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:
Jul. 27, 1976
Filed:
Oct. 10, 1974
Glenn A Mayfield, Columbus, OH (US);
Esterline Corporation, New York, NY (US);
Abstract
A circuit for providing an output direct current which is a linearly proportional analog of the average and the effective magnitude of a sinusoidal input voltage or current. A transformer couples the sinusoid to a rectifier which applies a rectified sinusoid to a filtered current mirror circuit of low power requirements in order to provide a ripple free, high impedance current source output. The current mirror circuit is imbalanced in order to provide a non-linear characteristic which compensates for the transformer-rectifier non-linearity. The current mirror circuit also has an RC feedback network with sufficient feedback and gain to obtain an active, low pass filter characteristic. Component values are selected to give a sharp cutoff, active filter just below the ripple frequency to give efficient ripple elimination yet permit a rapid response time. Matched, parallel connected semiconductor devices in the current mirror circuit permit circuit balance with the current in one branch being an integral multiple of current in the other branch.