Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [quality]

14 questions
10
votes
1 answer

What to check for when buying an electronic component or module

This has been raised as a canonical Q and A for future reference How can I acquire electronic parts/items/modules and ensure that there is minimal risk of them being unsuitable for my project or design?
Andy aka
  • 434,556
  • 28
  • 351
  • 777
4
votes
3 answers

Is it reasonable to qualify a component by testing only?

Just got assigned (sole) responsibility of a major product group in my company. I have discovered that we regularly use components outside of their specifications, and justify that by testing the snot out of them. Specific example --- We have a…
Kyle B
  • 4,558
  • 10
  • 29
3
votes
2 answers

Why does the quality factor include 2*pi?

The quality factor is defined as the ratio of stored energy and dissipated energy (see below). The formula includes \$2\pi\$ as a constant coefficient. Why do we need \$2\pi\$ to calculate the stored and dissipated energy? I cannot understand the…
ilyas aslan
  • 41
  • 2
3
votes
3 answers

Designing a filter: does the order i which we cascade the sections matter?

So I am designing a 4th order lowpass filter using two biquadratic sections. I decided to split the gain evenly between both sections. After some calculations, one of the sections has a quality factor of 0.9 and the poles frequency is 1.65 kHz, the…
Granger Obliviate
  • 1,391
  • 10
  • 29
2
votes
1 answer

How to monitor Ethernet packet loss real time on different connections?

For an embedded application we have a network with star topology, where we want to determine if there is packet loss for the different point-to-point (SMAC => DMAC) connections. We consider inventing some scheme where the source (SMAC) sends a…
EquipDev
  • 561
  • 5
  • 14
2
votes
1 answer

On the topic of Quality factor in arbitrary RLC resonance circuits

In question Quality factor in arbitrary RLC resonance circuits, the OP asks about the Q of more complex circuits other than simple series or parallel RLC topologies. The responses I read, in particular the one by LvW made me wonder why it wasn't…
jrive
  • 616
  • 4
  • 14
1
vote
0 answers

Functional discrepancy within PCBA batch

When manufacturing a small prototype batch of an embedded system at EMS I have detected different behavior between the units. All units work as expected, except that some units fail to operate same pump properly when it is controlled at a high speed…
NoobPointerException
  • 730
  • 4
  • 18
1
vote
0 answers

1-port VNA quality factor measurement

I am using an Anritsu VNA (MS2034B) to obtain the LINEAR MAGNITUDE and PHASE of S11 via a calibrated 1-port measurement. The DUT is an inductively coupled RLC resonator (schematic below). However, I don't really know how to extract the quality…
D. Zambrano
  • 43
  • 4
0
votes
3 answers

Formula for Q of a parallel tank circuit

We have defined the Q as the following: Now I tried to apply that to the parallel tank circuit, I get : $$Q = RC\omega_0 + \frac{R}{\omega L}$$ However in the lecture notes and the textbook the formula used is: $$Q = RC\omega_0 $$ Question is: Why…
Ait-Gacem Nabil
  • 37
  • 1
  • 7
0
votes
3 answers

What are the invisible reasons why many discrete transistors do not qualify for automotive use?

I looked today at the datasheets of this unqualified and this qualified product (per the AEC-Q101 automotive standard) and found no substantial difference, but I assume some stress damages only the unqualified one. So, what is the most common…
bobuhito
  • 454
  • 2
  • 11
0
votes
0 answers

Q factor of higher order circuit

I am trying to understand the concept of Q factor for higher order circuit. Consider the circuit as shown in the figure I calculated Zin using Matlab and the transfer function looks as follows: $$Zin(s)=\frac{{\left(c_1 \,c_2 \,c_3 \,l_1 \,l_2…
RAN
  • 179
  • 1
  • 15
0
votes
2 answers

If a PCB is inspected to an IPC-A-600 class higher than specified what are the negative impacts?

I have received several parts from a PCB manufacturer which should have been inspected to IPC-A-600 Class 2 but were instead inspected to IPC-A-600 Class 3. I believe I have received PCBs inspected to a higher degree of accuracy, meaning potentially…
313Ctron
  • 57
  • 6
0
votes
1 answer

Measuring experimentally the poles parameters

I have the following Sallen & Key lowpass filter: $$T(s)=\frac{\frac{1}{R_1R_2C_1C_2}}{s^2+(\frac{1}{C_1R_1}+\frac{1}{C_1R_2})s+\frac{1}{R_1R_2C_1C_2}}$$ The parameters values are $$R_1=10 k\Omega$$ $$R_2=10 k\Omega$$ $$C_1=150 nF$$ $$C_2=1.65…
Granger Obliviate
  • 1,391
  • 10
  • 29
-2
votes
1 answer

How to perform quality assurance?

The site description is given as "Q&A for electronics and electrical engineering professionals, students, and enthusiasts" and I'm interested in "QA for electronics". Though I guess QA is not explicitly engineering but it's also not reverse…
Ben
  • 615
  • 8
  • 15