The circuit is from 1994 National Semiconductor documentation. The component is not easy to obtain, but there are equivalents that can be searched.
With this circuit, from an old operational datasheet, it is possible to measure the CMRR,...
Found in a Popular Electronics from the 90s, this circuit can be adapted to use LEDs. The power...
The circuits shown in the figure, that of an infrared video signal transmitter and receiver, were...