摘要 |
An AC-to-DC-converter (100) for driving a dynamic load (160), such as a motor, has a rectifier bridge (110), a coil (120), and a switch (130) to boost an output capacitor (150) by a coil current I(t). The current (I(t)) has periodical minimum values. The converter (100) is controlled by a monitor (170) and a modulator (180). The monitor (170) monitors the converter output (signal 102) during a predetermined monitoring interval (tM1, tM2) which is inside a minimum-to-minimum interval of the current (I(t)) and classifies changes (voltage DELTA VOUT) and/or current DELTA IOUT) into a first case (A) where the change exceeds a predetermined threshold ( DELTA VTH) and a second case (B) where the change does not exceed the threshold. In order to shape the current (I(t)), in the first case (A), the modulator (180) immediately alters the current (I(t)), and in the second case (B), the modulator (180) alters the current (I(t)) when the current has its next minimum. Optionally, immediate altering can be prevented.
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