Patent ID: 7994857
Filing Date: 2011-08-09
Classification: H03F,H03G

Abstract:
1. An amplifier device, comprising: a switching amplifier including an input for receiving an audio input signal and an output to a load, and the switching amplifier including a high voltage supply rail; a voltage sensor circuit connected to the high voltage supply rail and the voltage sensor circuit measures the power supply voltage of the switching amplifier; a current sensor circuit connected to the high voltage supply rail and the current sensor circuit measures the power supply current of the switching amplifier; an error amplifier connected to the switching amplifier receives a value based on the measurements taken by the voltage sensor and current sensor and produces an error signal when a predetermined power limit is exceeded; and a signal limiting circuit connected to the error amplifier and the switching amplifier, and the signal limiting circuit limits an output power to rated power at any rated load impedance when the error amplifier produces the error signal; wherein the amplifier device is capable of automatically limiting output power at rated power into all rated load impedances, and dynamically reacting to the frequency-dependant impedance of a typical audio system.