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

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-3
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3answers
29 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
130 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
38 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
40 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
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2answers
64 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
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2answers
155 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
46 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
60 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
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2answers
197 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
364 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
144 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
143 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
116 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
159 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
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1answer
32 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
42 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
32 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
44 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
164 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
57 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
41 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
53 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
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2answers
76 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
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1answer
51 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
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2answers
302 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
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1answer
82 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
123 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
112 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
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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 ...
0
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0answers
73 views

Variable frequency drive power transistor selection

I'm designing a variable frequency drive for a single-phase induction motor driving a water pump. The motor power is 1.3 kW, it has 2 windings with resistance of 1.5/3 Ohms. My local electrical grid ...
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
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0answers
37 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
88 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
249 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
64 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 ...
0
votes
2answers
74 views

What possible issues with running a fan inside a freezer?

I need to turn on a fan inside an ice cream display cabinet when the lid is closed, and turn the fan off as soon as the lid is opened. I'm looking for a way to have as little temperature derivation ...
2
votes
1answer
78 views

What type of transformer would be required to boost a voltage signal by 2?

In books, everything is theoretical and if you want to boost your signal up by 2, you get a 1:2 transformer. Great. However, in the real world, there are different types of transformers which I think ...
0
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2answers
142 views

LM2623 Regulator

I'm implementing a DC/DC regulator and you can find the datasheet in this link. What I'm trying to do it's basically reproduce the application note in order to have Vin = 12V and Vout = 5V 1Amp but ...
0
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1answer
90 views

chosing the right Hall effect sensor

For a student project, I need a Hall Effect current sensor. What I am going to do is to charge 8 rechargeable Li-Ion batteries of 3.7 volts in series with 34 volt supply and the buck circuit frequency ...
1
vote
1answer
81 views

Why is this a bad MOSFET/Driver for a Tesla Coil, what does one look for in a good one?

MOSFET: http://ixdev.ixys.com/DataSheet/99175.pdf Driver: http://www.irf.com/product-info/datasheets/data/ir2183.pdf What factors should one consider in selecting a good MOSFET/Driver combo, and ...
0
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5answers
182 views

Practical Considerations of a Butterworth Filter

I'm trying to design/implement a low-pass filter for the amateur 2M band (144-148 MHz). To meet FCC regs, I need harmonics to be at least 40dB down, so I calculated a 7-stage Butterworth Filter with ...
2
votes
2answers
55 views

Components with multiple possible values - how to designate on schematic?

Quite often it happens to me that values of resistors or capacitors don't play such a significant role. This is mainly the case with decoupling capacitors and e.g. LED series resistors. Often in ...
1
vote
1answer
100 views

How do I select transistors for logarithmic amplifier?

I need a logarithmic amplifier and found this equivalent schematic in the datasheet for the LOG104: The LOG104 is rather expensive, so I want to build this myself. What are the requirements for the ...
0
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0answers
41 views

How does one change only the frequency of an alternating current? [duplicate]

Suppose standard voltage, current, and frequency AC power is readily available for a project that requires the available standard voltage and current, but also requires an arbitrary number of cycles ...
2
votes
2answers
386 views

LED capable of either IR or visible light (not at the same time) [closed]

I'm looking for a type of LED (or some other small light emitter) with two modes: IR light only Visible light, if it also emits IR light here it doesn't really matter Could something like an "RGB ...
0
votes
1answer
57 views

Which MOSFET is best for me? [closed]

I plan on driving a heating coil of about 1.4 Ohms from a 3-4V power source; which gives an current draw of 2.14-2.85 A. So Watts from the following info is 6.42-11.4 W of power. The MCU will output a ...
0
votes
3answers
139 views

LED Resistor Choice with changing voltage

I'm planning on adding leds to a small quadcopter which runs on a 1s lipo battery. I am planning on attaching the leds straight to the battery rather than the regulated voltage the main circuit board ...
0
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1answer
70 views

Short 2 wires when a third is powered

I'm using an Arduino for a home project. Say I have 2 wires, connected to a breadboard in different columns (not shorted). When one of my digital outputs on the Arduino is HIGH, I'd like to short ...