Questions tagged [high-pass-filter]
A high-pass filter is an electronic filter that passes signals with a frequency higher than a certain cutoff frequency and attenuates signals with frequencies lower than the cutoff frequency.
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First order RC highpass filter input capacitance
I'm trying to find the capacitive load repreented by an RC first order highpass filter.
Intuitively, I tend to believe the load will not be the C series capacitance, since the capacitor is not being ...
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What is this following filter circuit called? (For amplifiers)
Noob here. I have a doubt on these passive low and high pass filters for amplifiers. If this is called high pass filter (which is doubled in series),
then what is this filter circuit called?
Here's ...
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Are RC /CR - Highpass filter the same?
I‘m quite new to electrical engineering and one of the tasks is to showcase and plot an CR high pass filter. I am familiar with RC HP filters but this is new to me. Just changing the order of the ...
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What is the coil for in these cheap tweeters?
I disassembled a cheap tweeter because I wanted to use only the inner part of it since it is just about 5mm tall (1/4 inch). I thought the coil that surrounds it was just a cheap inductor to "...
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I want to implement a 2-active crossover circuit with LM833 and amplify it using LM386 and now the problem is I couldn't understand the circuit [closed]
I can understand up to certain level that we used a buffer, low pass filter but I can not connect with circuit and coming to components we used 120 Ω, 6.8 nF for active crossover with power supply + ...
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HP filter for MHz pulses
I need a high pass filter for my measuring setup and I'am a total newbie to analog filters. I have weak hf pulses (0.5-1.2 MHz, 10 mV) superimposed on lf sine wave (8-40 kHz, up to 5 V), I'm ...
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Filter out one square wave while retaining the other
I have two square wave signals. The first signal has a frequency around 10 kHz, while the other signal has a higher frequency of about 50 kHz. How can I filter out the lower frequency signal without ...
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Why do my high and low pass filters look like high pass filters in LTSpice plot?
I am new to this and trying to learn about designing analogue audio filters. I looked at a couple of tutorials online that gave examples about how to implement and simulate high and low pass filters. ...
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What is the purpose of loading an analog input?
Theoretical question: I have seen in many analog signal circuits that the analog input pin is pulled down through a resistance. Sometimes it is also pulled up and sometimes there is a capacitor ...
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Frequency response and phase response
In filters there is frequency response and phase response but why we consider these two parameters.
What is the significance of these responses in practical applications?
In Bessel filters, after ...
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LIS2DE12 accelerometer configurations
I am working with LIS2DE12 accelerometer. Communicating with it via I2C. Retrieving simple data works fine, but now I want to configure it to generate interrupt on strong acceleration, but I'm a bit ...
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Op-amp high-pass filter and low open-loop gain at higher frequencies
How can a high-pass filter work when the open-loop gain of an op-amp completely attenuates from a certain frequency?
I understand that the open-loop gain of an op-amp is what limits every closed-loop ...
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My LTspice simulation results don't match the breadboard
I was testing a high pass filter like this. And here comes the simulation result on LTspice as well.
This is the AC analysis result followed by the transient analysis.
The 8Hz transient analysis ...
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How can I only let a specific frequency pass in an AM receiver?
I wanted to create an AM receiver and I know partly how to demodulate the signal. I know I need to use a low pass filter to get the low frequency audio signal, but I don't know how to only get data ...
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Wrong frequency response of an active HPF filter
I am trying to simulate an active high pass filter on OrCad, but the frequency response of it looks like a band pass filter, does anyone know why ?
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Cut off frequency of a passive second order low pass filter
I was trying to do a simulation for second order low pass passive filter, and the equation of the cut off frequency is $$f_c=\frac{1}{2\pi\sqrt{R_1C_1R_2C_2}}$$
when I calculate it on the values of ...
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Designing a crossover for dual woofers and a single tweeter
I recently purchased a cheap tower speaker set which has two woofers per channel. This does not have a crossover circuit as i understand and only has a filter capacitor for the tweeter.
Can a three-...
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Are ready made crossover circuits universally compatible?
I am planning on modifiying the crossover circuit in a speaker unit. and after doing some research came across a plethora of ready made crossovers available for purchase on the internet (like the one ...
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Transfer function of a 3rd-order high-pass filter
Can we take the transfer function of the below 3rd-order high-pass filter as
$$\left (\frac{R}{R+\frac{1}{j\omega C}}\right )^3$$
?
This circuit is a part of RC oscillator. To calculate the β of the ...
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Need help with pulse sensor design modification [closed]
So I've got the below pulse sensor design. I don't understand why they filter before they amplify. I'd like to modify it in a way that I amplify the signal first, LPF second, HPF last. For some reason ...
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Why do we need R1 in a non-inverting op-amp?
I am quite new to learning op-amps.
What is the purpose of putting R1 there? Does this have any meaning in the design of a microphone amplifier?
I read about this from another answer, which says that ...
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Will separate high-pass filters work properly with two speakers wired in parallel?
I have wall-mounted satellite speakers – inexpensive Orbs are in one room and more expensive Gallo Divas are in an adjoining room. I need to wire these speakers in parallel with high-pass filters. The ...
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3 dB frequency of first-order active high-pass filter
Using the KCL law in the red dot in the circuit shown above, I got this equation:
$$\frac{V_\text{in}}{R_1 + \frac{1}{j\omega C}} + \frac{V_\text{out}}{R_2} = 0$$
From this equation the transfer ...
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RC differentiator / RC integrator explanation (input waveform is square wave, triangular wave, sine wave)
The circuit below is an RC differentiator (RC high pass filter.)
The input and output waveforms:
I can understand this. Mainly due to capictor charging and discharging.
