is illustrated in fig2 with the solid line 14 1 is the sum of the output voltages of the rectifiers 13 and 13a according to fig2 it has a small ripple component in fig3 the high voltage circuit of the x ray generator according to fig1 is illustrated in a variation the secondary winding parts 11 and 12 or 11a and 12a respectively lie in two circuits each consisting of a diode and a capacitor 15 16 17 18 19 20 21 22 each of the capacitors 16 18 20 22 is charged to the peak voltage at the secondary winding parts 11 12 so that the four fold peak voltage lies at the x ray tube 14 for example if the peak voltage at one of the series circuits 11 12 or 11a 12a respectively amounts to 20 kv then the x ray tube voltage amounts to 80 kv in the example according to fig1 the x ray tube voltage in this case amounts to the doubled peak voltage namely for example 40 kv the example according to fig4 also represents a voltage doubling circuit in this case the secondary winding parts 11 12 and 11a 12a are illustrated as a single winding these winding parts feed a circuit consisting of a capacitor 23 and a diode 24 or a capacitor 25 and a diode 26 respectively thereby the doubled voltage of the voltage at the secondary winding parts 11 12 or 11a 12a respectively lies at the diodes 24 and 26 so that in this case too the x ray tube voltage has the four fold value of the voltage at the series circuit of two secondary winding parts 11 12 or 11a 12a respectively in the examples according to fig3 and 4 too the.