Decibel question

Discussion in 'Homework Help' started by joka2188, Nov 19, 2006.

  1. joka2188

    Thread Starter New Member

    Nov 10, 2006
    9
    0
    If there is a voltage signal loss of - 6 dB along a cable, giving a 2V output, determine the input voltage.
    Basically, i know how to find the voltage signal loss which is VdB = 20log (vout/Vin), (if anyone thinks this is incorrect would you let me know). So basically how would you maniuplate this formula so you can find out Vin if you're only give Vout and VdB.
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,157
    1,795
    Proceed as follows
    Code ( (Unknown Language)):
    1.  
    2. VdB = 20 * log (Vout / Vin)        (divide both sides by 20
    3. VdB/20 = log(Vout / Vin)           (exponentiate both sides
    4. 10^(VdB/20) = Vout / Vin           (multiply both sides by Vin
    5. Vin * (10^(VdB/20)) = Vout         (divide both sides by 10^...
    6. Vin = Vout / (10^(VdB/20))
    7.  
     
Loading...