NOR gate with the 7400 (CB22406E)

The configuration below shows how to use the 7400 as a NOR function. The circuit is TTL and must be powered with 5V.

RIAA Transistor Amplifier (CB19171E)
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
Instrument Scale Modifier (CB4159E)
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
Chime delay (CB9679E)
Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime...