A filter modifies signals based on their frequency.

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1answer
47 views

Twin T notch filter vs RC HPF for 120 Hz sinusoid

I am sending a data with On-Off keying over the air using an LED and receiving it with photodiode. A figure below is a stream transmitted (blue) and a stream received (yellow). A symbol rate of this ...
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3answers
65 views

Electrical noise sources in farms

I am designing the data logger of a solar-powered automatic weather station that will be installed in farms. It's used to gather data from environmental sensors (wired) and send it to a host using the ...
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1answer
64 views

Distinguishing between FIR and IIR filters from transform function

I was good at this but unfortunately I have forgot almost everything...So the question is what are the steps to tell if a transform function is for IIR or FIR filter: $$H(z) = ...
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0answers
22 views

Return Loss \$ (S_{11} ) \$ Equation for a nth-order Chebyshev Type 2 Filter [duplicate]

I need an closed form equation for the return loss \$ S_{11} \$ of an n-th order Chebyshev Type 2 low-pass prototype filter. I am designing a high power RF (lumped element) n-th order Chebyshev Type ...
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1answer
30 views

Return Loss \$ (S_{11}) \$ Equation for a nth-order Butterworth Filter

I need a closed form equation for the return loss \$ ~S_{11}~\$ of an n-th order Butterworth low-pass prototype filter. I am designing a high power RF (lumped element) n-th order Butterworth bandpass ...
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2answers
48 views

How to measure cutoff frequency of a low pass audio filter?

I've built a low pass filter for use in a synthesizer and would like to measure the cutoff frequency compared with various different control voltages to profile its characteristic. I have access to a ...
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1answer
68 views

Low Pass Filter For Square Wave Through An Optoisolator

I've got a higher voltage square wave input that I'm feeding through FOD817B Optoisolator. The square wave frequency is in the range of 30 to 300 Hz. The Circuit is like this: simulate this ...
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1answer
55 views

which of these is more efficient for AC coupling

In the beginning I was using the circuit (at the bottom) to separate the AC from the DC ( the second order filter ) which in fact is just a second order high pass filter and the DC is a zero Hz ...
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30 views

IIR filter: why always a0=1

I have worked with IIR filters for some time and always assumed a0 (absolute part of the recursive path) to be one. I know this allows me to get my output y(n) out of the equation without having to ...
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1answer
67 views

Does position error from accelerometer still build up quadratically when using Kalman filtering?

I want to implement an inertial navigation system that uses a basic IMU for indoor position tracking. From all the things I've read you need to assist the IMU with something like GPS or other means of ...
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1answer
58 views

Cut Off Frequency in three phase LC filter

Good afternoon all My question is what will be the formula to calculate cut off frequency of attached LC filter. Its a three phase LC filter. \$(L1=L2=L3= 6.1 \mathrm{mH}) \;\mathrm{and} ...
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1answer
67 views

How to determine the value of a decoupling capacitor across a Peltier device?

I have a TEC device (Thermoelectric Cooling device/peltier device), and I have seen several datasheets recommend placing a bypass capacitor across the TEC device (i.e. parallel to the TEC, and in ...
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3answers
55 views

Calculating Fc (cutoff) of series to RC to ground on inverting input of non-inverting amplifier

Regarding the chosen answer for: How does this OP-AMP non-inverting amplifier work? The following circuit is given, and it says that $$F_c = \frac{1}{2\pi R_1C_1}$$ simulate this circuit ...
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3answers
130 views

Using wxMaxima to obtain a transfer function from T-twin filter & op amp

I'm trying to get the transfer function from this circuit using wxMaxima So first using the ideal op amp model I know Vx = Vy and I can know Vy from that voltage divider from Vo Now I solve this ...
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0answers
31 views

Results analysis of the sequential filter and strength-reduced filter in frequency domain

I realized two low-pass filters by Verilog. The filter can be represented as following equation: 1. Sequential filter with 32 stages. For saving the multipliers, I only use one multiplier and do ...
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6answers
342 views

Capacitor selection for filtering of low level signal

I am currently dealing with low level signal(voltages in milli-volt from the sensors) for the first time. I was advised to use filtering circuit moreover RC filtering which I have already implemented. ...
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1answer
69 views

What is the harmonic content of a PWM signal?

