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.

Precision Limiter (CB15883E)
The circuit in the figure is based on an LM101A; diodes can be replaced with equivalents. The...
Transistorized tachometer (CB9355E)
This circuit, with magnetic sensor, uses an operational amplifier of the time. The circuit is from...
Remote control analyzer (CB7812E)
Found in a 90s Popular Electronics, this circuit checks if a remote-control transmitter is...