Found in American documentation, this circuit for modulated infrared signals can be tuned to a certain frequency. The photodiode can be of any type.
This sensitive receiver with earphone was found in an English documentation from 1963. The...
Found in a 1980s American documentation, this circuit inhibits ignition. The circuit is valid for...
This crystal-controlled circuit was obtained from a 1980s documentation. The power supply should be 5...