Abstract: A LAN cable identifier for testing and identifying copper-conductor LAN cables in conjunction with a LAN cable test instrument is provided. Series combinations of resistors and diodes allow for both resistance measurements and polarity determinations for selected pairs of conductors of the LAN cable. Resistance values are chosen to allow for identification of each combination in order to diagnose wiring errors and to identify the particular LAN cable identifier. In addition, capacitance measurements are accommodated with minimal contribution to measurement error by careful orientation of the resistors and diodes so that the diodes may be reverse biased by a d.c. bias voltage provided by the LAN cable test instrument. The reverse biased diode junctions contribute only a small amount of shunt capacitance to the measurement.

Abstract: A cable testing system includes a far end unit for alternately connecting the wire ends at the remote end of a cable with either a resistive load including a plurality of resistors connected with the wires, respectively, or a source of a-c signals of different frequencies supplied to the lines, respectively. A near end unit connected with the ends of the wires at the adjacent end of the cable is operable during the resistive mode of operation of the far end unit to measure open-circuit and short-circuit conditions of the wires. During the frequency signal mode of operation, crossover between wires is mapped by the use of a differential amplifier, a full-wave rectifier an a slope detector circuit, to provide pulse width, cycle length and slope data for identifying the various wires.

Abstract: A micro-processor controlled apparatus for testing a network cabling. The apparatus is permanently installed at the network cabling site. The micro-processor controls a driver which sequentially provides a voltage carrying current to the individual conductors of each cable in the network. In this manner each conductor of each cable is tested. Hard-wiring and a shorting bar which disengages upon installation of a terminal apparatus provide the voltage carrying current with at least one current path at a remote network port. The voltage carrying current is returned from the remote network port on at least one conductor coupled to a receiver. The receiver samples a plurality of conductors, preferably for evidence of the voltage. In this manner, the receiver samples for the parallel return of a digital word. If the returned digital word agrees with an expected digital word stored in the memory of the micro-processor, an indicating device will signal proper wiring of the tested cable.

Abstract: A system for detecting the presence of and/or identifying wires at the first end of a cable comprises a signal generator for selectively applying an electrical signal to one or more wires at the second end of the cable. At least one electrode is provided for detecting the electrical signal at the first end of the cable and electronic circuitry evaluates the signals coupled to the electrode. The signal generator is an ac generator for delivering an ac square-wave signal and the electrode comprises a conductive tube of a predetermined length for inserting a wire at the first end of the cable. The wire is electrically insulated from the electrode such that the ac signal is capacitively coupled to the electrode.

Abstract: An apparatus and method, using a computer, for the efficient generation of a wiring map of the connectivity between two sets of terminals at different locations which have established communication links between respective terminals at the two locations. A signal at a first location uniquely identifies each of the terminals, by code, frequency, sequence of connection or the like, and is transmitted to a respective terminal at the second location via a respective communication link. The terminals at the second location are sampled and the presence of the transmitted signal correlated to the identity of the first terminal. The correlation may be direct, as by unique terminal identifier, or by a comparison of data bases stored by computers. The computer-based correlation is used to generate a map of the limited terminals.

Abstract: A single hand-held tester performs both off-line continuity tests and on-line voltage tests for electrical cables and equipment such as that used in entertainment, studio or stage lighting. A test plug and a test socket fixed one at each end enable the tester to (a) plug into a power outlet socket to check for the correct presence of a.c. line voltage, (b) engage both ends of an extension cable to test continuity and correct wiring of each wire in the cable or (c) engage the plug end of an extension cable to provide audible indication of the continuity of a load such as a lamp connected to the cable. In a three-conductor (hot, ground and neutral) embodiment, a row of three test pushbuttons, one for each conductor, corresponds with an adjacent row of three LED continuity indicators. Three neon lamps indicate the presence of a.c. voltage between contact members of a power outlet under test.

