# Passive Attenuating Overview

Passive Debilitator is a fully resistant network used to weaken the signal level of a transmission line, improving impedance matching and making passive debilitators the opposite of amplifiers. Passive Attenuators are electrically connected between the weld feed and the load, with a fixed amount of induced weakening. The connected debilitating section can provide constant weakening, impedance compatibility or insulation between welding and load. Since it has only resistant elements in a passive attenuator design, the weakened signal is not affected by distortion or phase shift. Passive attenuating designs can be fixed, gradual or variable; Constant attenuators are known as "pad debilitators" with widely used attenuation networks ranging from 1dB to 20dB. The amount of weakening offered by the debilitating pad is determined by the voltage ratio between the input source signal and the output load signal, which is expressed in decibels. The ratio between the input signal (Vin) and the output signal (Vout) is given as follows: This voltage ratio can also be derived from weakening in decibels. A factor known as the "K factor" can be used in the calculation of debilitating resistance elements. Tables that give the value "K" can be produced, as shown, because the "K" factor corresponds to a certain amount of weakening in decibels.

## "K" Factor Tables for Debilitating Loss

 dB Loss 0.5 1 2 3 6 7.5 9 10 K value 1.0593 1.122 1.2589 1.4125 1.9953 2.3714 2.8184 3.1623
 dB Loss 12 18 24 30 36 48 60 100 K value 3.9811 7.9433 15.849 31.623 63.096 251.19 1000 105

A voltage weakening of 6dB will be 10^(6/20) = 1.9953. Passive Attenuators can be symmetrical or asymmetrical in the form and can be of a balanced or unstable type. Common passive attenuating circuits include the type "T-type", "Pi-type" and "Bridged-T", as shown below.

The L-pad Debilitating is the simplest debilitating design consisting of only two resistant elements and is more commonly known as the voltage dividing circuit. L-pad debilitating is an unstable asymmetric debilitating circuit that can only match impedance in one direction. The balanced equivalent of "L-pad Debilitator" is called U-pad debilitator.