| 摘要 |
The analog signal (V1) is amplified in a gain-controlled amplifier (1) and converted from analog to digital mode. It is supplied to an input on a microprocessor (3) which compares the amplitude values of the digital signal with stored upper and lower limit values. This emits, depending on this comparison, a gain-control signal (Vs) to the amplifier (1). The gain control signal (Vs) is of such a value that the dynamic range of the analog signal (V1) is adapted to a prefixed digital ward length. The analog signal includes an electric analog signal which is to be gain-controlled, and a second undesired electric analog signal whose amplitude is higher than that of the first signal. The frequency of the first signal is computed using previously stored values of the digital signal representation of the first signal. The frequency of the second signal is determined using the stored values of the total digital signal representation of the two signals. The stored values of the second signal are detected if the frequencies differ. |
