Questions tagged [electrical]

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1answer
22 views

What plant species generate the highest amount of bioelectricity? [closed]

I just want to ask which plant species produces a high amount of electricity. I'm very confused with the units that's why I don't know which species produce the highest amount of electricity. Also, ...
2
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3answers
75 views

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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3answers
85 views

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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1answer
38 views

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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0answers
15 views

Is there a way to output a variable from matlab simulink function block and use it to specify other parameters?

This function block outputs 'phase' which I then want to use as a variable like this: But as you can see simulink throws an error. I tried using Simout but it doesn't work. I am sure I am missing ...
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2answers
54 views

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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0answers
48 views

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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2answers
37 views

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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3answers
58 views

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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3answers
40 views

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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0answers
13 views

Stepdown transformer core magnetizing

I am looking to get better understanding of transformers as I would like to connect a Variac to the primary of a step down transformer to create a linear variable dual rail test power supply for audio ...
1
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0answers
32 views

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 ...
1
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2answers
101 views

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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4answers
4k views

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 ...
2
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4answers
97 views

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 ...
1
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1answer
54 views

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 ...
1
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1answer
48 views

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 ...
3
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1answer
50 views

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 ...
1
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2answers
73 views

How to drive variable power (up to 1500w) to a grill heating element [closed]

I have a heating element like the following: which is rated to 1500W. I need to be able to drive up to 1500W of power to it, but potentially less. I will be plugging it into a 120V wall outlet. I am ...
1
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1answer
61 views

Do DC generators require more maintenance than AC generators?

Whilst researching, I found several sites that suggested DC generators required much more maintenance than AC generators. From what I can tell these sites seem to have assumed that the AC generator ...
3
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1answer
158 views

Does electricity go through non-metal materials or not?

Ever since I was a little boy, I've always had this idea that electricity can only go through metal materials. For example, if I put a 100% metal screwdriver into the socket in the wall, I'm going to ...
0
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1answer
52 views

Peltier Module Set up isn't cooling

I have set up a peltier module with an aluminium heat sink, cooling fan, 12v, 7ah battery supply and thermal paste for the purpose of cooling water. At first, it performed well. It dropped down to 3.5°...
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2answers
78 views

Solder joints advice

Do you think these power distribution joints would suffice or should I improve on them?
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1answer
44 views

Back EMF from a motor

I have a large DC Motor I ripped out of a treadmill and I'm curious if the back emf generated from manually rotating the motor is a DC output or an AC output. Is it AC only when it's from the power ...
2
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0answers
24 views

Transferring the project from "Altium Design" to "SolidWorks" while maintaining silk-screen printing, sizes and everything else

I want to transfer the PCB project to solidwork from altium design, I read forums on how to do it better, and so: Save to STEP. The option is good and working, but I did not like the option, since ...
2
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1answer
173 views

Raspberry pi, Stepper Motor and level shifter

It is my understanding that a Rasperry Pi cant handle 5V on the GND-pin. For that reason I got myself a level-shifter which is supposed to be able to change the output from 3.3V to 5V. I need it to be ...
1
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0answers
79 views

VFD or soft start to minimize power consumption on starting a motor?

I want to use the smallest generator possible to run a standard three-phase AC well pump. According to this website and others, it is advisable to use a generator capable of 3x the running kVA if the ...
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0answers
20 views

Convert values of utilization category from AC7a / AC7b to AC5a / AC5b - Is it possible to estimate?

I have a contactor which is rated at 440V and 25 A for utilization category AC7a and 8.5 A for AC7b. Is it possible to give an estimate about the maximum current and power usage for appliances of ...
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0answers
25 views

RLC circuit problem

After the switch is open for a long time, it is closed at t = 0. How can I find iL(t) and Vc(t) for t>=0? I tried step response for RLC circuit but I could not apply.
-1
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1answer
33 views

How can I create an RL circuit?

I want to create a RL circuit that has a dc voltage source, lamp, switch, R and L elements are connected in series. How can I design the circuit so that the lamp flashes from the moment the switch is ...
0
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1answer
65 views

Motor sizing for modelling

Im working on a headrest for a car that will electrically adjust up and down and have drawn up my plans. it now comes to the important questions, such as what motor to use. Ive been looking at motor ...
2
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1answer
31 views

Transformer Phase Fault

I have a transformer for troubleshooting. It is a 3 phase DELTA-WYE Step down (11KV/400V) transformer, the low side voltages (secondary) are Line to line voltages: RED-YELLOW : 400 V YELLOW - BLUE :...
2
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2answers
58 views

How do electric vehicles' motors run at high speeds above 10000rpm?

