This circuit for an optical audio link using LED or LASER was found in a 90s QST magazine. The circuit can use operational amplifiers like the 741.
MCP19124/5 Contains Independent Voltage and Current Control Loops Plus a Full Suite of...
A flash of light on one sensor or the touch of your fingers on the other type of sensor will turn...
This 1-transistor timer was published in Radio Electronics magazine in December 1960. The circuit has...