The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 26, 1989
Filed:
Feb. 07, 1989
Miran Milkovic, Schenectady, NY (US);
General Electric Company, , US;
Abstract
An electronic watthour meter employs a first analog signal representing either a load current or voltage to pulse-width-modulate a second analog signal representing the other of the load current or voltage. The resulting signal contains a DC component proportional to the product of current and voltage. AC components are removed from the product signal in an integrator before applying the DC component to a threshold circuit. The threshold circuit alternates its output between positive and negative values each time the DC component of the product signal passes through a predetermined positive and negative value. This pulsed signal is transmitted to a register for integrating the energy usage. A pulse-width modulator produces a constant-frequency pulsed output whose positive and negative alternations have lengths which are proportional to the line signal it receives. At each alternation of the pulsed signal, the output of the pulse-width modulator alternates between a direct and an inverted signal. Thus, integration is driven in alternate directions, whereby offset signals of active circuits are balanced out.