For example, for a squirrel cage induction motor, the speed of operation is given by Ns = 120*f/P depending on the number of pole pairs and supply frequency. Now the supply frequency is 50/60Hz while ...
-1
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1answer
30 views

Removal of bonded kettle element from kettle base using chemical methods

I have asked the below question via electronic SE site, which is off topic, so tried to ask here, the question text is: --------------- I have one tea maker ...
1
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2answers
69 views

Is it possible to build a DIY RLC circuit for a classroom demonstration?

I was describing the mathematics of RLC circuits to my students, and was wondering if it's possible to build an actual RLC circuit with coils of wire and an inductor and a variable capacitor. The ...
2
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2answers
59 views

How is electrical building code defined and applied to new constructions?

A new home (completed in early 2020) in San Jose California does not have GFCI outlets in all the bathrooms. I thought this was a requirement (according to https://www.redwoodcity.org/home/...
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2answers
66 views

Where does the energy stored in a capacitor come from?

My textbook reads, “the power supply does work on the electrons, so their potential energy increases. You recover this energy when you discharge the capacitor.” I don’t get why this is the case... ...
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0answers
13 views

DIY device to repeatedly depress and release gas pedal on a vehicle

The pedal needs to be depressed about 1/2 to 1 inch, once every three minutes. I believe the best way to do this will be with a rotating arm of length 2 to 2 1/2 inches that has rollers on each end, ...
2
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1answer
162 views

Can I connect a power supply main (SPH) and inverter main (SPH) with common neutral to a TP MCB?

I have limited knowledge of MCBs and just doing research to secure my kitchen. I want to connect my power supply main and inverter main with common neutral to a TP MCB. This MCB will be placed in the ...
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0answers
39 views

What is the fastest possible slot car

What is the fastest possible slot car one can build? What are the limiting factors? Obviously, we have to require that the motor is aboard the car and that it's propelled by the wheels (we don't want ...
2
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3answers
129 views

Why does audio equipment buzz/humm when a long signal cable is used and how do I eliminate it?

I have two 5.1 speaker sets, one in the front and one in the back of my living room. I have connected them together with an "audio wire" (non-shielded unfortunately) that's 12 meters in length. Since ...
0
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1answer
168 views

Pspice ac sweep problem

I want to run an AC sweep from 1 Hz - 10 MHz and calculate the output of the circuit (the voltage on RL), however spice shows that my voltage is 0 in a lot of parts that it shouldn't. I believe the ...
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2answers
91 views

Is there well known equation (formula) to calculate maximum practical current which copper wire of fixed diameter can handle

I found many online calculators or tables which can give maximum current for the wire. Like 1 mm diameter can handle up to 10 Amperes, 2 mm diameter wire can handle up to 30 Amperes, etc. Is there ...
1
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1answer
60 views

What is the best practice for ensuring the best possible connection between a battery cable and a battery terminal

I've seen a number of opinions on conductive gels to ensure the best conductivity between battery terminals and battery cables. I'm interested in knowing an expert's opinion on the matter. I'm ...
1
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1answer
35 views

Design of a hydrogen and corrosion sensor query

I’m designing a hydrogen and corrosion sensor. A thin film changes resistance based on hydrogen concentration. Then the capacitance between two electrodes will change depending on substrate thickness (...
9
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5answers
2k views

How do electric companies supply electricity to homes in countries where energy is privatized?

Before I start, sorry if this doesn't make sense English is not my first language. In my country electricity is nationalized so there is only one energy company and one grid. When you build new ...
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0answers
18 views

solving short electricity interruptions with an UPS

Context A plastics factory with installed power of about 500 kVA. Most of the consumption is represented by motors and resistances. Problem There are several (8+ a day) power interruptions, lasting ...
1
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1answer
181 views

Static electricity in PE foam rolling

In a PE (polyethylene) foam factory there have been some incidents with static electricity that have created minor fires. Fire is a concern in such a factory, as PE is highly flammable, and even more ...
1
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1answer
161 views

Do kids under a certain age not hear the warning beeps that smoke detectors make when they are running out of battery power?

I've always been very annoyed by those regular single beeps that smoke detectors start doing increasingly often as the batteries start to run out, to warn the user to replace the batteries. Lately, I'...
1
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3answers
56 views

what to learn to design mechatronics device that move [closed]

I want to design an artificial leg for disabled people. The idea is design of a Device for patients with problems on one side of the leg from the knee down. This device first detects intent to move ...