Questions tagged [electrical]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
0 answers
34 views

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 (...
user avatar
0 votes
0 answers
21 views

Differences between satellite dishes and Hertzian antennas

I have a text of notes for the electronics and telecommunication course, there is a section that talks about both the parabolic reflector antennas and the Hertzian antennas, in a test a question asked ...
user avatar
0 votes
0 answers
30 views

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 ...
user avatar
0 votes
0 answers
36 views

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 ...
user avatar
  • 1
0 votes
1 answer
22 views

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 ...
user avatar
1 vote
1 answer
36 views

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 ...
user avatar
  • 271
1 vote
1 answer
33 views

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 ...
user avatar
0 votes
0 answers
13 views

What conditions to properly measure surface resistivity using surface resistance meter?

I have some JEDEC trays that I need to measure it's surface resistivity. I have a surface resistivity meter to measure it, but I do not know what environmental conditions it is supposed to be measured ...
user avatar
0 votes
1 answer
126 views

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 ...
user avatar
  • 249
0 votes
0 answers
25 views

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 ...
user avatar
0 votes
0 answers
66 views

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 ...
user avatar
0 votes
1 answer
41 views

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 ...
user avatar
  • 271
2 votes
3 answers
82 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 ...
user avatar
  • 121
0 votes
3 answers
108 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 ...
user avatar
  • 82
0 votes
1 answer
45 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?
user avatar
0 votes
0 answers
33 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 ...
user avatar
1 vote
2 answers
61 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 ...
user avatar
0 votes
0 answers
50 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 ...
user avatar
  • 1
1 vote
2 answers
42 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 ...
user avatar
0 votes
3 answers
60 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 ...
user avatar
  • 123
0 votes
3 answers
47 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 ...
user avatar
  • 113
0 votes
0 answers
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 ...
user avatar
1 vote
0 answers
33 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 ...
user avatar
  • 11
1 vote
2 answers
103 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 ...
user avatar
10 votes
4 answers
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 ...
user avatar
2 votes
4 answers
98 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 ...
user avatar
  • 21
1 vote
1 answer
73 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 ...
user avatar
  • 31
1 vote
1 answer
52 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 ...
user avatar
3 votes
1 answer
75 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 ...
user avatar
  • 33
1 vote
2 answers
74 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 ...
user avatar
  • 121
1 vote
1 answer
66 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 ...
user avatar
  • 11
3 votes
1 answer
167 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 ...
user avatar
0 votes
1 answer
63 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°...
user avatar
  • 1
0 votes
2 answers
114 views

Solder joints advice

Do you think these power distribution joints would suffice or should I improve on them?
user avatar
0 votes
1 answer
48 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 ...
user avatar
  • 25
2 votes
0 answers
38 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 ...
user avatar
2 votes
1 answer
264 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 ...
user avatar
  • 43
1 vote
0 answers
104 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 ...
user avatar
0 votes
0 answers
28 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 ...
user avatar
  • 101
0 votes
0 answers
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.
user avatar
  • 1
-1 votes
1 answer
39 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 ...
user avatar
  • 1
0 votes
1 answer
88 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 ...
user avatar
2 votes
1 answer
32 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 :...
user avatar
2 votes
2 answers
71 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 ...
user avatar
-1 votes
1 answer
35 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 ...
user avatar
1 vote
2 answers
103 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 ...
user avatar
2 votes
2 answers
60 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/...
user avatar
  • 247
0 votes
2 answers
68 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... ...
user avatar
1 vote
0 answers
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, ...
user avatar
2 votes
1 answer
202 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 ...
user avatar