Abstract: A multi-conductor cable tester and continuity analysis system having two groups of connector sockets wherein each group of connector sockets includes a plurality of different connector sockets designed to mate with the connector ends of the cable under test. An end of the multi-conductor cable is inserted into one cable socket from each socket group and the interconnection between the inserted cable ends is automatically determined by the system which interrogates each connected end of the cable separately, revealing unidirectional coupled data paths as may be provided with diodes or other electronic components. Additionally, the system compares the determined bi-directional continuity with previously stored cable continuity data corresponding to different, known cables and provides reference to one of the cables corresponding to the pre-stored cable data.

Abstract: A connector utilizing a number of electrical connectors wires equal to the number used to provide the static binary indications of the particular piece of equipment attached to the device, and further including diodes and direct connections between the electrical connectors arranged to provide a number of unique coded readouts when each of the individual ones of the electrical connectors are interrogated.

Abstract: A system for tracing routes of conductors is disclosed. An alternating signal is applied to the object to be traced (12), and the field produced by this signal is detected remotely from the object. In order to distinguish between signals produced by the object being traced and those produced by nearby conductors (14) due to capacitive coupling, the alternating signal has first and second components, related in frequency and phase, and the field is detected at a plurality of positions. The phase relationship of the detected signals is investigated to determine unambiguously the position of the object concerned. In one embodiment, the second frequency component is a harmonic of the other. In another embodiment the frequency of the second component is the frequency of the first, plus or minus a sub-harmonic of the first.

Abstract: A hand-held test probe is employed which uses a capacitance measuring circuit to measure capacitance as the probe is scanned along a pattern of conductors (pads or pins) at a steady rate. The capacitance measurement is stored in a memory during the scan, then maximums are detected in the stored data, corresponding to the conductor pattern. If a particular conductor has a short or a break in continuity, its capacitance will be more or less than it should be. The detected maximums are compared with recorded values for a known-good printed wiring board for this scan pattern. If the comparison shows a difference greater than a selected threshold, an error is indicated for this pin location. The known-good is scanned in a "learn" mode, in which the capacitance values are stored for each scan, identified by scan number.

Abstract: A control circuit for a cable tester having a computer interface and a cable adaptor. The latter comprises a current source having inputs from the computer interface and outputs to a first group of solid state switches having inputs from the current source and the computer interface and having outputs to an input of the cable adapter; a second group of solid state switches having inputs from the first group of solid state switches and the computer interface and having outputs to a first amplifier; and a third group of solid state switches having inputs from a fourth group of solid state switches and the computer interface and having outputs to the first amplifier. The fourth group of switches has inputs from an output of the cable adapter and the computer interface and has an output to ground, and the first amplifier has an output to the computer interface.

Abstract: A system for electrical continuity and insulation testing of the electrical conductors of a portion of wiring. Outputs (11b.1, 11b.2, 11b.3) of the connecting elements of the conductors are disposed on a support (12.1, 12.2, 12.3) in the form of a matrix and the means for selecting the output comprise a first set (13.1) and a second set (13.2) movable along rows and columns of the matrix to connect to the measuring means (5) those two outputs of the connecting elements which correspond to the first and second connecting elements of the conductor being tested and a third set (13.2) movable along the rows and columns of the matrix to connect to the measuring means (5) such an output of the connecting elements as corresponds to a connecting element of the conductor under test, and a fourth set (13.3) for connecting other outputs of the connecting elements to the measuring means (5).

Abstract: Method and apparatus for determining nets among nodes in a circuit board that includes applying a potential to a reference conducting surface oriented with respect to the board; measuring a parameter of an electrical response at a node of interest; and comparing the measurements to determine a plurality of nets among the nodes. The tentative net list developed from the measured parameters is then verified using continuity testing.

Abstract: A method and apparatus for detecting an improper connection of one or more cables to signal a cable misconnection error. On a board at one end of the cable there is provided a transmit circuit unique to one of the pins or sockets of the connector and at the other end of the cable at an opposite board there is provided a receive circuit that, when the cable is properly connected, receives the signal from the transmit circuit. A misconnection of the cable eliminates the signal from the transmit circuit thus signaling an error at the receive circuit. In addition, semi-dedicated connector positions are also employed so as to assure a detection of a number of different misconnections of the cable, particularly in a multi-cable system.

