This circuit was found in the October 1994 issue of Electronics Now magazine. The 40446 IC is a PLL that is not very common today. The circuit has two types of effects.
Found on a 1969 EDN this circuit switches a current from a digital control signal. The impedance...
This circuit was found in an old Radio Electronics, but can still be assembled as the components are...
Found in a 1970 documentation this circuit makes use of components still common in the market. The...