| Patent Number |
Title Of Patent |
Date Issued |
| T955007 |
Method and apparatus for metering apparent energy |
February 1, 1977 |
| Metering kVA and kVAh in an electrical system is accomplished by generating pairs of analog signals representing current and voltage variables. Each of the analog signals is synchronously rectified to provide a pair of full-wave rectified signals which are multiplied together in a pulse- |
| RE28851 |
Current transformer with active load termination |
June 8, 1976 |
| A current transformer and transresistance amplifier are combined; the secondary winding of the current transformer being connected to the input of the transresistance amplifier and being virtually short-circuited because of the very low input impedance of the transresistance amplifier. |
| 4942367 |
Auto-zeroing switched-capacitance buffer amplifiers with minus-unity voltage gain |
July 17, 1990 |
| A switched-capacitance amplifier has a common terminal and an input signal terminal for receiving an input signal voltage therebetween, and it has an inverted output signal terminal for supplying, during each of a second series of separated time intervals interleaved without overlap with |
| 4912423 |
Chopper-stabilized operational transconductance amplifier |
March 27, 1990 |
| Current mirror amplifiers are disclosed, each having first and second ports that can be interchanged as to which is input port and which is output port in response to an electric control signal. A chopper-stabilized differential amplifier that uses such a switchable current mirror am |
| 4894657 |
Pipelined analog-to-digital architecture with parallel-autozero analog signal processing |
January 16, 1990 |
| A pipelined analog-to-digital converter architecture comprises three pipeline stages wherein the first stage includes a low-resolution flash A/D subconverter (10), two sample-and-hold amplifiers (12 and 14), two D/A converters (16 and 18), and two unity-gain buffers (20 and 22). Para |
| 4894656 |
Self-calibrating pipelined subranging analog-to-digital converter |
January 16, 1990 |
| An approach to A/D converter architecture is based on a "pipelined and submerged" architecture which includes a pipeline of elemental stages (10.sub.i). Each stage of the pipeline comprises a low-resolution flash A/D subconverter (12), a D/A converter (14), and a unity-gain buffer (16). |
| 4808942 |
Continuous mode auto-zero offset amplifier or integrator |
February 28, 1989 |
| An error signal, i.e., offset, noise or drift, is sampled in an input capacitor at an error sampling interval and held during the amplification interval. During the amplification interval, the signal is amplified offset-free. The circuit has two paths which operate alternately in such a |
| 4800333 |
Switched-capacitor watthour meter circuit having reduced capacitor ratio |
January 24, 1989 |
| An electronic energy consumption measuring circuit capable of being fabricated on a single integrated circuit chip employs a switched-capacitor integrator for integrating the product of first and second voltages which are proportional, respectively, to load voltage and current in an |
| 4794333 |
Continuous switched-capacitor dual slope watthour meter circuit with charge injection offset com |
December 27, 1988 |
| Transient offset error voltages due to charge injection by MOS analog switches in switched-capacitor integrators of electronic metering circuits are compensated by use of a continuous switched input capacitor network on the inverting input of the integrator amplifier. Any residual charge |
| 4754219 |
Low cost self-contained transformerless solid state electronic watthour meter having thin film f |
June 28, 1988 |
| A transformerless, self-contained, low cost, small size, light weight solid state electronic watthour meter is described which employs thin film ferromagnetic current sensors of the type which are magnetically coupled to power conductors whose current flow is to be sensed and metered and |
| 4733171 |
Differential switched-capacitor dual slope watthour meter circuit |
March 22, 1988 |
| Transient offset error voltages due to charge injection by MOS analog switches and DC offsets of multipliers in switched-capacitor integrators of electronic metering circuits are compensated by the common mode rejection of a differential switched-capacitor integrator. To cancel inter |
| 4556843 |
Electronic solid state Q-hour meter and/or combination Q-hour and kilowatt-hour meter |
December 3, 1985 |
| An electronic solid state Q-hour meter for measuring leading and lagging VARS quantities of electric power over a defined range of power factor. The Q-hour meter comprises first and second time division/pulse width-amplitude modulated/analog multiplier circuits. First and second curr |
| 4535287 |
Electronic watt/watthour meter with automatic error correction and high frequency digital output |
August 13, 1985 |
| An improved solid state semiconductor integrated circuit electronic watt/watthour meter circuit having analog and high frequency digital outputs with automatic error correction. The meter comprises first and second transformers for developing first and second voltage and current indi |
