Found in Philips' 90s documentation, this small source can use modern transistors like the BD135 for TR4 and the BC series for the rest.
This charger was found in an old Motorola manual using an SCR from this company, which, however, can...
This two-stage amplifier has an input impedance of 100 M ohms and a unit voltage gain. It can be...
We found this circuit in an American 1980s documentation, but it can be implemented with modern...