Method and apparatus for pulse width modulation
AssigneeSiemens Aktiengesellschaft
InventorsUwe Krause, Uwe Nolte, Jan Spannberger
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Abstract
There is described a method and an apparatus for pulse width modulation with a predefined switching period having an adjustable ratio of the switch-on duration to the switch-off duration, in which a quantized signal is converted into a pulse-width-modulated signal and is generated in the form of a discrete pulse sequence of switch-on operations and switch-off operations with the predefined switching period, the switching edge for the switch-on duration and/or the switch-off duration being determined on the basis of the ratio of the switch-on duration to the switch-off duration.
Claims20
A method for pulse width modulation, comprising:
- providing a predefined switching period having an adjustable ratio of a switch-on duration to a switch-off duration;
- converting a quantized signal into a pulse-width-modulated signal;
- generating a discrete pulse sequence of switch-on operations and switch-off operations with the predefined switching period;
- and
- determining a switching-free period of time based on a switching edge for one of said switch durations established with double negation, to allow for detection of electrical and non-electrical measurement variables, that are typically not measurable when interference is present, with minimum interference, based upon a ratio of the switch-on duration to the switch-off duration, wherein the switching-free period of time occurs at a same time within the switching period.
An apparatus for pulse width modulation, comprising:
- a predefined switching period with an adjustable ratio of a switch-on duration to a switch-off duration;
- and
- a control unit having a negation means to convert a quantized signal into a pulse-width-modulated signal and to generate the pulse-width-modulated signal in a form of a discrete pulse sequence of switch-on operations and switch-off operations with the predefined switching period, wherein a switching edge for one of said switch durations is determined, to allow for detection of electrical and non-electrical measurement variables, that are typically not measurable when interference is present, with minimum interference, based upon a ratio of the switch-on duration to the switch-off duration, wherein the switching-free period of time occurs at a same time within the switching period.
Dependencies are inferred from the claim text.