Konstantin Dimitrov over at Electronics Lab writes:
This project is a 8-12Vdc to +48Vdc DC-DC converter based on MC34063 switching regulator.
It’s a simple project of a DC-DC converter to make a phantom power supply for professional microphones. It can deliver 15-20mA at 48VDC. It ‘s based on MC34063 DC-DC step-up, step-down and boost converter. Input is between 8-12V DC and the output +48VDC/10-20mA.