Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

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1500 questions
22
votes
3 answers

Design a veroboard/stripboard layout from an Eagle schematic

So I have just finished learning the basics of Eagle (Lite) and I really like it. As I don't have the full kit to start home PCB etching yet (something I am looking into now) I would like a tool that could help me design a layout for a…
Mr. Hedgehog
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5 answers

How can we test the lifespan of electrical components?

We work with some electronic devices in our projects. We are at the stage where we need to create some test strategy to validate the lifespan (e.g. 1 to 5 years) of our devices for which we provide warranty. We need to standardize this test strategy…
MKSJ
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22
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2 answers

ADC is detecting a sine wave as several clusters of points

I'm using an ADC (ADS4129) running at 125MSPS. I'm applying a 100kHz sine wave to a low pass filter (fc=15MHz). The ADC is being driven differentially, as intended. When probing the input signal with a scope I see a decent sinusoid. My problem is…
user264107
22
votes
7 answers

How to remove enamel from wire?

I want to repair my computer mouse cable which has become disconnected from the PCB. The wire is insulated with enamel and I have to remove it before soldering it back onto the board. How should I remove the enamel?
Mohammad Etemaddar
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22
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4 answers

Difference between negative terminal and copper ground?

What's the difference between Negative and Ground? Like a negative terminal and a copper ground? I was reading that they are both the same; one person stated that negative is just more negative than ground. What's the difference? Do I even need…
learningtech
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22
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10 answers

Why is impedance represented as a complex number rather than a vector?

I am trying to understand why impedance is not represented using vectors. I assume it is due to complex numbers having the property that $$j = \sqrt {-1}$$ but with my limited knowledge I can't see how this relates to impedance or why this property…
JShorthouse
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22
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8 answers

Why did they design new connectors for USB?

At the time when the USB standard was being developed, there were a number of widely-available connectors that they could have used instead of making a new custom connector. Why did they not use mini-DIN or DE-9 or some other common connector of the…
Hearth
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22
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7 answers

C - wrapping globals in a struct?

A firmware style question concerning C. I have some legacy code I am tidying up. One of the nasty features is global variables being scattered through the source files. I can make a few of them locals, which is fine. However, how to deal with the…
Dirk Bruere
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22
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6 answers

Where do overtones in a 555 generated square wave come from?

I have built a 555 oscillator and connected it to a speaker. Using an oscilloscope I adjusted the 555 to generate a 2.5kHz square wave. I then held a microphone up to the speaker and fed the input into a spectrum analyser. What I expected to see was…
JShorthouse
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22
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4 answers

Why do we need hardware programmers?

I use a Boarduino and a 30-row bread board to program my ATtiny. I load a not too complicated sketch called ArduinoISP (included by default now in the Arduino IDE), and suddenly I have a working programmer. Atmel sells a nice programmer for…
Jack Schmidt
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22
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5 answers

Cortex-m3 toolchain

I am looking for a free (as in freedom) tool chain for Linux (Ubuntu) that allows me to develop for an ARM cortex-m3 (lpc1343) microcontroller. Where do I find such a toolchain? Are there any tutorials?
txwikinger
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22
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6 answers

Can I disable a battery powered device by reversing half of its batteries?

When I have a device that is powered by two batteries, can I disable it by turning one battery around? For illustration, the purpose is to leave batteries in the device for storage, but it does not have an off switch. There are multiple solutions…
Volker Siegel
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22
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5 answers

How does the oscilloscope trigger really work?

I'm trying to learn more about digital oscilloscopes, especially triggering. Here is how I think the trigger works: Let's say I set the trigger to edge mode, and the level to 5V. When the signal measured then hits 5V, the scope's ADC activates and…
S. Rotos
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22
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5 answers

Astable 555 circuit not oscillating

I'm a complete beginner to electronics, but I'm trying to follow Ben Eaters video series "Building an 8-bit computer". I tried to do the first part of an astable 555 timer, but the LED does not oscillate and on top of that the timer draws A LOT of…
Mr Filp
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22
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2 answers

Why do we need a voltage divider when we get the same voltage at the output as the input?

I am using a voltage divider circuit of 100 Ω and 10 kΩ resistors, and using their output for the (IRF740) transistor's input. I'm trying to figure out why do the resistors have those specific values. It makes sense that if I use voltage divider, I…
Edi
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