This circuit, obtained from a 1965 magazine, can still be assembled using some modern equivalent components. The transistors may be BC558 and the transformer is obtained from a disused transistor radio.
Bipolar transistors are types of general use like BC548, while the power MOSFET can be of any type...
The output voltage of the circuit shown in the figure is approximately 7.0 V for a 15 V supply...
Of course, other frequencies can be generated by changing the components. The circuit generates a...