Medium Frequency X Ray Generator Also named high-frequency generator and inverter generator Uses a high-frequency current to produce nearly constant potential voltage to the X ray tube with a transformer of much smaller size than found in ordinary X-ray generators. The incoming power supply to a medium frequency generator may be an ordinary 50 Hz (230 V) single phase current (Fig.1). The current is rectified and smoothed (YELLOW block below figure) Current then fed to a chopper and inverter circuit which transforms the smooth, direct current (DC) into a high-frequency (5 - 100 kHz) alternating current (AC). (The chopper "chops" the continuous DC into high-frequency DC pulses and the inverter transforms this into AC.) [Green block in below figure] A transformer converts this high-frequency low-voltage AC into high-voltage AC, which then is rectified by half wave rectification and smoothed to provide a nearly constant potential high voltage to the X-ray tube. [ Blue block in below figure] The voltage is controlled by varying the frequency of the chopper/inverter circuit, which determines the frequency of the current delivered to the transformer. Fast exposure switching, in the order of 1 ms, is easily obtained with the medium frequency generator. It is important to be able to relate this working to the waveforms involved at each stage: The electrical waveforms are shown below: (Identify which waveform belongs to which component.) Note esp the chopper-inverter which takes a DC waveform and produces an AC waveform. The transformer amplifies this waveform. The rectifier removes one half of this (so the waveform is once again a DC waveform). The final smoothed waveform is then input to the X ray tube.