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Power filtering -- why, and how do I "see" it? (simulation program? Something?)

I know little about electrical engineering, I am just starting out. I have a question about power filtering. It all started when I noticed that this product has it: https://www.dfrobot.com/product-...
Merc's user avatar
  • 139
0 votes
3 answers
61 views

Positioning of Inductor and Capacitor for Mains Voltage Noise Filtering

In the datasheet of this power supply, it is recommended to place the capacitor before the inductor for the mains voltage filtering circuitry, as it is shown on this image featured on the datasheet: ...
Dinis's user avatar
  • 73
-1 votes
2 answers
175 views

Band pass filter not filtering?

I am putting together this band pass filter for a guitar project but it doesn't seem to be working. Here is the diagram and the breadboard I'm working with. There is a button there that isn't doing ...
Alexander's user avatar
3 votes
3 answers
2k views

Replacing 1960s Motor Capacitor - Vintage Sewing Machine

I'm restoring a 1960s sewing machine (a Necchi Lydia 544, pure italian-made robustness). Inside of the foot pedal a capacitor is completely dead (gets hot and fume). I'm confident into changing it, ...
apinto's user avatar
  • 41
1 vote
1 answer
181 views

RC delay only on negative input voltage transition

I would like to construct an RC delay circuit that has no filtering/delay when my gpio transitions to voltage logic high (Vlh) but does filter the voltage as the pin transition to voltage logic low (...
Feynman137's user avatar
  • 1,263
1 vote
1 answer
97 views

Dual brushed motors digital controller works on only one side

I'm actually developing a way to control, digitally, the speed of brushed motors with a Raspberry Pi. To do so, I use the following diagram where: The raspberry controls the shift registers (purple) ...
zepeu's user avatar
  • 63
0 votes
0 answers
39 views

Instrumentation box, digital input signal conditioning [duplicate]

I'm designing an instrumentation box with opto-coupled digital inputs (BNC). For better noise/ground loops immunity/signal reflections I added 50 ohm resistors and 1n filtering capacitor (if needed). ...
Mr No's user avatar
  • 71
2 votes
2 answers
153 views

Custom LED light bulb protection /

I wanted to design a custom LED light bulb, so I bought a couple and tore them down in the hope to reverse engineer them. Most of them implement a circuit with a chip shown as below, with the circuit ...
coriv's user avatar
  • 81
21 votes
9 answers
5k views

"Rounding" a square wave's corners?

I'm trying to create a keying envelope for sending morse code without nasty clicking and the consequential excess bandwidth. My current plan is to take the switching (essentially a square, but not-...
Toby Eggitt's user avatar
0 votes
1 answer
219 views

How do you interpret LTSpice graphs?

I've created a circuit in LTSpice to model a fan assembly I'm looking to build. In the below circuit the current sources represent the fan and the voltage sources represent the voltage source I'll be ...
timsweeney7's user avatar
0 votes
1 answer
126 views

Car power supply filtering circuit check

Could someone give me some advice if the power supply filtering on my automotive project is OK? The project will be running in a 12 V car, and pull around 4 to 5 A max. I have use a PMOSFET for ...
Trev's user avatar
  • 13
1 vote
3 answers
981 views

Improved method of instrumentation amplifier input noise and RFI filtering

The following circuit diagrams are taken out of Niel Albaugh's The Instrumentation Amplifier Handbook I understand how the RC (tolerances) mismatches in Figure 4-16 (left circuit) cause the two time ...
KMC's user avatar
  • 1,428
18 votes
6 answers
5k views

What does this transistor circuit do?

I found a schematic which had this bit of circuitry between the +9 V (which apparently the author assumed to be > 9 V, more like 10-11 V) barrel connector and the +9 V supply rail. I tried to ...
Xaser's user avatar
  • 439
1 vote
0 answers
22 views

EKF Design And System Augmentation Bearings Only Tracking

I am hoping someone can help me with some guidance or knowledge on the matter. Basically im setting up a "Bearings Only Tracking" simulation using the EKF/UKF toolbox within Matlab. I have a ...
jpg4321's user avatar
  • 89
0 votes
0 answers
128 views

Electro magnetic interferences (EMI) generated by power circuit reset low voltage integrated circuits (ICs)

The main question here is (explanation will follow): Is there a way to filter out low voltage oscillations (>10MHz) on pins that have to stay high for the system to function? Oscillations are ...
Krzych's user avatar
  • 21
2 votes
2 answers
383 views

Question about Third order Butterworth Filter Design

I'm new to PSpice and filter design and I'm trying to design a third order Low pass Butterworth Filter with cut-off frequency = 10 Hz. Here is the circuit that I've designed: I've applied a 5V ...
Rafael D'Ávila's user avatar
1 vote
1 answer
183 views

Is it easy to siphon power from a powered antenna?

