CLOSED LOOP POWER CONTROLLER

摘要

A power controller includes a closed loop system (10) having a summer (12) t o sum an input signal with a derived output signal to produce a difference signal. A comparator (22) compares the difference si gnal with a reference signal to produce a digital signal representative of the polarity difference between the difference signal and the reference signal. Two switching networks (30) respon d to the digital signal to produce high energy outputs representative of the digi tal signal which are used to reduce the level of the dif ference signal in a frequency band of interest at the comparator (22). A low pass fi lter (32) between the high energy outputs and the compar ator (22) attenuates high frequency noise. A low-pass filter (32) of at least the third order, connected in the closed loop, enhances the signal to noise ratio. A specific application of the power controller is a power ampli fier with the input signal in the audio frequency range.