Electronic control of cryogenic refrigerators
US4543793A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1984 |
| Grant date | Oct 1, 1985 |
| Priority date | — |
| Expiry date | Mar 15, 2004 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B2309/003
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
In a cryogenics refrigerator having a piston or piston-like displacer reciprocating in a cylinder, the position of the piston or displacer, the temperature at the cold end of the cylinder and/or a refrigeration gas pressure wave are monitored to provide one or more feedback signals. Valves or a linear motor drive are controlled through electronic control circuitry which responds to the feedback signals. A displacer may be driven by pressure differentials on a drive piston or by an electric motor. The preferred elements provide feedback throughout the refrigeration cycle and include a linear variable displacement transformer and an encoder disc. Preferably, the control circuitry is in the form of a programmable digital processor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.