System for providing electrical power to a computer input device according to the interface types through the shared use of wires and a voltage clamp
US5920734A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 21, 1996 |
| Grant date | Jul 6, 1999 |
| Priority date | — |
| Expiry date | Jun 21, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0383
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system permits the shared use of lines in a cursor control device coupled to a PS/2 interface or a serial interface. A computer pointing device such as a mouse can be coupled to either the PS/2 interface or the serial interface. The current supplied by the serial interface is limited by conventional circuitry within the interface itself. However, a clock line, normally used when the pointing device is coupled to the PS/2 interface, can be used to supply additional current to the pointing device when coupled to a serial interface. A Schottky diode is coupled in series between a V.sub.cc /RTS line and a power supply node within the pointing device. A second Schottky diode is coupled from a CLK/DTR line to the power supply node. When the pointing device is coupled to the PS/2 interface, the first Schottky diode provides current from a V.sub.cc source within the PS/2 interface. The second Schottky diode is not active when the pointing device is coupled to the PS/2 interface. When the pointing device is coupled to the serial interface, both the first and second Schottky diodes are active and both supply current to the power supply node. The first Schottky diode also prevents reverse c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.