Electricity: measuring and testing – Measuring – testing – or sensing electricity – per se – Plural inputs
Patent
1985-12-23
1987-07-21
Eisenzopf, Reinhard J.
Electricity: measuring and testing
Measuring, testing, or sensing electricity, per se
Plural inputs
324107, 324111, G01R 1102
Patent
active
046821023
ABSTRACT:
A switched-capacitor integrator is employed in an electronic watthour measurement device for integrating the average component of a product signal formed by pulse-width modulating an analog signal proportional to one of a load current and voltage at a pulse duty ratio proportional to the other of the load current and voltage. A hysteresis comparator forces the direction of integration to alternate between positive and negative limits for balancing out offset voltages in the integrator and comparator. A triangular-wave generator employed as part of the pulse-width-modulation technique is also implemented using a switched-capacitor integrator. The switched-capacitor integrators permit fabrication of the circuit with the required accuracy without needing external, discrete time-constant-determining resistances and capacitances. Measurement accuracy is determined by the ratio of capacitances of two on-chip capacitors, the accuracy to a clock signal and two reference voltages. These parameters are closely controllable on a single MOS or CMOS chip using normal process control whereby the entire electronic watthour measurement device may be realized on a single chip without requiring off-chip components.
REFERENCES:
patent: 3665305 (1972-05-01), Petrohilos
patent: 4315212 (1982-02-01), Gamoh
patent: 4408283 (1983-10-01), Kovalchik et al.
patent: 4453130 (1984-06-01), Bennett
patent: 4535287 (1985-08-01), Milkovic
patent: 4604584 (1986-08-01), Kelley
"A Polyphase Microelectronic Watt-Hour Meter", Miran Milkovic, Int. J. Electronics, 3/1980, vol. 48, #3, SO4550054.
"Potential of MOS Technologies for Analog Integrated Circuits"; David Hodges et al; IEEE Journal, Solid State Circuits, Jun. 1978, pp. 285-294.
"MOS Sampled Data Recursive Filters Using Switched Capacitor Integrators Bedrich Hosticka et al; IEEE Journal Solid State Circuits, Jun. 1987, pp. 600-608.
"Effect of Switch and Routing Related Parasitic Capacitances. M. S. Ghausi et al; Modern Filter Design, pp. 456-461, Prentice Hall, 1981.
"Offset-Compensated Switched-Capacitor Leapfrog Filters"; S. Eriksson et al; Electronic Letters, Aug. 1984, pp. 731-733.
"Technique for Offset Voltage Cancellation in MOS Operational Amplifiers"; S. Wong et al; Electronic Letters, pp. 389-390, Apr. 1985.
Brunson Robert E.
Burns W.
Eisenzopf Reinhard J.
General Electric Company
Morrison Thomas R.
LandOfFree
Solid state watthour meter with switched-capacitor integration does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Solid state watthour meter with switched-capacitor integration, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solid state watthour meter with switched-capacitor integration will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-209420