Questions tagged [electrical]
The electrical tag has no usage guidance.
137
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Calculate the current on RN2
What the answer to this question it is based on Edison 3 wire distribution circuits from electrical engineering and I have some difficulty in solving this question If anyone can help then please can ...
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34
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Calculating cooling required in electrical panel box
I have a single electrical distribution panel in an insulated metal panel building (a standalone shed) which has no active cooling or air vents. I need to determine whether the latter are required in ...
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Panasonic VCR ND-SV350
I need help on the Panasonic NV-Sd 350 There is a circuit board next to the servo motor, and there are two Black wires with a Small Brown connector that goes on the Ereaser head.
Now need to confirm ...
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3
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What does 12CC refer to when talking about voltage?
Is it 12V with a connector?
For example in the data sheet here: https://www.hydraulicmegastore.com/product/vcf12nc12cc/
Is this related in any way? (A DMP-12CC connector cable)
https://www.monacor.com/...
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Connecting Busbars Safely
I would like to design a 500-700V battery system such that I can laser weld a subset/module (i.e. a building block of ~12 cells each) with an open terminal on each end. This way, I can jump the ...
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Can wireless charging become more energy efficient?
I've stumbled upon a few articles saying that wireless charging takes more energy to charge something compared to the cable. Like this one.
Like in the test from the article, it takes 47.33 % more ...
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1
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49
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Why does 4-wire resistance measurement change after a period of time?
I have a plug that I am measuring the resistance using the kelvin probe.
The plug is as below. The measurement is taken from the contact point of the plug the other end that has a PCB inside that ...
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Unexpected UART communication behavior on Basys 2 FPGA using USB-to-UART converter
I am facing an issue with UART communication on a Basys 2 FPGA board (design in Verilog). My board doesn't have a built-in UART, so I'm utilizing a USB-to-UART converter for the purpose.
In my ...
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Does triboelectric generator made with powder and wire mesh work?
One of the greatest challenges for triboelectric generators is surface charge, which ultimately depends on surface area. Why don't we make one triboelectric layer a powdered form and a crazy forest of ...
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Does static electricity dissipate if object is sealed in insulator sphere?
I rub a piece of glass against some silk. Normally, left in open air, it would lose its acquired charge. What will happen if after rubbing, I immediately seal it inside a sphere made of insulator ...
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Is there a way I can turn off the ACS ACR122U NFC Reader while still connected to a USB port?
I have a use case where I need to turn off the ACS ACR122U completely and put it back on while still connected to the USB port. I cannot disconnect the reader from the PC. Disabling the port still ...
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Residential 120V AC vs 12V DC
Can I repurpose residential LED lights (slim, 120V recessed) for my RV by directly providing them with 12V DC power, or is a more accurate approach required to bypass the existing circuit board?
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9
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Force applied on a ferromagnetic shaft by a coil
I have a perfectly cylindrical ferromagnetic shaft (say, made out of iron). I want to apply an axial force on the shaft (along the centerline of the cylinder) using a coil through which an electric ...
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56
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In UK, are new smart energy meters secure?
I have read this newspaper article about insecurities in smart meters.
Some quotes from the piece:
To communicate with the utility company, most smart meters use GSM, the 2G mobile standard. That has ...
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Confusing terminology for "normally closed/open" - It means the opposite in electronics (relays) versus fluids (valves)
I'm an electrician and "normally open" / "normally closed" is well known to me. I recently started to also work on heating systems including the pneumatic system that controls some ...
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Standards for the sign of the power factor; IEC and IEEE; is there an ANSI standard?
Working with some power factor measurement, this article (reference: https://www.se.com/ww/en/faqs/FA212521/) has this interesting bit:
Issue: Understanding and interpreting the sign of a power factor ...
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Is it really sane to drop buckets of water into a (CRT) TV on fire after unplugging it?
Today, I read this absurd (to me) claim on what to do if your TV catches fire:
Collect water and fill the unplugged TV. You can fill in only from the side. This is a necessary security measure. The ...
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Why do inorganic LEDs wear out?
Why do inorganic LED bulbs have a limited lifespan? For example, a manufacturer may quote that a bulb or monitor powered by an organic light emitting diode(s) has a lifespan of 50,000 hours, while it ...
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mg996r - maximum weight for robot arm [closed]
I want to build a robot arm (see https://youtu.be/F0ZvF-FbCr0) to move a dumbbell of 2 kg (roughly 2.2 lbs).
However, since I have no background in engineering, I have no idea how to calculate / find ...
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3
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141
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Modifying bike wiring harness to add hazard lights
I'm trying to modify my bike's harness.
Only trafficator functionality is supported by means of SPDT switch. I tried to add blinker functionality:
Kindly excuse the symbols for both Relay and Switch.
...
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61
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Force required for a power generator in a coal power station
I am unsure about how to word this question properly and I assume that it might take two directions probably because of the unknown variables involved but here goes...
On the actual physical power ...
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Why does an electric motor, of 800 kW at 400 V, have 7 connectors for power cables?
I found a Vybo electric motor and noticed that it has seven connectors for power cables.
I also found a Variable Speed Drive, Altivar Process ATV900, System ATV960, 800/630 kW, 400 V and its datasheet ...
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What should be the clearance and creepage for the line to line 440 Vac and line to neutral 240 Vac of the three-phase system on PCB?
Also is there any link to calculate this as per the UL and other industrial standards
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Why did the metal railings to the stairs in the big ferries used to shock me?
When I was a kid, and even in adult age, I sometimes went on these large (well, to me, at least) cruise ships which had multiple (like ten) levels to roam around in.
You either got there with the ...
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57
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Why do identical-looking power plugs randomly not fit in some sockets in the same power strip?
