| 摘要 |
790,313. Protective arrangements. TELEFONAKTIEBOLAGET L. M. ERICSSON. Jan. 27, 1955 [Jan. 27, 1954], No. 2551/55. Class 38 (5). [Also in Group XL (c)] In an arrangement for indicating and locating a fault in one or more units within a group of such units, e.g. electron tubes 1 ... 4, each unit is arranged to apply a " blocking " potential to a rectifier 15 ... 45 in opposition to a reference potential provided by a source 27 connected in series with the secondary winding of a transformer 26 controlling an indicating device 28. Should a fault cause a fall in any of the blocking potentials, the corresponding rectifier 15 ... 45 becomes conductive and the impedance presented to the secondary winding becomes low, resulting in the operation of the indicating device 28. Then under the control of the device 28, or manually, a selector 16 is operated to disconnect the secondary winding from the common rectifier connection L2 and to connect it in turn through a rectifier 20 to each unit. When the device 28 indicates the faulty unit, the selector stops, or is stopped, and a changeover switch 19 may then be operated so that the voltage of the faulty unit may be measured at 18, the switch 19 disconnecting the source 27 and earthing the rectifiers 15 ... 45. Specification 764,096 is referred to. Reference has been directed by the Comptroller to Specification 612,362, [Group XL (c)]. |
