| 摘要 |
<p>In order to amplify a plurality of input signals, the input signals received on a plurality of input channels (2, 3) are passed to a corresponding plurality of amplifiers (20, 30) via first switches (10, 12) which permit each input channel (2, 3) to be connected to each amplifier. Similarly, the outputs of the amplifiers (20, 30) are passed to a corresponding plurality of output channels (17, 18) via second switches (11, 13) which permit each amplifier (20, 30) to be connected to each output channel (17, 18). By controlling the switching of the first and second switches (10, 12; 11, 13), the input on any one input channel (2, 3) is output via a corresponding one output channel (17, 18), but is amplified subsequently by the plurality of amplifiers (20, 30). This prevents variations in the amplifiers affecting comparison of the output, particularly if the outputs on the output channels (17, 18) are time averaged.</p> |
