Method and apparatus for detecting the insertion or removal of expansion cards using capacitive sensing
First Claim
1. A detection system for detecting the insertion and removal of an expansion card relative to an I/O connector of a computer system, the expansion card including a connector having a plurality of conductive pins for interfacing corresponding pins of the I/O connector, said detection system comprising:
- a conductive plate for mounting to the expansion card to capacitively interface a corresponding pin on the I/O connector, wherein capacitive coupling develops between said plate and said corresponding pin which changes as the expansion card is moved relative to the I/O connector;
an oscillator coupled to said capacitive coupling between said plate and said corresponding pin, wherein said oscillator has a frequency which varies with changes of said capacitive coupling; and
a processor coupled to said oscillator for detecting movement of the expansion card through changes of said frequency.
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Accused Products
Abstract
A detection system for detecting the insertion or removal of expansion cards having a standard edge connector using one or more capacitive plates coupled to corresponding variable frequency oscillators. The capacitive plates are preferably mounted on an internal layer of the expansion card and preferably aligned with corresponding pins of the edge connector for establishing capacitive loading with respect to the corresponding pins. The frequency of the oscillators change with changes in the capacitive loading of the corresponding plates. The detection circuitry includes a processor which continuously monitors the frequency of the oscillators to thereby detect movement of the expansion card, and preferably includes a control and isolation circuit which electrically isolates the power and data pins during insertion and/or removal as controlled by the processor. The detection circuitry may be mounted to either on the expansion card or the planar of the computer system. If mounted on the expansion card, the power and data pins are in a tristated condition while the option card is removed from the planar. The processor detects that the expansion card is being inserted or removed when the frequency of one or both oscillators is at a predetermined frequency or shifts by a predetermined amount.
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Citations
28 Claims
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1. A detection system for detecting the insertion and removal of an expansion card relative to an I/O connector of a computer system, the expansion card including a connector having a plurality of conductive pins for interfacing corresponding pins of the I/O connector, said detection system comprising:
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a conductive plate for mounting to the expansion card to capacitively interface a corresponding pin on the I/O connector, wherein capacitive coupling develops between said plate and said corresponding pin which changes as the expansion card is moved relative to the I/O connector; an oscillator coupled to said capacitive coupling between said plate and said corresponding pin, wherein said oscillator has a frequency which varies with changes of said capacitive coupling; and a processor coupled to said oscillator for detecting movement of the expansion card through changes of said frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A detection system for detecting the insertion and removal of an expansion card relative to an I/O connector of a computer system, the I/O connector including a plurality of conductive pins, said detection system comprising:
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an expansion card including an edge connector having a plurality of conductive pins for interfacing corresponding conductive pins of the I/O connector; a first conductive plate mounted on one end of said edge connector for capacitively interfacing a first pin of the I/O connector; a second conductive plate mounted on the opposite end of said edge connector for capacitively interfacing a second pin of the I/O connector; a first oscillator coupled to detect capacitive coupling of said first plate, said first oscillator oscillating at a frequency which varies with changes of capacitance between said first plate and said first pin; a second oscillator coupled to detect capacitive coupling of said second plate, said second oscillator oscillating at a frequency which varies with changes of capacitance between said second plate and said second pin; and a processor coupled to detect said frequencies of said first and second oscillators for detecting said expansion card being inserted or removed. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification