The setting of this power supply is only 0.1%. We found it in a 1969 US documentation. Transistors may be current equivalents. Note the use of symmetrical power supply.
This circuit generates a rectangular signal whose frequency depends on the electrolytic...
This circuit was found in an old publicatio n from the year 1958. The circuit controls an external load by...
This circuit that converts very low currents into voltage was obtained in the 80's used component...