| 摘要 |
PROBLEM TO BE SOLVED: To provide a protective device for a digital amplifier capable of detecting current with high accuracy and of protecting the components from overcurrent. SOLUTION: The protective device for a digital amplifier is provided with a digital amplifier unit provided with a pulse amplifier 7 for converting an audio input signal into a pulse signal, applying switching amplification to a converted pulse signal and supplying the amplified signal to a speaker and a low-pass filter 8 including a reactor and a capacitor and for smoothing an output of the pulse amplifier; a voltage detector for detecting an applied voltage to the reactor L which is the component of the low-pass filter; a compensation unit 12 for compensating the nonlinearity of an output of the voltage detector, on the basis of the nonlinearity of the frequency characteristic of the impedance of the reactor; and a protection unit 14 for protecting the digital amplifier from an overcurrent, on the basis of the output of the compensation unit 12. COPYRIGHT: (C)2005,JPO&NCIPI
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