Abstract: An apparatus for indicating electric meter tamper is disclosed having a switch provided with normally closed contacts in the nature of an enclosed race having a central inner contact and a plurality of spaced outer contacts operating in conjunction with a conductive, magnetic ball disposed in the race such that when the ball is in a stable position one of the outer contacts is electrically connected to the center contact and when the ball is disturbed from a stable position the circuit is temporarily opened. The system further includes an actuator device responsive to the opening of the normally closed contacts and an indicator device responsive to the actuator device to indicate the opening of contacts which marks the meter or otherwise signals a tampering incident. Thus, the system is sensitive to changes in position of the meter, vibration and/or magnetic fields, which are sufficient to cause said contacts to temporarily open.

Abstract: The power theft detector circuit (10, 110 and 210) detects when current is being diverted around a line conductor (20 or 220) passing through a meter housing (14 or 214). The circuit (10, 110 or 210) includes a current transformer (12, 112 or 212) coupled to the line conductor (20 or 220) within the meter and defines a primary winding (20 or 220) of the current transformer (12, 112 or 212). A secondary circuit (23, 123 or 224) includes a secondary winding (22, 122 or 226) of the transformer (12, 112 or 212) and sensing circuitry (24, R.sub.m, R.sub.1, and S; 124, R.sub.m, R.sub.1, S and 126; 232, R.sub.m, and 240) for sensing a change in the impedance reflected from the primary circuit into the secondary circuit (23, 123 or 224) when a low impedance jumper (26, 260) is connected in parallel with the line conductor (20 or 220) in the meter thereby to sense a power theft condition.

Abstract: A watt-hour meter with a rotatable metering movement responsive to the flow of electrical energy through the meter having a flagging means that indicates if someone has tampered with the meter by attempting to drive the metering movement in reverse and a stop element to prevent the metering movement from rotating in reverse.

Abstract: A register pointer for an electric utility meter is described as having a weakened section at which fracture can occur to break away the pointer when an attempt is made to tamper with the pointer, such as by manually resetting the pointer's position on the register to show a lower reading of energy consumption. Various forms of breakaway means are described which will permit separation of the pointer portion of the device from its shaft portion when a torque is applied to the pointer end.

Abstract: A watthour meter enclosure with tamper resistance means characterized by a meter cover and a meter base assembled for preventing unlocking rotation of the cover and including locking means between the base and cover for preventing unlocking and/or for indicating surreptitious tampering if it occurs.

Abstract: A mechanical apparatus for indicating watthour meter tampering of a typical single phase induction watthour meter which includes a base member, a plug-in mechanism mounting member and a cover glass fixed to the mechanism mounting member. The device includes an easily rupturable, normally glass, container juxtaposed the mechanism mounting member of the watthour meter and fixed through said mounting member to the meter base in a manner such that attempts to unplug the mounting member from the base will cause said container to rupture and thereby indicate meter tampering. The container may also be mounted next to the cover glass of the watthour meter and adhesively connected thereto in a manner such that movement of the cover glass relative to the mechanism mounting member results in the rupture of the container.

Abstract: In an electronic energy consumption meter using a mark-space amplitude multiplier, including a current-frequency transducer, a first supervisory circuit is coupled to, and supervises the mark-space modulator multiplier, a second supervisory circuit is coupled to, and supervises the current-frequency transducer, and a fault indicator is coupled to the output of each of the supervisory circuits for indicating a fault in the meter.

Abstract: An electricity meter for metering the amount of electrical energy supplied by a power supplier to a power consumer is provided with fraud detection means for detecting the presence of an external shunt which has been connected to by-pass its internal current sensing means. The detection means, which comprises a differential current sensor for sensing the difference between the respective currents flowing to and from the consumer via the meter and a multiplier for multiplying this current difference by a signal derived from the supply voltage, is arranged to operate a circuit breaker, and/or to compensate the energy measurement of the meter, and/or to provide a warning to the supplier. The differential current sensor also senses when current is being taken between the live wire and earth on the consumer's side of the meter.

