Telephonic communications – Substation or terminal circuitry – Impedance matching or line equalizing
Patent
1990-05-01
1991-12-17
Dwyer, James L.
Telephonic communications
Substation or terminal circuitry
Impedance matching or line equalizing
379414, 379416, H04M 100
Patent
active
050739247
ABSTRACT:
Filter circuitry for filtering noise from a pair of telephone conductors connected to a modem or a facsimile transmission unit includes a capacitor in series with a fixed resistor. A vaariable resistor is connected in series with the capacitor and the fixed resistor. The capacitor is non-polarized. A switch is connected in series with the filter elements for selectively connecting and disconnecting the filter from the telephone conductors.
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Augustus Jhancy
Dwyer James L.
Shields H. Gordon
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