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1500 questions
54
votes
5 answers
I don't care how a transistor works, how do I get one to work?
Every reference I can find on transistors immediately launches into theory-heavy alphabet soup. The above seems also to be assumed knowledge for reading a datasheet. I don't care; I just want to get one to work.
I understand there's some…
Robert Atkins
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54
votes
14 answers
Solid ground-plane vs hatched ground-plane
Recently while routing a PCB, I came across the option to fill/pour my ground plane with either solid or hatched copper. I've also noticed that the old Arduino Duemilanove also had a hatched ground plane.
What benefits does a hatched ground plane…
Vikram
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54
votes
3 answers
How to go from a development board to a production board?
Ok, I am a software guy and new to electronics. My product needs a small computer and currently I have developed everything on development boards like raspberry pi and such. As the development board does not have all the hardware that I need, I have…
iCode
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54
votes
13 answers
What kind of components in a computer power supply can explode loudly?
Today I heard a loud bang that tripped the circuit breaker in my server room. It must have been really loud because I could hear it 2 rooms away through 2 heavy doors and it was like a firecracker going off right next to me.
Long story short, it…
user81993
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54
votes
9 answers
How safe is 48V DC?
In many Power over Ethernet (POE) setups the transmission voltage is 48V or slightly more. While higher voltage has obvious efficiency advantages, how safe it is? Is there any risk of electrocution when accidentally exposed, in particular to…
Petr
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53
votes
7 answers
How do you simulate voltage noise with LTSpice?
Is there a way to setup a voltage supply with voltage jitter/noise? I want to experiment with filtering out noise on various voltages etc. but not sure how to configure LTSpice to create a noisy voltage supply.
josef.van.niekerk
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53
votes
5 answers
Why does music synthesizer built from chain of astable multivibrator circuits get "out-of-tune" after a few hours?
I built a prototype keyboard/sound synthesizer using a chain of 13 astable multivibrator circuits whose outputs are connected to an audio amplifier chip (LM386) and speaker, all powered off a 9V DC battery.
Each individual circuit gets tuned to one…
Assad Ebrahim
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53
votes
7 answers
The best stack-up possible with a four-layer PCB?
I'm designing a 4 layer PCB and I know that the standard stack-up is
Signals
GND
VCC
Signals
(GND and VCC can be switched depending on the layer with more signals)
The problem is, I don't really want to connect all ground pins through vias, there…
mux
- 1,906
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53
votes
5 answers
Is a CAN enabled microcontroller sufficient to drive a CAN bus?
There are a number of CAN modules built into microcontrollers these days. The PIC18F2480 is an example of that. Is that microcontroller (with built-in CAN) capable of driving a CAN bus on its own or is an external CAN transceiver/controller…
efox29
- 11,955
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53
votes
3 answers
How to drive a Peltier element?
Maybe the underlying question is what the Voltage-Current curve looks like. Can I drive it from a voltage source (like you drive a heater) or from a current source (like you drive an LED)? Or even different than those two options?
ADDITIONAL1: Say…
jippie
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53
votes
6 answers
Why do transformers use so many turns?
Transformers have hundreds of turns on both the secondary and primary winding, and as a result use very thin copper wires for each. But, why do they not just use fewer turns on each winding and get the same voltage ratio?
More importantly, why not…
user3503966
- 663
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53
votes
9 answers
Why are copper cables round?
Why are cables only made of round shapes? What is the advantage of it? Why aren't there triangular or quadrilateral or pentagon shapes of cables?
lucenzo97
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53
votes
2 answers
Why are USB devices slower than 480 MBit/s
Motivation
With a signaling rate of 480 MBit/s USB 2.0 devices should be able to transmit data with up to 60 MB/s. However today's devices seem to be limited to 30-42 MB/s while reading [Wiki:USB]. That is a 30 percent overhead.
USB 2.0 has been a…
Chris
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53
votes
11 answers
Can a radio transmitter somehow detect the number of receivers in its area?
During conversation, a colleague proposed that over-the-air television and radio broadcasters can determine the number of viewers or listeners based on the "load" on their signal. This seems to me like total bupkis, but he's piqued my curiosity and…
ghaberek
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53
votes
11 answers
Why three-phase power? Why not a higher number of phases?
Is there a reason, beyond historical reasons, that three phases has become the dominant number of phases?
I am aware of the advantages against one phase and two phase, namely the reduced amount of conductor needed, and that motors can provide torque…
Hugoagogo
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