Load sensitive rotating anode x-ray tube speed selector

Claim 1

A CONTROL SYSTEM FOR A MULTI-SPEED ROTATING ANODE X-RAY TUBE COMPRISING: (A) AN X-RAY TUBE HAVING AN ANODE ROTOR AND FIELD WINDINGS FOR DRIVING THE ROTOR, (B) RELATIVELY LOW AND HIGHER FREQUENCY POWER SUPPLIES IN CIRCUIT WITH THE FIELD WINDINGS FOR DRIVING THE ROTOR AT RELATIVELY LOW AND HIGHER ROTATIONAL SPEEDS, (C) AN ELECTRONIC SWITCH INCLUDING A CONTROL ELEMENT WHICH IS ADAPTED TO RENDER THE SWITCH CONDUCTIVE AT A PREDETERMINED BIAS LEVEL, (D) ADJUSTABLE SOURCES OF POWER FOR THE X-RAY TUBE AND AN ADJUSTABLE CONDUCTION INTERVAL TIMER THEREFOR, (E) MEANS FOR APPLYING A CONTROL BIAS ON THE ELEMENT IN ACCORDANCE WITH ADJUSTMENT OF THE POWER AND TIME FACTORS FOR THE X-RAY TUBE, SAID CONTROL BIAS HAVING ONE VALUE THAT CORRESPONDS WITH THE LOWER ROTATIONAL SPEED OF THE ANODE, (F) SAID CONTROL BIAS MEANS RENDERING SAID ELECTRONIC SWITCH CONDUCTIVE IF THE BIAS CORRESPONDS WITH AN OVERLOAD ON THE X-RAY TUBE FOR THE LOWER ROTOATIONAL SPEED OF THE ANODE, (G) RELAY MEANS ENERGIZED BY OPERATION OF SAID ELECTRONIC SWITCH TO CONNECT A HIGHER FREQUENCY POWER SUPPLY TO THE FIELD WINDINGS TO THEREBY INCREASE THE ROTOR SPEED, AND (H) MEANS OPERABLE CONCURRENTLY WITH SAID LAST NAMED RELAY MEANS TO CHANGE THE VALUE OF THE BIAS AND TO OPERATE THE FIRST SWITCH MEANS AGAIN IF THE SIGNAL CORRESPONDS WITH AN OVERLOAD ON THE X-RAY TUBE FOR THE CHOSEN TUBE FACTORS AT A HGHER ANODE ROTOR SPEED.