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Questions tagged [failure]

The tag has no usage guidance.

-1
votes
1answer
175 views

Logic Circuit Completely Failing (Cue Lights System)

I have been working on a circuit the details of which are below. Today I finally got round to finishing and testing it. Guess what! It failed... I don't know if this is the place for this but would ...
1
vote
1answer
123 views

What might be the reason for improper turn on of IGBT

Here I am applying 3-phase rectified dc to the non-isolated boost converter, the magnitude of applied voltage is 450V and desired o/p voltage is 475V. Switching frequency of PWM is 28k. I am using ...
15
votes
3answers
268 views

Puff of smoke in air. 3 different PCBs. PCB has ghosts?

Yes, that is a haiku.  (EDIT: fixed it... it is now actually a Haiku) No I'm not smiling. I'm doing some standard testing; seeing what happens when one of the two power rails gets shorted to GND on ...
0
votes
1answer
45 views

Redundant system question

so in short. I am building a redundant system of multiple atmega micro controllers. The way it works is that they are all connected to a single bar, when the system is booted, the first micro ...
0
votes
1answer
71 views

Keep spare LED bulbs or increase dimming? [closed]

I have a luminary with 12 light points for standard E14 bulbs and a LED dimmer in the wall. Using Calex bulbs, I only need 6 bulbs, which I run most of the time at 80% light output (measured with the ...
2
votes
1answer
103 views

How do failure modes of high voltage cables play out?

I fix x-ray equipment, and here is the connector that fits into the x-ray tube. It carries up to 150kV, and maybe 500mA during exposure. My boss tells me if I see some black carbon deposit on the ...
3
votes
1answer
154 views

Cause for failure after short circuit Step-Down Converter Input

I'm currently evaluating the Semtech TS30042 step-down converter. My input voltage is 24V, output voltage is 5V. I followed datasheet recommendation in my layout in most aspects. The problem is, as ...
1
vote
1answer
246 views

Can a MOSFET be used for dimming instead of switching a LED?

I have a simple circuit that uses a MOSFET to switch on and off a ~100W LED spotlight (30V, 3A). It works for this application. I have been asked to modify the circuit so that the LED can be dimmed ...
19
votes
6answers
2k views

Why would a buck converter IC fail and blow up?

I have a deployed design in which we are experiencing a high (~4%) failure rate in the 12V to 5V step-down buck converter portion of the PCB. The buck converter's role in the circuit is to step down ...
8
votes
2answers
2k views

What causes loss of power over lifetime of a magnetron?

The power of a magnetron declines over time\$^1\$. While not noticable for most consumer applications (A 2000-hour lifetime would last over 20 years if the device is used only 15 minutes a day), this ...
1
vote
1answer
72 views

DC/DC step-down regulator destruction because of inductive load?

I was evaluating PAM2316 DC/DC step-down converter and destroyed several of them, I suppose the cause could be an inductive load. See my schematic and my layout here: Let me explain: The circuit was ...
0
votes
4answers
140 views

Is there a motor designed to be constantly overloaded?

So I'm very, very new to electronics so this may be a really dumb question but here goes. Is there a motor that either a. is designed to be constantly overloaded or b. run in such a way that ...
51
votes
13answers
10k views

What kind of components in a computer power supply can explode loudly?

Today I heard a loud bang that tripped the circuit breaker in my server room. It must have been really loud because I could hear it 2 rooms away through 2 heavy doors and it was like a firecracker ...
10
votes
4answers
2k views

My PCBs etch all bad! (sodium persulfate)

I've recently started having problems with etching my PCBs. I use a permanent marker to do the traces and etch them in a stainless steel cup, heated with a tea light (small candle.) The PCBs come ...
1
vote
0answers
83 views

Failures on underside layers of a chip in IGBT power modules

Does somebody know how I can detect a layer of IGBT modules in which a thermal failure, e.g., voids, cracks, delaminations of solder joints, has taken place? We know there is fatigue in both solder ...
0
votes
1answer
160 views

Modelling catastrophic component failure

For most of the time in circuit simulation, the component models used are ideal and don't feature fail-states e.g. this answer here. Have there been any projects that have attempted to model what a ...
1
vote
1answer
228 views

