Abstract: A method and apparatus for testing the proper operation of the optical elements in the optical detection circuit of an electronic register in an energy meter. The light emitter circuit is periodically pulsed adequate to turn the emitters to the on condition, and a comparison circuit is provided in which the voltage across a monitor point in circuit with the light emitters and a switching circuit is monitored both before and after each pulse. The absence of a voltage change upon pulsing the light emitter circuitry is used to generate a first error or failure signal. The light detector is read prior to each pulse to determine if unprogrammed light is being received prior to the pulsing of the light emitter as an indication of tampering with the accurate reading of the energy meter, and a second error signal is generated in response to unprogrammed light.

Abstract: An input protecting mechanism for a measuring device, such as a digital multi-meter, wherein a shutter is provided to open and close selectively input terminal holes for leads, depending on the particular measuring function selected so that the test lead cannot be placed in an improper terminal, so that advantageously, damage to the internal circuitry is prevented by preventing erroneous signals from being applied to the wrong circuits.

Abstract: An apparatus for detecting illegal tampering with an electricity meter which is adapted to record the amount of electricity supplied to the meter through cables has a first signal generating sensing coil situated externally of, and upstream of, the meter which generates a first signal representative of the current flowing through one of the supply cables and a second signal generating second sensing coil, located within the meter, which generates a second signal representative of the amount of electricity to be recorded by the meter. A Monitoring device monitors the first and second signals and produces a third actuation signal when one of the first and second signals differs from its correct value as a result of tampering. The first and second signals charge and discharge a capacitor. When the voltage on the capacitor reaches a predetermined level, the third signal, which may cause the load to be disconnected or may produced a warning, is generated.

Abstract: A vent (180) for an electricity metering device (30) having a housing (34) having a generally planar surface thereon with a cavity (35), a plurality of vent openings (182) on the surface of the housing (34) which extend through the surface for allowing passage of air therethrough and a plurality of vent shields (184) positioned on one side of the surface adjacent each of the vent openings (182), preventing access through the vent openings (182) into the interior of the housing (34), the vent shields (184) including a first wall (190) extending generally perpendicular from the surface of the housing, and a second wall (192) attached to the first wall (190) extending generally parallel to the surface.

Abstract: A system for monitoring use of a utility at a consumer's premises is disclosed. The system may include monitoring apparatus to detect use of the utility, a first register to store an indicator signal indicating whether or not use of the utility at the consumer's premises is authorized, and an unauthorized use signal generator, responsive to the monitoring apparatus output and the contents of the register, to generate an unauthorized use signal when the monitoring apparatus output indicates use of the utility and the first register contains an indicator signal indicating that use is not authorized.

Abstract: A totalizer and rate meter is totally enclosed within a permanently sealed, fluid tight body formed of a low cost, transparent epoxy material. The meter can be programmed in the field by means of an optical transmitter communicating with an optical receiver enclosed within the transparent body of the meter.

Abstract: A securing mechanism for an electricity metering device (30) including a housing (34) having a cavity, a cover (36) positioned on the housing (34) and enclosing said cavity, the cover (36) including hinge pins (120,122) for attaching the cover (36) to the corresponding hinge slots (80,82) on the housing (34) and a sealing screw (126) connected to the cover (36) for releasably securing the cover (36) to the housing (34). The sealing screw (126) is threaded through a hole (124) in the cover (36), and includes an opening (158), and the cover further includes a lug (162) defining a second opening (164) positioned for cooperation and registration with the first opening (158) when the sealing screw (126) has secured the cover (36) to the housing (34).

Abstract: In multimeters having a plurality of input connections there is a danger of the measuring conductors being incorrectly connected in such a manner that the setting of the measurement range switch does not correspond to the input connections to which contact is made. In order to avoid damage which may be caused by making an incorrect contact to the input connections, an electrically and/or mechanically acting disabling device is coupled to the measurement range switch for permitting a disabling of particular input connections. The disabling is carried out in such a manner that contact can always only be made to that input connection for receiving a test signal through the measuring conductors, to which a measurable variable is assigned that corresponds to the measurable variable set with the measurement range switch.

