This sound effect circuit is from a Radio Electronics magazine from December 1969. The transistors support equivalents and the power is provided by a battery to reduce the possibility of noise.
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime...