This 1980s documentation circuit uses a 741 in a different high-speed comparator configuration. The feed must be symmetrical. The diode is general-purpose.
This circuit was found in an article in Radio Electronics magazine. The issue is from July 1992...
This circuit works both as a preamplifier and activates a relay when speaking in front of the...
We found this code switch circuit in the January 1999 Electronics Now magazine. Some of the...