This TTL circuit has a well-known configuration, having been found in a Radio Electronics magazine from December 1980. The power supply must be 5 V.
The sensor in this circuit is a BA315 diode. Other diodes can be experimented, but this is one...
This circuit tunes MW radios to apply the signal to a good audio amplifier. The circuit is from an...
This circuit can use both separate LEDs and a common cathode display when one segment indicates...