The role and symbol of the intermediate relay

The role of the intermediate relay: it is to play the role of conversion and transmission of control signals, that is, its input signal is the coil power on and off signal, while the output signal is the contact action of the intermediate relay. In essence, it is a kind of voltage relay, which has the characteristics of a large number of contacts (there can be six pairs or more). The contact can withstand a large current (range is 5A-10A of rated flow), and the action is more sensitive (action time range is less than 0.05s). The middle relay symbol is shown in the figure below.