Found in Philips' 90s documentation, this small source can use modern transistors like the BD135 for TR4 and the BC series for the rest.
We found this circuit in factory documentation from the 70s. The operational amplifier is from...
This circuit is from a Radio Electronics from the 90's. The integrated circuit is from the time...
This circuit was found in an old American publication. It is valid for any operational. Formulas for...