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US 3,971,979 AGranted
Current/voltage transducer
AssigneeEsterline Corporation
InventorGlenn A. Mayfield
Life of this patent
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AssigneeEsterline Corporation
InventorGlenn A. Mayfield
Estimating the term…
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.
In a magnitude transducer for driving an output load with a direct current which is directly proportional to the magnitude of a voltage or current sinusoid at a selected part of an electrical circuit, said transducer being of the type including a coupling means connected at its input to said electrical circuit, a rectifier means connected to the output of said coupling means for providing a rectified sinusoid corresponding to the magnitude of said voltage or current sinusoid, and a current mirror circuit having a reference input branch connected to the output of said rectifier means and having said output load connected between the output branch of said current mirror circuit and the output of said rectifier means, said current mirror circuit including a first semiconductor junction sampling means for sampling the current in one of said branches and a second semiconductor means for controlling the current in the other branch, wherein the improvement comprises:
In a magnitude transducer for driving an output load with a direct current which is directly proportional to the magnitude of a voltage or current sinusoid at a selected part of an electrical circuit, said transducer being of the type including a coupling means connected at its input to said electrical circuit, a rectifier means connected to the output of said coupling means for providing a rectifier sinusoid corresponding to the magnitude of said voltage or current sinusoid, and a current mirror circuit having a reference input branch connected to the output of said rectifier means, said current mirror circuit including a first semiconductor junction sampling means for sampling the current in one of said branches and a second semiconductor means for controlling the current in the other branch wherein the improvement comprises:
Dependencies are inferred from the claim text.