Abstract: An apparatus and method to detect and avoid inaccuracies in an electronic energy meter due to reverse rotation of the eddy current disk in response to pull-back and creep of the disk, or tampering, including the detection of reverse rotation by checking each three successive states of light transmission between two light emitter/detector pairs in response to an optical castellated disk passing between the emitter/detector pairs, storing pulses generated by the reverse rotation and subtracting the stored pulses upon a subsequent reversal of rotation to the forward direction. Upon reverse rotation in excess of one revolution, the stored pulses are counted along with the counting of the additional reverse rotation pulses and an error signal is generated for subsequent display in response to a command signal.

Abstract: A disposable tamper detection device for electricity meters of the type having a meter housing with current-carrying blades protruding therefrom for insertion into a meter socket, comprises a non-conductive board-like member having a pair of slots adapted to fit over a pair of respective protruding current-carrying blades so as to bridge them. Terminals establish contact with the pair of protruding blades. A fuse and current limiting device are connected in series between the terminals. The current limiting device limits the current flow through the fuse to a sufficiently low level to prevent the fuse from blowing under normal conditions. A switch, spring biased into the closed position, is connected in parallel with the current limiting device. The switch means has a retainer adapted to be engaged by the meter when fully inserted into its socket to retain the switch in the open position against the spring bias.

Abstract: An arrangement for electrical measurement ascertains "subordinate" quantities, and is also "main" quantities with great accuracy and safety against falsification. An active energy to be measured is a main quantity, and a subordinate quantity is at least one of the following quantities: effective value of the voltage (u.sub.N) or of the current (i.sub.N), volt hours, volt square hours, ampere hours, ampere square hours, active power, reactive power, reactive energy, apparent output, apparent energy or power factor. The arrangement may comprise a voltage sensor (8), a voltage/current-converter (9), a multiplier (10), a current/voltage-converter (11), two analog/digital-converts (12 and 15), a signal/frequency-converter (13), a counter (14), an interface circuit (4), and an indicator (7), wherein the current/voltage-converter (11) consists of a constant current source (16) and a further multiplier (17).

Abstract: A method and apparatus for testing the proper operation of the optical elements in the optical detection circuit of an electronic register in an energy meter. The light emitter circuit is periodically pulsed adequately to turn the emitters to the on condition, and a comparison circuit is provided in which the voltage across a monitor point in circuit with the light emitters and a switching circuit is monitored both before and after each pulse. The absence of a voltage change upon pulsing the light emitter circuitry is used to generate a first error or failure signal. The light detector is read prior to each pulse to determine if unprogrammed light is being received prior to the pulsing of the light emitter as an indication of tampering with the accurate reading of the energy meter, and a second error signal is generated in response to unprogrammed light.

Abstract: A sealed utility meter having internal automatic disconnection. The meter contains a battery source of power for energizing the circuitry and is used in its operating environment in a horizontal position. In order to minimize battery drain prior to operation the meter is provided with a tilt switch mounted at a substantially 45.degree. angle to horizontal to energize the meter when it is in its operating position and deenergize the meter when it is removed from that position. The meter is packed in a container with packaging material which determines the packed position of the meter and the packing carton is provided with indicia to indicate the proper shipping and storage orientation of the carton. When the meter is thus packed and the carton thus oriented the circuitry is deenergized.

Abstract: A method and apparatus for enabling the continuous monitoring of the operational state of circuit components includes a scheme for generating a plurality of voltage signals representing neutral-to-line voltages of the system and adding to each of those signals a second signal, each second signal being identical. This addition is done vectorially to yield a modified signal. A representation of the modified signal as acted upon by the circuit to be monitored is compared with a representation of the neutral-to-line voltage signal to yield an output signal representative of the operational state of the circuit components.

