GB764096A - Improvements in or relating to apparatus for indicating abnormal functioning of one (or more) electrical device(s) - Google Patents
Improvements in or relating to apparatus for indicating abnormal functioning of one (or more) electrical device(s)Info
- Publication number
- GB764096A GB764096A GB23143/54A GB2314354A GB764096A GB 764096 A GB764096 A GB 764096A GB 23143/54 A GB23143/54 A GB 23143/54A GB 2314354 A GB2314354 A GB 2314354A GB 764096 A GB764096 A GB 764096A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rectifiers
- source
- indicating means
- arrangement
- supervised
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/08—Indicating faults in circuits or apparatus
Landscapes
- Emergency Protection Circuit Devices (AREA)
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
764,096. Protective arrangements. TELEFONAKTIEBOLAGET L. M. ERICSSON. Aug. 9, 1954 [Aug. 7, 1953], No. 23143/54. Class 38(5) In an arrangement for indicating abnormal operation of one or more devices within groups of supervised devices, each device is arranged to apply a D.C. biasing voltage U11...U14, U21...U24 to one side of an associated rectifier L11...L14, L21...L24, the other sides of the rectifiers associated with each group being connected through rectifiers L1, L3 respectively, in series with a source E2 providing a D.C. reference potential and a device responsive to changes in the A.C. impedance of the arrangement and forming part of an indicating means. In addition, the rectifiers associated with each group are connected through rectifiers L2, L4 in series with a further source E1 providing a D.C. reference potential, or with the source E2. In the arrangement shown, the indicating means includes a transformer having a winding c, d connected in series with the source E2 which provides a D.C. potential normally below the biasing potentials U11 &c. Thus under normal conditions the rectifiers L11 &c., associated with the supervised devices are blocked and a high impedance is presented to the winding' c. d and the indicating means is not operated. Should a supervised device become faulty so that one of the biasing voltages falls, e.g. U11, the associated rectifier L11 is unblocked so that direct current can flow from the source E2 and a low impedance is presented to the winding c, d. from which alternating current can flow resulting in the operation of the indicating means. The rectifiers L2, L4 and the source El provide circuits between points 1 and 2 and earth of low impedance to avoid "cross-talk" should the arrangement be used for supervising telephonic equipment and also to prevent incorrect operation of the indicating means due to reverse leakage currents through the rectifiers. Fig. 3 (not shown) illustrates the use of a thermistor to amplify the voltage derived from a supervised device before application to the associated rectifier. Specification 749,442 is referred to.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE764096X | 1953-08-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB764096A true GB764096A (en) | 1956-12-19 |
Family
ID=20329946
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB23143/54A Expired GB764096A (en) | 1953-08-07 | 1954-08-09 | Improvements in or relating to apparatus for indicating abnormal functioning of one (or more) electrical device(s) |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB764096A (en) |
-
1954
- 1954-08-09 GB GB23143/54A patent/GB764096A/en not_active Expired
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