This circuit is temperature stabilized. Modern equivalent transistors can be used, and the power supply can actually be between 9 and 12 V. The circuit is from an old 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...