Circuit structure that connects an electronic part to a conducting path

There is provided a circuit structure in which a control circuit is formed on the upper surface of an insulating plate by control busbars , and a power circuit is formed on the lower surface of the insulating plate by power busbars . By this configuration, the circuit structure can be made small in size as compared with the case where the control circuit and the power circuit are formed on separate circuit boards. Also, the insulating plate is formed with an opening , and a power busbar is positioned over the opening . In the opening , a terminal B of a relay is positioned, and is connected to the power busbar . Thereby, the connecting work process can be simplified as compared with the case where the power circuit and the terminal B of the relay are connected to each other, for example, by a jumper wire.