Abstract: The present invention relates to an automatic bandwidth adjusting method comprising steps of receiving at least one radio signal, converting the at least one radio signal in a preset filter bandwidth into at least one audio signal; generating at least one signal-to-noise ratio (SNR) information based on the at least one audio signal, wherein the filter bandwidth is adjusted between multiple preset range intervals, and the range intervals are different; comparing the at least one SNR information with a preset first critical SNR and a preset second critical SNR to determine whether to adjust the filter bandwidth or not; outputting a bandwidth adjustment signal when the filter bandwidth needs to be adjusted; and adjusting the filter bandwidth according to the bandwidth adjustment signal.

Abstract: A multimedia player having battery backup power has a housing, a battery seat, a rechargeable battery and a circuit module. The battery seat is formed on a periphery of the housing and has a battery connector electrically connected with a power circuit of a power module mounted inside the housing. The rechargeable battery is conveniently and directly mounted on the battery seat and supplies backup power to the power circuit of the power module through the battery connector. As the power circuit is connected with an AC power source, the power circuit further converts the AC power into DC power to charge the rechargeable battery when the AC power supply is normal, thereby reducing the frequency of battery replacement.