Abstract: A pilfer proofing system and method for electric meter boxes having a meter base box, which carries a plug-in terminal block set and a meter box cover having an opening through which a plug-in-meter passes to engage contact jaws or sockets the terminal block set. An anchoring bar is secured to the meter stops and a conventional meter locking collar is secured to the cover and the bridge of the locking collar is secured to the anchoring bar. Metal extension adaptors are secured to the meter blades for entering into the contact jaws or sockets of the terminal block set and a conventional locking ring is utilized to lock the meter in place on the added meter collar thereby providing a substantial obstacle to easy pilfering of electricity.

Abstract: An electricity meter has one of its bayonets slidably carried by the meter base. When the meter is inserted in a meter socket, the bayonet in its normally retracted position conducts electrical power to the full potential coil. When the meter is removed, the socket functionally holds the bayonet until it slides to a detented extended position where the bayonet is locked into position and is connected so as to bypass a portion of the potential coil. When the meter is reinserted, the meter runs fast.

Abstract: An electricity meter has one of its bayonets provided with a movable barbed member which engages a terminal in the meter socket upon installation and causes the normal circuit to the measuring circuitry of the meter to be irrevocably broken when the meter is removed from the meter socket.

Abstract: An input terminal adapted to receive 0 to 300 volts AC or DC is connected through AC or DC connecting circuits, coupled into the path by switches, and attenuating apparatus including a plurality of ranges automatically switched into the path in response to the amplitude of an input signal, to a buffer which includes overvoltage protection and provides a relatively high input impedance with a relatively low output or source impedance. A frequency counter is connected through a hysteresis amplifier, a digital volt meter is connected through an amplifier including 60 cycle filtering and an oscilloscope is connected through an independent gain amplifier to the output of the buffer.

Abstract: A theft resisting device for use as part of an electric watthour meter includes a moveable slide bar positioned in a housing within the base plate of the meter. The slide bar is normally retracted, but when unauthorized removal of the meter from its socket occurs, the bar extends thereby preventing reinstallation of the meter in the socket in any position. Locking means engages the slide bar to prevent retraction of the bar. An access aperture to the housing permits a tool to be inserted to reset the locking means and permit slide bar retraction.

Abstract: A circuit tester is disclosed which automatically open-circuits a main lead to an input circuit in response to an excessive overcurrent. The circuit tester of the present invention will automatically sense the existence of an excessive current which, in turn, open-circuits a main lead to the input circuit, actuates a buzzer and energizes a light-emitting diode. Since the main-lead to the input circuit has been open-circuited, the base voltage at a first transistor drops. This renders this transistor non-conductive and tends to cause the main-lead to the input circuit to short-circuit. This tends to restore the circuit tester to its initial condition. However, if the excessive current is continuing, the above sequence will re-commence, the sequence continuing until the excessive current no longer exists or until the tester is adjusted to a higher range of operation.

Abstract: To detect tampering of a kilowatt-hour meter by the connection of a bypass link across the live connection through the meter, a voltage transformer within the meter unit is coupled to this live connecton so that a small volage is induced in the live connection in opposition to the supply voltage. The induced voltage produces a circulating current in the loop formed by the live connection and the bypass link and the transformer coupling is such that, with a bypass link of negligible resistance, the total current in the live connection is in opposite phase to the applied voltage. By means of a current transformer, a logic unit and a microprocessor, the phase of the current in the live connection within the meter is determined and is indicated by a latched flag indicator and/or transmitted to a distant data processor by a data link.

Abstract: A watthour meter with a rotatable metering movement responsive to the flow of energy through the meter includes a gravity activatable contact or stop element to engage the metering movement when the meter is inverted for preventing deregistration of consumed energy. Latching means can lock the element in a position showing that the meter had been inverted.

Abstract: Apparatus for measuring and/or supervising the output power of an induction motor comprising means for generating a first voltage signal proportional to the synchronous speed of the motor, means for generating a second voltage signal proportional to the actual speed of the motor in operation and means responsive to the first and second voltage signals for generating a third voltage signal proportional to the difference between the first and second voltage signals. The third voltage signal is applied to a meter for providing a continuous indication of the output power of the motor.

Abstract: Apparatus for providing automatic compensation of direct current magnetization of a current transformer in an alternating current watthour meter utilizing a magnetic field sensor and electronic circuitry to keep the transformer operating in its linear region when a DC component is superimposed on an AC current being provided to the transformer.

