Magnetize an Iron Rod
Science Project on an Electric Bell
How Does a Solenoid Work?
Types of Metals That Attract Magnets
What Types of Metal are Attracted to Magnets?
What Is a Ferrite Clamp?
Science Facts About Magnets for Kids
How to Build a Super Magnet
Modern Day Uses for Magnets
How to Remagnetize Old Magnets Using Neodymium Magnets
How Do Magnets Attract & Repel?