Found in a Popular Electronics from the 90s, this circuit is intended to measure the harmonic distortion of an audio signal. The circuit can be tuned between 970 and 1030 Hz.
We found this circuit in the April 1975 Radio Electronics magazine. The circuit has a latch and...
We found this sophisticated home alarm in a 1994 documentation. The circuit supports sensors of...
This circuit was found in the 1991 Electronics Experimenter's Handbook. It activates a relay when...