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7254230 Subscriber line interface circuitry  
A subscriber line interface circuit apparatus includes a signal processor having sense inputs for sensed tip and ring signals of a subscriber loop. The signal processor generates linefeed driver...
7197138 Programmable device and methods for disabling a ring signal in response to a detected off-hook condition  
A method and structure for cutting a ring current when a telephone enters an off-hook state. The method includes: (1) activating an off-hook detected signal when the telephone enters an off-hook...
7162027 Voice messaging system caller ring bypass control  
A voice messaging system such as a telephone answering device which allows a calling party to bypass the ring signal and substantially immediately allow the calling party to leave a voice message....
7158633 Method and apparatus for monitoring subscriber loop interface circuitry power dissipation  
Subscriber line interface circuitry includes an integrated circuit having sense inputs for a sensed tip signal and a sensed ring signal of a subscriber loop. The integrated circuit generates a...
RE39406 Telephone line coupler  
The telephone line coupler circuit has a single transmit opto-coupler whose output includes a DC bias component connected to a gate of a line seize switch for connecting a DC line seize load across...
7103175 Systems and methods for an electronic hook switch for customer premises equipment  
Embodiments of the present invention relate to systems and methods for an electronic hook switch for customer premises equipment. In an embodiment, a system includes a first lead configured to be...
7099462 Silent ringing with reduced device sizes  
A system and a method selectively switch between two different voltage supplies supplying a common node. A first of the voltage supplies is coupled to the common node by a first switch and a second...
7095824 Instructive out-of-service telephone lines  
A method ( 10, 20 ) and apparatus ( 30 ) enables a customer ( 47 ) to distinguish between a dead or broken Internet Protocol telephone line and an out-of-service Internet Protocol telephone line....
7092512 Call control device and call control method  
An object of this invention is to provide a method and a device for easily connecting and disconnecting a telephone communication line using an auditory organ instead of using a complex mechanism...
7085373 Circuit and method for detecting AC voltage pulses  
A detection circuit and method for detecting AC voltage pulses at a defined frequency relate to first transforming an input signal to a low-frequency signal by multiplying the input signal by a...
6999581 Event detection circuit  
A network interface circuit that screens out transient signals and provides an indication to the line side that an actual event has occurred, so that appropriate discrimination circuitry is powered...
6980643 Fallback function telecommunications device  
The invention herein is fallback function communications device comprised of a microprocessor, utilized to perform a predetermined operation and processing of a predetermined input signal and then...
6978008 Zero crossing detection circuit  
A PNPN structure thyristor and a third P-type impurity region are formed on a semiconductor substrate, and a fixed current circuit using an NPN transistor 20 and a resistor 30 is connected to a...
6940970 Ring boost circuit to extend ringing range of telephone SLICs  
A ring boost circuit has a first switching device coupled to a ring node. The first switching device is responsive to a ring operation. A charge pump is connected to the ring node, and the charge...
6925178 Returning ringing signals through the tip amplifier of subscriber-line interface circuitry  
A subscriber-line interface circuit (SLIC) has tip and ring amplifiers connected to the tip and ring lines, respectively, of customer premises equipment (CPE). The SLIC returns the ringing signal...
6920220 Pre-zero crossing signal generator for sinusoidal voltages with DC offsets such as telephone ring voltages  
A circuit for closing a relay when an active AC voltage connected to one of the contacts of the relay is approximately zero volts includes a monitoring circuit that monitors the active AC voltage...
6879686 Line take-up detection circuit  
An interface circuit including a galvanic isolation barrier between a transmission line and a user equipment, and a detector for detecting, independently from a transmission, the idle or busy state...
6868156 Non-voice signal repeater for speech coders  
A method of repeating a non-voice signal such as a dual tone, multiple frequency (DTMF) signal, by inserting a delay sequence of data values into an output data sequence of data values, a portion...
6853723 High impedance polarity detector  
A method and apparatus for measuring signals conveyed by a varying polarity voltage signal across a tip and ring in a telephone system is disclosed. A voltage present across the tip and ring is...
6845157 Linear polarity guard and method for DSL-ready pots devices  
A plain old telephone system (POTS) device, for example but not limited to, a telephone, facsimile machine, analog modem, caller identification (ID) system, speaker phone, cordless phone, etc.,...
6700974 Switching power supply for generating a ringing voltage  
An apparatus and method for providing a ringing voltage to a communication device such as a telephone or a modem. Typically, communication devices are coupled to a ringing voltage providing...
6687370 Method and an arrangement for securing an ADSL connection  
To secure an ADSL connection between a first ADSL transceiver ( 4 ) in a central office and a second ADSL transceiver ( 5 ) on a subscriber's premises on a telephone line ( 1 ) between a SLIC ( 2 )...
6665397 Telephone signal detecting circuit  
A telephone signal detecting circuit is provided, which can identify an input signal is a line reversal signal or a ring signal. Providing this telephone signal detecting circuit into a ring...
6631190 Telephone system  
A telephone system capable of judging kinds of various signals (line input signals) obtained through a line is disclosed, that enables reduction of the number of parts, detection with high...
6625276 Method and circuit for detecting ring and caller-ID signals  
A method and circuit for distinguishing between a first voltage signal having a high amplitude and a second voltage signal having a low amplitude, the first and second voltage signals comprising...
