Solid state relay.

摘要

A solid state relay comprises a radiator (203), a control circuit block (210) and a power circuit cartridge (202). The radiator (203) has a base portion (203b) and fins (203a) extending from this base portion. The control circuit block (210) includes a printed circuit board (227) having a pair of input terminals (5), a pair of load terminals (6), and a control circuit (9). The control circuit block is attached to a front surface of the base portion of the radiator. The power circuit cartridge (202) includes therein a power semiconductor element (11) which is turned on or off by the control circuit (9) in the control circuit block, an absorber (12) which is connected between the pair of load terminals (6), and a heat radiating plate (266) to radiate a heat of the power semiconductor element (11). The power circuit cartridge (202) is detachably attached to the radiator so as to be electrically connected to the control circuit block. The control circuit block has a box-shaped enclosing portion (221c) to enclose the printed circuit board. At least two groove portions (296) are formed on the front surface of the base portion of the radiator. The box-shaped enclosing portion (221c) is inserted into one of said groove portions and in this inserting state, the printed circuit board is vertical for the base portion front surface. The power circuit cartridge is inserted into the other groove portion.