This fuzz effect for guitars was found in an American 1980s documentation. The transistors may be the BC549 and should be battery powered for noise sensitivity. Diodes are commonly used.
This circuit for measuring very low currents was found in an American documentation from the...
The charging current of this circuit is controlled by the temperature of the accumulators, which is...
This circuit was obtained from old documentation and has a very simple 6 or 12 V configuration...