Electronic remote data recorder with facsimile output for utility AC power systems
First Claim
1. An electronic remote data recorder with facsimile output for utility AC power systems comprising:
- a. a first analog measuring apparatus coupled to an AC power line for measuring voltage and current signals through the power line;
b. a first isolation circuit coupled to the AC power line for isolating appropriate voltage levels from the voltage signal;
c. a scaling circuit coupled to the first isolation circuit for scaling the signals;
d. a first filtering circuit coupled to the scaling circuit for filtering unwanted frequencies out of the signals and forming a filtered signal;
e. an integrating circuit coupled to the first filtering circuit for integrating the filtered signal over time;
f. a multiplexing circuit coupled to the first isolation circuit, the scaling circuit, the first filtering circuit and the integrating circuit for multiplexing the signals;
g. an analog-to-digital converter coupled to the multiplexing circuit for converting the signals from analog to digital thereby forming digital signals representing the signals;
h. a second digital measuring apparatus coupled to switch contacts on the power line for measuring digital signals from the switch contacts;
i. a second isolation circuit coupled to the second digital measuring apparatus for isolating appropriate voltages from the digital signals;
j. a second filtering circuit coupled to the second isolation circuit for filtering out frequencies not of interest from the digital signals;
k. a level shifting circuit coupled to the second filtering circuit for shifting the level of the digital signals to an appropriate level;
l. a digital multiplexer coupled to the second isolation circuit, the second filtering circuit and the level shifting circuit for multiplexing the digital signals;
m. a first microprocessor coupled to the analog-to-digital converter and the digital multiplexer;
n. a first RAM coupled to the first microprocessor for storing system data and accumulated measurement data;
o. a first ROM coupled to the first microprocessor for storing data and instructions used by the first microprocessor;
p. a real-time clock and calendar coupled to the first microprocessor for keeping the current time and date accessible by the first microprocessor;
q. a second microprocessor coupled to the first microprocessor, the first RAM and the real-time clock and calendar for issuing a report of the accumulated measurement data when triggered by the first microprocessor;
r. a second RAM coupled to the second microprocessor for storing setup and system data and a format for the report;
s. a second ROM coupled to the second microprocessor for storing data and instructions used by the second microprocessor; and
t. a facsimile modem coupled to the second microprocessor for communicating with other remote systems for receiving the setup data and for transmitting the accumulated measurement data to a remote system periodically or upon a trigger condition.
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Accused Products
Abstract
A stand-alone electronic measuring instrument for measuring AC (alternate current) power parameters on a utility distribution system wherein the measurement results are communicated telephonically to a facsimile device. Well-known techniques are used to acquire and accumulate analog signals representative of voltages and currents on an AC power system and digital signals. If the signals exceed a programmed threshold, or if an interval of time elapses, or if some other triggering even occurs, the instrument prepares a bit-mapped digital report on its accumulated input signals which may contain text, graphics, or both. The instrument then employs well-known techniques to telephonically transmit this report directly to a facsimile receiver without employing an intervening computer system.
40 Citations
1 Claim
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1. An electronic remote data recorder with facsimile output for utility AC power systems comprising:
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a. a first analog measuring apparatus coupled to an AC power line for measuring voltage and current signals through the power line; b. a first isolation circuit coupled to the AC power line for isolating appropriate voltage levels from the voltage signal; c. a scaling circuit coupled to the first isolation circuit for scaling the signals; d. a first filtering circuit coupled to the scaling circuit for filtering unwanted frequencies out of the signals and forming a filtered signal; e. an integrating circuit coupled to the first filtering circuit for integrating the filtered signal over time; f. a multiplexing circuit coupled to the first isolation circuit, the scaling circuit, the first filtering circuit and the integrating circuit for multiplexing the signals; g. an analog-to-digital converter coupled to the multiplexing circuit for converting the signals from analog to digital thereby forming digital signals representing the signals; h. a second digital measuring apparatus coupled to switch contacts on the power line for measuring digital signals from the switch contacts; i. a second isolation circuit coupled to the second digital measuring apparatus for isolating appropriate voltages from the digital signals; j. a second filtering circuit coupled to the second isolation circuit for filtering out frequencies not of interest from the digital signals; k. a level shifting circuit coupled to the second filtering circuit for shifting the level of the digital signals to an appropriate level; l. a digital multiplexer coupled to the second isolation circuit, the second filtering circuit and the level shifting circuit for multiplexing the digital signals; m. a first microprocessor coupled to the analog-to-digital converter and the digital multiplexer; n. a first RAM coupled to the first microprocessor for storing system data and accumulated measurement data; o. a first ROM coupled to the first microprocessor for storing data and instructions used by the first microprocessor; p. a real-time clock and calendar coupled to the first microprocessor for keeping the current time and date accessible by the first microprocessor; q. a second microprocessor coupled to the first microprocessor, the first RAM and the real-time clock and calendar for issuing a report of the accumulated measurement data when triggered by the first microprocessor; r. a second RAM coupled to the second microprocessor for storing setup and system data and a format for the report; s. a second ROM coupled to the second microprocessor for storing data and instructions used by the second microprocessor; and t. a facsimile modem coupled to the second microprocessor for communicating with other remote systems for receiving the setup data and for transmitting the accumulated measurement data to a remote system periodically or upon a trigger condition.
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Specification