Portable X-ray unit with self-contained voltage supply

In X-ray apparatus, a portable unit including an X-ray tube having a cathode and an anode, means for supplying alternating current to said unit at a relatively low voltage level and high voltage transformer means having primary and secondary winding means in said unit for transforming said alternating current to a high voltage applied between said cathode and said anode of said X-ray tube, said unit comprising:

• capacitor means, diode means, first connection means for applying said AC current to said primary winding means, and second connection means interconnecting said secondary winding, capacitor and diode means and said anode and cathode of said X-ray tube for operation in a first mode in which said capacitance means are charged to a high potential during each cycle of said alternating current and in which a substantially constant corresponding potential is maintained between said anode and said cathode of said X-ray tube, said diode means comprising first and second diodes each having a cathode and an anode, said capacitance means comprising first and second capacitors each having first and second terminals, and said second connection means including a first connection between said anode of said X-ray tube and said cathode of said first diode and said first terminal of said first capacitor, a second connection between said cathode of said X-ray tube and said anode of said second diode and said first terminal of said second capacitor and a third connection between said anode of said first diode and said cathode of said second diode with said secondary winding means being connected to said third connection and to said second terminals of said first and second capacitors, the AC voltages measured with reference to said third connection being in the same phase at said second terminals of said first and second capacitors in said first mode of operation in which a substantially constant potential is maintained between said anode and said cathode of said X-ray tube said portable unit further comprising phase switching means associated with at least one of said connection means for selective operation in a second mode in which the charge voltage developed across said capacitance means is added to the alternating voltage developed across said secondary winding means to produce a pulsating voltage applied between said anode and said cathode of said x-ray tube.