Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

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1500 questions
36
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6 answers

What is a "digital" motor?

Dyson keeps going on about their new "digital" motor. What is a digital motor? How can a motor be digital, if it is inherently analog? Is it just marketing doublespeak?
Thomas O
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5 answers

Why 2.4 GHz Band?

Bluetooth, WiFi, Zigbee, Remote Controls, Alarms, Cordless Phones etc.. Why all of these protocols, devices, etc. use 2.4 GHz band instead of 3.14 GHz. What is so special about it?
cbr
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30 answers

Electronics Blogs and Podcasts

There are some great blogs out there for programmers (Joel on Software, Paul Graham's Essays, etc.). I would love to know about any similar quality content for electronics. Do you have any great blogs or podcasts you love? (submit one answer for…
Shawn J. Goff
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4 answers

Safe current limit for human contact?

What's the point below which electrical current is generally considered safe for "casual" human contact? Is either voltage or amperage more "dangerous" (e.g. high voltage / low amperage vs. low voltage / high amperage), or is the only consideration…
Mark Harrison
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5 answers

What pad hole (drill) size is appropriate for a given through-hole lead diameter?

I am making some new through-hole parts in Eagle for components that are not already in the various libraries. I've realized that the drill size needs to be a little larger than the lead diameter, but I'm not sure by how much. With some research, I…
JYelton
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35
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7 answers

Debouncing buttons

I recently read an article about button debouncing and was wondering if I should keep this in mind when working with, for example, an Arduino (ATMega mC)? I assume it is an issue, especially when working with interrupts. So is it better to detect…
Vincent Van Den Berghe
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Is MCP23017's I2C address matching broken?

I'm struggling to get an I2C master to communicate reliably with a slave, because there's also an MCP23017 port-expander on the same bus. The MCP23017 seems to detect - and ACK! - its address, even when that bit pattern appears coincidentally in the…
SusanW
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How did 455 kHz end up being a commonly used IF (intermediate frequency)?

Of all possible IF frequencies, why did so many consumer radio and amateur HF radio manufacturers (and filter component vendors, etc.) end up converging on 455 kHz as the IF frequency, from the vacuum tube era, and onward? Is there something…
hotpaw2
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2 answers

Heuristic explanation of the usage of a pull-up (or pull-down) resistor needed

First, I acknowledge that there are several questions regarding this topic in the forum, however, the answers assume too much background knowledge of electronics to be of use to a true beginner (like myself). That being said, if you choose to…
Zak
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2 answers

Schottky transistor, Not sure I understand it?

So I've been looking through and going through my Digital Computer Electronics book, and I came to this... It seems so simple and I understand the "point" of it, but I'm not sure I understand exactly how it works. "In a Schottky transistor, the…
user3073
35
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8 answers

Why is the output of stateful elements often named Q?

In logic circuit diagrams, I've seen various conventions for naming inputs and outputs of logic gates and combinatorial circuits. However, stateful elements like latches and flip-flops often have their "state" called Q. I suspect there is a…
Gyom
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5 answers

How to determine position from gyroscope and accelerometer input?

I have a 3-axis accelerometer and a 2-axis gyroscope. I intend to measure something that only moves in the X and Z axis. I've heard of using Kalman filters to smooth out the acceleration vectors, but I can't find a good tutorial for a complete…
Steven
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7 answers

What does "For disconnect use only" mean on a connector?

I recently bought some Andersen connectors for connecting high-amp devices to my camping setup in my truck. The idea is they hold together through much rougher conditions than a regular cigarette lighter 12v plug would, as well as being superior in…
Mark Henderson
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2 answers

What's the purpose of this checkerboard pattern?

This gigabit Ethernet NIC has a checkerboard pattern out of copper etched on the PCB: Each square is electrically isolated. What's the point of adding these? I guess that the PCB isn't filled with a copper plane due to cost concerns, but why don't…
Catherine
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3 answers

How to compare mAh and Wh

When looking at consumer electronic devices with batteries I sometimes see the battery capacity listed in Wh (watt hours) and sometimes in mAh (milliamp hours). I would like to be able to compare the two different metrics and I'm wondering how to…
Gabriel Southern
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