All related to methods to select the correct components and/or component values to specific applications

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1answer
32 views

Simple Reverse-polarity Protection for Automotive DC-DC Converter: FET or Diode?

I have recently decided to upgrade my old van by installing a few 5V/3A sockets using a 100W 12V-to-5V downstep buck that has no reverse-polarity protection. A little bit of searching here and ...
5
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1answer
108 views

How do I find compatible coax connectors if I don't know the type of coax?

I have some small diameter coaxial cable, which we use in harsh environments. I want to buy connectors for it. Most suppliers list thousands of connectors by cable designation, so finding compatible ...
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2answers
62 views

Reliability of edge connectors for production

I'm looking for an 6 pin .1 standard edge connector to program for production my board without any connector. And I cannot find the number of cycle they can support. Does anyone has used such ...
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1answer
61 views

Passive components swapping and replacement

I am trying to writte a small note for our staff when they purchase components. Quite often some resistors, capacitor, inductor, diode and transistor (NPN and MOSFTET) may not be availble on the ...
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3answers
80 views

Best way to get components for a new electronics lab [closed]

I recently joined a lab that is still in the process of getting set up. Our approach to acquiring electrical components (e.g. resistors, caps, opamps, etc.) so far has been to just wait until we ...
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1answer
95 views

Power consumption of Cortex-M7-based microcontrollers

I'm designing a USB-powered microcontroller board, and I'm considering choosing a Cortex-M7-based microcontroller for it (I want a double-precision FPU, along with other features M7 offers). Currently,...
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2answers
100 views

When to “wind-your-own” vs “scavenge” a transformer?

I often see answers for one-off designs including the advice, "Just wind a transformer...." Like it's no big deal. Did I miss a class in which they handed out a sheet listing the formulas for core ...
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0answers
27 views

How to make 12 hours timer? [duplicate]

I want to make a timer that trigger every 12 hours and when it triggers it stays high for 30 min then reset again until another 12 hours, and so on. I want to make this circuit with the simlest ...
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4answers
508 views

Selecting passive components [closed]

I am in the case where I read a lot of datasheet and I quite often see some circuit where the chip manufacturer indicate some value for resistors and capacitor but by not indicating any part number, ...
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2answers
59 views

What is this component called

Suppose I have 512 leds in a 16 by 32 grid. I want to control what is displayed on the grid. To do this suppose I have a timer counter that is constantly counting between 0 and 31 in binary. This ...
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7answers
408 views

Role of Electrolytic Capacitors and whether they can be replaced by Film capacitors in battery operated power converters

In battery operated power converters such as motor controller ( half bridge or full bridge ) bulk capacitance is placed across Vdd and Gnd . I thought this was unnecessary since the input is DC and ...
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0answers
49 views

Looking for a compatible microphone - need advice

I have bought a HIO EMB 1200 HW development board which runs Yocto Linux. I plan to do some audio processing on this board. For that reason, I also had to add the HIO 1240 IO module which provides the ...
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2answers
70 views

High voltage DC current measurement by inductance?

I'd like to incorporate a few permanent ammeters in a 600V DC circuit. I've found all sorts of nifty panel ammeters, both analog and digital, but most are rated to less than a tenth that voltage. I ...
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3answers
62 views

Is it OK to use electronics with slightly different ratings? [closed]

e.g. is it ok to use a 464R instead of a 470R (where the circuit indicates 470R). Here is the circuit: I figure it "should" be OK be OK since it difference is roughly 1% but I thought I should ask....
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1answer
46 views

RJ45 Magjack connection

my doubt TXP,TXN of phy chip is connecting to P1 and P3 of the connector. I thought it must connect to P4 and P6 of the connector. Can somebody please let me know which is correct point 1 or 2 ?
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1answer
70 views

Help choosing component values for a relay delay circuit

I want to build a circuit that controls a relay with the following specifications: the relay should turn on and stay on for ~60 seconds after the button is pushed the relay should stay on as long as ...
2
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1answer
118 views

How to choose an op-amp used as a buffer [closed]

