| 摘要 |
An adjustable attenuator comprises first and second inputs, first and second resistors connected in series from the first input, and a switch for selectively connecting the end of the second resistor remote from the first resistor either to the first input or to the second input, the output of the attenuator being taken between the junction between the resistors and the second input. Thus when the switch is in its first state, the two resistors are connected in parallel with each other and in series with the first input, providing an attenuation factor substantially equal to one, while when the switch is in its second state, the two resistors are series connected between the first and second inputs as a potential divider chain.
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