Car type relay connection : training course / polarized relay with freewwheel diode.
The relay is regularly used in on-board electrical installations. (Light vehicle, heavy goods vehicles, public works equipment, agricultural equipment, etc.
The relays separate the control circuits from the power circuits. The objective is to use a control switch deported to the dashboard to control a power relay. The relay, once excited by the switch, powers a high-powered receiver (such as a headlight).
The relay can also be used to create automatisms.