Questions tagged [reliability]

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4
votes
1answer
290 views

Does the separation of the differential pair shielding of a SATA cable matter?

Basically I want to replace a consumer grade SATA cable with something a bit more tolerant to high temps and other environmental stresses. The general cross section of a SATA cable looks like this: ...
1
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2answers
1k views

What is the expected lifespan of those 16x2 character LCD?

I want to use the HD44780 character LCD (commonly available in 16x2 characters, though I am using the 20x4 version) in an industrial application but since it will be on 24x7, I am just a bit worried ...
68
votes
6answers
10k views

What happened to electrolytic capacitors in the 21st century?

We can sometimes see decades-old capacitors (such as ones made in the USSR) still working. They are bigger and heavier, but durable and not desiccating. Modern aluminium capacitors serve for about 11 ...
6
votes
2answers
508 views

Hardware reliability Test

I am doing aging of my product by placing to a chamber for 2hrs 50degrees 95% humidity and 2 hours 0degrees 24/7, I have finished 1 week and the product is still okay. I am wondering what does this 1 ...
37
votes
10answers
16k views

Why is the temperature range of industrial and military products so high?

From Wikipedia the common temperature range for electrical components is: Commercial: 0 to 70 °C Industrial: -40 to 85 °C Military: -55 to 125 °C I can understand the lower part (-40°C and -55°C) ...
3
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2answers
217 views

Comparing accelerated ageing with “real” ageing

In the electronics industry (and many others fields, but I'm interested in electronics here), it is common to submit electronic components and boards to accelerated ageing processes. The aim is to ...
1
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1answer
2k views

What are typical failure modes of piezoelectric transducers?

How do piezoelectric transducers in ultrasound probes fail? I have a machine whose elements are being driven by an amplifier that is very noisy. The signal I see arriving from the power amplifier ...
2
votes
2answers
180 views

Principles for premature failure analysis of PCB tracks and vias

I have just given a task to implement a setup to detect whether or not a track or via on a PCB is going to fail in any time in the future. The PCBs are supposed to be used in harsh environment e.g. ...
2
votes
1answer
229 views

Circuit reliability, especially tin solder, under wide temperature range -40 degree to +85 degree

We are trying to have our Lab product work in industry environment. One key factor we are thinking about is the operating temperature, since we have never done any environment test before. Our ...
25
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4answers
2k views

Reliability problems with an array of 91 high-power LEDs

I have designed and printed a 4-layer PCB that accommodates 91 infrared LEDs in a 7x13 rectangular layout. This will be used as a backlight for a machine vision project. I am having a problem where ...
0
votes
1answer
250 views

Where does the spark come from? (an embedded system circuit)

We are developing an embedded system product. As an inexperienced engineer, I am really scratching my head to make our product reliable: temperature, ESD and etc.. The following diagram shows my ...
-2
votes
1answer
146 views

Electronics (IC) reliability in aerospace engineering

This question was asked to me by a colleague earlier that day : For how much operating time does an IC has to be qualified in the aerospace sector ? My guess was about fifty years, but are there any ...
0
votes
1answer
414 views

FITS in reliablity. How to convert number of failures in actual hardware testing to MTBF

In the following post What are FIT's and how they used in reliability calculations? Barry stated "There are standard formulas that convert the number of failures in a given test time to MTBF for ...
0
votes
1answer
213 views

How to specify HALT / HASS limits?

How does one go about picking the limits for a HALT test? Voltages, temperature, ramp rate, how much vibration and at what frequency? Is there a science to it or some standards? I remember one lab ...
1
vote
2answers
186 views

understanding the use of MTBF

I have on a few occasions calculated the MTBF using the FITS of all the components on a BOM and something like the telcordia standard in some spreadsheet tool I was given. We get a number say 1 ...
2
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3answers
673 views

Triple Modular Redundancy w/ Majority Voting when a microcontroller fails

In a simple majority voting system, the majority input values will be the output, as shown below. majority voting http://6502.org/users/dieter/a4/a4_maj1.jpg However, how does one deal with ...
0
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1answer
71 views