| 4495463 |
Electronic watt and/or watthour measuring circuit having active load terminated current sensor f |
January 22, 1985 |
| An electronic watt and kilowatt hour measuring circuit susceptible of being fabricated for the most part in solid state semiconductor monolithic integrated circuit form is provided. The electronic measuring circuit uses an active load terminated current transformer sensor for sensing |
| 4492919 |
Current sensors |
January 8, 1985 |
| A sensor for measuring large magnitudes of A.C. current utilizes a conductive member having a higher-resistance element parallelled by a pair of elements with lower, and substantially equal, resistance and so arranged as to cause cancellation of magnetic field effects upon the higher |
| 4485343 |
Electronic watt and watthour meter having analog and digital outputs with automatic error correc |
November 27, 1984 |
| An improved solid state semiconductor electronic combined watthour and watt meter circuit providing both analog and digital outputs and having automatic error correction comprising first and second input transformers for developing first and second signals proportional respectively to th |
| 4451784 |
Electronic watt transducer circuit with constant DC current output proportional to watts |
May 29, 1984 |
| An electronic wattmeter in the form of an electronic watt-transducer circuit requiring a minimum number of components that can be fabricated by monolithic semiconductor integrated circuit manufacturing techniques and which provides a direct current output signal that is proportional to |
| 4414510 |
Low cost sensing system and method employing anistropic magneto-resistive ferrite member |
November 8, 1983 |
| A sensor comprising a member of ferromagnetic ferrite material having anistropic magneto-resistive properties wherein the resistivity characteristics of the ferrite member vary in response to variations in strength of a magnetic field applied longitudinally with respect to a selected |
| 4296413 |
Resistance-bridge to frequency converter with automatic offset correction |
October 20, 1981 |
| A circuit for converting changes in a sensed physical parameter, such as resistance and resistance change as a function of pressure, temperature and the like, into a digital signal of proportional frequency. A sensor bridge, monitoring the parameter to be measured, forms a part of a |
| 4286214 |
Current sensor for phase inversion-modulation of AC signals |
August 25, 1981 |
| A circuit for sensing the magnitude of an AC signal applied to the circuit includes control means for reversing the polarity of the AC signal to thereby generate an output signal which is proportional in amplitude to the magnitude of the AC signal and which has a phase, with respect to t |
| 4278940 |
Means for automatically compensating DC magnetization in a transformer |
July 14, 1981 |
| 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 su |
| 4262532 |
Pressure and temperature sensor |
April 21, 1981 |
| A hybrid sensor for simultaneously sensing pressure and temperature in non-interacting manner, includes an insulative substrate having a temperature-sensitive printed thick film resistor fabricated thereon. A conductive plate is insulatively spaced above the resistor and supported by |
| 4255705 |
Peak detection and electronic compensation of D. C. saturation magnetization in current transfor |
March 10, 1981 |
| 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 |
| 4255704 |
Zero crossing detection and electronic compensation of D. C. saturation magnetization in current |
March 10, 1981 |
| 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 |
| 4217546 |
Electronic energy consumption meter and system with automatic error correction |
August 12, 1980 |
| An electronic energy consumption meter and system includes means for automatically correcting for overall system signal and voltage errors and offset errors created by circuits in the system to provide a meter requiring no adjustments for the compensation of the various system and ci |
| 4198595 |
Apparatus and method of phase shift compensation of an active terminated current transformer |
April 15, 1980 |
| Apparatus and method of compensating for a shift in the phase of the current applied to a current transformer terminated in a low impedance operational amplifier. The operational amplifier phase response is altered to minimize the phase angle between the transformer current and the a |
| 4092592 |
Electronic kWh meter having virtual ground isolation |
May 30, 1978 |
| An electronic kWh meter is disclosed which measures electrical energy consumed in an electrical system. A current transformer generates an analog voltage which is proportional to a current in the electrical system. An operational amplifier has an input resistor connected across the l |
| 4066960 |
Electronic kilowatt-hour-meter with error correction |
January 3, 1978 |
| An electronic kilowatt-hour meter having internal error correction is disclosed for metering electrical power and energy consumption in a single phase or polyphase electrical system. A comparator compares an analog signal which is proportional to the voltage in the system with a rela |