Detecting power loss in a microcontroller to save context

I am trying to detect sudden power loss in my micro controller to save its state before the MCU dies. I have been thinking to utilize one of my GPIO pin to detect the supply voltage and use a large ...
0
votes
1answer
129 views

Circuit Testing failed (Reverse polarity and Buck-Converter)

Hello guys, today I tested my circuit. Its a simple Reverse Polarity Protection Circuit with a Buck-Converter. As I supplied voltagae to my circuit, everything was well (3.5V output). Going higher ...
0
votes
1answer
85 views

Searching for root cause of TC4422A failure

I'm working with a device which employs the Microchip TC4422A to drive a series LCR load in the low kHz range, PWM, 50% DC. The device actually has several of these driver circuits, for several loads, ...
0
votes
2answers
119 views

probable cause of damage to small SMD part: ESD, heat, something else?

The part in question is a 2 x 2 mm LGA accelerometer. 1. First soldering scenario, 10% non working parts after the assembly: no ESD protection gear hot air gun smoothly brought near / away from ...
-3
votes
1answer
141 views

how can I repair a blown USB flash drive circuit? [closed]

paragraphed to sooth Bimpelrekkie's brain :) So I was assembling an older windows PC with a socket 775 Intel motherboard. During assembly I unintentionally mounted the USB connector one pin over to ...
1
vote
2answers
153 views

Failure of Bourns Common Mode Chokes, Series SRF2012

I work for a company that designs and manufactures electromagnetic flow meters. One component, a Bourns common mode choke, PN SRF2012-361YA, seems to have a failure rate in the field of approximately ...
4
votes
1answer
73 views

Component failure in say LTSPICE

Does anyone know through direct experience if LTSPICE or other major circuit emulators actually report component failures in some way. If I were to plug in say over voltage values to known components ...
1
vote
1answer
87 views

Why do LEDs in simple battery circuit flash?

I have an LED flashlight with 13 LEDs. Some of the LEDs do not light, but some flash regularly at different rates, and some flash irregularly. The circuit is simply a resistor in series with the ...
0
votes
2answers
310 views

Transient Power Supply with LM317 and LM2576

I have a power supply to power up a 8W LED board and a raspberry pi. I have used a 24VAC (12-0-12V) 2A transformer to feed the bridge. I have also used a LM317 to provide a voltage of approx. 15.8V ...
0
votes
0answers
50 views

How to remove deposit from leaky alkaline cell

I have an LED torch that must have been left turned on when put aside for some time, so one of the AAA alkaline cells in it has leaked and left a white deposit. It is worthwhile trying to recover the ...
5
votes
1answer
493 views

Mosfet failure in DC-DC switching converter: root cause analysis and countermeasures

I'm dealing with a pilot project which involves several units on the field (around 15 units) powered by a control card which needs to drive two resistive loads in DC in the range of 13-5 VDC. Each of ...
0
votes
1answer
77 views

A switching mechanism which when fails should fail open to cut off the power to the load

I am working on a circuit design where a heater (10 Watts) load is switched ON and OFF using a relay. The relay is in turn switched ON and OFF from N-MOSFET. MOSFET is switched ON and OFF using a ...
2
votes
4answers
609 views

Why did my solder joint fracture?

I've been in the habit of making vias on homemade pcb's by putting the leg of 1N4148 diode into a 0.5 mm hole, cutting it off to length and soldering both sides. However, now my led controller broke ...
1
vote
1answer
183 views

How to make this AC amplifier better [closed]

A few years ago I made this speaker amplifier circuit for a sound source which was essentially an AC signal -- the two signal pins (d9 and d10, 5v logic) were pulled high and low out of phase to ...
0
votes
0answers
425 views

48V 10-50V 60A motor speed controller pwm shorting and running full speed

I’ve google quite a bit to find anyone with the same problem I have and found nothing. I bought a cheap 3000W speed controller from eBay to use on a small 24V motor, probably 250-350W. I have a ...
5
votes
2answers
151 views

ESD and equalizing static charge of sensitive ICs before handling and soldering

When I'm handling an IC that is sensitive to ESD that comes packaged in an antistatic bag, do I nullify my ESD protection procedures if I peel back the cut-tape and dump out the IC into a plastic cup ...
1
vote
1answer
1k views

