Questions tagged [filter]
A filter selectively processes input signals in frequency- or time-domain.
2,027
questions
0
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1answer
56 views
First order low pass filter - Calculate capacitance change
I'm trying to calculate the relative change in permittivity of a capacitor.
I have created a circuit that feeds a 80MHz square wave signal into a first order low pass filter.
I don't know the ...
-2
votes
1answer
70 views
Why is the capacitor filter in parallel with the load and the choke in series in a choke input filter?
What will happen if we interchange them?
In a capacitor filter, the capacitor discharges through the load, it was connected in parallel to load. From what I have concluded, if the capacitor is in ...
1
vote
2answers
55 views
Bubba Oscillator - Last filter not buffered
Let's say that we have the following circuit of a Bubba Oscillator
The purpose of the four low pass filters is to achieve a 45 degrees phase shift in the oscillation frequency. Meanwhile, the three op ...
-4
votes
3answers
122 views
Resonant LC filters on a spherical capacitor [closed]
In the setup below, the circles are plates of a capacitor, and there are two LC filters mounted on it.
Would the current prefer to pass via the filters if they are tuned to resonate at the frequency ...
1
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0answers
57 views
IMU gives wrong pitch angle after 70°
I am currently using this library, in particular the Mahony filter within it, for sensor-fusion on an IMU in my diploma project.
The library works great, but I have encountered a problem which only ...
0
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3answers
85 views
Choose the cutoff frequency from the sampling rate
I want to use a low pass filter for the input of my ADC, and I would like to choose the most appropriate cut-off frequency based on the sampling rate of the ADC, which is 40 SPS. Is there a simple ...
2
votes
6answers
788 views
Filters: what kind of capacitor?
Until recently, I (foolishly) believed that the capacitance of a given capacitor was the capacitance given by the datasheet +- the tolerance.
I recently learned about the DC derating of MLCC (multi-...
0
votes
1answer
52 views
DC Block/high pass filter
I'm looking to design a DC blocking capacitor for an eternal antenna, to ensure no DC voltage can pass to the antenna.
Is this the correct way to simulate it, with the probe between the capacitor and ...
0
votes
1answer
52 views
Instrumentation amplifier AD8293G160 - Why RC filter calculations don't match?
I am using an AD8293G160 to handle a signal, for a known bandwidth.
The part is an INA with a fixed internal gain of 160x. It has 2 outputs, one direct, the other with an integrated 5k resistor to ...
0
votes
1answer
111 views
How to Calculate Voltage across R2 for any Value of R1, R2, and Frequency?
I know this is really simple, but I'm really new to electronics, so please bear with me.
CircuitLab said that the voltage across R2 was -14.24 dbV, given the component values shown and a source ...
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votes
1answer
46 views
RLC circuit: change R and C because of constraint in L
I am trying to build this circuit, but I can only find 47 μH inductors. Is there any way I can change R and C to get an equivalent circuit?
0
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1answer
68 views
Butterworth Active Low Pass Filter Design
I'm designing a low pass active filter with a butterworth response. The passband is DC to 1.5k Hz, so the -3dB cut off frequency should be around 2k-5k Hz to be safe.
The topology I've decided to use ...
1
vote
1answer
69 views
How does send and receive work in Ethernet over power and what standard describes this?
From what I understand in 100/1000BASE-TX Ethernet, two pairs are adopted; one for transmitting and the other for receiving. What I'm wondering is how Ethernet over power works given that it's ...
2
votes
1answer
92 views
Simulating an RLC bandpass filter with LTspice
I have analyzed the filter in question both in practice and in simulation (with LTspice)
The calculations I performed to determine the high and low cutoff frequency and the resonance frequency are as ...
8
votes
7answers
2k views
Is there any advantage or disadvantage of using high value capacitor instead of high value resistor in filter?
For filter design, one can choose the resistor and capacitor value according to one's wish. But is there any disadvantage of using a high-value resistor with a low-value capacitor or vice versa?
0
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1answer
59 views
RLC circuit as an average filter
I have simulated a buck converter in LTSPICE, and below is the switching signal (red )that goes into an RLC filter( vout as green).
The filter does not average the switching pulses, So I believe the ...
