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1500 questions
29
votes
5 answers
Tinning wires that will be screwed in to a chocolate block/terminal strip
This is subjective, but I am looking for other people's experience.
If I am going to screw eight wires into a daughter relay board's terminal block, is there a benefit or advantage to tinning the copper end before?
The environment that the units are…
kingchris
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29
votes
3 answers
Why does VGA have so many ground pins (compared to DVI-I for example)?
If you look at the pinout for VGA, there are several ground pins:
I was curious as to why, and I found this answer. To sum it up, the extra ground pins are so that each pin has its own ground in order to prevent interference in the analog…
user112513312
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29
votes
6 answers
What is a flip flop?
There seem to be a number of different definitions of flip-flops and latches out there, some of which are contradictory.
The Computer Science text book for the course I teach is probably the most confusing (in fact I have little faith in the book…
Drummy
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29
votes
4 answers
Why are the three component LEDs in an RGB LED so unbalanced?
I was recently spec-ing some RGB LEDs for a project, when I noticed that the millicandela ratings on the three colors are rarely close to the same number. (i.e. 710mcd Red, 1250mcd Green, 240mcd Blue).
Does this cancel out somehow, or does this mean…
Tustique
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29
votes
6 answers
Compute the minimum number of 120Ω resistors to get 80Ω of resistance?
I recently had to take test in basic electronics. I didn't get one question right, but I don't quite understand why.
How many 120Ω resistors are at minimum required to get a resistance of 80Ω?
The possible answers to this question are 2, 3, 4 and…
Marius Schär
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29
votes
8 answers
When should one switch from ASCII to advanced serial protocols?
All my microcontroller devices that communicate with the PC via UART use ASCII strings for sending commands and receiving data (as implemented in Arduino). That's what I learned when I began digging into electronics and I always found sending bare…
I have no idea what I'm doing
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29
votes
7 answers
Why do ADCs use 10 bit rather than 8 or 16?
Why is it that most ADCs, like the ones on the Arduino, give 10 bit resolution rather than 8 or 16 bit?
It just seems wierd that they don't match standard data sizes, particularly on integrated ones.
Jesse Quisenberry
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29
votes
7 answers
How to carry high current on PCB
I need to pass high current on some part of my circuit. I used an online PCB track width calculator to see that required track width is about 5mm and minimum clearance is 1mm, which makes it about 7mm width at total just for one track. I need…
hkBattousai
- 14,073
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29
votes
9 answers
Why are op amps used so frequently in analog electronics?
I've read in several books and papers the observation: "Op amps are the bread-and-butter of analog electronics", or "... op amps are the most commonly encountered building block in analog circuits ..." and to that effect.
Although my experience is…
scanny
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29
votes
5 answers
Silicon bugs, errata sheets
In many (most??, all??) microcontrollers that I have used over the past years, there where sometimes some silicon level bugs, and the manufacturers provide the engineers with the errata sheets, describing what unexpected behaviour they may face.
Why…
Fotis Panagiotopoulos
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29
votes
5 answers
Puzzled by Nyquist frequency
Say I have a 1kHz sine, so no higher harmonics, then I need to sample it at least at 2kHz to be able to reconstruct it.
But if I sample at 2kHz, but all my samples are on the zero-crossing, then my sampled signal doesn't show a sine at all, rather…
Federico Russo
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29
votes
4 answers
VHDL: Component vs Entity
I am wondering what is the difference between component an entity.
I would like to know in which cases is better to use components instead of entities.
Thank you so much.
Peterstone
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29
votes
6 answers
How do I physically work with a hobby motor?
How do I incorporate a hobby-style motor into a project, physically. How do I mount it and connect a wheel to it? (Assume that I have a working H-bridge or even switches, and am not concerned about how to use the motor electrically, just…
Clinton Blackmore
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29
votes
3 answers
Why do they crimp capacitor leads?
Most manufacturers produces crimped and straight lead pairs of their capacitors which has exactly same capacitance and voltage rating. Why do they bother crimping the leads? What advantage does it make? In which cases a crimped lead capacitor should…
hkBattousai
- 14,073
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29
votes
9 answers
High-voltage capacitor in a low-voltage system
Quick question: is using a capacitor rated for high voltage (let's say 35 V) in a system that, let's say, supplies 5 V (like for LEDs or what have you) dangerous?
Since it can store up to 35 V, will it like somehow store a bunch and then release it…
user3073