Abstract: A system for detection of tampering with a utility meter provides not only an indication that tampering has occurred but also sufficient information to enable an estimation of actual consumption to be made as opposed to the tampered metered consumption. The device includes a plurality of tampering sensors sensing tilt, electric field, magnetic field, temperature, sound, reverse rotation of a moving element and excessive difference between metered consumption and an approximate actual consumption. The device also measures the movement of the moving element. These sensed signals are recorded in sequential time periods of for example eight hours so that an analysis can be made on a daily basis to provide an accurate pattern of consumption as opposed to the tampered meter consumption pattern.

Abstract: A method and apparatus for adjustment of the assembly of an electric power meter which rotates in response to power consumption which enables successive test positions to temporarily support the assembly without marking the bearing, and provides only a single mark on the bearing at the final factory adjustment position with an indication on the bearing of any subsequent tampering with that position.

Abstract: A method for detecting tampering with a dial of a utility meter is used with a meter of the type including at least one rotary dial having angularly spaced circumferentially arrayed indicia and an indicator, the indicator and said indicia being relatively rotatable by a gear train having at least one gear which rotates in unison with the dial in operation. The method includes emcoding the gear with a code which corresponds in a predetermined fashion with the indicia of the dial and anotating on the meter a predetermined key to the initial correspondence of the code with the relative position of the dial indicator. The invention extends to an apparatus for carrying out the foregoing method.

Abstract: A radio communications network for transmitting data from a plurality of remote stations to a central station is provided. This system is particularly proposed for automatic meter reading systems in which the remote stations are located at utility meters. The system includes an array of receiving stations arranged relative to the remote stations so that the mesages from each remote station can be received by at least two and preferably four of the receiving stations providing a high level of duplication of messages. The remote stations transmit utility usage information obtained from the previous time period at a random time subsequent to the time period so that message collisions can occur. High level of duplication provided by the increased number of receiving stations reduces the message loss. A quiet period during which the remote stations are prevented from transmitting can be used for communication between the receiving stations and the central station.

Abstract: A watt-hour meter cover is provided which has an optical coupler including a conduit, lens, and means for engaging an external programmer/reader. The conduit has improved signal transmission properties. The cover may be designed to disable test mode hardware when replaced after meter servicing. A battery access hatch and module with a reset and scroll actuator is installed through the cover.

Abstract: A voltage rotation indicator for testing the phase sequence of live multi-phase electrical power is mounted within a housing. The housing is provided with structure for removably mounting the indicator on a meter box or can during voltage rotation testing. Contact plungers extend from the housing and contact meter jaw test points in the meter box during testing. Field personnel are thus not required to insert their hands into the meter box to attach test clips to the live circuit.

Abstract: An electromagnetic and thermal shield for an electronic energy meter which includes a base, a register and intermediate electronics. The tapered form fitting shield extends from the register to the base and includes intermediate resilient fasteners formed from the shield to position, secure, and shield the components of the meter.

Abstract: There is described a magnetic field detecting device having a pickup coil surrounding a tee shape core of magnetic material which is packaged in a housing having external indicia to indicate location and orientation of the magnetic core. A battery operated voltage sensitive relay circuit activates an audible annunciator when the pickup coil is placed adjacent a current-carrying potential coil in a polyphase watthour meter. Scanning the watthour meter with the device placed against the meter glass housing serves to reveal an open circuited potential coil.

Abstract: An electronic energy meter is provided with a plurality of push button switches on the face of the meter which are selectively actuated by an actuator extending through the transparent cover to display various different meter functions. Switch restrictors are removably provided around a section of the actuator of selected switches which may then be readily actuated only from the inside of the meter, after unlocking and removing the cover.

Abstract: A high voltage pulse regulator which is capable of measuring and correcting voltage perturbations on the top of a high voltage square wave pulse is disclosed. The regulator uses: a rectifying diode, an oscilloscope, a variable zener diode, a variable biasing current source and pulse capacitor. The rectifying diode receives and rectifies the high voltage square wave pulse from a high voltage pulse source to produce a rectified square wave pulse. The rectified square wave pulse is received and regulated to a voltage level acceptable to the oscilloscope by the variable zener diode pulse capacitor, and current source, which are connected together in a parallel circuit and act as follows. The variable zener diode is activated by the biasing current.

