PWM control circuit and PWM control method
AssigneeSeiko Epson Corporation
InventorKesatoshi Takeuchi
Life of this patent
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Abstract
The PWM control circuit includes a polarity determination unit, a full wave rectification unit, an adjustment unit that generates an adjusted waveform signal by adjusting waveform of the full wave rectification signal, and a carrier signal generating unit that generates a fixed frequency carrier signal. The PWM control circuit further includes a comparator that generates an original PWM signal by comparing the adjusted waveform signal and the carrier signal, and a PWM waveform shaping unit that generates a first PWM signal for the positive polarity section and a second PWM signal for the negative polarity section, by shaping the original PWM signal according to the polarity signal.
Claims14
A PWM control circuit that generates PWM signals based on an analog sensor output from a sensor provided in a device to be controlled, comprising:
- a polarity determination unit that generates a polarity signal based on positive polarity sections and negative polarity sections of the analog sensor output;
- a full wave rectification unit that generates a full wave rectification signal by doing full rectification of the analog sensor output;
- an adjustment unit that generates an adjusted waveform signal based on waveform of the full wave rectification signal;
- and
- a PWM waveform shaping unit that generates a first PWM signal for the positive polarity section and a second PWM signal for the negative polarity section, based on the polarity signal and the adjusted waveform signal,
- wherein the adjusted waveform signal includes a part of the full wave rectification signal and excludes the other part of the full wave rectification signal.
A method of generating PWM signals based on an analog sensor output from a sensor provided in a device to be controlled, comprising:
- (a) generating a polarity signal based on positive polarity sections and negative polarity sections of the analog sensor output;
- (b) generating a full wave rectification signal by doing full rectification of the analog sensor output;
- (c) generating an adjusted waveform signal based on waveform of the full wave rectification signal;
- and
- (d) generating a first PWM signal for the positive polarity section and a second PWM signal for the negative polarity section, based on the polarity signal and the adjusted waveform signal,
- wherein the adjusted waveform signal includes a part of the full wave rectification signal and excludes the other part of the full wave rectification signal.
A PWM control circuit that generates PWM signals based on an analog sensor output from a sensor provided in a device to be controlled, comprising:
- a polarity determination unit that generates a polarity signal based on positive polarity sections and negative polarity sections of the analog sensor output;
- a full wave rectification unit that generates a full wave rectification signal by doing full rectification of the analog sensor output;
- an adjustment unit that generates an adjusted waveform signal based on waveform of the full wave rectification signal;
- and
- a PWM waveform shaping unit that generates a first PWM signal for the positive polarity section and a second PWM signal for the negative polarity section, based on the polarity signal and the adjusted waveform signal,
- wherein the adjusted waveform signal includes only a part of the full wave rectification signal.
Dependencies are inferred from the claim text.