Thread: Power MOSFETs
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Old 16th May 2019, 2:02 am   #56
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Default Re: Power MOSFETs

Originally Posted by Julesomega View Post
The feedback should be internal to the supply system, and a class-B amplifier (or class-D) has its own NFB loop to achieve this. You set the 1600Hz source amplitude and the amplifier gain to give the required output voltage and rely on the amplifier's (internal) feedback maintain the output voltage.
The amount of NFB built into audio amplifiers is nowhere near enough to stabilize the output voltage under widely varying loads compared to the feedback around a power supply circuit with a synthesized low Z output. In the audio amp case its useful to reduce distortion, not regulate output voltage. So I still think if an audio amp is deployed as a power supply device, it requires additional feedback to give it (synthesize) the stiff low Z output it requires for voltage regulation, or likely, its output voltage will be too load dependent.Though it is true that hefty semiconductor based power amps can have an intrinsic very low Z output, which is obviously helpful.

Last edited by Argus25; 16th May 2019 at 2:11 am.
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