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 circuit, from the 1990 Motorola Dataar Databook, can use any LM139 series comparator. The circuit...
We find this circuit in a 1980s documentation for amateur radio. The circuit shows how to switch...
With this circuit found in a 1965 Electronic Design, it is possible to read a peak voltage of up to...