This circuit with the LM741 operational amplifier can be applied to other operational amplifiers. We found it in the September 1989 Radio Electronics magazine.
We found this circuit in an old publication on oscilloscopes. Its purpose is to observe the Ie /...
The sensors in this alarm are reed-switches. In the diagram we have only one, but several can be...
This circuit can be controlled by an external signal which allows its use as a shield. The circuit...