Found in a 1980s documentation, this circuit uses as base a component of the era. The formula for determining the conversion is given next to the diagram.
This traditional transistor source uses only two transistors found in a 1998 documentation. The...
In fact, it is a RF field indicator with an operational amplifier equivalent to the 741. This...
We found this circuit in a Motorola documentation from 1968. Phototransistors are common and...