This circuit was originally recommended to give the call signal on intercoms. However, it can be used with other applications. The circuit is from 1978 documentation. The transistor may be the BC548.
This is a traditional configuration of a series regulator with zeners, found in a documentation from the...
This circuit is connected to the inputs X and Y of an oscilloscope to display the characteristic curve of a...
The circuit presented is from the Linear Applications Handbook of the National Semiconductor of...