Abstract: A hand-held apparatus for testing cable harness for faults and performance impairments comprises three sets of voltage references, CMOS comparator circuitry, programmable DIP switches, an LED status display for error detection, an LED for indication of overall system condition, and a power source. The voltage dividers are utilized to determine reference voltages; each voltage divider comprises a resistor pair. In the preferred embodiment a first set of voltage references is utilized for checking open conditions and is generally associated with odd-numbered wires in the cable harness. A second and a third set of voltage references may be employed for all types of testing, with the second set of voltage references being generally associated with odd-numbered wires and the third set of voltage references being generally associated with even-numbered wires.

Abstract: An identification module and identification determination circuitry are provided for the purpose of identifying an apparatus and electrically determining the identification number of that identified apparatus. The identification module comprises a plurality of resistive identification circuits which, in turn, each comprise a plurality of resistive elements selected to have resistive magnitudes that relate to each other by powers, or orders, of two. The identification determination circuit of the present invention places each of the resistive identification circuits in series with a resistor of known magnitude between two connection points to provide a voltage potential and a resulting current flowing through the resistive identification circuit. The invention also provides a means by which the input voltage can be determined and used to adjust the determined magnitude of the resistive identification circuit.

Abstract: In a preferred embodiment, a cable for serially connecting segments in a multisegment array, at the terminus of which cable the position of a first conductor uniquely identifies that conductor as originating at the nearest segment, the position of a second conductor uniquely identifies that conductor as originating at the second nearest segment and so forth. In a further aspect of the invention, segments can be connected with any one of identical cable sections.

Abstract: A system for forming, in a plane, a wiring harness having a plurality of conductors each of which must follow a predetermined path, of the type which has: (a) a flat support; (b) a unit for representing each of the paths on the support; and (c) a unit for provisionally holding the conductors in position along their path. The representation unit is a coherent light beam generator, for which the flat support plays the role of screen, and which is capable of scanning the flat support so as to display thereon the light trace of the path of a given conductor of the harness. The system further has a unit for storing the information relative to the paths of the different conductors of the wiring harness, which unit is connected both to a unit for identifying a given conductor and to a unit for controlling the beam generator for displaying, on the support, the path specific to the given conductor.

Abstract: A circuit tester includes a light-weight portable transmitter and receiver, with the transmitter being provided with several interchangeable plugs for the testing of power circuits of different voltage. The plugs are alternately firmly electrically and mechanically coupled to apply power to the transmitter, which does not need a battery. The transmitter transmission circuitry operates on a relatively low voltage such as 9 volts, and the transmitter input circuitry operates without switching circuits to reduce the applied power to this operating level. The transmitter only weighs 21/2 or 3 ounces and the receiver only weighs 7 or 8 ounces. Unique modulation or interruption of the transmitter operates audio and/or visual signalling elements in the receiver.

Abstract: A system for tracing a conductor connected between a terminal of one terminal block and a terminal of another terminal block within a network of conductors and terminal blocks includes a supervisor associated with each terminal block for imposing a trace signal selectively on any of the terminals of said block. The supervisor also detecting a trace signal appearing on any of said terminals. A controller communicates with the supervisors to cause a selected supervisor to impose a trace signal on one of the terminals of its associated terminal block, and receives from the supervisors a report of another terminal at which the trace signal appears.

Abstract: Method and apparatus for identifying and determining the energization status of a cable having a conductive neutral member and an internal resistive screen layer involving probes radially movable relative to the cable to contact the neutral member and the internal resistive screen. Narrow-band AC signals and resistance measurements are utilized for self-testing and for cable testing. A microprocessor controls probe-heating in the advancing of probes through plastic sheath to reach the neutral wire and resistive screen layer. Resistance measurements made under control of the microprocessor are monitored with probe advance. Oscillators provide two signals of different frequencies, one of which is that of the power being transmitted through the cable, to provide distinctive signals indicative of cable energization status.

