Flip flop rectangular generator 7400 (CB22409E)

The circuit below shows how to configure 3 gates of a 7400 to obtain a rectangular signal from a sinusoidal. The circuit must be powered by 5V.

Divide-by-8 TTL (CB238E)
This circuit uses the 7493 to divide a TTL square signal by 8. The circuit must be powered from a...
Ramp generator with integrator (CB21845E)
This circuit uses a feedback integrator. We found it in Ferranti's transistor manual from 1974....
Current shield RS232 (CB8075E)
Found in a Popular Electronics from the 9s, this circuit has output for RS-232 interfaces and current...