Abstract: A watthour meter installation of the type including an input current transformer having an input winding for connection to an AC power supply line, an output winding for connection to a watthour meter for measuring AC power being consumed and a core on which the input and output windings are wound and which is susceptible to DC magnetization by a DC component superimposed on the AC being measured. In order to overcome the effect of the DC component on the magnetization characteristics of the input transformer, automatic compensation circuitry is provided which includes a sensor coupled to sense the current flowing through the input winding and for deriving a sensed output signal proportional to the sensed current which includes both AC and DC components of the input current.

Abstract: A watt hour meter installation is described which is of the type including an input transformer having an input winding for connection to an alternating current power supply line, an output winding for connection to a watt hour meter for measuring alternating current power being consumed and a bore on which the input and output windings are wound. The core is of the type which is susceptible to DC magnetization by a DC component superimposed on the alternating current being measured. In order to overcome the effect of the DC component on the magnetization characteristics of the input transformer, automatic compensation circuitry is provided which includes a sensor coupled to sense the current flowing through the input winding and for deriving a sensed output signal proportional to the sensed current and which includes both AC and DC components of the input current.

Abstract: A conventional electric utility meter is equipped with special circuitry and components which work in conjunction with an inserted magnetic card to regulate the supply of electricity to the structure to which the unit is attached. In addition to including the conventional dials which indicate overall kilowatt hours, the exterior of the unit includes a receptacle for the card and additional displays which show the kilowatt hours, and corresponding dollar value thereof, for the current payment period. The special circuitry includes a microprocessor, a set of magnetic read/write/erase heads, and a power relay. The circuitry interfaces with the conventional meter components by means of a photocell positioned above apertures or notches in the rotating disk of the meter. In the primary mode of operation, a prepayment card is inserted containing a predetermined kilowatt hour credit. The special circuitry senses this amount and adds it to the amount of power the customer is entitled to receive.

Abstract: An RF connector has an overrated fuse located therein which is electrically connected in series with the center conductor. An overrated fuse is utilized because a fuse rated to give the desired protection is undesirable due to the resistance caused by its small diameter. To obtain the desired protection with the overrated fuse, current shunting means, such as diodes, are mounted within the RF connector and are electrically connected between the outer and inner conductors. The current shunting means are positioned within the RF connector to present minimum inductance to the RF circuit. The operation of the fused RF connector is such that when the power applied to the connector exceeds a predetermined amount, the current shunting means conduct the excess current to ground to provide protection to the associated equipment until the input power is sufficient to blow the overrated fuse.

Abstract: Apparatus for and the method of simplifying and economizing upon transmitter power amplifier output stage circuitry is illustrated. By grounding the anode of the RF power amplifier, the FCC required plate voltage meter and plate current meters can be connected to near ground potentials and the requirements for a high voltage coupling capacitor between the anode and the antenna is eliminated. Although the specific embodiment illustrated uses a pulse-width modulated cathode modulation scheme, any type of cathode modulation will perform in accordance with the concepts of this invention.

Abstract: A tamper-proof adaptor is secured to an electric meter or is formed as a part thereof to form a unitary device which, upon first being plugged into a conventional wall pan and thereafter being removed therefrom, automatically restrains reinsertion of the device into the wall pan. The forces necessary to disengage the device from the wall pan are utilized to physically disengage the meter prongs from extension prongs within the adaptor and, thereafter, an insulating bar is disposed blockingly between the extension prongs and the meter prongs to prevent reconnection thereof.

Abstract: In a circuit for preventing breakdown of a load resulting from a wrong connection of a power source, there are provided a first load to which a DC voltage source should be applied at a predetermined polarity and to which a wrong polarity connection of the DC voltage source should be prevented, a second load to which the DC voltage should be applied, and a transistor having the base thereof connected to the second load and the collector thereof connected to one terminal for connection with the DC voltage source. The first load is connected between the base electrode and emitter electrode of the transistor. The junction of the first and second loads is connected to another terminal for connection to the DC voltage source.

Abstract: A tamper-detection switch is built into a device such as an encoder for a gas or water meter. The switch has a contact arm biased to complete an alarm circuit, but this is prevented by a restraining post. On installation, an actuator is moved by contact with the meter to lift the contact arm free of the restraining post, at the same time restraining the arm from completing the circuit. If the encoder is subsequently moved away from the meter, a biasing spring causes the actuator to move out of the path of the contact arm, freeing it to complete the alarm circuit.

