Railon

Meet Railon, a metal bar who makes a voltage simply by sliding through a magnetic field.

Picture a metal bar resting across two parallel rails, with the rails joined at one end to complete a circuit. A magnetic field points straight through the loop. When the bar slides along the rails, the free charges inside it move through the field and feel a magnetic force along the length of the bar.

That force pushes charge around the circuit, producing an electromotive force ε = BLv. In a field of 0.5 T, a bar 0.2 m long moving at 3 m/s produces 0.5 × 0.2 × 3 = 0.3 V.

Push the bar faster or use a stronger field and the voltage grows. Stop the bar and the voltage disappears. The current that flows also feels a force that opposes the motion, so you have to keep pushing to keep making electricity, just as energy conservation demands.

Every generator, from a bicycle dynamo to a power station turbine, works on this same idea of moving a conductor through a magnetic field.