The most common method of making magnets today involves placing metal in a magnetic field. CRStocker/Shutterstock To make a permanent magnet, all you have to do is encourage the magnetic domains in a piece of metal to point in the same direction. That's what happens when you rub a needl...
Electromechanical relays provide a good all-around solution, although they have limitations in package size, switching speed, and mechanical lifetime. Reed relays improve on package size, density, and speed but are less robust in situations where surge currents may be present. SSRs are a nice alt...
How to measure magnetic field strength of permanent magnet. What causes a magnetic field? Does Earth have a magnetic field? How do electrons create a magnetic field? What is magnetic field strength? How can a magnetic field produce an electric current?
Traditional electric motors use electromagnetism: when an electric current flows through coils inside them, it creates a temporary magnetic force that pushes against a ring of permanent magnets, making the motor shaft rotate. Hydraulic motors are more like pumps working in reverse. In one example, ...
As the permanent magnets on the outer rotor sweep past them, the Hall-effect sensors figure out where the north and south magnetic poles of the rotor are and which coils to activate to make it keep spinning. The trouble with this is that it means the motor does need an electronic circuit...
How to Choose Permanent Magnets? 3 KEY PARAMETERS TO CONSIDER WHEN CHOOSING A PERMANENT MAGNET Every type of permanent magnet has a unique set of characteristics that can affect how is performs in various applications. When evaluating magnet options for your project, pay attention to the following...
magnets and a conductor. The conductor is typically a coiled wire. Inside the generator, the shaft connects to an assembly of permanent magnets that surrounds the coil of wire. In electromagnetic induction, if you have a conductor surrounded by magnets, and one of those parts is rotating ...
Permanent magnet bearings are used in high rotating speed systems. Their stiffness must be as high as possible for a given airgap and a minimum radial dimension. Several configurations have been previously proposed to maximize the ratio "stiffness / magnet volume". In this paper we show that a...
If the car travels faster, the permanent magnet inside the speed cup will rotate faster, which creates a stronger magnetic field, larger eddy currents and a greater deflection of the speedometer needle. If the car slows down, the magnet inside the cup rotates more slowly, which reduces the ...
In a rollercoaster ride, you might have a series of powerful, permanent magnets permanently mounted at the end of the track, which produce eddy currents in pieces of metal mounted on the side of the cars as they whistle past. The cars move freely along the track until they reach the very...