Questions tagged [fault]

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DRV8262 not working with PWM signal

I designed a motor driver with the new Texas Instruments DRV8262 at its core. It will be used in robots controlled by an ESP32. It works well when using non-PWM signals to switch the outputs in PWM ...
Louis's user avatar
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1 answer
46 views

Ground Fault Interrupter

I was trying to simulate a circuit where it can detect grounded neutral conditions in the household. I need to have a current transformer which can detect the current differential ans sends a signal ...
M S's user avatar
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1 answer
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What might cause this strange pattern on an LCD monitor?

Recently my laptop has been showing a strange effect on its monitor: This is supposed to be a black screen, but the bottom fifth or so is affected by some kind of interference pattern. The pattern is ...
Rocketmagnet's user avatar
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3 answers
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Ground fault detection on an ROV

I'm helping my friend's kid with a school project where their team has to produce a small ROV. Most of their design I was able to review and help make corrections with them but I'm stumped at one ...
Jedi Engineer's user avatar
1 vote
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97 views

LM317 does not regulate 12V to 8.2V

I am working on a project for which I needed to design a small linear regulator circuit in order to supply 8.2V for reading out sensors. I chose to use LM317, since it is quite simple to design and ...
karolista's user avatar
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3 answers
79 views

Why does adding this capacitor cause other segments to come on when they should not?

I have designed and built a clock, that uses a microcontroller to drive a 4x7 segment common-cathode display. Each digit is driven sequentially, with all appropriate segments of that digit driven in ...
Sod Almighty's user avatar
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3 votes
0 answers
61 views

Ground to L1 in 3-phase have almost 0 V potential

I am in Peru and was helping check ground rod to line and neutral and see higher than one leg to ground voltage. This is at a plant with 3 phase power 220/440 volts. The local utility doesn’t provide ...
Dososo56's user avatar
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27 views

Which faults of dual transistors on isolated dice must be considered according to IEC 60335-1?

I got the task to upgrade one of our products to comply with the requirements of IEC 60335-1, which means, that no safety function must be lost in case of a single component fault. To save space and ...
christoph's user avatar
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1 answer
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Help IDing a high-power IC - OODOW 836 T57

I'm fault finding for a Korg M50 Synthesizer. Symptoms: on every boot a message appears saying the device is updating the left/right control panel firmware, after which it requests a re-boot. ...
aaronsnoswell's user avatar
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35 views

In Etap, why don't I get a selective tripping sequence when I simulate a fault knowing that the relays' curves are selective with each other?

In ETAP, I have two relays that are selective with each other in the Star View. However, when I simulate a fault in the bus that's right after the downstream relay, the tripping sequence is buggy and ...
A.Bukhari's user avatar
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21 views

General approach to fault analysis for a rechargeable battery

I have a pair of over ear headphones which work fine except that the rechargeable battery in the circuit is no longer charging. I have replaced the battery, but the new battery also does not receive ...
GMeister's user avatar
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84 views

How to calculate short circuit current contribution of a PV plant into network?

I want to calculate the short circuit current contribution of my PV plant. I have only data from the inverter manufacturer but I am not sure if I have to simply add up all the inverter's short circuit ...
Smrtngy's user avatar
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1 vote
2 answers
88 views

Is there any way to easily gain access to "actual ground" in an IT grounding system?

As the title asks, is that possible? By "easy access" I mean through some connection I can find inside my home, rather than burying my own grounding electrode and running wires from it to ...
Outis Nemo's user avatar
7 votes
4 answers
451 views

Troubleshooting a new PCB

I designed and got a PCB manufactured for the first time, and have soldered the component and powered it up. However it is not behaving as expected. I think I may learn something by everyone here for ...
David777's user avatar
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2 votes
1 answer
75 views

Do I need to ground the thermal pad on the MAX8808?

I have designed the MAX8808 LiPo charger IC into one of my designs. It doesn't seem to be working, in the sense that no current is flowing into the LiPo cell, despite all of the DC conditions ...
Rocketmagnet's user avatar
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4 votes
2 answers
169 views

Information leakage due to fault propagation in XOR gates

From the paper Fault Template Attacks on Block Ciphers Exploiting Fault Propagation, in the concept of Automatic Test Pattern Generation (ATPG), two events are required to perform in sequence: Fault ...
Mohammadsadeq Borjiyan's user avatar
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21 views

What is the phase displacement of fault currents on each phase in a symmetrical fault?

In a Line-Line-Line-Ground symmetrical fault, is the fault current on each phase also displaced from each other by 120°?
ethelrl's user avatar
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Do you think the output voltage is caused by an old capacitor?

