A low-pass filter is a filter that passes signals with a frequency lower than a selected cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency. The exact frequency response of the filter depends on the filter design. The filter is sometimes called a high-cut filter, or treble-cut filter in audio applications. A low-pass filter is the complement of a high-pass filter.
In optics, high-pass and low-pass may have different meanings, depending on whether referring to frequency or wavelength of light, since these variables are inversely related. High-pass frequency filters would act as low-pass wavelength filters, and vice versa. For this reason it is a good practice to refer to wavelength filters as short-pass and long-pass to avoid confusion, which would correspond to high-pass and low-pass frequencies.Low-pass filters exist in many different forms, including electronic circuits such as a hiss filter used in audio, anti-aliasing filters for conditioning signals prior to analog-to-digital conversion, digital filters for smoothing sets of data, acoustic barriers, blurring of images, and so on. The moving average operation used in fields such as finance is a particular kind of low-pass filter, and can be analyzed with the same signal processing techniques as are used for other low-pass filters. Low-pass filters provide a smoother form of a signal, removing the short-term fluctuations and leaving the longer-term trend.
Filter designers will often use the low-pass form as a prototype filter. That is, a filter with unity bandwidth and impedance. The desired filter is obtained from the prototype by scaling for the desired bandwidth and impedance and transforming into the desired bandform (that is low-pass, high-pass, band-pass or band-stop).
For that we will need a laser pen and two square pieces of opaque, non reflecting material. In both these squares a slit will be cut, wide enough to let a beam of the laser pass through without any refraction effects.
First, after the laser has been turned on, one of the squares is placed in...
I have been assigned the task to design an active bandpass filter with a passband of 0.1 to 10 Hz. At these two frequencies, there should be an attenuation of -6dB or more. So far I have selected my circuit layout which can be seen below
I found my transfer function so that I could calculate...
I was wondering if it would be possible to remove diseases such as cancer from the blood with a mechanical device similar to the one used for dialysis. When the blood passes through the device certain cells would bind to the walls that have just the right binding sites so that they get stuck...
Hello!
Consider this filter,and that I have to find the transfer function U2/U1 with the norm Ω= ωRC (also double fractions are not allowed)
Now I can see that that the resistor and capacitor left as well as right are parallel to each other. So simplifying that
## Z_1 = \frac{R}{jωRC +1}...
I am trying to simulate the active converter, I have seen in you tube video the output of the grid 3 phase voltage is given to LCL filter, the output of the LCL filter is then given to the half bridge section. I assume that the output of the LCL filter is a DC instead of the sine wave, as it is...
I have found a fair amount of sources for studying polarized light but I haven't found sources discussing synthesis of polarizers in detail along with mechanistic discussion.
The summary describes the situation. Most coffee ground beans let the hot water go through the filter paper more or less slowly maybe taking a few minutes to brew a serving of coffee through the coffee filter paper. Some other beans, usually of African origin, take much longer to brew. The...
Hey is it possible to run a normal pond filter of a solar panel my pond is placed at the top of my garden and there's lots of sun around the pond i already have solar panel water fountain in there running with solar lighting to.
The pond is to far away from the house to run cables down and I am...
A few days ago, I learned to make an AC to DC converter. One question is troubling my mind. How does a High Pass Filter Capacitor work? Going through some websites I got a sketchy idea.
As the current after passing through the bridge rectifier comes to capacitor, the capacitor starts charging...
What mechanism or mechanisms cause filter paper to block coffee oils? As I understand it, these "oils" are mostly cafestol and kahweol, which are both functionalized polycyclic molecules with a molar mass around 315.
Cloth filters do not prevent these oils from getting into the brewed coffee...
Hi everyone, I've been having trouble on how to answer this question
This is my attempt at it below, but I am not sure what values of t to sub in for evaluating the integral.
Any help would be appreciated! Thanks
Design a linear phase low pass filter whose specification is:1) Maximum tolerance in the passband equal to 0.01% (linear) in the passband;2) Cutoff frequency at ω_c = 0.3π and transition band at 0.05π;3) Minimum reduction of the 0.95 rejection band.
Being mistaken gives me the creeps because, to the extent that truth matters, it's my only tool, shield, and weapon. So I'm always looking over my shoulder, worrying that I might believe something that's not true.
Are any of these NOT true?
The spacetime interval is "absolute distance,"...
