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 amplifier from 100 to 150mW was found in a Japanese documentation from 1967. The circuit uses...
This circuit is from a manual of JFETs and can be implemented with the BF245 and for the bipolar...
This source of some amps for voltages up to 40 V was found in an Italian magazine Elettronica...