This circuit operates at a voltage of 1.3 V from a single mercury cell. We found in an old documentation and for the components used the frequency is 500 kHz.
This configuration can be found in other articles on this site. This was obtained in 1998...
In the figure we show how to polarize a phototransistor to obtain sensitivity. The circuit is from...
This compact power supply can be used on the workbench for up to 1 A load. The transformer has 1 A secondary...