Isolated signal conditioner
AssigneePhillips Petroleum Company
InventorVernon R. Clark
Life of this patent
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Abstract
An isolated signal conditioning circuit is provided whereby control or measurement circuitry is isolated from a load, such as a control instrument, through the use of an optically coupled isolation amplifier. The control or measurement signal is conditioned by the signal conditioning circuit so as to provide a signal to a load, such as a control instrument, which is compatible with the input requirements of the load.
Claims30
Apparatus comprising:
- an isolation amplifier having an input stage which is optically coupled to an output stage where said output stage has a first power input and a second power input;
- means for grounding said second power input;
- means for supplying a voltage level of V.sub.2 to said first power input;
- means for establishing a reference potential for said output stage of said isolation amplifier at a voltage level V.sub.2 /2, which is a voltage level other than zero volts, a first signal representative of the output signal from said output stage of said isolation amplifier having a voltage level which ranges from +(V.sub.2 -V.sub.2 /2) to -V.sub.2 /2 around said reference potential of V.sub.2 /2 in response to an optical input signal from said input stage.
A method for utilizing an isolation amplifier, having an input stage which is optically coupled to an output stage where said output stage has a first power input and a second power input, to electrically isolate a first signal representative of an input electrical signal from a load comprising the steps of:
- grounding said second power input;
- supplying a voltage level of V.sub.2 to said first power input;
- establishing a reference potential for said output stage of said isolation amplifier at a voltage level V.sub.2 /2, which is a voltage level other than zero volts, a second signal representative of the output signal from said output stage of said isolation amplifier having a voltage level which ranges from +(V.sub.2 -V.sub.2 /2) to -V.sub.2 /2 around said reference potential of V.sub.2 /2 in response to an optical input signal from said output stage.
Dependencies are inferred from the claim text.