SOLID STATE RELAY

摘要

A solid state relay comprises a radiator (3), a control circuit block (10) and a power circuit cartridge (2). The radiator (3) has a base portion (3b) and a plurality of fins (3a) extending from the base portion. The control circuit block (10) has a pair of input terminals (5) and a pair of load terminals (6) and is attached to a front surface of the base portion of the radiator. The power circuit cartridge (2) includes therein a power semiconductor element (11) which is turned on or off by a control circuit (9) in the control circuit block (10), an absorber (12) which is connected between the pair of load terminals (6), and a heat rediating plate (67) to radiate a heat of said power semiconductor element (11). The power circuit cartridge (2) is detachably attached to the control circuit block so as to be electrically connected thereto. A through space (140) is formed in the control circuit block so as to pierce from a front surface of the control circuit block to the front surface of the base portion of the radiator. The power circuit cartridge is inserted into the through space. The heat radiating plate of the power circuit cartridge is joined to almost a central portion of the base portion front surface of the radiator.