| 摘要 |
Switch assembly, such as a keyboard switch assembly, comprises a plurality of polled conductors, a plurality of scanned conductors, and switch sites, each of which has an associated scanned conductor and polled conductor adjacent thereto. When a switch at each switch site is closed, the associated polled conductor is connected to the associated scanned conductor and closure of the switch is determined by a polling and scanning means. Each switch has a switch resistor in series therewith and each scanned conductor has a scanned conductor resistor between the scanned conductor and one side of the power supply. The analyzer associated with the switch assembly has the ability to determine whether a signal indicating that a particular switch is closed is a true signal caused by actual closure of the signal or alternatively is a phantom signal caused by the closure of a group of switches in the switch matrix. The determination is made on the basis of the difference in voltage detected when a true switch closure is made and when a phantom switch closure is indicated.
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