Questions tagged [reliability]
The reliability tag has no usage guidance.
2
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1answer
26 views
Failure Rate calculation based on manufacturing defects (capacitor)
Electronics failure rates typically follow the exponential distribution and models like Prism, Mil-Hdbk-217 or 217Plus (newer) are used to predict failure rates.
We are currently in the production ...
6
votes
4answers
1k views
Measuring AC voltage without a transformer using a microcontroller
As I have no practice with AC voltages, I'm asking if the following circuit is reliable for measuring AC voltages about 110Vca and 220Vca 50Hz/60Hz.
I have already made it with a small transformer. ...
3
votes
0answers
98 views
Could a pic32 run for thousands of years? [closed]
By estimates based on known parameters of IC aging, could a standard pic32, if it is kept running in a vacuum or inert gas filled chamber, run for thousands of years or would effects like electro ...
0
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0answers
72 views
Waterproof PCB pump driving stage
We are having issues with a small 12V DC pump which is used in a number of test systems in the field. The pump is powered by a standard DC power supply and integrates a small PCB driving stage, with ...
0
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0answers
56 views
Sawtooth wave generator reliablilty question
I previously designed the sawtooth wave generator in the image below without the capacitors C3R and C5R. The SAWTOOTH output was a constant DC voltage. Through some trouble shooting the issue was that ...
1
vote
0answers
80 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
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3answers
97 views
Can you approximately detect the closure of up to 100,000 switches using a resistor chain?
Consider the following outline circuit:-
It is a series of switch controllers that can short out parts of a chain of serially connected resistors. The short is accomplished with a BJT or MOSFET. A ...
2
votes
2answers
164 views
Reliability of electronic components in space [closed]
The Tesla car being recently shot into space made me wonder about the reliability of common electronic components in hard vacuum. I'm asking about the kind of components you would find in Musks's car-...
2
votes
1answer
51 views
What is maximum ESD current flowing through the pin for HBM model?
I have a given specification HBM ESD tolerance on my IC (For instance 1kV). I just want to estimate the maximum current which will flow on the pin in question and so determinate the clamp point on the ...
3
votes
2answers
98 views
Detecting on- and off-state of a micro switch
For safety reasons I need to make sure that I am still detecting the correct state of a micro switch and not for example a loss of power, broken cable, etc.
What are cheap and reliable ways of doing ...
1
vote
1answer
136 views
What components have a MSL of 5 and 6?
Moisture Sensitivity Level (MSL) relates to the packaging and handling precautions for some semiconductors.
Components with an MSL of 1 have an unlimited floor life, whereas components with an MSL of ...
6
votes
1answer
93 views
Test fixture PCB reliability metrics?
I am working on a project for a client that involves developing a reliability test fixture that will be used for stressing the end test device (DUT). The test fixture is a PCB which has linear power ...
1
vote
1answer
59 views
unique lead acid application question
Can anyone tell me what the non-cycling lifetime of a lead acid cell(s) is, under some kind of float or trickle charge?
Specifically, I need:
300W for 2 seconds
either at +24V with no conversion, ...
0
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0answers
71 views
Connect unused inputs/outputs on RS232 line driver/receiver Chip
What is the safest (and reliable) way to deal with unused input/output pins of serial comm. chips like MAX232, ST3232, etc..
So far i'm familiar with these three options:
Input and Output Not ...
5
votes
1answer
363 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 ...
2
votes
2answers
185 views
Reliability and MTBF
For an electronic device the the MTBF requirement is 4500 hours per year for 10 years, what does this MTBF mean and how to convert it into hours?
0
votes
1answer
85 views
Quality parameters to include in contract with hardware supplier [closed]
my company (not related to electronics at all) is now getting a simple control board for a product designed by a third party. The very same third party will also be in charge of building such control ...
1
vote
1answer
434 views
Driving relay with PC serial port fails after few hours
Ive been trying to use this schematic:
to drive relay (from this answer).
(Components are as specified in schematics, with D2 being 1N4007)
...
2
votes
2answers
205 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 ...
3
votes
2answers
499 views
Board to Board Connections in Potted Electronics
We are contemplating a design which will need 2 PCBAs and be potted. One board is quite "special" so it's rather impractical to reduce the design to a single PCBA.
The conventional wisdom is that ...
4
votes
1answer
2k views
How to calculate aging tolerance of Resistor?
I wanted to calculate the worst case minimum and maximum value of Resistor 1K by considering all the
tolerances(initial tolerance,temperature,environmental factors and aging).
Here is the link for ...
1
vote
6answers
339 views
MOSFET reliability for critical applications
I am working on a critical circuit that drives a DC motor in an aircraft landing gear system. The electric motor is a simple DC motor where one polarity extends the landing gear and reversing the ...
3
votes
1answer
194 views
Thermal Stability of Electrolytic Capacitors
Aluminium Electrolytic Caps do dissipate power .This can be significant when the ripple current is large leading to Ohmic heating due to the ESR .Reputable manufacturers do provide Ripple current ...
0
votes
2answers
157 views
24AWG vs 26AWG for mechanic reliability
I have to choose a cable that will be bent and may be "stretch" a bit by our users. Which gauge would you advice between 24AWG and 26AWG to resist better ?
I guess it is better also to have more ...
1
vote
1answer
145 views
Any reliability concern if I don't add UVLO protection circuit?
I am designing a lithium-ion battery operated device. My concern is when the battery voltage drains to near min. operating voltage (3.3V) of the system, the system starts to reboot and struggles to ...
0
votes
1answer
303 views
Trimpot potentiometer rotational life Vs load life
I'm dealing with an application which makes use of an adjustable linear voltage regulator (LT3080). A trimpot potentiometer is used in place of the set resistance Rset to regulate the output voltage. ...
2
votes
1answer
187 views
Pluggable terminal connector long term reliability
I'm investigating the issues related to long term reliability of pluggable terminals of "Phoenix" style. This terminals are available in a range of pitch and configurations (right angle, straight...). ...
4
votes
2answers
665 views
Refreshing flash memories. Does it work?
We all know that the flash memories have data retention time of around 10..20 years.
But what if we need to design a device that has to work for 1000 years?
The obvious solution is to make a flash ...
-1
votes
1answer
121 views
Does merging the chip and the contact pad in a chip-and-pin card make the whole module less reliable?
This picture is from here (A and B letters are irrelevant for this question). A chip-and-pin card like Visa Electron has a ...
-3
votes
4answers
266 views
How to design schematic with infinite life expectancy [closed]
Well I know there is nothing infinite and every device can break on some circumstances.
But still, how to design electronic devices that to be able to function continuously for very long time.
Lets ...
1
vote
1answer
59 views
Is there an electronic pre-treatment spray for long life reliability in connectors?
Is there a good spray or paint-on treatment that I can apply to small electronic connectors before connecting them, that will help them maintain a good connection over long spans of time?
I am ...
4
votes
1answer
168 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
vote
2answers
542 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 ...
65
votes
6answers
9k 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
389 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 ...
36
votes
10answers
13k 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
votes
2answers
90 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
1k 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
154 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. ...
3
votes
1answer
219 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 ...
24
votes
3answers
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
228 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
119 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
282 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
159 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
145 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
votes
3answers
538 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
votes
1answer
65 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
287 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
521 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
