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

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-1
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3answers
57 views

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

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 ...
0
votes
1answer
38 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 ? ...
-2
votes
1answer
63 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
votes
1answer
90 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
votes
5answers
851 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, ...
0
votes
2answers
38 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 ...
0
votes
0answers
44 views

finding a voltage controllable resistor to replace 1M potentiometer in audio application

I want to replace a 1M potentiometer with some kind of remotely controllable solution. The potentiometer handles an audio signal of \$\pm9V\$. Zippering is unnacceptable in this application, so ...
0
votes
0answers
18 views

Immersion heater electrical specifications

I have a design problem with regards to immersion heaters. I need to heat 20L of oil (sp grav=0.98) from 25C to 170C and maintain the temperature at 170C for 20 minutes. The equipment is plugged in to ...
-5
votes
1answer
38 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 ...
3
votes
1answer
78 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 ...
-2
votes
1answer
36 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
votes
2answers
86 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 ...
0
votes
1answer
71 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
votes
2answers
138 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. ...
-5
votes
3answers
72 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
votes
2answers
148 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 ...
-1
votes
1answer
44 views

I want to know when the AD9235BRUZ-65 outputs data? I cant 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. Would appreciate any help, thanks. DATASHEET : ...
1
vote
1answer
66 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 ...
1
vote
2answers
66 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 ...
1
vote
2answers
162 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 ...
0
votes
1answer
53 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 ...
3
votes
1answer
63 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 ...
4
votes
2answers
219 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
votes
3answers
396 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 ...
6
votes
2answers
166 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
votes
3answers
170 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
vote
1answer
127 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 ...
2
votes
1answer
205 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 ...
0
votes
1answer
35 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
votes
3answers
43 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.
1
vote
2answers
34 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
votes
1answer
48 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
288 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
vote
1answer
58 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
vote
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
vote
1answer
59 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 ...
0
votes
2answers
124 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
votes
3answers
109 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
votes
1answer
55 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 ...
0
votes
2answers
520 views

MOSFET selection for BLDC motor drive

This question is related with the one I asked sometime ago about the heat generated when driving a BLDC motor BLDC drive inverter circuit problem. The problem is, the MOSFET chip got heated up ...
2
votes
1answer
98 views

choosing the right Opto isolator?

In the process of developing an RDM Compatible DMX receiver board (using a ATMEGA328) and I have been fortunate enough to come across kimliv's most informative answer concerning such a board; DMX on ...
0
votes
1answer
183 views

Choosing ADC with wide input voltage range (0-10V)

I faced with the task to measure several inputs (0-10V analog) with galvanic isolation. Using plain Google search (like '0-10V adc') I found several solutions like Linear Technology LTC1854/55/56 ...
3
votes
2answers
138 views

What's the main differences between a TSSOP and a SOIC and when would you use one over the other? [closed]

I was recently looking at some SPI SRAM chips at Mouser and noticed that a particular IC came in both a SOIC-8 and TSSOP-8 ...
0
votes
2answers
103 views

Where can I search components according characteristics, not model?

I'm 2 years disconnected of electronics, and i don't know how i get and know the components i used, and i want to get and know few more components, but i can't get to know them... and well i was ...
1
vote
1answer
34 views

SSR selection - how is on resistance related to output IV curve?

I am looking at the datasheet at the link below, and I can't for the life of me figure out what I am missing. http://www.digikey.ca/product-detail/en/TLP3542(F)/TLP3542F-ND/871299 This is a Toshiba ...
0
votes
0answers
40 views

Bootstrap capacitor selection considering parasitic current

I have been trying to determine how to calculate a bootstrap capacitor value for a synchronous gate driver IC implemented for a buck converter. I understand the the demand of the MOSFET gate itself ...
1
vote
1answer
95 views

Switch high frequency AC on/off at zero crossing

I have a 3 phase generator which is powering some system. (50Vrms @3A, with variable frequency from 50-5KHz). I've used mechanical relays to control each phase to the load. However, there was no real ...
1
vote
1answer
47 views

IC to replace 4 FETs (switches)?

I have 4 data lines that I want to put to high-Z if a pin (let's call it EN_OUT) is high (or low, if necessary), otherwise connect through. I've successfully done that by putting an N-FET on each ...
4
votes
5answers
266 views

A “fuse” that blows upon liquid exposure instead of overcurrent?

I have a board that is mounted inside a waterproof housing, but occasionally the housings develop leaks and expose the internal circuits to water. This can cause unpredictable failures as the ...
1
vote
1answer
73 views

'Dielectric Strength' parameter meaning for cheap inductior coils

Initially I need an inductor to be used in cheap low-power AC-DC power supply. I'd like to use LNK304 solution: When I reached 1mH coil I found Bourns 77F coils: very cheap (only 8 cents at some ...