LT123 Low Voltage Linear Regulator (CB4399E)

The circuit presented is from the 1993 Linear Technology Applications. The components used were common at the time.

Polarity Test (CB14701E)
This polarity test or indicator indicates the polarity of a power line by LEDs. The circuit is...
Digital clock MM53149 (CB24361E)
This is the circuit of a digital clock published in the January 1975 issue of Radio Electronics magazine....
Powergrid timer (CB9364E)
Found in an Elektor from the 90s, this circuit can be powered directly by the power grid. The...