Abstract: A power supply provides the stable DC voltages needed for a computer terminal from a wide range of line voltages and frequencies. The line is rectified and fed to a flyback transformer wherein primary current is controlled in duration for providing the desired energy transfer to the secondary winding. The outputs from the flyback transformer are rectified and filtered. A separate start-up circuit uses a transformer across the line voltage, and a positive coefficient resistor provides a time limit to allow the use of a small transformer even though the line voltage may be high. The start-up circuit must produce a minimum voltage for the switching transistor in the flyback arrangement to allow operation of the power supply, and the start-up transformer is disconnected from the circuit after operation to prevent electromagnetic interference within the terminal.