How about an RC integrator (...
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Modulating a high-frequency signal to get rid of an undesired low-frequency component
So when I ask my function generator for 2 MHz, it gives me that with a 19 Hz oscillation. For my application this low-frequency signal is very problematic. I've tried high passing it which does close ...
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Lux meter 50 Hz sine noise filter
I've built the circuit with diagram:
I used R1 10 MΩ instead of 50 kΩ to get a higher gain. I wanted to measure light intensity, so I'm interested in DC output ...
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Converting two cascaded first-order high-pass filters circuit to a second-order high-pass filter using Sallen-key configuration
Below is the transfer function of the two cascaded first-order high-pass filters (each with 20.6 Hz cut-off frequency) and their circuit:
And then there is the transfer function of the second-order ...
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How much power passes through the shunt component of a high-pass Pi or Tee filter?
I would like to send ~100W through an RF filter. Can you estimate the current passing through the shunt component without a circuit simulation assuming a reasonably high S21 value?
MLCC's are cheap, ...
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Chaotic Highpass Filter Output
I'm trying to build an RF transmitter circuit using LTSpice. Built a diode balanced signal mixer connected to a high pass filter to distinguish high frequency from low frequency. However, I'm kinda ...
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Concatenating first-order high-pass filters
I have the following circuit, which is an active high-pass filter with the knee frequency \$ f_{-3 dB} = \frac{1}{2\pi RC} = \text{1 kHz}\$
I wanted to concatenate two of those systems in order to ...
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Designing a second order HPF with a high gain common-source
I have a High gain (A = 22k) Common-Source circuit, and I was wondering If I can make a second order HPF like this circuit:
My circuit is just an NMOS with an input at the gate, output at the Drain, ...
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Second order active high pass filter
I am trying to design an active filter, which I assume is an active high pass filter according to what I see from the Bode plot.
I can get the transfer function from this plot and then I need to ...
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Noise of low-frequency RC high pass filter preamplifier circuit with LT1028
I want to build a low-noise and low-frequency preamplifier with the first-stage opamp of type LT1028 offering an input-referred voltage noise density of about \$2~\mathrm{nV}/\sqrt{\mathrm{Hz}}\$ at \$...
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Add Voltage Bias/Offset to 2nd-Order Sallen-Key Highpass
I need to add a highpass filter between a signal source and an ADC to get rid of high-amplitude low-frequency signals that would cause clipping.
I built a second-order Sallen-Key filter and the ...
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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 ...
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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 ...
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What would the output waveform be in each of these cases?
In the second picture, the source is a step function from 0 to 1V.
I feel like I solved them, but I am not convinced that my understanding is air-tight. Any help is appreciated.
Edit: Adding my ...
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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 ...
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Frequency response of a low-pass, band-pass, and high-pass adder circuit
I'm doing a project and one of the steps consists of filtering a signal through a low-pass, band-pass and high-pass filter.
All the filters are Sallen-Key with a passband gain of 1. The pass-band ...
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Why is the instrumentation amp distorting the signal on the input?
Here's my schematic. A current source is driving a resistive sensor. The sine wave is to mimic the behavior of the current real supply and doesn't play a role in the distortion. It's approximately ...
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Active high pass filter experiment result
The pictures above are the circuit model and plot. uA741 of Texas Instrument was used as an op-amp on the circuit.
1 Vrms was used as an input voltage so that the output can be the voltage gain.
The ...
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Why do diplexer low-pass filter output have more inductors than capacitors and vice versa?
I am reading "Practical Radio Frequency Test & Measurement A Technician's Handbook" by Joseph J. Carr. On page 41, it has a diagram (figure 2.29 shown below). In that figure, why do ...
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Is using a passive RC high pass filter at the output of an opamp a good method to remove DC offset?
All the information I am able to find related to this discuss about AC coupling the inputs of an amplifier but never the output. I wish to know if there are any issues with AC coupling at the output. ...
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How does using a high-pass filter and an amplifier maximize the signal amplitude for analog-to-digital conversion?
I am currently reading the Fringe Contrast section of this document. This section says the following:
Use a high-pass filter (HPF) and an amplifier (G) to maximize the signal amplitude for analog-to-...
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How is this high pass filter?
I am new to electronics. I am watching this video.
At 5:48, you can see the high pass filter:
I understand the high pass filter, look at this:
Then, I thought the first circuit should be like this:
...
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How to calculate values for decoupling capacitors
For decoupling we just use a capacitor like 1 uF bulk and 0.1 uF ceramic caps at each power pin. But how are these values calculated? How many caps do we need to use in parallel? Can anyone explain it ...
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Help understanding combined High/Low Pass filter circuit
I am a newbie and trying to understand the operation of this White Noise Coloration Filter - I have contacted the original author but at time of writing have bot received a response.
The circuit is as ...
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Trying to understand why op amp voltage follower goes high when fed negative input
I have a project where I want to take the positive and negative outputs of a passive differentiator and produce only positive pulses. E.g. when the switch feeding the differentiator is closed I get a ...
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I need to design a second-order high-pass filter, gain 2 and cut frequency of 500 Hz. Using chebyshev response of 0.1 dB
I took the parameters from the MT-206 table of Analog Devices. I did not find in any book the chebyshev response of 0.1dB. https://www.analog.com/media/en/training-seminars/tutorials/MT-206.pdf
I ...
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How to prepare observation table and plot frequency response of Butterworth Sallen-Key High Pass Filter
My assignment:
Design and simulate a Butterworth Sallen-Key High Pass Filter with the, fc = 10 kHz.
Prepare the observation table and plot the frequency response.
My answer so far:
I want know how ...
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