Found in American documentation from the 1990s, this circuit receives modulated infrared signals. The baud rate depends on the operative used. The main application is like audio link.
This shield circuit for lamps and other charges was found in a Popular Electronics from the 90's....
This setting applies to virtually any photo transistor and any operational amplifier. The power...
This circuit is from a 1975 technical documentation on filters. The FET can be a BF245 and the...