This circuit was found in a 80s American documentation. The zener diodes determine the points of action of each stage and the transistors can be general purpose types.
The circuit in the figure is a current regulator with adjustment in the range of 0 to 3 amps. The...
This filter with the operational 741 passes the frequency range between 300 Hz and 3,400 Hz. This...
Taken from an Electronics Now from the 90s, this circuit generates signals whose frequency depends on...