| 摘要 |
1,247,072. X-ray apparatus. SIEMENS A.G. 28 July, 1969 [27 July, 1968], No. 37843/69. Heading H2H. An X-ray apparatus having a plurality of grid-controlled tubes parallel connected to a common high-voltage source has a control means operated by individual exposure devices to cause a desired voltage to be applied for a selected time to the respective tube and to disable other tubes while one tube is conductive. The tubes 1, 2 may be activated alternately for cinematograph operation and interlocked with film changers 16, 17. With film changer 16, for example, in exposure condition a contact 18 will be closed and on depression of a button 14 on panel 9 a negative voltage previously applied to tubes 3, 4 is removed which tubes become conductive for a period determined by a control 11. Tube 1 is then rendered conductive for a period adjusted by a control 12 which period extends beyond that during which the controlled rectifiers 3, 4 remain conductive in order that the highvoltage supply a, b which rises to a no-load value will not be applied to a still heated X-ray tube. On completion of the exposure contacts 18 are opened and 19 are closed and a similar sequence operates with respect to tube 2 except that contacts 20, 21 selecting tube voltage are changed over to an alternative position on to taps 26, 27 adjusted by a control 10<SP>1</SP> which taps adjust the conductivity of the rectifiers 3, 4 and hence the voltage applied to a tube. Operation of the film changers 16, 17 are effected by known means (not shown). |
