This circuit was found in the February 1970 issue of Radio Electronics magazine. The integrated circuit is a type of the time. It consists of a high-gain differential amplifier.
This circuit found in a European publication from the 1980s, is based on PLL 566. The frequencies...
The circuit shown, with the printed circuit board, was found in an article in the June 1990 issue...
In the figure we have a simple timer with two voltage comparators of the four of an LM339. The...