# RLC parallel filter question.

#### Virium

Joined Jan 8, 2016
4
Hello everybody, trying to simulate RLC filters in multisim, and I am stuck on this particular one. There is no voltage difference between input and output, no matter the frequency. I have also added small resistances in series with the capacitor/inductor. Any hints to what I am doing wrong ?

#### Veracohr

Joined Jan 3, 2011
772
Put some resistance before the LC.

#### crutschow

Joined Mar 14, 2008
34,078
Show the simulation schematic with parts values and results.

#### Marley

Joined Apr 4, 2016
501
Of course in real life the source would have some impedance. So the voltage across RL would change with frequency. But impossible to simulate without knowing the source impedance.

#### Virium

Joined Jan 8, 2016
4

#### Jony130

Joined Feb 17, 2009
5,487
But how can you be able to see any difference between the input and output if you driving this circuit form a ideal voltage source?
LC tank circuit and the load resistance is directly connected to the voltage source. Vin is the same voltage as Vout = Vin.
Try use a current source instead of a voltage source or put LC tank in series with the load resistance.

#### Papabravo

Joined Feb 24, 2006
21,030
How can there be any difference because they are the same nodes in your network. What happens if the impedance of your voltage source is (equal to, very much less than, very much greater than) the load resistance.