I have a vacuum tube power supply which isn't producing the correct output voltage. I have removed the tube and all that is left is the transformer, inline 22 ohm resistor, CR201/202, R202/203 and ...
Tom's user avatar
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1 vote
2 answers
1k views

Sparking when using multimeter

I was trying to measure the voltage across two connectors that connect to a 3-pin, 13 A plug as part of troubleshooting, to verify I had circa 230 VAC present. However, when I connected my multimeter ...
Brandon Kellett's user avatar
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0 answers
126 views

Transformer output too high. I'm sure this should be 12V but it is outputting 25V

I have a faulty circuit board taken from a garage opening unit powered by a transformer. I have 25V from each of the transformer terminals (4 of them), 50V on the 24V relays and all terminals have ...
CptChronic's user avatar
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0 answers
81 views

Short circuit delta

Assuming I have the following system: and a single-phase fault is on the 2.4 kV side. How do I calculate the voltage between the neutral resistor and ground? How do I calculate the zero sequence ...
Felipe's user avatar
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How is a fault location detected in a power system?

Electrical transmission lines can face various types of short-circuit faults, for example, line-to-ground, line-to-line, etc. How do power system engineers find the fault location by observing from ...
Wanderer's user avatar
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6 votes
5 answers
2k views

Is it possible to make an MCU hang by messing with its power?

We have a bunch of ARM microcontrollers on test at the moment. The test runs for 360 hours and mostly completes without a hitch, but very occasionally, one of the microcontrollers will hang. We have ...
Rocketmagnet's user avatar
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4 votes
0 answers
141 views

Can chips be sensitive to mechanical stress after an electrical incident?

Is it possible to electrically damage a microcontroller (or any chip) in such a way that it becomes very sensitive to mechanical stress? Some background: We are developing a board with 7 identical ...
Rocketmagnet's user avatar
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1 vote
1 answer
64 views

Is the same overcurrent relay used for both phase-to-phase faults and 3-phase faults?

In MV grid with no distributed generators, 50-51 overcurrent relays are used to detect both phase to phase faults anf 3-phase faults. In Italy, time independent characteristics are used inside these ...
Samuele Benito Di Gioia's user avatar
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0 answers
37 views

Fault analysis- per unit query

im trying to do fault analysis on image 1. I was little confused for the line as there wasnt a j component so unsure how to find the pu. In images 2 and 3 show a line with R+jX and the R id ...
kingkunta's user avatar
2 votes
3 answers
275 views

CAN bus fault protection

Question: Is there a way to implement with discrete components the 70V CAN bus fault protection found in some transceivers, such as TCAN1051H-Q1? Background: We are using the CAN transceiver ...
lmlmlmlm's user avatar
0 votes
1 answer
236 views

All Mosfet terminals internally shorted in voltage controlled resistor

I was planning on making a voltage controlled resistor using a power MOSFET in order to load one 12V lead acid battery. I tried implementing the circuit below; everything was going well for a few ...
A.H.Z's user avatar
  • 633
1 vote
1 answer
209 views

Fault impedance type?

Usually fault impedances are resistive type. But is it possible to have a mix of resistive and reactive component in fault impedances? Looking at many simulation tools, they give the possibility to ...
Samuele Benito Di Gioia's user avatar
3 votes
1 answer
512 views

Actual Line-to-Line voltage from per unit value

In this question, I am able to find the per unit phase voltages using the symmetrical components. Taking the base MVA and base voltage to be the same as that of the alternator, \$ (I_a)_1 = \frac{E_a}{...
curious_direwolf's user avatar
1 vote
1 answer
911 views

Insulation monitoring device for electric vehicle

Good day to all! I am planning on designing an electric vehicle architecture from scratch. My main DC bus voltage is 400 V. However, I have got different voltages in my system. I have got a 600/400 V ...
gr3en_apple's user avatar
2 votes
1 answer
177 views

What can cause a surge in one 110 V line feeding a 240 V appliance, melting the connector?

One of the Hot wire (#10/3) going to my oven appear to have experienced a sudden very high in rise temperature inside the junction box, melted the connector, creating a contact with the face plate ...
Denys Picard's user avatar
0 votes
1 answer
804 views

Why is the line-neutral fault current 1.5x higher than the line-line fault current?

My commercial wiring textbook and several documents discussing fault current calculations stated "The L-N fault current is higher than the L-L fault current at the secondary terminals of a single-...
solenoids are cool's user avatar
2 votes
0 answers
108 views

Get alpha-beta plot of Clarke Transform in Python

For a project I'm working on, I want to use the Clarke Transform to detect faults in a power system. To do this, I already wrote a script in Python which returns the sine wave behavior of the Alpha, ...
Juan Pablo Naranjo's user avatar
0 votes
1 answer
219 views

Difference between a relay and a fault passage indicator (FPI)?