0
votes
0answers
37 views
Electret mic - power source noise
I'm working on a project that requires connecting an electret mic to an STM32 nucleo board. The mic is on a amplifier board with the following specs:
MAX4466 microphone breakout board; You can set the ...
1
vote
0answers
62 views
Single-ended to differential ADC driver with one pole active low pass filter
I have this ADC driver circuit:
There is a passive filter downstream of the driver which works as desired. I'm focused here on the active filter. When I run AC analysis on this circuit configured for ...
-1
votes
1answer
53 views
Need help choosing a toroid to wind an inductor for a high-pass filter
Trying to listen to HF but my RTL-SDR V3 is being overloaded by AM broadcasts so I'd like to build a high-pass filter to block the AM broadcast band. I thought I'd start simple and try making the one ...
0
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0answers
38 views
Filter for AC line coupling with audio signal source
I need a sharp notch filter (higher order) for the 50-60 Hz band, to be placed between AC 220/125 V power line and an audio source (not necessarily amplified), such that the input signal from the ...
2
votes
1answer
60 views
RIN measurements of a laser
I want to measure the relative intensity noise between 0 and 1 MHz of a laser using a photodiode (20 MHz BW), a voltage amplifier (10 MHz BW), and a spectrum analyzer. Since I don't have so much ...
1
vote
1answer
61 views
Topology of a multiple feedback filter with differential input
While looking for a multiple feedback filter with differential inputs and single ended output I came across those two low-pass filter which are identical excepted for C2 capacitor.
Will the transfer ...
2
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2answers
462 views
High capacitance C0G (NPO) capacitor
[EDIT] : modified the value of cutoff frequency to 4.8kHz after reading the answer of Andy aka.
[EDIT2] Added somme information regarding comments under the question.
I need to build a LC high-pass ...
0
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1answer
76 views
Does every transfer function in a circuit have its own resonant frequency?
When I studied the resonant frequency of an RLC circuit in series and parallel, there was the definition that I read in books that the imaginary part of the total impedance of the circuit has to be ...
6
votes
2answers
432 views
What is meant by filter order of a passive filter?
When we talk about passive filters (filters that are made up of only R, L & C), we often study that the filter order will be equal to the total number of reactive components (L & C) in the ...
0
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1answer
69 views
How to make band stop filter from low pass and high pass filters?
I know that we can make a band pass filter by arranging a passive Low pass filter & passive high pass filter in series, and I have found lot of information on the Internet in this regard.
But what ...
2
votes
2answers
68 views
Second Order LTI Low Pass Filter solving for Voltage Out
I'm having a problem with understanding my textbook for solving the Voltage Out for the second order LTI Low pass RC Filter.
Why do you need to find the square root in the given equation with the red ...
0
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2answers
53 views
Parallel resistor in pi filter
What is the purpose of resistor in this filter circuit? Is it really needed?
-1
votes
1answer
48 views
Capacitor in LC filter
Please excuse me for this noob question. I have been wrapping my head around this for some time. If it's irrelevant here please comment, I'll delete this question.
If a capacitor blocks DC and passes ...
0
votes
4answers
100 views
Confusion regarding active band pass filter [duplicate]
I have seen some Google results where a band pass filter is made by cascading low pass and high pass stages. I am confused what will happen if we interchange the stages (first stage is high pass and ...
0
votes
2answers
97 views
Decoupling capacitors in power card
This is a power card. I have highlighted the part between the EMI filter and the Transient protection module. Are those capacitors needed? As per the data sheet, there has to be an R*C cell.
Please ...
0
votes
3answers
95 views
How exactly does the inductor in an LC filter reduce motor noise?
I'm currently working to quiet down the emissions from a stepper motor drive circuit.
The motor drive frequency is 22kHz, and there is significant 60MHz noise that comes ONLY from the 36V side as ...
0
votes
1answer
47 views
Designing a pi filter (C-L-C) for the output of a TPS62740 buck converter
We are using a TPS62740 IC as DC-DC converter.
We are getting ripple at the output in the range of 10 mV to 12 mV, so we are thinking to add a pi (C-L-L) filter at the output of the DC-DC converter.
...
0
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1answer
71 views
Old sewing machine motor filter/capacitor schematic/wiring
I have an old Pfaff 97 sewing machine that suddenly started to run at full speed regardless of the pedal input.
