Is a Low Pass Filter Suitable for a Basic Noise Filtering Circuit?

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In summary, the conversation is about building a laser listener device and the author mentioning the need for a low pass filter and a preamp. However, it is advised not to build it as the CDS cell used in the device does not have a fast enough response time. The author suggests using a high speed photodiode or a laser doppler vibrometer, but it may not be feasible due to cost.
  • #1
ice109
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i want to build one of these

http://funditor.110mb.com/LaserListener.html

but he alludes to some kind of circuit at the end that could filter out the noise using analog components and I'm thinking it's some kind of low pass filter. am i right? i really only have a little electronics knowledge? i guess i need something called a preamp too? note I'm not malicious or anything i just think it would be a fun little project.

basically i want it to be portable cause i don't have a laptop
 
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  • #2
Don't bother. I can't believe the author has actually built that. A CDS cell (cadmium sulfide) does not have a fast enough response time to actually be useful with audio.
 
  • #3
Averagesupernova said:
Don't bother. I can't believe the author has actually built that. A CDS cell (cadmium sulfide) does not have a fast enough response time to actually be useful with audio.

:( really ? that's exactly the kind of photocell i bought, what kind can i use?
 
  • #4
A cheap CDS cell has a response time of the order of 0.1sec so you are not going to get much audio out of it.

You could use a high speed photodiode, but you would have to redesign the rest of the circuit, and the whole idea looks a bit far fetched to me.

You use a proper laser doppler vibrometer (LDV) - that would work, but not in your price range!
 

FAQ: Is a Low Pass Filter Suitable for a Basic Noise Filtering Circuit?

What is a basic filtering circuit?

A basic filtering circuit is an electronic circuit that is used to remove unwanted noise or signals from a desired signal. It works by attenuating certain frequencies while allowing others to pass through.

How does a basic filtering circuit work?

A basic filtering circuit works by using passive electronic components such as resistors, capacitors, and inductors to create a frequency-dependent impedance. This impedance is then used to filter out unwanted frequencies from a signal.

What are the different types of basic filtering circuits?

There are three main types of basic filtering circuits: low-pass, high-pass, and band-pass. A low-pass filter allows low frequencies to pass through, a high-pass filter allows high frequencies to pass through, and a band-pass filter allows a specific range of frequencies to pass through.

What are some applications of basic filtering circuits?

Basic filtering circuits are commonly used in electronic devices to improve signal quality and remove unwanted noise. They can also be used in power supplies to eliminate ripple voltage and in audio systems to enhance sound quality.

How do I choose the right basic filtering circuit for my application?

The type of filtering circuit you choose will depend on the specific application and the frequencies you need to filter. It is important to consider the desired frequency range, the level of attenuation needed, and the circuit's impedance characteristics when selecting a filtering circuit.

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