Two-tone solar buzzer (CB20493E)

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

600 mA Step down DC to DC Converter (CB15574E)
The circuit shown in the figure is suggested by Intersil (www.intersil.com) and makes use of the...
Negative Ion Generator (CB21000E)
This circuit was obtained from American documentation from the 1990s. The transformer can be a car...
Alternating Voltage Regulator (CB1581E )
National Semiconductor suggests the figure circuit for stabilizing the peak value of an...