In this circuit the LED lights up when the voltage drops below the value set in the trimpot. The transistors can be the BC548. The circuit is from a 1999 American publication.
This circuit was found in a General Electric documentation from 1965. The circuit is full wave for...
We found this circuit in the Texas Instruments' Linear Circuits Applications. It uses an...
In the presented circuit it is possible to vary the frequency of the rectangular signal produced. This...