Abstract: The present invention concerns a system to test wiring parts, said system comprising a test bench having connection means for said wiring parts, each of said parts comprising connectors.According to the invention, said connection means (1) comprise a plurality of identical connection locations (3) and the system further includes intermediate connection devices (5) between the test bench (4) and the wiring part to be tested, each of said intermediate connection devices comprising a first connector (6) complementary to the corresponding connector of the wiring part to be tested and a second connector (7) designed to be connected to certain of said connection locations (3) whose position is specific as regards the wiring part to be tested, said first (6) and second (7) connectors being connected to each other by a flexible linking cable (8).

Abstract: A tractor-trailer light system test circuit comprises: a first multi-pin plug; a plurality of circuit breakers; a second multi-pin plug; an audible buzzer; an ON-OFF push button switch; a first LED, a second LED, and a third LED; a plurality of resistors; a first resistor, a secon resistor, and a third resistor; a first test plug and a second test plug; and a first plurality of light emitting diodes, a second plurality of light emitting diodes, and a third plurality of light emitting diodes.

Abstract: Testing apparatus is coupled to the plug used to connect the electrical system of a towed or trailer vehicle with a main or powered vehicle. The plug typically has terminals which connect related trailer vehicle electrical components with components in the main vehicle, e.g., the back up lights of the trailer vehicle are coupled to the back up lights (or transmission reverse gear) of the main vehicle. After coupling the testing apparatus to the plug portion attached to the trailer vehicle, switches can be used to activate selectively the trailer vehicle components. Instruments in the testing apparatus measure the electrical response to each activation and can be used to determine when the components are operating correctly. Similarly, when the portion of the plug coupled to the main vehicle is coupled to the testing apparatus, the response to activation of the main vehicle components can be monitored by the same instruments.

Abstract: An apparatus and method for testing the integrity of wiring cables provides a transmitter and a receiver that electrically connect to opposite ends of group of wires to be tested. The transmitter produces a voltage test signal applied to a test set of wires and a different voltage reference signal is applied to a reference set of wires. At the receiver, indicator circuits interconnect the wires to a common bus. The reference signal is applied to the common bus and, when the test signal is present, the indicators operate to produce a display. The test signal can be cycled through a plurality of test sets making up the entire test group.

Abstract: A cable tester for testing the individual conductors of a multiconductor cable. The cable tester includes a transmitter for connection to one end of the cable and a receiver for connection to the opposite end of the cable. The receiver includes a microprocessor having an EPROM memory. The receiver also includes an LCD display and a key pad for data input. In use the transmitter sequentially generates voltage pulses through each conductor of the cable and to the receiver. The receiver monitors these pulses at the opposite end of the cable and feeds this data into the microprocessor for processing and display on the LCD display. The cable tester quickly detects shots, opens, or crossed conductors within the cable and provides results of the testing on the LCD display.

Abstract: A continuity tester comprising a transmitter operatively connected to the ends of a plurality of wires which are extended through an electrical conduit. The other ends of the wires are connected to a receiver unit. The transmitter sequentially supplies power to the individual wires connected thereto with diodes being sequentially illuminated at the receiver to establish the identification and continuity of the individual wires.

Abstract: A coding device for an electric cable plug connection having a plug connected to wires of a cable and insertable into a socket, both the plug and the socket being formed with a plurality of contacts, has a coding arrangement for assigning the plug to the socket in a correctly oriented position. The coding arrangement includes at least one jumper link connecting various of the contacts of the socket. The jumper link forms together with the cable connection an electrically interrogatable test loop.

Abstract: A method and apparatus for determining the conductive integrity of a plurality of lines which transmit electromagnetic radiation.

