Medium frequency x-ray diagnostics generator power control

A medium frequency x-ray tube generator comprising:

• a power rectifier connected to a main power source of unknown internal resistance;
• an x-ray tube having a filament;
• a low-voltage filter stage, an inverter, a high-voltage transformer and a high-voltage rectifier sequentially between said power rectifier and said x-ray tube supplying said x-ray tube with a tube voltage and a tube current;
• and
• a control unit connected to said filament of said x-ray tube and having inputs connected between said low-voltage filter stage and said inverter, said control unit controlling the filament current dependent on the input voltage to said inverter, thereby controlling the tube current so as to maintain the tube voltage constant independently of the internal resistance of said main power source.

A medium frequency x-ray generator comprising:

• an x-ray tube;
• means connecting said x-ray tube to a power source having an unknown internal network resistance;
• an inverter connected between said means connecting said x-ray tube to a power source and said x-ray tube;
• a capacitance connected in parallel between said means connecting said x-ray tube to a power source and said inverter;
• and
• a control unit connected to said x-ray tube and having inputs connected between said capacitance and said inverter, said control unit controlling the x-ray tube input current dependent on the input voltage to said inverter so as to maintain the x-ray tube voltage constant independently of the internal resistance of said power source, and said capacitance being dimensioned such that the input voltage to said inverter cannot be changed at a rate faster than the x-ray tube current can be changed.