Відео

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@@wurthelektronikamericas Thank you for your so-called answer, but it doesn't reflect to the topic at all. You know: I talked about the *noise gate*, that truncates the words. This is not about the knowledge of the speaker. This is a telecommunication/broadcasting issue. Some sound engineer/technician in your company must know very well how to transfer audio without terrible information loss. Just somebody should care about it. Zoom for example contains a setting to keep high quality audio for musicians.

Thank you for asking! You can download the PDF of the slides here- bit.ly/FeedbackLoopCompenstation_Aug2022

Thank you for the question. The right-half-plane zero (RHPZ) is not created by any component as such, but by the way the energy is transferred from the input to the output stage of the converter during each switching cycle, so it depends on the converter topology. Especially, topologies in which energy transfer to the load only occurs during the off-time of the control transistor, like the boost, buck-boost and flyback converters, have a RHPZ on its control-to-output transfer function, whereas topologies in which there is energy transfer during the entire swiching period (Tsw), like the buck and forward converters, do not have a RHPZ. What the RHPZ ‘physically’ means can be intuitively understood as follows. Consider a sudden increase step in the load current of a flyback converter. The output voltage will start to decrease and the loop will react to increase the duty-cycle of the control transistor, so that to increase the primary peak current and with it the amount of energy transferred to the output in order to bring the output voltage back up to its target level. However, as the duty-cycle has increased, the off-time of the control transistor (energy transfer window) is now shorter (toff=(1-D)*Tsw). So if the peak current has not increased high enough (e.g. because too high magnetizing inductance (Lm) slowing down dI/dt), then the average current on the secondary winding of the transformer, which equals the converter output current, would actually be lower than before, and the output voltage will drop even more. So the control loop has reacted trying to increase the output current, but the result is the opposite, due to either too high Lm and/or too fast control-loop reaction speed. If the magnetizing inductance is lower (i.e. higher dI/dt and peak current increase for a set delta of the duty-cycle), and/or the control loop is slowed down (i.e. lower crossover frequency resulting in a lower rate of change of the duty-cycle) then the issue can be solved. Note how, for a set increase of the duty-cycle, a lower Lm will allow the primary peak current amplitude (and thus secondary peak current) to increase high-enough each switching cycle so that to compensate for the shorter energy-transfer window, and thus make the average secondary current to effectively increase, which is what the control-loop is trying to achieve. This also intuitively explains why the RHPZ frequency depends on the inductance (see formula on the presentation): lower Lm (higher dI/dt), then higher RHPZ frequency, and higher the crossover frequency can be set without any issues. Hope this answers your question.

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