So, car relays can be seen as a collection of two parts: the control circuit for coil operation and the main circuit for contact operation. In the control circuit of a relay, there is only a small working current. This is because the contact capacity of the operating switch is small and cannot be used to directly control loads with high electricity consumption. It can only be controlled through the contacts of the relay to make and break.

In addition, automotive relays are also widely used in scenarios such as automatic regulation, safety protection, and conversion circuits. In cars, relays usually need to be able to withstand harsh environmental conditions such as high and low temperatures, sand and dust, water, salt, oil, etc., as well as vibration and impact.