This circuit was found in a 80s American documentation. The zener diodes determine the points of action of each stage and the transistors can be general purpose types.
Found in a 1995 Hands-On Electronics, this circuit generates a sinusoidal signal whose frequency...
This passive loudness control was obtained in an old publication. The critical component is the...
Large-surface diodes and even neon lamps can function as radiation sensors. The circuit shown in...