I need help with part (a)... I know that the root-mean-square voltage is the dc-equivalent voltage for an AC waveform and what my book labels "##V_{dc}## is actually the average voltage. Hence I am assuming the question is asking me to find ##V_{rms}## ...
Is my assumption that the...
Hi,
I just have a quick question regarding image processing. What is the correct form of the Laplacian for image processing?
I have seen different versions online and don't understand which one is meant to be the conventional one. I know that:
\nabla^2 f(x, y) = \frac{\partial^2 f}{\partial...
Hi friends,
I have simulated two circuits, one is an RC filter and other is a Capacitance multiplier.
My aim of experiment is to validate a decrease in Iout (load current) of CM circuit as compared to load current in RC filter circuit.
Theoretically,
Iout (CM circuit) < Iout (RC filter)
Vp-p...
Fitness function for window length of filter
On a sinusoidal signal with amplitude 1, and period P, an exponential moving average (EMA) (with alpha = 1/n), and a linear weighted moving average (LWMA) (with window length n) are calculated; when you subtract the EMA from the LWMA, it can be seen...
Hi everyone
I am finishing the last problem for a DSP problem set and just frankly have no idea where to start this one. I'm thinking I could compute the magnitude of each filter and then compare, but again am not sure. Can anyone point me in the right direction?
Thanks
Hello ,am posting this thread because i need help with 1Q , i was told by my tutor to measure Vo and Vi over the range of frequencies 1khz to 100khz , but i have no idea how to do that ,am not very good at maths and that's why i been really struggling to do it , i have tried doing it but am 100%...
Hi,
Context:
I was looking through some circuits material in the topic of filter synthesis for two port networks. For simplicity, these networks have been synthesized for normalized conditions: 1 rad/s cut-off frequency and a termination resistor of 1 ## \Omega ##. An example filter is shown...
Say we have a transform of a line profile that extends out to the Nyquist frequency such that you cannot see the noise level, what could you change in your spectrograph arrangement that would allow you to see the noise level in the Fourier domain?
My thought is that we can apply a filter, P(s)...
I am starting the input filter design for a converter and only have the voltage and power specs. It will be the input filter to other converters on a parallel bus, so I could look at the datasheets for those and get some specs there. I do not have any information from the input converter to this...
Hi,
I have a question about calculating the Jacobian matrices for the Extended Kalman filter.
Question: If we have a system of the form:
\begin{align*} x_{k+1} =f_k (x_k , u_k) + w_k \\
y_k = h_k (x_k , u_k ) +v_k \end{align*}
where the state x_k comprises of the three variables p_1 ...
Hi,
I just have a quick question regarding the linear phase property of filters. It might be easier to provide some context before getting to the question, but feel free to skip to the bottom.
Consider a system input as a discrete sequence obtained by sampling at t = 0, T, . . . , kT from an...
Hi,
I have a question related to filter structures. Question: An FIR filter can also be implemented using a recursive structure. Can you find such an example?
I don't really know how to proceed here.
Method:
FIR filter is a 'finite impulse response', which means that the response doesn't last...
On arXiv: The Significance Filter, the Winner's Curse and the Need to Shrink
It's well known that it is difficult to publish null results in various fields. The authors try to quantify that by analyzing over a million z-scores from Medline, a database for medical publications. A very striking...
Below is the whole code. I can't change the whole code, I can only change the "Kalman class".
The Kalman class in the code below is my attempt to solve the problem.
But the code doesn't work well.
I have written these 5 equations in the Kalman-filter algorithm:
State Extrapolation Equation...
I am looking at the following IRAS filter profile IRAS Filter Profile and I am wondering how they computed ##\lambda_{mean}##? They provided the following equation below but what is ##T(\lambda)## and ##\lambda##?
Wondering where I can purchase the polarization filter rotator dial equipment? I tried searching online and couldn't find it. I will like to rotate the polarization filter sheets and measure the angle of the rotation but I can't find that equipment online.
I have attached the image below:
I consider the band-pass filter of the following configuration (the ##u_m## is a voltage controlled voltage source):
The transfer function is
$$K_1(p)=\hat{U}_o(p) = \frac{p}{RC(p+1/RC)^2} = \frac{\omega_c p}{(p+\omega_c)^2}, \quad \omega_c=\frac{1}{RC}.\qquad (1)$$
Now I connect ##n## such...
