This circuit is from a Radio Electronics from April 1964. The circuit uses power transistors of the time, which must be mounted on a good heat radiator. Modern equivalents can be used.
This circuit is from a Radio Electronics from October 1963. The LDR and transistors are from the...
The figure shows how to use an operational circuit as a voltage divider. The circuit is from a...
This is the basic configuration of an operational amplifier as a current regulator. We found it in...