Quotables
"It is my heart-warmed and world-embracing Christmas hope and aspiration that all of us, the high, the low, the rich, the poor, the admired, the despised, the loved, the hated, the civilized, the savage (every man and brother of us all throughout the whole earth), may eventually be gathered together in a heaven of everlasting rest and peace and bliss, except the inventor of the telephone. "
Mark Twain ; Christmas greetings, 1890
PatentStorm News
Make the Most of Our Site
See this month's Top Inventors and Most Cited Patents.
Stay on top of the latest innovations by subscribing to an RSS feed.
Registered users: Manage your profile.
| Number | Title | Issue Date |
| 4500755 | Electric hybrid circuits A hybrid circuit has its 4-wire path input coupled via a resistor to a 2-wire port and a non-inverting input of a differential amplifier, and via an active stage and another resistor to an inverting input of the differential amplifier, whose output is cou... | 02/19/1985 |
| 4498018 | Balancing impedance included in a fork A simplified balancing impedance (Z2) included in a transformer fork has a constant capacitor (C5) connected in series with the termination resistor (R1). The variable capacitance in the balancing impedance contains a resi... | 02/05/1985 |
| 4489222 | Telephone line interface A telephone line interface which performs the BORSHT functions employs pulse width modulation and eliminates dc in the transformer to reduce the size of the coupling transformer thereby reducing space and costs. The ring function is provided to the subscr... | 12/18/1984 |
| 4485277 | Apparatus for transmitting and/or receiving balanced signals on a two-wire telecommunication line A transformerless hybrid circuit arrangement for a subscriber line interface circuit of a telecommunications exchange is disclosed. A preferred embodiment of the hybrid arrangement comprises a first and a second operational amplifier plus a differential a... | 11/27/1984 |
| 4445006 | Four-wire conversion circuit for a telephone subscriber line In the circuit arrangement according to the invention, the two transistors with their main current lines connected in series cause no disturbance of balance in the subscriber's line. By means of exclusively alternating current coupling on the subscriber's... | 04/24/1984 |
| 4412102 | Key telephone system A key telephone system comprises a plurality of key telephones and a main equipment connected to at least one set of central office (CO) lines and capable of connecting thereto the key telephones. The main equipment includes a dual tone multifrequency (DT... | 10/25/1983 |
| 4406929 | Hook status detector for a subscriber loop interface circuit A circuit for use with a subscriber loop interface circuit (SLIC) to detect the hook/switch status of the telephone handset driven by the SLIC. Responsive to metallic current flowing through the handset when the telephone is taken off hook, a voltage is d... | 09/27/1983 |
| 4396805 | Ring trip detector for a subscriber line interface circuit A ring trip detector for a subscriber line interface circuit which couples a two-wire subscriber line with the transmitting and receiving branches, respectively, of a four-wire line in a telecommunication exchange. The subscriber line interface circuit in... | 08/02/1983 |
| 4381561 | All digital LSI line circuit for analog lines A digital telecommunication line circuit implementable on one or more large scale integrated circuit (LSI) chips is described. A simplified integrated hardware structure is provided so as to achieve the combination on an LSI chip of an electronic two-to-f... | 04/26/1983 |
| 4380690 | Hybrid circuit A hybrid circuit, in which the differential output of an amplifier of the four-wire receive port having the differential output of low output impedance is connected to a series-connected circuit composed of a variable impedance circuit and the primary win... | 04/19/1983 |
| 4377858 | Digital two-to-four wire converter for full duplex signals A digital electronic hybrid circuit for a telephone line circuit is described wherein the two-to-four wire conversion function is provided with an improved synthesized automatic impedance match between the telephone subscriber line and the digital central... | 03/22/1983 |
| 4377730 | Tone elimination circuit A cancellation circuit which may be utilized in a subscriber loop interface circuit to allow a tone to be supplied in the receive path of the hybrid circuit to be received by the calling subscriber and for cancelling said tone from being transmitted to a ... | 03/22/1983 |
| 4366566 | System for interconnecting subscribers lines to an automatic digital telephone switching system In the interconnection system between telephone subscribers lines and digital telephone electronic switching equipment, individual subscriber equipment is associated with each line, which is comprised of means for providing conventional line interface fun... | 12/28/1982 |
| 4358643 | Two to four wire hybrid circuit There is disclosed a two- to four-wire hybrid circuit of a telecommunication system. A line coupling circuit, preferably a transformer is connected to a terminal line. Between the coupling circuit and first and second amplifying means each assigned to a r... | 11/09/1982 |
| 4351060 | Automatic, digitally synthesized matching line terminating impedance A circuit for automatically digitally synthesizing an output impedance, which may be a matching line terminating impedance, is provided. The means for establishing the desired output impedance characteristic is accomplished using a simplified recursive di... | 09/21/1982 |
| 4326109 | Apparatus for coupling a two-way transmission path to a one-way transmitting path and a one-way receiving path A one-way receiving path is connected to the input side of a first phase-shift network which produces signals in phase quadrature at its output side, which is connected to the input side of a second phase-shift network which is conjugate to the first and ... | 04/20/1982 |