Abstract: A system for identifying interconnections between individual points in a communications network of the kind in which includes a plurality of multiple conductor links, individual conductors of which are selectively terminated and interconnected at corresponding individual terminals of terminal blocks; a controller broadcasts over a test network that includes the terminal blocks an inquiry that identifies a starting individual conductor to supervisors associated with the terminal blocks; the supervisor associated with the terminal block that terminates the starting conductor applies the inquiry to the individual terminal that corresponds to the starting individual conductor for transmission on the communications network, and each supervisor reports to the controller over the test network the identitites of any one or more individual terminals of its associated terminal block that detect the inquiry; whereby interconnections between the starting conductor and one or more other individual conductors in the commun

Abstract: An apparatus and method for identifying individual conductors in a multi-conductor cable, which will also identify a short or open circuit condition. One end of the multi-conductor cable is connected to a battery powered transmitter unit which sequentially generates a unique pulse on each conductor. That is, the transmitter generates a pulse on a first conductor having a unique pulse width and after a small delay follows the pulse on the first conductor with a pulse on a second conductor having a unique pulse width, preferably twice the pulse width. The transmitter sequentially steps through each conductor in a cable to generate the unique pulses. The battery powered receiver unit is connected to the other end of the multi-conductor cable with a test probe and a reference probe connected to any two conductors.

Abstract: An identification assembly designed to locate and identify one of a large number of collectively disposed electrical conductors such as coaxial cables, applicable when interconnecting one end of the conductor for interconnection to a control console. A control unit attachable to one end of a specific conductor is capable of directing current flow to the conductor to activate an indicator unit attached to the opposite end of the conductor wherein activation serves to distinguish and identify the opposite end for attachment to the correct positioning in a control console, panel or the like.

Abstract: A monitor for detecting miswiring in standard 3-spade AC electrical outlets. The monitor includes a housing, prongs for insertion into the outlet to be tested, outlet ports for an external plug, and a banana jack for a wrist strap or other anti-static device. If the outlet is properly wired, a lamp will illuminate. If, however, the outlet is miswired, one of two silicon controlled rectifiers will shunt current around the lamp, extinguishing it, indicating to the user the presence of a faulty outlet. A junction field effect transistor is also provided to activate one of the silicon controlled rectifiers when one particular miswiring condition is present.

Abstract: An apparatus is disclosed for automatically making and testing electrical cable assemblies. A novel coupling is provided between the bulk cable contained on a large reel and the logic circuitry of the automated machine so that individual wires within the cable can be identified, inserted into a desired terminal of a connector, and tested. The coupling utilizes a slip ring assembly to communicate with the individual wires of the cable through a connector that has been previously terminated on a pigtail extending from the central core of the reel.

Abstract: A self-contained polarity tester (1) tests connection within a device (40), e.g. a lamp fixture, of a power input plug (41) to a socket (53). A tester body (3) has a polarized receptacle (10) which receives the plug (41). A probe (20) mounted to the tester body (3) is moved by an operator to engage the socket (53). A low-level power source (35) in a circuit in the tester (1) is connected to energize one of a plurality of indicator devices (16, 17) dependent upon the polarity of the connection of the plug (41). Illumination of neither indicator device (16, 17) or both is indicative of a short or open circuit respectively.

Abstract: An apparatus and method for the efficient generation of a wiring map of the connectivity between two sets of terminals at different locations which have established communication links between respective terminals at the two locations. A single at a first location uniquely identifies each of the terminals, by code, frequency, sequence of connection or the like, and is transmitted to a respective termimal at the second location via a respective communication link. The terminals at the second location are sampled and the presence of the transmitted signal correlated to the identity of the first terminal. The correlation may be direct, as by unique terminal identifier, or by a comparision of data bases stored by computers. First and second data bases, each relating the terminal locations to the transmitted information, respectively, are correlated to create a third data base used to generate a map of the linked terminals.

