Regulating installation for power transmitted to a three-phase user

Claim 1

A regulating installation for the controlling power conveyed to a three-phase user, said installation comprising an X-ray diagnostic apparatus having an X-ray tube; a three-phase high-voltage transformer having three primary power windings; switch means transmissive in both current directions having triggering characteristics, respectively one of said switch means being positioned in each of two of the three power supply phases; first and second impulse generators; an element transmitting a control signal to said impulse generators upon the difference in the actual value and a reference value of the X-ray dose produced by said X-ray tube; each of said impulse generators controlling, respectively, one said switch means, said generators each being synchronized with a power supply phase and transmitting a triggering impulse to the respective switch means during the half-wave of its synchronizing power supply phase, the initiation of said triggering impulse within said half-wave being dependent upon said control signal, the improvement comprising: means connecting said first impulse generator to the one of said three transformer phases that does not have one of said switch means connected thereto so as to synchronize said first impulse generator with the phase that is uninterrupted by any of said switch means and means connecting said second impulse generator to the same phase that contains the switch means that are controlled by said second impulse generator so as to synchronize said second impulse generator with the phase containing the switch means that it controls.