Device for measuring the internal pressure of an operationally built built-in vacuum switch
US4672323A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1984 |
| Grant date | Jun 9, 1987 |
| Priority date | — |
| Expiry date | Nov 30, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H33/668
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A device for measuring the internal pressure of an operationally built-in vacuum switch which comprises a vacuum switching tube having a switching chamber and switch contacts as well as an associated drive for the contacts. For the measurement of the pressure, a cold-cathode discharge (so-called Penning effect) having crossed electric and magnetic fields is used, wherein the electric field is applied, for instance, between at least one of the switch contacts and a metallic wall of the switching chamber or a condensation shield disposed in the chamber and permanent magnets are used for generating the magnetic field. The permanent magnets are realized in the form of rods and have pole pieces formed such that the pole pieces encircle the switching chamber. A magnetic field is formed which is applied directly in the longitudinal direction to a circumferential section of the cylindrical switching chamber. In order to measure the pressure inside the vacuum switching tube built into a switching installation, the voltage drop across a resistor disposed in series with a d-c source and the switch is measured. The voltage drop corresponds to the ionization current, which is dependent on the g…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.