The figure shows how to use an operational circuit as a voltage divider. The circuit is from a Radio Electronics magazine from June 1986. The reference voltage is given by a zener diode.
Found in Popular Electronics from the 90s, this circuit uses a 2N2646 and a general-purpose transistor...
The crystal frequency of this circuit found in an American documentation is limited only by the...
These two circuits were found in Radio Electronics magazine from February 1960. The transistor is a power...