6590973 System and method for detecting an off-hook condition  
A line card for coupling to customer premises equipment at a termination for detecting hook condition in a telephone system, the line card comprising an interface for transmitting and receiving an...
6570984 Ring trip detection circuit and method for subscriber line interface  
A ring trip detector circuit and method for use with a plurality of subscriber line interface circuits each having at least one telephone unit connected to it, having a ring generator for feeding a...
6556673 Telephone ring signal detector  
A telephone ring signal detector is coupled to a telecommunication line for detecting a first telephone ring signal, and for discriminating the first telephone ring signal from other line signals...
6449360 Cleaning method for telephone number list and system implemented therefor  
A cleaning system retrieves a telephone number from a telephone number list to regard as a called party number and sends a SETUP message to the network, in which a SPEECH or an AUDIO is designated...
6411694 Arrangement for improving a telephone system  
The present invention relates to an arrangement, for improving a telephone system in which a plurality of analogue phones are connected to a single line, and for the purpose of providing an...
6393123 Method and modem circuit for determining connection status of a phone line  
A circuit for determining connection status of a phone line shared by multiple telecommunications devices, such as modems and phones, is provided. The phone line includes respective tip and ring...
6359983 Digital isolation system with data scrambling  
A method and apparatus are provided for reducing the amplitude of signals that often are inadvertently coupled to a telephone line from an isolation barrier system, or that cause undesirable...
6351528 Integrated ringer for short telephone lines  
The invention provides an apparatus for use with a subscriber line interface circuit in a telephone system, the subscriber line interface circuit being interposed between a telephone central office...
6219417 Ring trip detection in a communication system  
A line card integrates subscriber line interface circuitry, A/D and D/A converters, and digital signal processing technology. The digital signal processing technology performs many line card tasks...
6191684 Remote supply circuitry  
Remote supply circuitry for remotely supplying a subscriber connections in a communications system wherein subscribers can be connected to a central point via subscriber lines. Subscriber supply...
6185296 Ring trip circuit for stopping call signal at different timing from zero-crossing point of call signal  
A ring trip circuit is incorporated in a telephone exchanger together with a call signal source and a relay unit connected between the call signal source and user's terminal, and determines current...
6178241 Switch hook status determination in a communication system  
A line card integrates subscriber line interface circuitry, A/D and D/A converters, and digital signal processing technology. The digital signal processing technology performs many line card tasks...
6173040 Telephone line state detecting device  
A telephone line state detecting device that is connectedly provided with a hardware detecting circuit when a telephone line is connected to a modem. The hardware detecting circuit is connected to...
6160885 Caller ID circuit powered through hookswitch devices  
The communication system disclosed herein allows for the hookswitch devices to draw loop current from the phone line in both on-hook and off-hook conditions. Thus, even though an on-hook condition...
6141414 Data access arrangement having combined remote hang-up/ring detection circuitry  
A data access arrangement (DAA) for interfacing a modem with a telephone line which requires only one safety barrier device for providing electrical isolation of the modem from the telephone line...
6044149 Device for detecting DTMF tones  
A self-contained signaling and control device for detecting DTMF tones and generating a signal, such as an audible, visual, or control signal, upon detection of one or more predetermined DTMF tones...
5987120 Device for identifying line reversal/ringing signal of a telephone set  
A device for identifying a line reversal signal and a ringing signal of a telephone set having a built-in ringing detection circuit includes a counter, a comparator and a latch connected with each...
5982878 Combined loop current sink, battery detector, and ringing detector circuit  
A combined loop current sink, battery detector, and ringing detector circuit as used in a channel unit at a telephone central office connection to a digital loop carrier circuit, to provide...
5978471 Method and device for detecting a ringtrip  
A ringtrip detector comprises a reference counter for controlling a battery current generator, which shapes the ring signal, a zero pass detector for detecting zero passes in a voltage at a node,...
5943419 Subscriber circuit with built-in polarity switching circuit  
The subscriber circuit has a balanced amplifier and a built-in call-current polarity changing circuit. Moreover, the output stage circuits of the direct feed-back and offset cancel circuits of the...
5943418 Ring-trip circuit  
A ring-trip circuit monitors the voltage developed across a source resistor coupled to one of the leads of the subscriber line circuit, regardless of the ringing frequency of the ringing voltage...
5915014 Communication system  
An apparatus and a method of setting and confirmation of a value indicative of an on-hook period of a terminal is provided. The value is used as a threshold when distinguishing a hooking pulse for...
5910985 Ground start and tip ground detection without the use of -48V or tip bait circuit  
A loop detector circuit for detecting the loop current of a telephone circuit in a ground start mode and a normal mode which obviates the need for a separate TIP ground detector circuit. A pair of...
5909488 Communication apparatus having a non-ringing call receiving mode and an energy-saving stand-by mode  
A communication apparatus has a power saving stand-by mode for reducing power consumption during stand-by and a non-ringing call receiving mode for communication without ringing an attached...
5905794 Caller identification interface using line reversal detection  
An interface for modems is described which provides rapid identification of a caller and limited access based on a variety of parameters obtained from caller identification information encoded by...
Matches 1 - 50 out of 256 1 2 3 4 5 6 >