AC stands for Alternating Current. It usually applies to voltages with >100 V RMS, but can also be used for other AC voltages, like 24 V industrial AC power.
Questions tagged [ac]
3313 questions
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Using clothesline steel core wire rope for AC and DC
As I am currently in a war zone, I don't have many options for cabling.
I found this clothesline (steel core plastic wire rope) that appears to be one mm of diameter (steel core diameter.) 13 meters of it measured 7 ohms resistance.
Edit: It is 3.8…
USER249
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230V AC to 5V DC converter, lossless
Is there any IC which converts 230V AC to 5V DC? As lossless as possible. I want to connect my microcontroller to an ordinary electrical socket and I don't have enough space available. Thanks.
arminb
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Why do fundamental circuit laws break down at high frequency AC?
We're just starting the whole RF scene having dealt with DC and low frequency AC for all our previous courses.
I understand that at high frequency AC, fundamental circuit laws don't apply anymore and the classic passive component models need to be…
AlfroJang80
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Why use complex numbers to represent amplitude and phase of AC
Why is it that in AC circuits, sine waves are represented as a complex number in polar form? I don't logically understand from a physical perspective why there is an imaginary part at all. Is it purely from a mathematical point of view to make the…
Prevost
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Creepage distance for PCBs handling line voltage AC?
What is the required creepage (e.g. trace-to-trace) distance for PCBs handling 240VAC rms? What about 120VAC?
This is for UL and CE certification.
The standards for PCB Creepage (e.g. the distance across the surface of a PCB between high-voltage…
Connor Wolf
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How can I detect a power outage with a microcontroller?
I have the following power supply configuration:
AC MAINS -> UPS -> 24V POWER SUPPLY -> 5V VOLTAGE REGULATOR -> PCB (microcontroller).
What's the best solution to detect the power outage on the mains with the microcontroller?
I also need to detect…
m.Alin
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What exactly are harmonics and how do they "appear"?
From reading so many sources online, I still cannot grasp why a different waveforms have harmonics.
For example: when designing a silly amplitude modulation (AM) circuit that puts a square wave from a microcontroller in to an antenna, how are…
John Quinn
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AC: Why differentiate between Ground and Neutral?
Current flows through a conductor connecting points at different potentials.
Leaving aside multi-phase details, common/conventional AC systems use a 3-wire setup:
Wire-1: a line/live/hot/phase wire presenting a point that oscillates between 2…
BVN
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How precise is the frequency of the AC electricity network?
If I make a digital clock which first detects the AC frequency roughly (whether it is 50, 60, 100Hz, etc), then uses it as its clock pulse source, how precise would it be? Would it work world wide precisely?
For instance, in USA, what is the mean…
hkBattousai
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Why do power grids tend to operate at low frequencies like 60 Hz and 50 Hz?
I understand that a two-pole AC generator has to rotate at 3600 rpm (60 Hz USA) in order to maintain a 60 Hz frequency and higher frequencies would require these generators to spin even faster which could be problematic.
I also understand that…
ZekeC
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Why can I put an electrolytic capacitor on AC?
I have seen here and there schematics with electrolytic capacitors put on AC. This sounds weird to me.
Electrolytic capacitors have a polarity, right? If we invert the polarities on DC, bad things happen. As far as I understand, AC inverts polarity…
Antoine_935
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NEMA 5-15P blade holes
Why do most NEMA 5-15P (North America 125V 15A) line and neutral blades have holes in them? I've been wondering this for quite some time and haven't yet found a satisfactory answer.
Adam Lawrence
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Why does a capacitor block DC and not AC?
If someone can explain why a capacitor blocks DC, but not AC, with some math, I will understand all of that much better. I know that there are picture animations illustrating this, but I really want to know this a little bit more detailed.
Junior
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How do the tiny AC->USB power supplies work?
The iPhone and Kindle both come with tiny power supplies that take in 120v AC and output around 5V at 0.85 to 1 amp. They seem to be too small and light to have a transformer, and generate very little heat. What is the electrical topology of these…
ObscureRobot
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AC to DC without transformer. How does this thing work?
I disassembled a Chinese-made flashlight and found they use just capacitors to bring down the voltage instead of a transformer. They are using it to charge small lead-acid battery.
My question is how a capacitor alone can be used to bring 220 V down…
Ryu_hayabusa
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