Modern high voltage power supplies employ power conversion topologies based on SMPS technology, to convert the low-frequency low voltage input to high voltages at the output. The principal idea of SMPS is to achieve this conversion utilizing high-frequency switches, such as MOSFETs, and a high-frequency transformer.

The high voltage power supply transforms the rectified and filtered DC bus voltages, gained by rectification of the mains input, to high-frequency AC with the help of high-frequency switches. These switches are usually switched above 20kHz and are controlled by varying the duty-ratio, to regulate the power transfer.

This high-frequency AC is further amplified to higher voltages by a high-frequency transformer. This transformer is the prime source of galvanic isolation. The stepped-up voltages are rectified, multiplied, and filtered at the secondary of the HF transformer to provide the desired voltage levels as the output.

Complex control circuitry is implemented in a high voltage power supply which enables the user to control the output as per the user demand. This circuit includes the fail-safe protection circuitry and the switching frequency drive to the switches.