Abstract: A fusing and detection circuit includes a diode fusing element which is coupled to a fuse input terminal of an integrated circuit. Upon the application of the proper voltage at the fuse input terminal, the fuse element is blown, causing the diode to become a low impedance resistor. The detection circuitry senses whether the fuse has been blown or not and provides a lock or unlock indication at an output terminal. The fusing and detection circuit is designed to thwart attempts to change the lock status to an unlock status after the fuse has been blown.

Abstract: A current detector comprises a primary current transformer (21) having a core made of silicon steel sheets and permalloy sheets overlapping each other, together with secondary current transformers (22) and (23) having cores made, respectively, of silicon steel and permalloy sheets. As a result, the detector exhibits linear current transformation throughout any current range, so that current detection errors are minimized.

Abstract: A portable electrical energy monitor for measuring the electrical energy usage of an appliance or the like is disclosed. The monitor includes an enclosure having a cover for opening and closing the enclosure. An electrical measurement device or circuit is positioned within the enclosure and includes a receptacle plug for complementary interconnection to a receptacle plug of an appliance, also to be received within the enclosure. The cover of the enclosure is closed when the appliance receptacle plug is operatively interconnected to the receptacle plug of the electrical measuring device or circuit. A visual display device is connected to the electrical measuring device and is mounted to the enclosure for visual display of electrical energy usage of an interconnected appliance.

Abstract: A non-destructive reverse-bias second breakdown tester for testing semiconductor devices such as transistors and thyristors that have a base-collector-emitter configuration. The tester basically comprises a socket for holding the device under test. A base drive provides a drive current to the base of the device under test. A collector supply provides a collector current to the device under test. A current diverter diverts current away from the device under test when the device under test experiences reverse-bias second breakdown. The diverter includes first, second and third switches arranged in series. A diode diverter is connected to the current supply and the third switch. A detector produces a first signal at the onset of reverse-bias second breakdown in the device under test. In response to the first signal, the first, second and third switches are activated in seriatim.

Abstract: A method for nondestructively electronically detecting a short circuit in a conductor system which is composed of two parallel inductor groups connected together to form a selected current path when no short circuit exists, by the steps of: disposing a current probe at a selected location of the current path for sensing changes in the current flowing in the path at the selected location; and injecting a fast rate-of-rise current pulse into the path; and monitoring the response of the current probe to provide an indication of the existence of a short circuit.

Abstract: A device for use in connection with electricity meters incorporating current transformers is disclosed. The device detects saturation incidents of the magnetic cores of the transformers, thereby reducing measurement errors.

Abstract: An anti-tamper device is disclosed for utility meters of the type comprises comprising a fixed base unit and a removable plug-in unit associated with said base unit. The device comprises an electronic indicator for generating a new indication in response to a trigger signal, and a detector operable in response to the insertion of said plug-unit into the fixed base to generate said trigger signal. A different indication is generated each time the plug-in unit is inserted into the fixed base, thereby facilitating the detection of meter tampering.

Abstract: A self contained sensor module mounted on a power transmission line. The module is capable of measuring various parameters such as line current, voltage, conductor temperature and ambient temperature. The parameter values are processed by sensor electronics which digitize and periodically transmit the values to a ground receiver. The module power supply is coupled to the transmission line conductor by a transformer. The line conductor extends through a magnetic core in the module housing. A secondary shunt magnetic core is provided to limit induction of high voltages as a result of excess current flowing through the transmission line conductor.

Abstract: A meter tampering detection device, comprising a sealed housing adapted to be installed in the cover of a utility meter, a supply of flexible tape in said housing having a graduated scale which changes as the tape is withdrawn from the housing, an aperture in the housing through which the free end of the tape is passed, said tape being arranged so that it can be withdrawn from the housing by exerting a pull on the free end, and said tape being arranged and having a flexibility such that it cannot be pushed back into the housing once withdrawn, and gripping means for installation on a fixed part of the meter for gripping the free end of the tape such that said tape is withdrawn from the housing as the cover is removed.

