| 摘要 |
1,077,569. Automatic current control. SIEMENS A.G. Nov.18, 1965 [Dec.3, 1964], No.49118/65. Heading G3R. In a system for supplying several X-ray tubes such as X1, X2 and X3 in parallel from a single high-potential supply source T, G1, the control circuit for automatically regulating the tube current is arranged to operate at a safe low potential. Thus, the tube current of X1 is controlled by a circuit which includes the operating windings of a transductor TK1, a controller R1, a correcting member ST1 and the primary winding of a transformer HT1 having its secondary winding connected to the cathode heater of the tube, so that the heater current is correctively varied in dependence upon tube current variations as detected by the winding W1 of transductor TK1. The secondary winding of transformer HT1 and the winding W1 are at a high potential, and are suitably insulated from their associated magnetic cores which are earthed. The control circuit is thus isolated from those parts of the system which operate at high potential and which may be provided with an earthed shield. In modifications described in relation to Figs. 2, 3, 4 and 5 (not shown), the transductor TK1 is replaced by a current sensing circuit which includes a magnetorestrictive element, a diode, a triode, and a transistor respectively. |
