Two-tone solar buzzer (CB20493E)

This circuit was found in a 1991 publication. The transistor can be a general-purpose type.

Distribution Amplifier (CB19012E)
This amplifier for distributing audio signals appears in other articles on this website and even...
MOSFET Parameter Meter (CB21398E)
This circuit was found in a 1964 MOSFET applications manual. The circuit uses period general...
Time Light (CB18745E)
This circuit works only with incandescent lamps, timing its activation at intervals that depend on C1....