Series Electrolitic Cap life

My country has 230V mains. Many imported SMPS have a 230/115 VAC switch that means that the SMPS cap filter input stage runs like a fullwave bridge here. It means that it runs like a full wave ...
0
votes
1answer
509 views

connector recommendations for CAN bus and power supply to distributed PLCs

I'm looking to build a distributed PLC system with up to 20 devices spread throughout a building, controlling lights, HVAC, irrigation, security, etc, and want recommendations on what connector to use ...
-3
votes
1answer
769 views

How to make a 240v ac to 12v 2amp dc transformerless step down circuit [closed]

I want to make a 100-240vac to 12vdc 2amp transformerless stepdown circuit any safe reliable circuit digram is accepted
2
votes
3answers
343 views

What components work better when they warm up? (apart from vacuum tubes) [closed]

Conventional wisdom is that heat is bad for electronics. Metals and most doped semiconductors conduct more poorly, and everything ages faster. But in my experience, some faulty appliances don't work ...
0
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1answer
318 views

Reliability FPGA depending on its number of gates

I am currently working on a little project and the goal is to find a new model for calculating FPGA's reliability. I have been working with the MIL-HDBK-217F+N2, but when it comes to the complexity (...
1
vote
1answer
513 views

How signifigant of an issue is Gold Embrittlement?

I have heard about gold embrittlement but have not seen any data regarding failure rates, or how long before solder joints are at risk of failing. We use an ENIG finish on all our boards and I'm ...
3
votes
1answer
205 views

Wire Wrap Joint in High Humidity

How does a wire wrap joint compare to a soldered joint in high humidity conditions? Corrosion? Electrolysis? Joint resistance creeping up?
5
votes
5answers
4k views

Through Hole Soldering- Minimum lead protrusion

I am working on a bit of a strange design: all components, SMD and Through-Hole, are mounted on the top side of the PCB, except for some really beefy MOSFETs, which are mounted to the bottom side of ...
2
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3answers
11k views

Can a faulty USB device fry other devices on the same hub?

Some Googling revealed that a faulty USB device may fry the entire motherboard+processor of a computer if it is not fitted with appropriate fuses (if it is known though, I wonder why they wouldn't!), ...
30
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3answers
1k views

Design for long term reliability?

I need to design a small board that will go into a large piece of public infrastructure intended to last many decades. I am looking for papers and the like that give guidance on such design based on ...
8
votes
2answers
246 views

How reliable is a daisy-chained USB bus? What are the risks and how can they be minimised?

Introduction USB has been around for quite a long time now, used extensively even in the automotive, marine and space industries to some extent. However certain communication ways are more reliable ...
0
votes
1answer
62 views

Bench top reliability test chambers

I am thinking about buying a benchtop (small, low cost, only to be used during initial design of the products) reliability test chamber. What are the key features I should check for ? I am thinking ...
1
vote
1answer
65 views

Reliable connectors for digital sensors

I have designed a data collection device which is mounted on a moving vehicle. Is there any recommended connectors that can survive high vibrations for digital sensors?
1
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1answer
268 views

Is there a good physical model for what happens when a light bulb suddenly goes out?

Sometimes a light bulb just stops working and goes dark for seemingly no reason. Can Dirac δ impulse to a light bulb serve as a mathematical model for what happens so we can assume that the electric ...
1
vote
0answers
119 views

Reliable docking charging connector?

I am designing a mobile robot which needs to re-charge in a docking station, but I'm having difficulty deciding what to do about the connector. I have two choices: design and make our own connector, ...
2
votes
1answer
147 views

Firmware reliability for over temperature detection

I am speaking about an industrial equipment that is generating gas. It is under certification test (CE marking) IEC 61010 in a third party lab. In the device there is an over temperature detection ...
9
votes
5answers
2k views

What tools or standards can be used to improve embedded C code reliability?

I typically program PICs in C, usually for switched-mode converters. I've heard of various static analysis tools and standards like MISRA C that can be used to help improve the reliability of code. I'...
4
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2answers
2k views

Potting Connectors

I work for a company manufacturing electronics. We have a few products where we pot boards into enclosures. Where it is done the incoming connections are always soldered for fear of condensation ...
5
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1answer
684 views

Reliability of battery retainers for coin cells

I'm thinking of using a coin cell battery retainer on an upcoming project. The target application will be in a medium-to-high vibration environment with around 1-2 years between battery changes. ...
13
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2answers
1k views

Why are BJTs more reliable than MOSFETs under severe weather conditions?