| 4066959 |
Electronic volt-square-hour metering method and apparatus |
January 3, 1978 |
| An electronic meter for measuring V.sup.2 hr in an electrical system includes a center tapped transformer for deriving two analog signals proportional to a detected voltage in the system with the analog signals being 180.degree. out of phase with respect to one another. A comparator |
| 4058768 |
Two-way electronic kWh meter |
November 15, 1977 |
| A two-way electronic kWh meter is disclosed for metering electrial power and energy consumption in a single phase or polyphase electrical system wherein power and energy may be imported to the system or exported from the system to another system. Pairs of analog signals representing curr |
| 4056775 |
Electronic kWh meter having internal power supply and error correction system |
November 1, 1977 |
| Metering kWh in an electrical system is accomplished by generating pairs of analog signals representing current and voltage variables. A comparator compares an analog signal which is proportional to the voltage in the system with a relatively high frequency triangular waveform. The outpu |
| 4032798 |
Low cutoff digital pulse filter especially useful in electronic energy consumption meters |
June 28, 1977 |
| A digital electrical pulse filter which provides output electrical pulses directly corresponding to input electrical pulses when the input pulses have a repetition rate greater than a predetermined repetition rate and which provides no output pulses when the input pulses have a repetitio |
| 4015140 |
Multiplier for producing phase shift error-free signal representing product of out-of-phase inpu |
March 29, 1977 |
| Metering kWh in an electrical system is accomplished by generating pairs of analog signals, representing current and voltage variables. Each pair of analog signals is multiplied together in a direct pulse-width conversion in a time-division multiplier network. A constant amplitude triang |
| 3995210 |
Variable gain electronic current transformer |
November 30, 1976 |
| A variable gain electronic current transformer for detecting the current flow into a power consuming system. An operational amplifier amplifies the detected current and the output of the operational amplifier is converted into a magnetic flux field which is directed onto one surface of a |
| 3976941 |
Auto-ranging system for an electronic energy meter |
August 24, 1976 |
| An auto-ranging system for an electronic watt-hour meter includes a current transformer for measuring the electrical current in at least one line of an electrical power consuming system. The measured current is converted to a voltage which is proportional to the measured current by means |
| 3961257 |
Single phase 3-wire electronic electrical energy meter |
June 1, 1976 |
| Metering kWh in a single phase, 3-wire, F.sub.L Hertz a.c. electrical system is accomplished by detecting the current flow in two lines of the three-wire system by means of a current transformer having two primary windings and a single secondary winding. The voltage in the system is |
| 3955138 |
Electronic energy consumption meter with input transformer having single resistance terminated s |
May 4, 1976 |
| In the exemplary embodiment, a double-pole double-throw-C-MOS analog switch provides output signals alternately 180.degree. and 0.degree. with respect to the output of a single secondary winding on a current transformer, which single secondary winding is resistance terminated. The switch |
| 3947763 |
C-MOS electronic kWh meter and method for metering electrical energy |
March 30, 1976 |
| Metering kWh in an electrical system is accomplished by generating pairs of analog signals, representing current and voltage variables. Each pair of analog signals is multiplied together in a direct pulse-width conversion in a time-division multiplier network. A constant amplitude triang |
| 3942110 |
Analog to pulse rate converter |
March 2, 1976 |
| A bipolar C-MOS analog to pulse rate converter is disclosed which provides a pulse train at its output having a frequency which is proportional to the magnitude of an analog input signal over a wide dynamic range. An analog input signal is integrated until the output of the integrator |
| 3939413 |
Low cutoff digital pulse filter especially useful in electronic energy consumption meters |
February 17, 1976 |
| A digital electrical pulse filter which provides output electrical pulses directly corresponding to input electrical pulses when the input pulses have a repetition rate greater than a predetermined repetition rate and which provides no output pulses when the input pulses have a repetitio |
| 3934198 |
Multi-wire electronic kWh meter |
January 20, 1976 |
| The metering of kilowatt hours in a single phase, three wire electrical system is accomplished by generating a first analog voltage which is representative of the voltage of the power consuming system. Second and third analog signals are generated which represent the current flowing |