I am having difficulty choosing an op-amp for essentially a one-off design. All I am trying to do is buffer inputs to a +/- 10V 16 bit ADC. Super high precision is not necessary, but I would like to ...
11
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5answers
903 views

What's cheaper & faster for my lab, keep a stock of electronics components or order? [closed]

We are four electronic engineers working in a company, and we have a lab, I think we have a logistic issue with our components, this might be a basic study case: We have few racks with resistors, ...
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2answers
44 views

Need help selecting a replacement thermistor

I have a used piece of equipment (basically a specialized laminator) that uses a thermistor to measure the temperature in operation. When I got it, I found that it was heating, but the system never ...
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1answer
41 views

Any suggestions on how to make a current limiting circuitry? [closed]

I am a student of Electrical Engineering and I am currently working on a biomedical device which stimulates a human arm through functional electrical stimulation technique. Now for instance, if short ...
5
votes
1answer
121 views

What's the typical way to manage components for a team in Altium? Component libraries in a vault? SVN Database? Other?

I'm an EE for a growing company, and I'm looking for what's typical to manage components across multiple designs. When I say growing, I mean that there used to be one EE, as of last year I got added ...
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1answer
52 views

Miniture bluetooth enabled accelerometer with API or SDK [closed]

I'm getting into electronics as a hobby. For my first hobby project I want to build something like a super simple fitbit. To achieve this I need a bluetooth enabled accelerometer. I've had a look at ...
5
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2answers
92 views

Manufacturer doesn't list self resonant frequency

To put it simply, some manufacturers don't list their inductors' self resonance frequency. I'm a bit baffled as to why they don't do this, and I have some concerns using inductors like this one on ...
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1answer
79 views

Decoupling Capacitor Calculation

I have few questions related to the schematics(BBB_SCH) sheet 2 in link There is a bulk decoupling capacitor of 10uF,10V connected to the pin ...
4
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2answers
153 views

Why do offline switching converters often use discrete rectifiers for bridge?

In conjunction with my independent study of switching converters using textbooks, I am more or less obsessively tearing apart all the low-ish power (say 5 - 25 Watt) switching converters I can find. I'...
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3answers
89 views

how can we make a signal out of a 2 pin mic output

ok im looking to make this type of setup so that i can use its output pin to read via analog. this is the mic i got and would like to make that 3rd pinout which as you can see it only has 2 and ...
3
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2answers
184 views

Mechanical Switch in parallel to the Micro Controller working in Sync

Here is the image for my requirement,want to operate Load Lamp of 230V AC with Mechanical Switch in parallel to Controller where one can 'ON' the Load Lamp from the Mechanical Switch and 'OFF' from ...
0
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1answer
49 views

I want to know when the AD9235BRUZ-65 outputs data? I can't make sense of the datasheet or find a way to simulate it

I need to know when data is output from the AD9235BRUZ-65 digital pins. I need this to create a type of handshake with a FPGA. Datasheet.
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1answer
96 views

Is NXP's PCA9548A compatible with TI's TCA9548A?

I am using TI's TCA9548A in my Projects, but I would like to know if I can substitute it with PCA9548A from NXP. By comparing the datasheets this seems to be indeed the case, but I am wondering why ...
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2answers
69 views

Is there a typical 'ferrite' for use in a PCB?

I have a circuit diagram that I am trying to replicate (actually the Teensy 3.0/3.1 circuit diagram shown here https://www.pjrc.com/teensy/schematic.html) and there is a component called simply '...
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2answers
169 views

In a circuit with the TI TPS61165, how was D2 chosen?

Looking at datasheet for the TPS61165, I don't see how they chose D2 - it looks like it will only work if the voltage supply is above 12v due to this diode, but the chip's input range is 3-18v. I ...
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1answer
54 views

Volume of sand in a cat box - ultrasonic sensor?

My cat is always making fun of the sand that is inside of his sanitation zone :) In order to better control the amount of sand that is present on the container I'm developing a communications circuit ...
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1answer
64 views

Advice needed: comparing two parts

I want to buy some 0402 SMD capacitors (well some is about 1 to 10k). I always use the method of use the cheapest part for the given specs approach. But today I ...
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2answers
312 views

In production, is there a significant difference between QFN or TQFP components other than space?

