Channel unit interface circuit
Patent 4852160 Issued on July 25, 1989. Estimated Expiration Date: 
March 3, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 3, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesTransmission bridge for a subscriber's circuit Remote supply circuit for analog two-wire connection Battery feed circuit Signaling protocol channel unit Battery feed circuit for a pair of subscriber lines Patent #: 4677669 InventorsApplicationNo. 07/021385 filed on 03/03/1987US Classes:379/405, Electronic noninductive379/339, With signal conversion (e.g., dial to DTMF, analog to PCM)379/398, LINE EQUALIZATION OR IMPEDANCE MATCHING379/399.02Circuitry to provide a coder and decoder functionExaminersPrimary: Ng, Jin F.Assistant: Vaas, Randall S. Attorney, Agent or FirmInternational ClassesH04Q 1/30 (20060101)H04M 11/04 (20060101) H04Q 1/50 (20060101) H04L 25/02 (20060101) AbstractA channel unit interface circuit for interconnecting a two-wire, bidirectional signal transmitting means and a four-wire signal transmitting means in a communication system includes a tip terminal line driver, a ring terminal line driver, a voice sense amplifier, a balance network, A/D signal processing circuit, D/A signal processing circuit, filter network, a voice codec/PCM filter, a channel logic circuit, and a DC-to-DC converter. The channel unit interface circuit is suitable for use with substantially all of the different alarm-signalling techniques utilized by the various alarm companies for connecting their equipment to a channel bank coupled to the four-wire means. The interface circuit simulates a transmission line or cable over carrier in the frequency range of DC to 3.5 KHz with an amplitude variation between +110 to -200 VDC.Field of SearchFor alerting signal at called station (e.g., ringing)Electronic REPEATER (E.G., VOICE FREQUENCY) With signal conversion (e.g., dial to DTMF, analog to PCM) Having line length compensation or equalization Pulse or tone repeater (e.g., electromechanical relay) Component processes bidirectional signals Including two-to-four wire conversion or hybrid circuit Transmission of power to distant repeater Central power source (e.g., common battery, line current feed) LINE EQUALIZATION OR IMPEDANCE MATCHING For line length compensation Voltage boosting circuit Hybrid circuit With adjustable balance circuit | |
