This circuit was obtained in an American documentation of 1964. The transistors are of the time. The circuit includes a counter circuit.
This circuit uses an LM339 and was found in the July 1995 Electronics Now magazine. The LED lights...
We found this circuit in an old Mullard (Philips) documentation on the 555 and 556 integrated circuit...
This circuit was obtained from an 80's documentation from General Electric. The circuit uses an...