I have two filter materials and I have manufacturer-supplied pressure drops across the filters at given flow rates. I know the desired flow rate and the negative pressure "sucking" on the downstream side of the filter, and I want to calculate the required filter surface area for each filter...
I came up with a curiosity whether having a facial mask on face to breathe can actually be safe to lungs in the following aspect.
I remember when I was young, Asbestos was so popularly used in construction.
and now, people wear Hazmat suits to remove any remaining Asbestos since it is...
Dear forumers,
I have two high performance AC feedthrough capacitors (47nF, 100A, class Y2, DC-60Hz) which I want to either combine with a general purpose EMC line filter, or build a custom one to filter the mains from of about 100khz to as high as possible (for shielding purposes).
I can see...
I am a using a mirror to reflect an image at an angle of incidence of 10 degrees. The mirror is also at an angle of incidence of approximately 30 degrees from the viewer and it creates undesired reflections when looking at the mirror. Here is a diagram illustrating the situation.
I am looking...
In the early parts of the books, Mars' ambient atmo pressure (and temperature) was increased, including not just CO2, but oxygen as well.
It rose to the point where they only needed masks that let through oxygen but not CO2.
In my amateur view, I would expect that this would not work very...
I just bought a Coronado and, typically, there are no sunspots to look at. If there were, then I could compare what I see in that dim dark red image with what my basic Baader shiny filter delivers. I understand that there's a learning process involved and I imagine all first-time users have had...
I'm interested in doing more detailed photos of the Sun using my solar filter and a 1.25" Hydrogen Alpha (Ha) filter. Is this possible to do or is it best to purchase a Coronado telescope?
Hello,
I am simulating the input impedance of a high-pass filter with the output voltage of the filter input to the non-inverting pin of an op amp. I'm confused as to why the input impedance can possibly dip below the resistance of the high-pass filter resistor. Please see the following circuit...
I wrote this code, but I am not sure its ture or not
from numpy import arange
from math import floor
from pylab import plot, show
Vout = 0 #inital condition
t_i = 0 #initial time
t_f = 10 #final time
N = 100000
h = (t_f - t_i) / N
RC_values = [0.01, 0.1, 1]
def f(Vout, t):
if floor(2 *...
Now home water filter is ubiquitous using almost every family. I am wondering who designed such systems (and become its standard form used today) ? I think after second world war the New York water is pretty dirty hence the development of such filter. But I am not sure whether it is correct or not.
I tried solving this problem and got it correctly until the part A of the question.
My solution is the same as the one given in the solutions manual until the part I put in the red box.
I don't understand what is the logic behind the calculation of the bandwidth and center frequency there...
Being an old school Newtonian engineering type, I have a model of a polarising filter that generally works for day to day stuff like taking photos, explaining sun glasses etc..
But it is clearly wrong.
Given that opening remark, the 'A' index, and the forum subject area, I trust you will...
Problem Statement: Computing AC voltage
Relevant Equations: cut off frequency, ac voltage.
Hey guys,
Amazing to be in this group ! Please find attached the diagram of the problem.
E = 10kV at 60Hz, C1 = 60pF and R1 = 1k.
I have to compute the ac voltage in reference to ground at point [1]...
Raman spectroscopy involves
Illuminating a target with a laser
Beam. This produces Raleigh scattering. Does The releigh scattering have the same frequency as the laser beam? So use an optical filter to block the same frequency as the laser?
Bought a stainless steel whole house water filter for a very good price ($100), turns out too good. On inspection I suspected it would leak so rather then installing it into the house water system I pressure tested it. There was a small leak that stopped after a minute or so. Relieve the...
Spike Walker, whom I semi-regularly consult with about my Ultraphot III, recently told me about a really cool optical device: a 'Varicolor' filter, manufactured (and discontinued) by Cokin. I found one for $10 on eBay, received it yesterday, and I can't put it down. Here's a set of images of...
Summary: water pressure issues
what happens when you take water from a 3/4 inch pipe copper to 1/2 inch flexible braided hose through a filter for a 3/4 pipe back through a flexible braided hose 1/2 inch tube to 3/4 inch copper pipe?
https://www.flairespresso.com/product-page/flair-signature made a manual espresso machine and specify using 30 lb of pressure in the manual. In order to determine the correct pressure, they literally tell the user to push down on a kitchen scale. I'm considering a competing product, and that...