This circuit was found in an American documentation from the 80's. The components are from that time. It provides a variable output of 18 to 30 V with a current of 200 mA.
The filter shown in the figure, using only an operational amplifier, is characterized by allowing 1...
This circuit converts pulse frequency to current, which is indicated on an analog instrument. The...
This circuit, found in documentation from the 1980s, uses an operational amplifier from that time....