Comparing Two Circuits: Can We Say Low Pass Filter?

In summary, the conversation discusses using source transformation to transform a voltage source with a series resistor into a current source in parallel with the same resistance. This can be useful for cascading multiple filters in a circuit. However, the interest and practical use of source transformation may vary and it is not always necessary.
  • #1
somasimple
Gold Member
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Hi all,

Here is a picture of two circuits.
The one at the left is stimulated with a current source and the other with a voltage source.
They give the same results V(1) = V(2).
Is it possible to say that the primer is a low pass filter?
 

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  • #2
Yes. Somewhere buried away in your textbook is something call source transformation. If you have a voltage source with a series resistor, you can transform it to a current source in parallel with the same resistance. The current source is simply the original voltage source divided by the resistor.
 
  • #3
Thanks Corneo,

I wasn't aware of such circuit but find a good description in this http://books.google.com/books?id=sx...r=&ei=v5_AScGeEp-8zgTIwOH3Bw&hl=fr#PPA118,M1"
What is its interest by the way?
Normally the simple nature of RC cells give us an entry point and an exit one. This permits a cascading with two or more filters.
In this configuration the applied source is modified by the filter but I see no way to assemble multiple filters?
 
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  • #4
What good is source transformation? Honestly I don't know. I have never ever had to use it at in career so far (2 years). If you want to cascade the filter, you could just place the next filter in parallel to the resistor and cap, the currents sources would add. The resistors would combine in parallel; the caps would add in value.
 

1. What is a low pass filter?

A low pass filter is an electronic circuit that allows low frequency signals to pass through while blocking high frequency signals. It is commonly used in audio and communication systems to remove unwanted noise and interference.

2. How is a low pass filter different from a high pass filter?

A low pass filter allows low frequency signals to pass through, while a high pass filter allows high frequency signals to pass through. In other words, a low pass filter attenuates high frequencies while a high pass filter attenuates low frequencies.

3. Can we compare two circuits that have different low pass filters?

Yes, we can compare two circuits with different low pass filters as long as they have the same cutoff frequency. The cutoff frequency is the frequency at which the filter starts to attenuate the signal.

4. How do we measure the effectiveness of a low pass filter?

The effectiveness of a low pass filter is measured by its cutoff frequency and its attenuation rate. A good low pass filter will have a sharp cutoff frequency and a high attenuation rate, meaning it can effectively block out unwanted high frequency signals.

5. Are there any limitations to using a low pass filter?

Yes, there are limitations to using a low pass filter. It can only attenuate frequencies up to a certain point, so it may not be effective in blocking out very high frequency signals. Additionally, it may introduce some phase distortion to the signal, which can affect the quality of the output signal.

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