Abstract: A tamper-resistant removable cover for a utility meter box assembly is disclosed, having a plate member with depending flange portions which engage the securing flange or ring normally used to secure a translucent cover over the viewing window or socket of the meter box. The cover provides a high degree of security for meter boxes, reducing theft of services and/or vandalism that is encountered with conventional methods of securing such boxes. The present cover may use the existing securing device or devices on the box or may be provided with fasteners to engage a portion of the box.

Abstract: A test enabling circuit for actuating specific testing circuitry contained within a programmable device, whereby the test enabling circuit and a portion of the normal operational circuits of the device share a common input pin. Because of the dual functionality of the common input pin, the test enabling circuit is designed to respond to a specified test signal, which is either of an opposing polarity, or of a higher magnitude of the same polarity with respect to the normal operational signal. The enabling circuit includes several IGFET devices arranged such that the noise margin of the enabling circuit may be adapted for accommodating varying environments of noise. ESD circuitry is included to protect the testing and test enabling circuits against electrostatic discharge.

Abstract: An electricity metering equipment wherein, in order to reduce the possibility of fraudulent consumption of electricity, there is provided in addition to the usual meter (3) for measuring the amount of electricity consumed in a load, an independent device (5) which produces a signal representative of the current supplied to the load. A comparison device (4) then compares the signal with the rate of electricity consumption measured by the meter, and an output signal is produced if there is a discrepancy which may be used to disconnect the supply and/or transmit a signal to the supply authority.

Abstract: A remotely controlled locking device is provided for preventing unauthorized withdrawal of watt-hour meters from their sockets. The locking device is typically located beneath the base of the meter in the socket, and both the meter and socket can be of standard design. The device may be associated with apparatus to indicate withdrawal of the meter and to count interruptions of power to the meter, thereby providing further security against tampering.

Abstract: A current measuring arrangement including a measuring resistor can be protected against excess currents by means of a PTC-resistor and an amplifier circuit. This protection is self-restoring in contrast to the conventional series-connected safety fuse. The amplifier circuit, the PTC-resistor and the measuring resistor may be arranged so that the property of zero voltage drop of a known circuit arrangement is maintained.

Abstract: A system for measuring electric power supplied through a power distribution network and, inter alia, detecting theft of power from the network, and a remote reading Hall effect based electric power meter for use therein are both described.

Abstract: A locking cover assembly for the ends of an electric meter retaining ring, to receive a lock bolt from the front side thereof to retain the cover in place and thereby prevent access to the clamping bolt that retains the ring in place. The cover comprises a housing having an internal locking plate apertured to receive the end of a lock bolt in a position such that it extends between the legs of the retaining ring and over the clamping bolt.

Abstract: Tampering with an optically encoded meter display register or metering mechanism can be readily detected by comparing the quantity shown by the meter display with the encoded values of the optical encoders. A discrepancy is indicative of tampering with the register display. Any tampering with the optical encoders or the metering mechanism can be detected by comparing the present position of the encoders with that of a previous position and generating a signal indicative of tampering when these positions have a predetermined relationship to each other.

Abstract: In order to maintain the torque of the ratio meter and the drive of amplifiers feeding it independently of the amplitudes of a sine signal voltage and a cosine signal voltage, a regulation is provided. The regulation makes use of two-quadrant voltage-controlled sources of current each of which is connected to a coil branch. Control voltage amplifiers, one connected in front of each source of current, are furthermore used. A sum-current resistor is provided to form the sum of the supply currents of two voltage-controlled sources of current. The supply currents represent the amounts of the sine signal voltage and cosine signal voltage which act on the voltage amplifiers. From the resistor for the formation of the sum of the supply currents a signal is derived which switches the amplification of the voltage amplifiers automatically in the direction of compensation.

Abstract: A device for assembly with a bolt or screw upon installation thereof to prevent tampering therewith, including a jacket member for encircling the enlarged fastener head with a collar portion for disposition adjacent its underside to clamp the jacket member in place upon tightening of the fastener and a cap member configured to fit within the jacket member to enclose the fastener head therewithin. A rounded annular channel is formed within the anterior wall of the jacket member and a square annular rib is formed on the outer surface of the cap member to provide a snap-tight interference fit therebetween. The interior jacket wall and the outer cap surface are also tapered at slightly differing angles to provide a supplementary interference friction fit. The snap-fit between the jacket and cap members is sufficiently strong that they cannot be separated using conventional tools without damaging or destroying the members. A special tool is provided for authorized separation of the jacket and cap members.