Abstract: Disclosed is an apparatus for providing non-destructive isolation voltage testing of circuit elements which includes a controllable full wave rectifier in series with the primary winding of a high voltage transformer, the secondary winding of which is connected to the circuit element under test. A current detector is responsive to a predetermined threshold current in the tested circuit element for providing a signal to control the rectifier to open-circuit the transformer primary winding prior to destructive breakdown of the tested circuit element. Opto-electronic elements are utilized in the rectifier to provide for the virtually instantaneous open-circuiting of the high voltage transformer primary winding.

Abstract: A method for making a heat sensitive fault detecting and indicating device for a watthour meter is disclosed herein. The illustrated method is particularly useful for a watthour meter that conventionally includes a potential stator and a current stator both of which are mounted thereon one or more permanent magnets and a rotatable disk assembly with disk rotation being recorded on the recording dials of a register assembly visible through the enclosing glass cover of the meter. The current stator of such a meter normally includes a pair of current coils that are heat responsive and a method is disclosed for providing a heat sensitive fault detecting and indicating device that may be associated with such coils.

Abstract: An enclosure for watthour meters includes a cover having an opening for connecting a meter data sending unit within the enclosure to an adjacent remote meter reading terminal unit. A cover locking rim has locking tabs for securing the cover to a meter base assembly so that the cover is rotatably positionable relative to the base. The rotated positions of the cover opening permit different orientations of a remote meter reading package at a fixed meter mounting position.

Abstract: Apparatus for attachment to watt-hour meter apparatus of the type commonly used to measure electrical power consumption, to prevent from being misinstalled so as to run the meter backwards. A first obstruction member or members are provided within the box which receives the watt-hour meter, and a second obstruction member is secured to the meter. These obstructions are asymmetrically disposed with respect to mating electrical contacts on the meter and within the meter box, so that the obstructions on the meter and in the meter box confront one another and prevent the meter from being installed in an inverted position which causes the meter to run backwards.

Abstract: A combined electric meter for measuring AC and DC voltage and ohms is provided with read-outs having indicators progressively actuated for simultaneously indicating AC and DC voltages and for indicating ohms. The read-outs are in the form of light emitting diodes in which the lights are progressively illuminated to indicate a range of voltage or ohms. A pair of probes are manually connected to the circuit to be tested and provide a common connection for the voltage and ohm section of the meter. Should voltage be sensed by the probes, the ohmmeter section is automatically taken out of circuit to protect it from damage. A high speed switch transistor is responsive to an external voltage across the probes for opening the ohmmeter circuit before the external voltage can cause damage to the ohmmeter. The meter has an internal power supply for operating the read-outs and providing a regulated voltage for a resistance to be measured by the ohmmeter section.

Abstract: A closed loop operational amplifier circuit for providing a constant current in the closed loop for generating a precision constant current through an unknown resistance for measuring the resultant voltage drop across the resistance. The closed loop circuit having a compliance circuit with a high voltage diode for preventing damage to a transistor in the compliance circuit in one polarity direction and a current limiting circuit including the transistor for preventing damage to the transistor from high voltage in the opposite polarity direction, and a voltage comparison circuit responsive to a high voltage in the opposite direction for reverse biasing the high voltage transistor to prevent it from entering the secondary breakdown mode.

Abstract: A heat sensitive abnormal current condition detecting and indicating device associated with a watthour meter indicates that a possibly damaging surge has been experienced by the meter. The abnormal condition detecting and indicating device includes indicator means retained in normal position by a heat sensitive material, such as solder, with the indicator means being biased to move from the normal position to an abnormal condition position should the conductor being monitored experience a heat rise sufficient to soften the heat sensitive material and release the indicator means.

Abstract: Capacitance is measured using a conventional meter while a DC bias voltage in a range from 0 to 10K volts is applied across the capacitance under test. An LC series resonant circuit is disposed between the capacitance under test and one input of the capacitance meter to provide a low impedance path for the 1 MHz test signal produced by the capacitance meter. P-I-N diodes are disposed across the input terminals of the capacitance meter to shunt the discharged energy from the resonant circuit capacitance should the capacitor under test short circuit. A resistance is in series with the resonant circuit to provide a voltage divider to lower the voltage appearing across the capacitance-meter input terminals to a value below the damage-threshold voltage level of the capacitance-meter.

