This TTL circuit uses LED indicators and must be powered by a voltage of 5 V. The capacitor determines the speed of the draw. We found it in documentation from the 90s.
This circuit appears in several configurations in this site. This is from American documentation from...
Using two LM377s, this amplifier provides a few watts of audio in a low impedance speaker and the power...
Found in a 1969 EEE, this circuit converts input pulses into linear sawtooth signals, as shown in...