This simple logic test circuit with 3 LEDs was found in October 1985 Radio Electronics magazine. The power supply is according to the logic, and this version is indicated for TTL.
We found this circuit in an American publication from the 90s. The power must be 2 V more than the...
Found in old American documentation, this circuit makes use of operational amplifiers from the 70s...
This linear LED scale circuit was found in the February 1992 issue of Radio Electronics magazine. Note...