Suppose I'm using a 3.6 kHz carrier to reproduce a 60 Hz sine wave. To properly design a filter for this application to hit a specific harmonic distortion target, I need to know the harmonic content ...
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2answers
52 views

Solving RC filter by differential equation

I'm trying to solve the differential equation of a simple RC filter. What i got so far is: $$CRV'+V=V_0\sin(\omega t)$$ Solving i get: $$V == \frac{V_0 \sin(\omega t)}{1 + R^2C^2 \omega^2} - ...
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0answers
51 views

How to discharge a capacitor quickly…(filter of an H-bridge/inverter)

I have used four IGBTs to build an H-bridge… the inputs of the h-bridge are SPWM and are programmed in a way as shown below: The output of the H-bridge is a three level pwm(as expected), and then its ...
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0answers
18 views

What is pulse train filter in the context of a control system?

I have recently seen some code written in modelling tool like Simulink, ASCET which uses PT1 filter? Why do we use a pulse train filter? What is the difference between FIR, IIR, Chebyschev, ...
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1answer
20 views

Finding the system function of a digital filter

I am studying for exams and I need help with a question I came across in a textbook. Given a digital filter $$y_n = a(x_{n-1} + x_{n+1}) + bx_n$$ find the system function of this filter and the ...
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2answers
42 views

What is the filter and the transfer function that shown below?

May i know above is below to which type of filter? is it a low pass filter? and what is the transfer function for the circuit, may i know the step to drive it? Thank you
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2answers
245 views

Filtering Capacitors before the fuse or after the fuse while limiting inrush current?

There are basically two questions I have for this circuit. 1) Which capacitor configuration is good? before fuse or after fuse 2) How do I limit my inrush current? My thoughts: I am confused ...
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1answer
95 views

How do I properly size components for an EMC filter for a variable frequency drive power supply?

One of the products my company designs is, essentially, common bus power supplies for variable frequency drives (VFDs). Thus far we have only sold into the United States. We are considering selling ...
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2answers
65 views

Anti Aliasing Filter and the bandwidth selection

I am currently analyzing the raw measurements of a sensor with the sampling frequency of 400[hz]. According to Nyquist theorem, the bandwidth must be less than a half of the sampling frequency, which ...
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2answers
55 views

RC network (Filter) output calculation

I have an RC circuit with a transfer function $$ h(s)=\frac{1}{1+0.0033s} $$ Is it possible to calculate theoretical output of this network for a set of input voltages? For this how do I solve this ...
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1answer
30 views

Input and out put SNR of Low pass filter

A low pass filter has L=20mH and C=0.0012F .the input signal amplitude is 2V peak to peak and its frequency is 5k Hz .An unwanted noise input is also prsent with amplitude of 0.2 V peak to peak and a ...
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2answers
663 views

Why are caps configured this way in EMC filters?

Every EMC filter I've seen has capacitors between the AC lines and earth, configured like this: simulate this circuit – Schematic created using CircuitLab Why are the caps not configured ...
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4answers
382 views

Rc network placing R before C vs after

simulate this circuit – Schematic created using CircuitLab Using a rc network to smooth a PWM signal from a microcontroller, to a true analogue voltage. What will be the effect of having ...
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2answers
48 views

Best Filter Type

I have a sine wave (uV level) that is in varying frequency (1kHz to 8kHz). I like to design a band pass filter that attenuates the other frequencies while amplifying my target frequencies and this can ...
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2answers
59 views

Determining the frequency response of an audio crossover (something seems off)

I'm in the process of putting together an audio crossover. I finished assembling the components, and I though it would be neat to do a frequency sweep on the filters. When I inspected the tweeter ...
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0answers
50 views

Is there any way to reduce THD for low pass filter?

I got low pass Sallen-Key filter for 8 kHz corner frequency but I still got too high THD for 8 kHz frequency and 10V output amplitude. THD I would like to achieve is less than 0,2% but now I got more ...
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3answers
274 views

Why are high values of capacitance in low pass active filters not recommended?

