Electrical system for controlling the operation of a heat exchanger, control device therefor and methods of making the same
US5102042A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 12, 1990 |
| Grant date | Apr 7, 1992 |
| Priority date | — |
| Expiry date | Dec 12, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/1909
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An electrical system for controlling the operation of a heat exchanger, control device therefor and methods of making the same are provided, the system comprising a first electrical transformer, a relay for causing the heat exchanger to be in one condition thereof when the relay is activated and for causing the heat exchanger to be in another condition thereof when the relay is deactivated, a switch for placing the relay across the secondary winding of the first transformer to activate the relay when the switch is in one condition thereof and to deactivate the relay when the switch is in another condition thereof, and a second transformer having a low voltage high current winding disposed in series with the switch when the switch is in one condition thereof so as to supply power to the low voltage high current winding and to increase the current flow from the secondary winding through the relay to activate the relay, the second transformer having only one other winding that is so arranged that power is supplied to the other winding when the switch is in the other condition thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.