Abstract: A circuit locater includes a passive signal device adapted to be plugged into a power outlet to draw a large amplitude current pulse of very short duration (identification signal) from the power source supplying the outlet. A receiver has a pickup coil that senses the magnetic field generated by the identification signal current. A sensitivity control reduces the sensitivity of the pickup coil until an output signal is produced only when the receiving coil is adjacent to the circuit breaker of the electrical control panel that is supplying power to the passive signal device.

Abstract: Telecommunications (e.g. ISDN) wiring is tested by sequentially supplying to each wire at a first location a pulse sequence identifying that wire while connecting to a common potential other wires, and detecting pulses on the wires at a second location while simultaneously providing a return path connection for the pulses to the other wires. The return path connection is provided by connecting between each wire and a local ground at the second location a resistor and a diode poled to be reverse biassed by pulses on the wire. The detected pulses are counted and the result used to drive a LED (light emitting diode) display comprising N green LEDs indicating correct wiring and N(N-1) red LEDs indicating incorrect connections, the LEDs being arranged in an N by N array with the green LEDs along one diagonal.

Abstract: An apparatus and method, using a computer, for the efficient generation of a wiring map of the connectivity between two sets of terminals at different locations which have established communication links between respective terminals at the two locations. A single at a first location uniquely identifies each of the terminals, by code, frequency, sequence of connection or the like, and is transmitted to a respective terminal at the second location via a respective communication link. The terminals at the second location are sampled and the presence of the transmitted signal correlated to the identity of the first terminal. The correlation may be direct, as by unique terminal identifier, or by a comparison of data bases stored by computers. The computer-based correlation is used to generate a map of the limited terminals.

Abstract: The present invention constitutes an apparatus for assembling multiple electrical contacts and filler elements into an electrical connector. The apparatus includes a filler assembly for automatically installing filler elements into the holes within the electrical connector which are to be unoccupied by electrical contacts, and a guide assembly which is functional for assisting the operator in manually inserting the electrical contacts into the correct holes within the connector by providing a visual indication of the holes into which the contacts should be inserted. The filler and guide assemblies operate on connectors held into position on a turntable-like indexing plate which allows the connectors to be rotated alternatively into position with respect to each of the assemblies. The filler assembly includes one or more filler element inserter tools which are adapted for inserting filler material from strands of such material into the holes within the connectors so as to form installed filler elements.

Abstract: A test assembly for testing a preassembled wiring harness for location of mounting brackets at spaced points on the harness assembly and for evaluating terminals of the wiring harness includes a faceplate with a plurality of slots formed across the full planar extent thereof to accommodate a variety of different holder and detecting device layouts corresponding to a variety of types of wiring harness configurations. A separate faceplate is supported on each of a plurality of modular units joined together to accept different length wiring harness configurations. Standard length cables are connected to each of the holders and detecting devices. The cables have a connector wired thereto which fits through the slots to provide access from the faceplate to the interface cards without splicing into the wiring system.

Abstract: The present invention provides a system for the identification of the phase of conductors in electrical circuits, at junctions location, regardless if the connectors are connected to ground. The system comprises two independent generators connectable to the phase conductors by electromagnetic coupling, and at any available location along these conductors, and generating different audio signals. An appropriate receiver is provided and connected to the phase conductors, at selected locations for the identification of the different audio signals. The present invention also provides a method for the identification of the phase of conductors in an electrical circuit, even when the conductors are connected to ground above the selected location for effecting the identification. The method consists in connecting, by electromagnetic coupling, two independent generators generating different audio signals, in pre-identified phase conductors.

Abstract: A coaxial cable testing device has a modular construction wherein the several pieces may be configured in different arrangements to fulfill the separate functions of a flashlight, a continuity checker, a cable identifier, and a bandit splitter detector. The pieces are provided with connector elements which allow each of the pieces to fit together and the pieces are small enough to conveniently fit in the shirt pocket of a cable television technician. In the flashlight configuration, a battery pack (10) and a flexible flashlight assembly (18) are interconnected. In the continuity checker or cable identifier configuration, the battery pack (10) is connected to one end of a cable (28) and the detector section (24) and shorting plug (26) are connected to the other end of the cable (28). In the bandit splitter detector configuration, the battery pack (10) is connected to the detector section (24) which is connected to the cable (28).