I am designing low pass active filter (Sallen-Key structure) and I have come to a point where I have to decide what should be the value of C (C1 = C2 = C) and then calculate values of resistances. I ...
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1answer
45 views

USB switching power supply filter

Good afternoon fellow students of life, I have a particular question that relates to the use of a Duracell USB switching power supply as the main supply for a high sensitivity sensor board. Most of ...
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1answer
42 views

Safe way to interface directly with HomePlug / Powerline

I'm looking to do some research into the actual messaging used by powerline adapters. I'm aware of the standards, but I'm specifically looking to see where real devices deviate from the standard, and ...
0
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1answer
35 views

How to determine if this filter is stable

Hi I have a filter which has the following transfer function: H(z) = (z^2 + 0.04)/(z^2 + 3.24) for which i need to determine whether this is stable or not. I'm not sure how to attempt this, but I'm ...
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1answer
38 views

Filters in IR alarm circuit

Electronics student here, so i'm printing a IR receiver for a project of my school. I'm trying to understand the filtering part of the circuit. The signal is received through the BP104 photodiode ...
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1answer
55 views

What should be the source impedance and load impedance in LC filter design?

My aim is to generate analog signals with class-D amplifier. For that I am using the following configuration: Class-D-->Low-pass filter(LC)-->load(complex, real+imaginary) class-D amplifies my PWM ...
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2answers
392 views

Obtain an accurate DC value in an AC+DC signal

Background: My goal is to use an Arduino with two proximity probe sensors to achieve some output. It is worth mentioning that the output of the proximity probe has two components: DC output that ...
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1answer
35 views

Superposition on a circuit with just one source

I'm trying to analyse this circuit (state variable filter): All the places on the web I've found solve it first using superposition, creating an equation of the form \$ V_2 = kV_1 + kV_4 + kV_3 \$. ...
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0answers
61 views

How do I decide upon the order of SINC filter for sigma delta modulator?

I have simulated a first order sigma delta modulator im Matlab simulink. The clock frequency of the modulator is 20Mhz (oversampling frequency). Now I am trying to convert a sine waveform (50Hz) to ...
0
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1answer
27 views

Drop on high pass filter measure

So I'm implementing an analog control scheme, and one important component is a first-order high pass filter. The source signal is the output of a shunt monitor (INA138 - in the circuit below the ...
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0answers
23 views

DWDM filter response

I have been trying to find an analytical expression of the frequency response of a DWDM filter, say at 40 GHz bandwidth. Any help would be much appreciated.
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1answer
72 views

Inverting Opamp on Noisy Ground. Would an LC filter help?

Alright, say I have this Inverting Opamp, but it so happens the positive input to ground is also connected with another sub-circuit that happens to produce a lot of noise (no pun intended): ...
0
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1answer
68 views

Filtering the output of an H-bridge

What's the best way to filter the output of a H-bridge? I have a PWM output at +/- 20 V and I want to get a 10V RMS sine wave out at 50hz Also is there a way to do it without inductors?
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2answers
107 views

Capacitor quenching circuit across Brush and Commutator of DC motor

To reduce the spark between brush and commutator segment there is capacitor and resistor spark quenching circuit is placed between each commutator segments. please find below images for detail idea ...
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2answers
104 views

Changing LC filter passband width

I am building a circuit that uses an LC bandpass filter (with the inductor and the capacitor in parallel between the signal and ground lines). However I am having a problem in that there is no way ...
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2answers
74 views

Calculating resistance and capacitance given the time constant

I'm currently conducting an experiment where I need to determine what a black-box component consists of. After measuring input and output voltage for various frequencies I have so far determined that ...
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0answers
71 views

EMI filtering at end of a long copper wire transmitting high DC power

I have a long (20 - 50 m) copper wire for supplying DC power. One one end there is a AC-DC converter supplying 600W-1000W of power at 60V output. At the other end I have a switching type (100-140 kHz) ...
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3answers
115 views

How to calculate resistors and capacitors values for analog RC filters?

How to calculate resistors and capacitors values for band-pass RC filters based on LM348 operational amplifier? In this example, 3.2KHz, 4.3KHz are standard center frequencies, that are individually ...