I have a property which is in a bit of a hole. My driveway goes up to an elevation above my house where semi-local TV signals are present. When they were still in local business, I bought a powered ...
Dewey's user avatar
  • 133
1 vote
3 answers
5k views

Differential filters: high pass, low pass, band pass

I am looking to use a band pass filter in an EMG circuit design using the differential signals you receive from an op amp (differential/instrumentation). I have been looking for what is the proper way ...
jakob's user avatar
  • 462
0 votes
2 answers
1k views

Matlab code to determine and plot impulse response

I have a signal y[n], represented by the vector y in this form y[n] =x[n] + ax[n−N] About this signal: x[n] is the uncorrupted speech signal which has been delayed by N samples and added back in ...
FFLS's user avatar
  • 115
0 votes
3 answers
370 views

Shifting level voltage of a signal

I have a signal, which can vary from 400 to 7000 Hz approximately. It is a kind of pwm signal and has the time of high level, Ton, 30 times longer than the time of low level, Toff. The shape of the ...
Daniel's user avatar
  • 917
1 vote
2 answers
417 views

Automotive tachometer signal interpretation

I'm trying to build a custom dashboard for a car (Daewoo Lanos 1998 with Delco ECU). Tachometer signal, that comes to dashboard with a separate wire looks a bit strange to me. It seems that the signal ...
Ruslan's user avatar
  • 21
0 votes
2 answers
160 views

Inducing noise for testing AC line filters

From a previous post of mine, you can see that I am trying to test the efficacy of some AC line filters. I got it to connect properly this time without frying my load, but we cannot seem to replicate ...
YNGVV's user avatar
  • 195
1 vote
0 answers
645 views

EMI filtering on multi-FFC assembly

an aspiring electronics engineer here. I do some electronics design for work and I'd like to know the following: If I have an assembly of a main board, to which an FFC cable connects into a second ...
steenou's user avatar
  • 11
1 vote
1 answer
86 views

Is a higher capacitance rating ok for filtering?

I am newer to electronic design and bought the mpu6050 sensor chip, which the documentation can be found here: https://datasheet.lcsc.com/szlcsc/TDK-InvenSense-MPU-6050_C24112.pdf It says that pin 20 ...
Braydon Burkhardt's user avatar
1 vote
1 answer
1k views

Ferrite bead pi-filter vs feed through capacitors in supply decoupling

How do I choose a feed through (feedthrough/feed-through?) capacitor to replace a ferrite bead pi-filter circuit? Manufacturers quote capacitance figures but what value should I choose this to be? ...
Jack Bourne's user avatar
0 votes
1 answer
184 views

Funtional role of op amps in a ADC filter circuit

I am a student trying to reverse engineer a rather interesting PCB, trying to learn from it but have come across some circuits that I am struggling to identify the roles of. This is the first part. ...
Jung Haemin's user avatar
1 vote
1 answer
670 views

Twin notch filter working

Can someone please explain to me in depth as to how this twin notch circuit is working. Also is what is the formula for finding the notch frequency because some sites give the answer as (1/2×pi×RC) ...
user183710's user avatar
0 votes
2 answers
479 views

Isolating A Noisy Component In A Circuit

I've been working on a project the past couple months or so and I am incorporating an lcd touch screen as an interface for it. The device is a small digital synthesizer. The problem I am having is ...
TokyoScarab's user avatar
-1 votes
1 answer
92 views

Would an 8 order analog filter be enough for creating a bandpass filter of 8-40 hz?

I am creating a project in which I need to an analog active bandpass filter. The opamps used in the active filters do need any feedback hence are more like comparators. There is a power line noise of ...
user183710's user avatar
4 votes
1 answer
466 views

Audio filtering circuit with capacitor shorted

I was looking at the Adafruit FONA cellular network modem breakout board schematic and found something that I can't quite understand. The breakout board has an audio input and output that both goes ...
Pier-Yves Lessard's user avatar
1 vote
1 answer
108 views

Conversion of a signal to digital pulses

The following signal is presented to me, and will vary in freq, but not amplitude from 10Hz up to around 25 KHz. Any ideas for a simple circuit that will convert this into a clean 3V3 square wave for ...
MattyT2017's user avatar
0 votes
1 answer
400 views

Filtering of a 5 V square wave

We are building a system that interfaces an approx 3-20 KHz square wave that comes from an engines crank position sensor. It is an open collector sensor, so we have a 1 KOhm pullup in our system to ...
MattyT2017's user avatar
0 votes
2 answers
104 views

Determining equivalent resistance to find the cutoff frequency

I am designing a low noise circuit for a precision application and require a stable voltage supplied to the circuit. I have determined that the MAX6250 voltage reference best suits my circuit. A ...
user5429620's user avatar
2 votes
2 answers
446 views

How ac coupling in scopes does not give you a phase shift? Or does it?