I disassembled and checked the foot pedal and it is working perfectly.
I took out the ...
1
vote
3answers
116 views
How to derive the transfer function of this op-amp?
For the 1st question, is this a Sallen-Key filter? What criteria must a circuit possess in order for it to classified as a Sallen-Key filter? I searched the internet but found no clear answer.
For ...
2
votes
2answers
109 views
Filter noise using MATLAB to include in LTspice
I have measured a voltage, and I need to include the .txt file in my LTSpice simulation. Before doing that, I first want to filter the noise I ended up measuring (see figure below).
How can I do that ...
1
vote
1answer
52 views
Removing noise generated by a servo from an audio signal
Background
I'm working on an Arduino-based audio visualisation project where I run an audio signal into the Arduino, using an FFT to calculate the intensities at different frequencies and then using ...
6
votes
4answers
936 views
Why is a 4th order circuit referred to as 2nd order?
An \$n^{th}\$ order circuit has \$n\$ reactive components. So a circuit with 2 capacitors and 2 inductors (total of 4 reactive components) should be considered a 4th order circuit.
However, I have ...
0
votes
0answers
58 views
LC Topology for band-pass filters
I, as a beginner, am looking to design a passive band-pass filter for a crossover speaker system.
This project that I am doing has the following specifications:
The filter should be a Butterworth ...
-1
votes
1answer
47 views
Loop filter R and C values rounding off
I am trying to design Loop filter with ADIsimPLL tool from Analog devices.
I got below values for loop filter:-
C1 --> 14.3 nF
C2 --> 69.9 nF
R1 --> 3.05 k
How can I round off these values to ...
0
votes
1answer
66 views
How does a PLL PFD produce a high frequency?
I am going to work with a PLL and a VCO.
I have read and understood the basic procedure in which the charge pump works. I understood that say, when the reference signal (or the divided signal) is up ...
1
vote
2answers
85 views
Connection of Cx capacitors to neutral in 3-Phase EMI filter
I'm working with a circuit which uses a common schematic for EMI filtering.
I simulated the schematic and I added a 200 kHz AC signal to the main 50 Hz line, to model the differential mode noise.
In ...
4
votes
4answers
176 views
Not understanding how the output is forming because of the diode
I'm rather new to electronics and I don't understand how the output is formed in this question:
I'm providing an input (Vin) of 5V peak-to-peak sine wave with a 1kHz frequency.
I simulated this in ...
0
votes
0answers
54 views
Sampling a continuous time signal in a DSP
We are tasked with sampling a continuous time signal in a DSP.
Before sampling, the signal goes through an analog filter of which I know the continuous frequency function H(ω). I also know the Fourier ...
2
votes
1answer
96 views
AC filtering: Medical vs Standard Version
I am looking at that Schurter's AC power entry modules to choose a AC filtering module and at page 5 I noticed the differences between Standard version and Medical version:
Their only difference is ...
0
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0answers
38 views
Output of filter is a pulse sequence
Like I have been advised in this question, I revised and updated the circuit to a more workable model,
but at the end Im getting this output(the blue is the input and the red is the amplified and ...
0
votes
1answer
57 views
How to calculate the 3dB frequency from an oscilloscope using Logarithmic sweep?
How do I calculate the 3 dB frequency from an oscilloscope reading using a logarithmic sweep? I made the mistake to use logarithmic instead of a linear sweep and now my data doesn't hold for the ...
0
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4answers
47 views
How to verify the voltage and frequency response in a simulated equalizer?
I am working on a simple equalizer, intended to filter bass, midband and treble frequencies.
I'm wiring the bode plotter of Multisim in a wrong way,perhaps.
The circuit is:
The idea is to measure the ...
1
vote
2answers
142 views
Will ferrite cores reduce the surge on the 5V line?
I think my ATMEGA AVR MCU is malfunctioning due to 5 VDC line surge.
The MCU is installed in a factory and the power line is very noisy.
I captured the 5VDC line. There were high frequency (10 MHz) 13 ...
0
votes
1answer
49 views
Is there a way to convert a time delay into a sample delay?
I have been given a time delay of a signal and the sampling frequency, however, I am trying to calculate the delay in samples. My logic is: delay frequency divided by sampling frequency, however, this ...
