This circuit works as both an injector and a signal follower. We found it in the May 1994 issue of Electronics Now. The Z1 headphone must be high impedance.
Found in an English documentation from 1989, this circuit uses components common today. The...
The LED frequency flashes depends on the value of the capacitor tested according to the table. We...
Found in a Popular Electronics from the 90s, this circuit generates a signal that depends on the...