Industrial controller permitting removal and insertion of circuit cards while under power
US5983298A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1995 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Nov 20, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D10/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A circuit card of an industrial controller may be removed or inserted under power without loss of memory or disturbance to the power supplies of other modules through the use of a power failure signal derived from shortened pins on the connector between the card and the industrial controller. The power failure signal activates a timer delaying connection of the board components to power until the physical connection between the card and the industrial controller has stabilized. At this time current drain is ramped up by a controlling series FET. Upon removal of the card, the power failure signal causes outputs of an on-board microprocessor to be pulled to particular states necessary to prevent disturbance of a battery backed-up RAM and to eliminate current flow through protection diodes on other memory type devices attached to the microprocessor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.