Found in the March 1989 issue of Radio Electronics magazine, this circuit is used to test printer and other cables. The indication is made by LEDs.
This decoder TTL circuit for 15-channel remote control was found in Selezione Radio, Italian...
This is the circuit of a sensitive voltmeter using a difficult-to-obtain 5 uA full-scale...
This circuit compares two light intensities, providing the indication on an analog instrument. The...