We find this encoding circuit in an American 1980s amateur radio documentation. The circuit can be implemented with equivalent modern components.
This two competitor version of the game is shown below and uses lamps as indicators. You can...
The first circuit we present consists of a step-down DC / DC converter with input voltage from 2.5 to...
) This is the original application of the National Semiconductor LM3909 low consumption pulsator. The LED...