Found in a 1990s American documentation, this circuit provides an output voltage approximately 4 times that of the input voltage. Diodes are general-purpose types.
This circuit can also be used as a simple thermoscope (temperature changes indicator) in the...
We show in the figure how to implement a current monitor circuit using only an operational...
This circuit was found on an old EDN and can be used as a shield. Optical couplers are from the...