This filter configuration used in telecommunications uses 4 Jaumnann crystals that are interesting for low and medium frequencies. The circuit is from an 80's documentation.
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...