1. Field of the Invention
The present invention relates to a control apparatus for controlling an engage switch of a starter for starting an internal combustion engine, and particularly to a structure of a starter relay having a control circuit board.
2. Description of Related Art
A starter for starting an internal combustion engine is provided with an engage switch including a main switch and a pinion transfer mechanism, and a starter relay for performing ON/OFF control of a power supply to the engage switch. The supply of power to the starter relay includes two types according to a circuit structure of a system, in which an earth system is a body earth type and is an earth float type.
In recent years, control for various safeties and parts protection is introduced into a vehicle, and a control circuit board for protection is provided also in a start circuit of a starter, and this control circuit board is generally provided in a starter relay (see, for example, patent document 1: JP-A-2000-87831 (page 3, FIG. 6)). Also with respect to the starter relay provided with the control circuit board as stated above (since the starter relay includes the control circuit, it will be referred to as the starter control apparatus), it becomes necessary to properly use the body earth type and the earth float type depending on a circuit structure.
The patent document 1 discloses that a control circuit board (protection circuit in the patent document 1) is incorporated in the inside of a cap having a terminal of a starter control apparatus (auxiliary switch in the patent document 1), and such structure is effective in miniaturization.
In the case where the control circuit board is provided in the inside of the starter control apparatus, it is concurrently fastened by a screw to attach a cap to a case for miniaturization and simplification of the structure. In the control circuit board of the body earth type, an earth pattern is provided in a thread fastening portion, so that the connection of the earth is performed at the same time as the screw fixation of the control circuit board, and on the other hand, in the control circuit board of the earth float type, a land for the earth is not provided at the thread fastening portion, so that both are properly used. However, although both have the same circuit content except for the existence of the land for the earth, two kinds of control circuit boards are required for setting the body earth type and the earth float type, and there are problems that the number of parts is increased, and erroneous fitting is performed since discrimination between both is difficult.