Hot air soldering without destroying ICs

I have designed a circuit board that has about 20 parts on it, including a surface mount LMV431 Adjustable Zener Shunt Regulator and MMBT2907 PNP transistor. It appears that every time I solder up a ...
0
votes
0answers
359 views

Cause of MOSFET failure

I currently use a repurposed server power supply for some projects. It can output 12VDC @ 60A. I want to load test the supply but it has a short circuit safety built in. Connecting a test load (...
0
votes
0answers
323 views

Safe MOSFET fail open mode

I am working with a circuit that is supposed to act like an incandescent light bulb (ilb). I will use a power resistor to eat the power the ilb normally would. The circuit will have the possibility to ...
1
vote
2answers
540 views

Designing a FET switching circuit that fails open

I'm trying to design a drive circuit for a car engine throttle valve. The valve is spring-loaded to close, and has a small DC motor for opening. (I'll also note that this only for my own vehicle.) ...
2
votes
2answers
210 views

How to roughly know if a electronic scheme will fail soon and protect from it?

I am thinking of a farming project that includes using some board like Arduino, Raspberry Pi or Onion Mega (the list is not exclusive). As the system will work with sensors and support life of its ...
2
votes
4answers
434 views

Why do I need transistor in the following mains power failure circuit?

In this main's power failure alarm circuit, when main power is connected the diode is reverse biased and so the buzzer is off. But when main power is not connected, the diode is forward biased and so ...
3
votes
6answers
1k views

Outcome when logic output of IC shorts to VCC

I wish to know how to determine what happens when the logic output of an IC becomes shorted to VCC (preferably without actually having to short it). I realize that there are a plethora of ICs out ...
0
votes
2answers
135 views

LED Applications

A 20mA, GaN, blue LED, 5mm (forward Voltage 4 volts max, reverse voltage 5 volts) in series with 47K 2W resistor worked fine as a continuity checker using power from a standard 120V AC electrical ...
4
votes
3answers
446 views

My IC keeps blowing up - PAC1720 current sense IC

I am using a PAC1720 current measuring IC to measure the current/voltage/power being delivered to a lead acid motorcycle battery that is being charged. Here is a newer datasheet and an older ...
5
votes
1answer
476 views

Why did I fry my lab power supply trying to charge a lifepo battery?

I hope the question is not off-topic: I want to know "why" it failed more than how I should use my equipment, even though the questions are probably linked. The power supply is a 0-3A, 0-30V lab ...
5
votes
1answer
1k views

Why do some capacitors not have vents?

Some (electrolytic) capacitors I have in a kit have vents, some do not (not on the top, not on the bottom). The vents are there to safely let the gas out instead of letting the capacitor shoot. So ...
5
votes
2answers
591 views

Electronic wearing of a printed circuit board?

I was told that electronic components and printed circuit boards have a limited lifetime. This is backed by several questions and answers: https://www.quora.com/Do-circuit-boards-have-a-useful-life ...
0
votes
1answer
26 views

Power off/ failure to trigger NO state on resumption

First of all I am no electrical engineer (would love to be one!) so apologies upfront if this question is only fit for the sci-fi section. If it is, I'd still like to see a solution to this: ...
4
votes
4answers
565 views

Why can a switched-mode-power-supply be dammaged without load?

I've read that some SMPSs can be damaged if they are being operated without any load (or under a specified current). What is the actual cause of this? What is happening if it is damaged due to this? ...
1
vote
3answers
632 views

SCR fail safe protection

I would like to use 2 SCRs in antiparallel configuration to control the power to a all resistive load (20A) using 240Vac (line to Line). Pretty typical configuration and part of a lot of SCRs ...
0
votes
2answers
363 views

Consequences of inrush current out of specifications in AC/DC power supply

What would be the consequence of an inrush current bigger than acceptable limits at the output of a AC/DC power supply? We are currently using a MeanWell model (GST160A15) whose datasheet reports a ...
0
votes
1answer
304 views

How to determine point of failure in photodiode circuit

I have a photodiode circuit which uses a fiberoptic pigtail photodiode as shown in the picture below: The photodiode is connected to an opamp as in the circuit below: The supply rails for the opamp ...
0
votes
1answer
35 views

Power Fail Monitor and ADC measurement

In my AVR project, I need to measure input voltage (before buck converter), and check for power loss to quickly save some data to EEPROM. Measuring input voltage is just to display its value, but I ...