The working principle of the relay

The essence of the role of the relay is to use a circuit (generally small current) to control another circuit (generally large current), and this control process, the two circuits are generally isolated, its basic principle, is the use of the electromagnetic effect to control the mechanical contacts to achieve the purpose of on and off, to the coil with an iron core energized coil current generates a magnetic field - the magnetic field adsorption armature The whole process is "small current - magnetic - mechanical - large current" such a process.

Relay (English name: relay) is a kind of electric control device, is when the input quantity (excitation quantity) changes to meet the specified requirements, in the electrical output circuit so that the controlled quantity to occur a predetermined step change of a kind of electrical appliances.

It has an interactive relationship between the control system (also known as input circuit) and the controlled system (also known as output circuit). Usually used in automated control circuits, it is actually a small current to control the operation of the large current of an "automatic switch.

Therefore, it plays the role of automatic adjustment, safety protection, and circuit conversion in the circuit.