This circuit is from the 1982 SGS Linear Circuits Manual. The circuit provides currents from 35 mA to 1.5 mA set at P1 and Vref voltages at 26 V set at P2.
The transistors are 2N918, 2N3464 and other RF equivalents of the time for Q1. For Q2, 2N3399, 2N2894...
This circuit, which can be used as a shield, was found in a 90s Electronic Design. The circuit...
This interesting intercom circuit was obtained from an Argentine publication from the 1970s....