For what i know, filtering something always gives some amount of phase shift. So how do oscilloscopes with ac coupling don't have that? Do they correct in software? If so, how they used to do it at ...
valerio_new's user avatar
  • 1,642
1 vote
1 answer
329 views

Step Down Switching Regulator irregularity with ripple on output

Using the L5973D- I have followed the Schematic as the datasheet instructs, but I have tried two different inductors. I have found problems with other systems on the board with the one inductor (744 ...
Gareth T.'s user avatar
  • 389
0 votes
1 answer
273 views

Filtering current spikes in photodiode transistor selector

I am building a circuit for sensing photocurrent from a photodiode. The diodes are manufactured with selection transistors to form an active matrix and below is a model of a single pixel consisting of ...
Olaf Sikorski's user avatar
0 votes
1 answer
976 views

12V Jacob's Ladder circuit introducing noise on input and messing with PSU

I have made a Jacob's Ladder display for fun. I have no oscilloscope to give exact details, but there must be some kind of noise or high-voltage ripple that is resetting the display of my Lab Power ...
Mono's user avatar
  • 25
0 votes
1 answer
91 views

Continuous Filter design for measure signals from Boost Converter out

So, I found a simulation that uses PID to control the voltage of a DC bus, for voltage measure the author use a "func transfer" in simulink. I wish to know what kind of filter he design and how can I ...
SrnLord's user avatar
  • 157
2 votes
1 answer
2k views

Usage Of Static Electricity To Remove Dust?

If I have a fine metal mesh -- say a stainless steel mesh at 50 micron, and I'm having dust build up on it, can I use static electricity to remove the dust? I have another mesh that's 500 micron, and ...
Sargun Dhillon's user avatar
0 votes
2 answers
6k views

How to choose a cut-off frequency by interpreting FFT

I have a question concerning low pass filtering of IMU acceleration and gyro data. To choose a reasonable cut-off frequency, I thought about making some observations in the spectrum. Now I have some ...
Mr.Sh4nnon's user avatar
8 votes
5 answers
8k views

Why aren't there any 400V ultracapacitors?

I thought that ulracaps could be better than electrolytic ones for filtering after a bridge rectifier in a compact switching power supply due to their higher energy density. But, for some reason, I ...
Karabin's user avatar
  • 81
2 votes
2 answers
1k views

What happens to Filtered High Frequency Noise?

How to filter out high frequency noise from power supplies has been covered ad nauseum, but no one ever discusses what actually happens to the noise itself. Surely it doesn't just disappear? My ...
Aven66's user avatar
  • 23
0 votes
1 answer
6k views

How to filter a signal through a differential amplifier

An input signal must be scaled and biased for an ADC (MCU is TMS320F28027). I following an answer for a previous post. Figure 1: Original answer If the signal needs to be filtered with a cutoff ...
rur2641's user avatar
  • 435
0 votes
0 answers
69 views

Speaker Cross-Over Network and Power Design

I have some speakers I want to drive from a single output: a 4Ohm 300W Subwoofer, a 6.44 Ohm 60W Midrange, and 2 8Ohm 3W Tweeters. All ratings are RMS. I know that if I were to wire all of these in ...
Michael E's user avatar
  • 288
2 votes
2 answers
3k views

Is possible compute the bandwidth of a Narrowband Twin-T Passive Notch Filter?

Exist any function of R and C, for calculate f1 and f2 at figure below?
Hagi Jakobson's user avatar
1 vote
4 answers
4k views

AC through Inductor

I know that Inductor opposes an instant change in current direction. But it is used in AC circuits and in low pass filter circuits. It's a little bit confusing for me. If it resists instant change in ...
CNA's user avatar
  • 673
3 votes
2 answers
7k views

Calculation of ripple voltage after rectifier (equation from TAOE)

I am reading The Art of Electronics, Third Edition by Paul Horowitz and Winfield Hill but I feel like I am missing something when the book comes to talk about (begins to, instead) Power-supply ...
vionyst's user avatar
  • 856
1 vote
4 answers
365 views

Unwanted voltages in inverter

simulate this circuit – Schematic created using CircuitLab At the top is a schematic of an H-bridge that I built. Im conducting experiments where I attempt to use it as an inverter. I built a ...
S. Rotos's user avatar
  • 3,217
1 vote
3 answers
599 views

Active filter and sine to square conversion issues

Background: I am currently using a SparkFun Electret Microphone and I need to both filter and amplify the signal before turning it into a square wave to be interpreted by an FPGA. The mic itself has a ...
chalsey's user avatar
  • 11
0 votes
2 answers
119 views

Smoothing sparsely sampled signal

I am looking for a method to smooth a very sparsely sampled signal, which is shown below. Digital filters did not work very well, because for achieving an acceptable smoothness of the offset, the peak ...
luis's user avatar
  • 319