Found in an Electronic Design from the 90's, this circuit uses an SCR according to the controlled power. The circuit is for 12V heating elements.
To use the instrument for AC measurement, the tips are A and B. For CC use tips A or B for...
The interesting circuit shown in the figure, can have its gain digitally controlled and present two...
This simple MW radio was found in a 1975 publication, but it can be mounted with BC548...