This has bothered me for many years, but I'm only now coming around to ask about it.
I don't know if this is unique to Sweden or something, but for whatever reason, when I try to plug things into the ...
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40
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Electric Standing Desk
So, I'm trying to build an electric standing desk for myself. I drew what I have in mind as a guideline for my questions here.
Basically I want a desk that varies in height from 65 to 130. I imagined (...
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39
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How to control speed of DC Gearmotor with Varying Torque
I have a system where the torque is constantly changing, but I need the speed to remain at 9RPM. I have enough room for error where I can be between 8 and 10RPM. How can I achieve this? All I can find ...
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92
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Can a grid connected PV system deliver power backwards through the distribution transformer?
If there is no local load demand can a residential roof top grid connected PV system deliver power across distribution transformer [up to the higher voltage grid]?
Suppose my grid connected solar pv ...
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how would I identify when and who enter through a doorway, assuming they can have part of the technology on their person
I am working on setting up a system that senses when an object goes though a door. I've seen things using lasers or induction. I have a set of objects smaller than 1 square inch. I just want to know ...
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Flood light pole components
I saw this flood light pole. It has two LED bulbs, but I do not know what the box in the middle is (it was not an LED), could you guys help me understand what this could be? This flood light is ...
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2
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Connection to periodically electrify equipment
I am designing a system where I have a set of 4 electrical components rotating in a circle. In the bottom stage, the electrical component is submerged in water. In the top stage, the electrical ...
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1
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183
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Can a battery-powered electric vehicle be driven through a dust storm?
I would like to know if a battery-powered electric vehicle such as a Tesla Model 3 automobile can be driven through a dust storm.
Back during the Dust Bowl days of the 1930s, driving through a dust ...
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Generation of Electrostatic induction
I need to generate a 500 volt electrostatic charge. How can I do this? I don't have a Van de Graaff generator. What are some practical suggestions?
Basically I want to do experiment in which I need to ...
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Are all boost converters isolated?
I have a few boost converters(3-6V to 40,000V) and I want to connect them serially. link
In order for them to be connected, they have to be isolated. Is there any way to check that? If they aren't ...
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50
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Power systems unclear voltages
I was looking at this problem:
"A balanced delta connected impedance load with (12+j9)Ω per phase is supplied by a balanced three-phase 60 Hz, 208-V source "
I do not wish to ask for help at ...
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Eliminate cat ear and nose shocks during the dry season
My cat, George Valentine, really enjoys being pet. However, when the air here in Canada gets very dry (mid-fall), this activity creates static charges. Once the petting starts giving him relentless ...
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Magnetising a needle with static electricity using silk cloth
A nautical navigation textbook on my table says that we can magnetise a non-magnetised needle by rubbing it with a silk cloth. I decided to cross check on the internet, and found some experts calling ...
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How to find the torque required to rotate wooden slab
How can I find the Torque needed to rotate a wooden slab with no weight applied on either end of the slab if I have a servo motor placed at the middle of the slab?
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2
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Do piezoelectric materials produce a current flow or just an electric field?
I was watching a video https://www.youtube.com/watch?v=uvT3XvDSSQw about piezoelectric materials.
They mentioned that "a current can flow when a pressure is applied to the material".
I have ...
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A regenerative braking system, what am I doing wrong?
I am currently working on a system of regen braking using two DC motors one of them is driven by the motor controller and the other one is using the main motor to spin in cases of full load and in ...
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2
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Precisely control voltage output
I think the component name is a rheostat- is that what allows you to control the voltage output please? I want to control it in steps close enough to 0.1 ish volts? So I would like to attach a knob ...
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Why materials with preferably a negative temperature coefficient for heating elements?
As far as I understood heating elements make use out of Joule heating. Hence, I wonder why one would preferably use materials with a negative temperature coefficient, therefore?
Isn't it, that, the ...
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AC/DC Laptop adapter power losses
I have a laptop power adapter shown in the picture below.
It is written there
170Watt
INPUT: 100-240V ~ 2.5A
OUTPUT: 20V 8.5A
I believe for AC Input they mean Root mean square voltage/current.
for ...
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Homogeneous magnetic field inside aperture of PCB
I need to create a homogeneous magnetic field of a certain strength across a 10mm diameter opening of a PCB by using a current track on said PCB around the opening. The signal sent through the ...
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How to manage real-world too-long data cables?
Answers to a recent question about a homemade USB cable mention that USB and other data (Thunderbolt, VGA, and HDMI) cables should not be coiled. So what is the proper method to manage long cables ...
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Extending USB cable makes it not work
I have a camera that uses a USB cable to connect to my computer. I want to extend the cable from 3ft to about 6ft. Originally I just created my own cable, soldering 4 26AWG wires to a blank USB ...
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Inverting motor polarities automatically to close and open a door
Hi,
I need to build a device that opens a chicken coop door.
The idea is quite simple, a motor connected to an axle that pulls a string up just like a wench. It would be activated by a relay timer ...
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108
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Equivalent Resistance Between Two Points in a Wye Network
I am interested in learning how to calculate the equivalent resistance between two points in a wye circuit for application to thermal networks (i.e. I'd like to calculate the equivalent thermal ...
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What is the difference between the power lines, USB lines, Signal, and PWM lines in a slip ring?
I'm currently sourcing a slip ring for a robotics gimbal I'm working on, and I'm not too sure how to properly source one.
Currently, I need a slip ring capable of transmitting USB 3.0 data alongside ...
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1
answer
298
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Electrostatic grounding of an electrically isolated concrete floor
I have a question regarding a not-so-common construction setup for a house.
In this situation, the concrete slab is "floating"/insulated with a rigid insulation underneath.
I understand the ...
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