Voltage and current signaling
AssigneeHewlett-Packard Development Company, L.P.
InventorDavid E. Smith
Life of this patent
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Abstract
Circuitry and methods are provided. Voltage and current of an electrical load are detected, scaled and biased to derive respective voltage and current signals. Frequency-modulated signals corresponding to the voltage and current signals are respectively derived. The frequency-modulated signals are communicated between different electrical domains by way of optical isolation barriers. The frequency-modulated signals are processed to improve linearity and to time-correlate the signals to discrete samplings of the load voltage and current. Control of a printer or other device is performed using the processed signals.
Claims15
An apparatus, comprising:
- first modulator circuitry configured to provide a first frequency-modulated signal corresponding to a voltage applied to a load;
- second modulator circuitry configured to provide a second frequency modulated signal corresponding to a current through the load;
- and
- control circuitry configured to process the first and second frequency-modulated signals so as to derive first and second processed signals respectively, the processing including removing offset signal content from the first and second frequency-modulated signals, the control circuitry also configured to control one or more aspects of the apparatus by way of the first and second processed signals.
A printing apparatus, comprising:
- an electrical load;
- signal derivation circuitry configured to provide a first electrically isolated signal corresponding to a voltage applied to the electrical load, the signal derivation circuitry also configured to provide a second electrically isolated signal corresponding to a current through the electrical load;
- and
- signal processing circuitry configured to remove offset signal content from the first and second electrically isolated signals and to derive first and second processed signals respectively.
A method, comprising:
- deriving a first frequency-modulated signal corresponding to a load voltage;
- deriving a second frequency-modulated signal corresponding to a load current;
- and
- communicating the first and second frequency-modulated signals across respective electrical isolation barriers from a first voltage level to a second voltage level;
- processing the first frequency-modulated signal and the second frequency-modulated signal so as to derive a first processed signal and a second processed signal respectively;
- and
- using the first and second processed signals to control operations of a printer.
Dependencies are inferred from the claim text.