Found in Popular Electronics from the 90s, this circuit generates signals in a frequency range set to R7 and basically determined by C1. Operational and equivalent transistors can be used.
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...