100 mA regulator (CB21168E)

This 2-terminal regulator was obtained from a 1990s National Semiconductor manual. The components admit modern equivalents.

Electronic doorbell (CB25029E)
This circuit was found in the April 1984 issue of Radio Electronics magazine. The integrated...
AC to DC converter (CB14124E)
The presented circuit was found in the National Semiconductor's Linear Applications Handbook from...
Power Oscillator 741 (CB15616E)
This circuit is basically the same as the previous configuration (CB15616E) with a power stage with...