This circuit is from a 1976 Motorola CMOS manual. It can be implemented with modern Darlingtons like those in the Texas TIP series. The load current depends only on the Darlington transistor.
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...