What is the difference between a fault passage indicator (FPI) and a relay (for example relay 50, 51, 67N) ? Are they the same thing?
Samuele Benito Di Gioia's user avatar
0 votes
1 answer
542 views

My light-dependent resistor gives a fluctuating serial output

I'm a high school student trying to make a light tracking single axis solar panel. I am using an Arduino Uno rev3 board. When I first finished building it, the system failed to operate. I spent a few ...
ElevenBits's user avatar
1 vote
0 answers
89 views

How to test if a domestic 3 phase power company meter is reading wrong?

BACKGROUND: Domestic 3 phase 220VAC supply in Thailand. Power company meter is 4 wire GE 3 phase 15A/45A. Massive power bills when mains breakers were turned off (back in home country for 9 months ...
David Supastore's user avatar
0 votes
1 answer
83 views

How did they arrive at an expression for resistance given the power of the load?

In Anderson's 1995 Analysis of Faulted Power Systems, there is the below example I am required to calculate the sequence network for the fault occurring at C. To calculate the resistance of the load, ...
Shankar Ramharack's user avatar
0 votes
1 answer
91 views

How to reproduce these audible clicking or popping sounds? [closed]

My fluorescent lamps (and other devices) are making clicking sounds. I want to reproduce these clicking or popping sounds or get an idea of how one might produce such sounds in electrical devices or ...
p4rch's user avatar
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0 votes
0 answers
132 views

Bench PSU leaking voltage to case and not working properly

Tl;dr at bottom Recently I found old bench power supply in my closet and tried to test it but display kept on displaying 0.00v and 0.00a - the power supply is voltage and current regulated and has two ...
bestestefan's user avatar
0 votes
1 answer
34 views

Is the impedance bus matrix method the same as the Ohmic method in power system fault analysis?

There are a few methods to do power system fault analysis, like the per-unit method, MVA method, and impedance method (Ohmic method.) I am doing fault analysis using per unit symmetrical component ...
Prasad's user avatar
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1 vote
3 answers
2k views

Would ground fault cause breaker to trip if neutral not bonded to ground in main panel?

Suppose normal residential main breaker panel (not subpanel) is wired correctly except the neutral bar is not bonded to ground. Assume a 15A breaker in the panel powers an exterior light with a metal ...
Ken Smith's user avatar
  • 111
3 votes
1 answer
114 views

Fault Ride Through requirements for wind turbines

First a short introduction: (the question is below the first image). The capability of fault ride-through of wind turbines is the most important requirement related to national grid codes. Based on ...
CG.'s user avatar
  • 155
0 votes
1 answer
916 views

What is the fault level of paralleled transformers? [closed]

When paralleling transformers the fault level at the bus is it the sum of the individual transformer fault level?
OMAR's user avatar
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0 answers
147 views

Reason behind coil melting

Today I managed to melt the ignition coil of my RC engine. First let me describe my circuit, I have also created a diagram, however I could not find all the parts in the designer so I think some ...
Yanick Salzmann's user avatar
-1 votes
1 answer
235 views

Can a solid state relay be energized from the same 120V AC source that it switches?

Can a 120V AC input / AC output solid state relay be energized with the same 120V source connected to its contacts? This can't be done with an electromechanical relay because it generates feedback and ...
VanGogh66's user avatar
  • 301
1 vote
2 answers
51 views

Opamp input fault current limit vs fault duration

A usual datasheet rating for maximum allowed input current into opamps is 10 mA. Initially I thought that this is some kind of DC limit of what the clamping diodes could handle before thermal ...
tobalt's user avatar
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0 votes
2 answers
2k views

Very hot live pin on kettle plug

I moved my kettle just after boiling it yesterday and noticed the live pin was very hot. None of the other pins are hot. It's a bs 1363 type plug and socket. And a <2 year old kettle. After a full ...
EdL's user avatar
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0 answers
45 views

Fault recovery of a UAV using MATLAB

I'm currently investigating fault recovery in a UAV using MATLAB. I've been given several variables: phi = the roll angle psi = the yaw/heading angle beta = the side slip p = roll rate r = yaw/...
gunter's user avatar
  • 107
2 votes
1 answer
233 views

Symmetrical Components - Three-phase D-Y transformer with unbalanced voltage and loads

I have a Delta-Wye transformer, N1/N2 = 4, and am trying to solve the circuit below, with 120VAC applied to terminals VAB only. On the secondary I have 1 ohms connected between a-n and 5 ohms between ...
Charles Wagner's user avatar