| 4301334 | Telecommunication subscriber line access circuit with ground key and insulation fault indication A subscriber line access circuit for use in a telecommunications system is disclosed. The subscriber line access circuit has a power supply bridge in the form of a first resistor inserted in the b-wire (ground potential side) of a subscriber line, a secon... | 11/17/1981 |
| 4287392 | Integrated circuitry for exchanging signals between telephone station and central office The two talking wires of a line loop extending from a subscriber station to a central office, provided with respective blocking capacitors, are connected on the subscriber side of these blocking capacitors to respective signal detectors fed from a common ... | 09/01/1981 |
| 4284853 | Telecommunication subscriber line access circuit with ground key indication and a device for call signal generation A subscriber line access circuit for use in a telecommunications system is disclosed. The subscriber line access circuit includes a power supply bridge in the form of a first resistor inserted in the b-wire (ground potential side) of a subscriber line, a ... | 08/18/1981 |
| 4197431 | Subscriber loop feed apparatus Telephone loop feed apparatus in which a hybrid couples audio signals to and from the subscriber loop and presents a high impedance to the loop relative to the loop impedance. DC power is coupled to the loop by matched resistors which determine the loop f... | 04/08/1980 |
| 4178569 | Hybrid for two-wire full-duplex transmission of digital signals The hybrid includes a control circuit which automatically matches the impedance of the balancing network to the input impedance of the two-wire line connected to the hybrid. For control, rectified voltages present on the two-wire side and across the balan... | 12/11/1979 |
| 4161633 | Subscriber line/trunk circuit A microprocessor controlled subscriber line circuit for interfacing analog telephone lines and trunks to a digital switching system is disclosed. All processing of incoming analog signals is accomplished by the line circuit, including the interface betwee... | 07/17/1979 |
| 4153817 | Digital conference circuit A digital conference circuit provides greater stability in voice transmission by selectively inverting the signal in alternate conference channels, thereby providing cancellation of parasitic echo signals which tend to create oscillations or ringing. Sele... | 05/08/1979 |
| 4150260 | Subscriber's circuit for four-wire-system local switch A subscriber's circuit for a four-wire-system local switch is provided with a two-wire/four-wire hybrid circuit that includes a two-wire/four-wire converter circuit. Connected between the converter circuit and a time-division switch section is an incoming... | 04/17/1979 |
| 4128743 | Circuit arrangement for blocking a bidirectional amplifier against receiving outgoing signals A circuit for the reciprocal transmission of signals through transmitting channels. The circuit has amplifiers therein for amplifying the signals being transmitted in opposite directions along the line. A pair of electronic hybrid circuits are provided so... | 12/05/1978 |
| 4103118 | Autobalance hybrid circuit This autobalance hybrid circuit is used to connect a 2-wire duplex telephone line to a 4-wire line which has separate receive and transmit pairs. The impedance of a balancing network automatically is adjusted to equal the impedance of the 2-wire line, the... | 07/25/1978 |
| 4090043 | Electronic hybrid circuit Disclosed is an electronic hybrid circuit which enables telephone conferences to be set up. The known systems have various limitations. For example, in one type of system, more than one person cannot be heard simultaneously. Known systems also tend to be ... | 05/16/1978 |
| 4032718 | Four-wire integrable hybrid A time-sampled port circuit is shown in which the charges impressed by the telephone set on the shunt capacitor of a low-pass filter associated with the port are passively sampled for transmission to the other port circuits, but which capacitor is impulse... | 06/28/1977 |
| 4027114 | Echo prevention circuit Echo propagation is prevented on four-wire signaling path to two-wire signaling path connections. A first transmission path portion is extended from the receive leg of the four-wire signaling path to the transmit leg and a second transmission path portion... | 05/31/1977 |
| 4002860 | Transmitting and receiving apparatus Only one reversible electro-acoustic converter is used to act without a press-to-talk switch or the like as a transmitter and a receiver. The electro-acoustic converter is connected to a communication line through two 2 - 4 converters in the form of hybri... | 01/11/1977 |
| 3987253 | Hybrid coupling for telecommunication system A coupling circuit for a telecommunication system comprises a resistance bridge whose four arms consist each of two identical halves in series with each other, the resistive halves of one pair of opposite arms being of relatively high magnitude while the ... | 10/19/1976 |
| 3943301 | Solid state four-wire switch for key telephones A compact, solid state four-wire switch for use with key telephones. The switch comprises a pair of transistors which, in the two-wire mode, electrically connect a telephone receiver with a telephone circuit balance network. In the four-wire mode a negati... | 03/09/1976 |
| 3934099 | Bias, feedback and network arrangements for hybrid circuits This specification discloses a time division communication system having a plurality of line circuits for coupling telephones over bidirectional lines to outgoing and incoming time division buses. Each of the line circuits comprises an active hybrid havin... | 01/20/1976 |