When producing a run of PCBs, does it matter if I choose QFN or TQFP components? Say, I want to have 1000 boards manufactured with an Atmel AVR that is available in QFN or TQFP packages. The QFN ...
3
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3answers
429 views

How do I simplify microcontroller-based prototype into a sensible production-like circuit?

First some context: I'm an IT person by trade, and I dabble in electronics as a hobby. I have rather limited experience - apart from some toy circuits I've only made a single "production" quality ...
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2answers
181 views

Is there any reason to prefer one MLCC manufacturer over another?

I'm specifying some SMD chip capacitors for the first time and I note there are several manufacturers out there: muRata, Yageo, Vishay, AVX, Kemet in particular, perhaps others. Is there any good ...
2
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3answers
190 views

Selecting a capacitor for use in feedback loop

I'm designing a DC Lab Power Supply; the voltage regulation circuit looks like this: I'm developing the BOM, component by component, and next in line is specifying the capacitor in the feedback ...
1
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1answer
135 views

Modern jack-of-all-trades cheap OPAMPs? [closed]

I am trying to design my first "big" project, and I have to choose the OPAMPs to use. The problem is that I am feeling overwhelmed by all the possibilities. I feel tempted to just stick on the LM741 ...
3
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1answer
260 views

Is there any science (or trick) to determining a replacement op amp?

I have a "mature" circuit design that calls for an LF411 op amp. I've built it up with a through-hole PDIP and it works just fine. Now I'm designing an SMD PCB for the circuit so I have the ...
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1answer
36 views

Building a motion/activity tracker with AVR Atmega or ARM?

I have worked with IMU and an Arduino before to build a motion/activity tracker. Even after making it wireless, the whole system is quite big due to the individual breakout boards that hold those ...
2
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3answers
45 views

Describing FM inductors

Why, when providing FM radio designs, do people use physical parameters instead of electrical? I.E. 2 turns, 20awg, 2cm dia.
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2answers
35 views

2 channel per circuit component election

I was looking for some references for a level shifter connected to an intel edison and a found that they used a 74LVC(H)1T45 which have one channel per circuit. Then I found the same IC but with two ...
4
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1answer
60 views

Replacing a schematic component by a connector

I'm currently designing a pcb in EAGLE (v7.4) for a school project and I've included a potentiometer for gain control. However, I will not be placing the potentiometer directly on the board. I want to ...
5
votes
3answers
426 views

Ceramic (MLCC) versus Tantalum capacitors

From the perspective of an electronics designer, but also taking into account price/cost and social considerations (see Coltan mining and ethics link below), I tend to avoid Tantalum capacitors under ...
1
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1answer
60 views

Diode selection for AM radio

Does the choice of diode for an AM radio matter, so long as its sufficiently biased? For example, will a 4001 work? Or maybe a high Vz Zener?
1
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1answer
48 views

How to measure relative light intensity (and ideally duration) of a xenon flashes, cheaply

I want to compare the light intensity (and maybe also duration) of multiple xenon flash designs. It does not have to give me the readings in any real unit, as long as it is linear (or mathematicaly ...
1
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1answer
66 views

What specifications must I consider for a DC motor?

I'm working on a project where I need a DC motor that is capable of tightening a bolt with a motor. The applications will typically be automotive, therefore, the bolts will need to be tightened to ...
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2answers
154 views

How to supply one or more servo motors from a PC power supply?

I have a PC power suply 800w. The 12V output has max 20A. How can I convert the 12V to 6V and 10A (when 5 servos will work in the same time)?
3
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3answers
111 views

Is there an electronic device that stays “on” until the current through the device reaches a certain level?

I have the vague recollection that a device like this exists. The device is gated on, after which it approximates a short circuit, until the current through the device rises to a set level, at which ...
0
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1answer
58 views

RTC capacitor with long lifetime selection

In my design I am using for RTC (BQ32000) circuit, for which I have used a 0.33F capacitor and it's rated lifetime is 2000 Hrs. But I need to select a capacitor with 5000 Hrs lifetime. I haven't ...