Abstract: An anti-tamper watthour meter includes a gravity actuated switch arrangement for reversing the meter voltage winding connections across the meter terminal blades when the meter is installed in an inverted position. An additional penalty metering arrangement includes a gravity actuated magnetic member which drops into a position adjacent a meter damping permanent magnet when the meter is inverted. The inverted meter operates at a faster than normal metering rate.

Abstract: An electrical meter assembly including a plug-in meter and a meter socket, each having terminals. An adaptor modifies a terminal of the meter socket, enabling the modified and unmodified terminals thereof to engage the terminals of the meter in only one orientation of the meter relative to the meter socket.

Abstract: An electronic meter circuitry for use in detecting an electrical signal vage in an ordnance firing circuit for providing an unidirectional signal to an indicator which shows the presence of the signal voltage. The circuitry utilizes a first limiter to reduce the amplitude of the detected signal to a predetermined level, a bridge rectifier to provide a unidirectional signal and a second limiter to prevent overloading the indicator. A self contained test circuit utilizing a current source and two current limiting resistors is supplied so proper operation of the meter circuitry prior to use may be readily ascertained.

Abstract: A device for periodic, automatic, readable recording of a meter value from a consumption measuring meter including a casing attachable to an otherwise conventional meter and provided with a slot, a printing unit disposed within the casing and located out of the plane of the slot in order to be tamper-proof, the printing unit being composed of an identification data printer and a consumption value printer and being adapted upon insertion of a record card in the slot of the casing to apply to the record card a visually readable marking of the identification data and meter consumption value, and a push button connected to the printing unit and manually actuable for causing the marking to be applied to the record card by shifting the printing unit towards the record card inserted into the casing through the slot.

Abstract: A heat sensitive fault detecting and indicating system and method for a watthour meter is disclosed herein. The illustrated watthour meter includes a potential stator and a current stator both of which are mounted on a frame assembly, the assembly also having mounted thereon one or more permanent magnets and a rotatable disk assembly with disk rotation being recorded on the recording dials of a register assembly visible through the enclosing glass cover of the meter. The current stator includes a pair of current coils which coils have a heat sensitive fault detecting and indicating device associated therewith. The heat sensitive fault detecting and indicating device illustrated includes a layer of low melting point metal, such as tin, for example, which layer is covered by a sheath, such as a plastic sheath, for example, with predetermined portions of the sheath being thinned, as by embossing, for example, with a predetermined symbol or other indicia.

Abstract: The invention relates to the supervision of a measuring circuit which is connected to a load by way of measuring leads. This load is connected to a generator via supply leads. The load is bridged by a resistor. If one of the four said leads is interrupted, the potential on one of the ends of the resistor changes. As a result, a transistor becomes conductive, which implies an error signal. In a preferred embodiment, two transistors are provided, the first transistor being rendered conductive by a voltage difference. The second transistor is rendered conductive either by a voltage difference or by the fact that the first transistor becomes conductive.

Abstract: A watthour meter of the self-contained detachable type has a protected meter testing arrangement. An isolated external test contact and an internal terminal blade connector are independently connected to a common terminal end of the meter voltage winding. The connector is manually disconnectable for testing the meter through the external test contact in an "open-link" watthour meter testing method.

Abstract: A tamper-resistant electrical meter housing includes an unbreakable cover assembly that cooperates with a matable base to enclose a meter device supportable on the base. The cover assembly includes an annular ring secured to the cover. A locking leaf spring is coupled to the cover assembly. The leaf spring is aligned to slide along the top of a rim portion of the base and snap into a recess to lock the cover assembly against rotation and removal. Once the cover assembly is locked to the base, the leaf spring is substantially concealed from view, so that an unauthorized person cannot effect removal of the cover to obtain access to the meter. The base also includes a specific area in alignment with the recess, which area is identifiable only by an authorized person. A hole may be drilled in this area by an authorized person and a tool may then be inserted through this hole to effect disengagement of the leaf spring and removal of the cover assembly from the base.