Patent ID: 8744366

Claim:
An apparatus for controlling an attenuator, the attenuator having a signal input and a signal output, the attenuator attenuating the signal in discrete steps to a degree determined by a control signal input to the attenuator, comprising: a first control having an input for the desired final attenuation value for the signal and a second control having an input for the desired rate of change of attenuation to achieve the desired final attenuation value, a third control for varying the control signal in discrete steps to vary the attenuation of the attenuator in discrete steps to control the rate of change of attenuation of the attenuator to the desired rate and the final attenuation to be the desired final attenuation value of the signal input, the setting of the attenuator to the desired final attenuation value being subsequent to varying the attenuation of the attenuator in said discrete steps, the inputs to the controls for the desired final attenuation value and the desired rate of change of attenuation being set at values which can be independent of the signal input to the attenuator.