Found in Popular Elecronics, this configuration also appears in this section, but obtained from other sources. The 14.4 V supply allows the circuit to be used in the car.
Found in old documentation, this circuit uses components that are still common on the market. The...
This circuit is from the American magazine that no longer exists Science & Electronics,...
This circuit was found in a 1969 US documentation. It provides a signal that can be externally...