Dynamically configurable personal computer card utilizing variable interrogation signal to detect connected extension
US5983288A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 20, 1996 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Aug 20, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K5/0256
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system comprising a personal computer card and an interchangeable extension consists of a personal computer card a card information storage (CIS) system and a coaxial connection socket. First logic means are arranged to control an interrogation means comprising a digital-to-analog current converter, comparator and reference voltage source in order to supply a series of DC currents to the socket. The extension has a coaxial connection pin and grounded resistor having a value which identifies the type of extension so that when a DC current is applied to the pin by the socket, a characteristic voltage is generated across the resistor which is compared by the comparator with the reference voltage. The comparator indicates the value of resistor as a digital value to the CIS system which communicates the characteristics of the extension to a host PC. A second logic means disables power upon removal of a previous extension from the socket. Each extension may comprise a radio frequency antenna which may be external to the extension.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.