Optically coupled device with high current protection

摘要

An optically coupled device is composed of input and output sides. The input side includes a light-emitting element while the output side includes: an element for driving; a light-receiving element for receiving light from the light-emitting element to turn on the element for driving; and a resistance element having a positive or negative temperature-coefficient and connected in series with the light-receiving element. By the above configuration, the optically coupled device by itself is constructed to prevent rush-current from occurring and to the device itself from being excessively heated due to excessive current.