Abstract: A multimeter is provided with two slide switches, one switch providing a selection of four functions, i.e. "OFF", "AC", "DC/JUNCTION" and "RESISTANCE/CONTINUITY" and the other switch providing a selection of six range settings and a "JUNCTION/CONTINUITY" setting. The multimeter also has three input sockets for insertion of test leads. At least two of the combinations of the switches and sockets are incompatible, i.e. "AC" and "JUNCTION/CONTINUITY", and a current input socket and "RESISTANCE/CONTINUITY". An internal buzzer is incorporated in the multimeter to provide an audible indication to a user that an incompatible combination has been selected. The buzzer is preferably also used in junction and continuity test modes.

Abstract: An electronic demand register for an electric meter includes a plurality of pushbutton controls for controlling material displayed or a mode of operation of the demand register. A lockable switch actuator includes an actuating paddle within a cover or housing of the meter which, when unlocked, can be rotated into alignment with a selected one of the pushbutton controls and then pushed inward to actuate the selected pushbutton control. A pair of bosses bracketing one of the pushbutton controls prevents actuation of its respective control until the actuating paddle is accurately positioned between them. A second pair of bosses bracketing another of the pushbutton controls are spaced too closely apart to permit the actuating paddle to pass therebetween and they thus prevent actuation of their respective pushbutton control.

Abstract: The present invention provides a recording system for recording operating parameter information on transportation equipment, such as large trucks and the like. The recording system includes at least one circuit line for operation thereof and is characterized by a sensor for sensing circuit line impedence changes indicative of unauthorized shut down of the system, as well as a recording member responsive to the sensor for visually recording any occurrences of these impedence changes on the recording medium.

Abstract: Electricity meter fraud is detected by incorporating a unidirectional cyclometer-type register into a meter. The register is actuated each time the meter and cover assembly (which is factory sealed) is removed from its associated socket by an actuating arm assembly which is in contact with the socket. In one embodiment the actuating arm includes a rod which protrudes through an opening formed in the base of the meter and is biased into contact with the socket so that when the meter is removed from the socket the register is actuated. Alternatively, the actuating arm is connected to a sliding-type meter terminal which is actuated upon insertion and/or removal of the meter base with respect to the socket. In a further arrangement, a switch is provided in the base of the meter and is arranged to energize a solenoid to actuate the register whenever the meter is removed from its socket.

Abstract: An apparatus for indicating meter tampering in a plug in meter with a transparent cover such as a watthour meter is disclosed which includes a spring loaded "mouse trap" mechanism including a tyne member adapted to be released so as to strike and rupture a dye-filled frangible container upon a tampering incident to indicate tampering.

Abstract: An electrical energy diversion measurement device includes a first clip-on transformer for location about the power cable at high elevation in the zone of the weather guard or at underground manhole location where power supply enters the consumer's dwelling. A second clip-on transformer is simultaneously located about a cable passing through the watt power meter housing supplying power to the consumer. A digital measurement means is responsive to the current sensed by either the current transformers or simultaneously by the transformers and digitally displays the current of each or the difference between the sensed current as a representation of current difference and energy diversion.

Abstract: An aircraft engine which may, for example, be a turbine engine, is provided with an engine temperature thermocouple harness for monitoring the temperature of the aircraft engine. A protective isolation assembly allows for the use of two separate aircraft circuits coupled to receive temperature indicating signals from the thermocouple system. The protective assembly includes two resistors sealed in a metal housing to be connected at the branch point from the existing aircraft temperature monitoring system; and the housing for the protective assembly is electrically and mechanically connected in direct proximity to the thermocouple harness output terminal housing. A short circuit of the second engine temperature monitor circuit would have negligible effect on the existing temperature indicator circuitry in view of the presence of the isolation block assembly.