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Old 20th Feb 2018, 3:06 am   #11
Herald1360
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Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
Default Re: Class D amplifiers.

Quote:
Originally Posted by 'LIVEWIRE?' View Post
TBH, despite nearly 50 years working with radio and audio gear, I'm not even sure how a Class 'C' amplifier works.......
Class C only works at a single (RF usually) frequency with a resonant tank circuit load.

The device is biassed beyond cutoff and simply delivers tall narrow pulses around the positive peak half cycles of the drive signal to kick the tank circuit into resonance. A typical pi tank circuit also acts as a low pass filter to clean up the large harmonic content of the driving pulses.

It's no use for linear amplification it's just a fairly efficient way to generate a high power CW signal. If the supply voltage to the device is varied you get an amplitude modulated signal output.
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