I read in a textbook (Microelectronic Circuits by Sedra and Smith, pg. 494, (2010) sixth edition) that BJTs are preferred by the automotive industry due to their reliability under severe weather ...
0
votes
3answers
538 views

Are modern processors safe from backdoor? [closed]

I have been reading so many thing about leaks of surveillance recently, Most of the things covered under NSA 2013 Mass surveillance disclosure I use the chips of Microchip for designing few ...
7
votes
1answer
3k views

What's the shelf life of ceramic & tantalum capacitors?

What is the shelf life of unused surface-mount ceramic and tantalum (low-ESR or not) capacitors? If they are kept at a reasonable temperature and humidity (at room temperature in plastic parts bins)...
2
votes
0answers
121 views

Does the Black's equation work for immortal wires / interconnections (or only for mortal ones)?

I'm trying to understand whether the Black's equation is only true for mortal wire / interconnections or it is also applicable to immortal wires (essentially when its \$jL\$ product is less than \$jL_{...
8
votes
4answers
1k views

Is it common for internal pull-up resistors to fail? or what would cause them to become intermittent?

I have a board based on an ASIC ARM Cortex-M3 that after months of work suddenly started to report spurious button presses. The ASIC is not our design, but a reputable company's. The buttons ...
2
votes
3answers
406 views

Do I need to use thermals on vias for reliability?

This question is further to Why thermal reliefs on vias? I have recently been advised (by someone I consider an expert) that I should add thermal reliefs to vias which are connected to planes, even ...
35
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10answers
20k views

Is an Arduino Uno capable of running 24/7?

I'm curious as to the reliability and durability of the Arduino Uno. Does anybody have experience in "killing" one due to excessive use? If so, how long did it take for the board to fail?
8
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2answers
10k views

Best Linux filesystem to use on MMC memory chip?

I have a new embedded Linux project coming up. The hardware team has chosen an MMC Flash chip (part # MTFC64GJVDN-4M) for the system's non volatile memory; data sheet at http://www.micron.com/parts/...
10
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3answers
38k views

What are FIT's and how they used in reliability calculations?

In Military, Medical, Space, Professional eqt. design there is a need to be able to prove that your device can last a certain length of time with a certain confidence level. Or that reliability must ...
29
votes
6answers
15k views

How precise is the frequency of the AC electricity network?

If I make a digital clock which first detects the AC frequency roughly (whether it is 50, 60, 100Hz, etc), then uses it as its clock pulse source, how precise would it be? Would it work world wide ...
14
votes
4answers
11k views

What is the lowest capacitor voltage rating that is safe to use?

I'm using a few Case R tantalum capacitors (10uF 6.3v) as bulk decoupling on the 3.3v power of a 100mbps Ethernet phy. I am also using 0.1uF ceramics closer to the pins. As usual, I'm terribly pushed ...
0
votes
3answers
1k views

Dynamic Range of an ADC

I am tasked with a situation where I have to analyse different ADC for a medical instrument (abstracted on purpose just to emphasize that the input is sensitive and results can endanger someone's life ...
12
votes
3answers
16k views

I2C minimum clock speed and reliability

Is there a minimum clock rate specified by I2C? I know the most widely used clock rate is 100kHz and there is a "fast" mode of 400kHz supported by some devices, and a faster yet mode supported by ...
8
votes
3answers
975 views

Does solder being or not being uniformly thin and shiny really indicate reliability of the circuit?

I'm currently reading an article (in Russian) and the author compares two devices (hard disks) of the same model one manufactured by Company A and the other manufactured by Company B. One of the ...
4
votes
3answers
23k views

Can a device be damaged by water even if there is no power supplied?

For example, say I submerged a computer mouse entirely. Assuming that I ensured that all traces of the water were gone, would the device suffer any issues? It is my understanding currently that ...