We found this circuit in a technical documentation for the National Semiconductor LM3909. The circuit consists of a low consumption continuity tester powered by a single battery.
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...