Abstract: A portable cable identifier and tester assembly for a four line token ring network type cable, including a first unit having a power supply and connector mateable to one end of the cable and a second unit mateable to ends of potentially matching cables to provide a signal indicating cable identification. Jumpers are provided in each of the units to ensure that the test signal current is routed through all four wires and connectors. Shorting bars between cable lines in unmated connectors, and spurious personal computer supply voltages, do not inhibit cable identification. User ease and self-test are inherent features.

Abstract: A multitude of alarm indicators are layed out in a signal line for the purpose of monitoring an extensive object. Such an object can be a large building, a pipeline or similar device. In order to determine which of the alarm indicators has triggered off the alarm, a repeated pulse is fed into the signal line whose echo is compared with a programmed-in echo signal. The programmed echo signal is acquired through the transmission of a pulse when all of the alarm indicators are out of service. By comparison of the programmed-in echo signal with the measured echo signal, the distance of the activated alarm indicator from the beginning of the signal line can be measured.

Abstract: The invention concerns circuit testing devices for connection to an existing electrical circuit to determine whether or not power is present across a pair of conductors. The devices are characterized by having a selector switch which may be placed in either a first position, wherein the device is so connected that an audible signal is emitted only when power is present across the conductors to which the device is connected, and a second position, wherein the audible signal is emitted only when power is not present. The device is disclosed in an embodiment which may be used with either AC or DC circuits, each at various voltage levels, and in a further embodiment wherein the audible alarm is actuated by a radio receiver which receives signals from a transmitter connected to the circuit being tested.

Abstract: Apparatus and methods for testing multiconductor data cables. A test connector having plural elements is engaged with one connector of the data cable, and a test signal is applied to a preselected common element of the test connector. The test signal is conducted through one conductor of the data cable to a connector on a breakout box and terminals on the breakout box are interconnected with one another while the presence or absence of the test signal at elements of the test connector other than the common element is detected.

Abstract: In a method and apparatus for discriminating between a broadband unipolar signal having a component within one or more of three predetermined frequency bands and a narrowband signal within one of the frequency bands, a signal under test is amplified by a gain which is inversely proportional to the DC content of the signal under test to normalize the signal under test. The normalized signal is bandpass filtered to attenuate components outside of the predetermined frequency bands and the filtered signal is compared to a reference signal. The signal under test is deemed to be a narrowband signal within one of the predetermined frequency bands if the filtered signal exceeds the reference signal. The method and apparatus are particularly useful for detecting test tones on optical fibers.

Abstract: A circuit tester provides an indication of open circuit faults of individual conductors in cables. An oscillator circuit in the tesster includes a capacitance as an internal part of the circuit. Test probes connect conductor pairs to the oscillator circuit, thus changing the effective capacitance of the circuit. This changes the frequency output of the oscillator in accordance with the length of the conductors. Test indications may include a low pass filter and an audio circuit, or a circuit to convert frequency to a voltage or digitalized output. The tester may be used with automated test equipment.

Abstract: An apparatus and method for determining which one of a plurality of circuit breakers in a breaker box controls a given electrical outlet supplied by one of the circuits emanating from the breaker box. A transmitter is plugged into the electrical outlet of interest which imposes a low frequency RF signal on the power line. The transmitter includes an indicator for indicating whether power is present at the outlet of interest. A receiver is plugged into a second electrical outlet near the breaker box, the receiver being configured to detect whether the low frequency RF signal is present at the second outlet, and includes an indicator to indicate whether the signal is present at the second outlet. The receiver also includes an indicator for indicating whether power is present at the second outlet. Each of the circuit breakers are turned off and back on in sequence until the circuit breaker is found which causes the receiver signal indicator to go off, while the receiver power indicator remains on.