Questions tagged [electrical]

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2answers
68 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 ...
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1answer
52 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 ...
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1answer
68 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 ...
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1answer
38 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
61 views

Solder joints advice

Do you think these power distribution joints would suffice or should I improve on them?
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1answer
41 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 ...
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0answers
21 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 ...
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1answer
71 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 ...
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0answers
53 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
16 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
24 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.
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1answer
26 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 ...
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1answer
55 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 ...
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1answer
28 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 :...
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2answers
53 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 ...
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1answer
27 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 ...
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2answers
52 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 ...
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2answers
57 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
60 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
115 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
34 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 ...
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3answers
73 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 ...
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0answers
126 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
83 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 ...
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1answer
38 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 ...
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1answer
33 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 (...
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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 ...
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1answer
66 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 ...
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1answer
46 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'...
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3answers
50 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 ...
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0answers
29 views

How can I find the length of 12 gauge wire needed for a cone of if I know it's surface area

So I'm working on a personal project, and I need to figure out how much 12 gauge wire (which is ~2mm thick) I would need to cover a cone shaped rubber core, which has a surface area of roughly 3,417,...
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1answer
41 views

What's the function of those coils there?

What do they do? The aux contacts are normally open and the device is MR PQM 500 reactive power compensation system.
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2answers
487 views

AC Motor On/OFF Control using SSR instead of contactor

I would like to control a 1-phase 3HP motor using a SSR ( the reason being, I need to switch it on/off using a signal (0-5VDC). Are normal SSRs (ex:Fotek 40A model) capable of handling the starting ...
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1answer
29 views

Low voltage power transmission

i want to transmit 9v dc power overhead in 500 meter range. please tell me most suitable method for it. i didn't tried it but i am making this system for operating 9 Volt router of wifi device.
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2answers
39 views

Voltage at node A respective to the ground

I want to calculate the voltage at node $A$ respective to the ground. $R_1=1.8\text{k}\Omega, R_2=3.8\text{k}\Omega, R_3=1.8\text{k}\Omega, R_4=5.8\text{k}\Omega, R_5=2.4\text{k}\Omega$ and $V1=4.3V, ...
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1answer
55 views

Circuit analysis, voltage in and voltage out

I want to solve $V_o$ in terms of $V_i$ from the following circuit. $R_1=95.7 \Omega, R_2=9.1 k\Omega, R_3=1.0 M\Omega$ So the solution is form $V_o=kV_i$ and I want the factor k. I know that:...
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1answer
51 views

How much rain water run off do I need to power an LED greenhouse

My question essentially is how much water to power green house LED lights. Specifics bellow : Say I have a warehouse with a flat roof with a bunch of water tanks or the whole thing being a water tank....
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0answers
14 views

Electric Current Based Shape-Memory Alloy

Would it be possible to create a piece of metal, made out of an alloy or combination of alloys, that undergoes a shape-memory-esque change in structure in reaction to an electric current? Could it ...
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2answers
51 views

DC Motor Question

I am not an engineer, just looking for a bit of advice. I hope that it is ok that I ask this here. I have a DC Motor from a treadmill. It is a DC 2.25hp, 180v, 4700 RPM, 7.5 amp motor. I want to use ...
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1answer
61 views

Electronic symboles in datasheets

I found these symbols in a electronic datasheet.. Are these all logic gates? or another?
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1answer
194 views

What's the point of ESD-safe tweezers?

ESD-safe tweezers have a black coating on the handle. If I am grounded to a work bench, and normal tweezers are already conductive, then what is the point of the conductive black coating? Screw ...
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2answers
256 views

PC Controllable DC Power supply (0-30V)

I have a Proportional solenoid valve that uses a 0-30VDC for control (opening the orifice) I only have capability to provide 0-5V or 0-10V. I need to control the valve using my PC. Is there any DC ...
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2answers
64 views

Electric bicycle and an electric scooter

Assuming that an electric bicycle and an electric scooter use the same motor and battery, which has more autonomy? that is, which makes more kilometers / miles per battery charge cycle? Obviously each ...
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0answers
34 views

Generally speaking are inrunner motors better generators than outrunner motors or vice versa?

Using a motor as a generator but looking to test something I understand that outrunners have a higher torque but would that be neccesarily good for generating electricity or not?
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0answers
111 views

best refractory cement for embedded heating element furnace

first post I designed a 2000 watts 1000 degrees Celsius furnace with following chamber size: 11 cm length, 12 cm width and 15 cm depth. The refractory that I use is 1880 C high temp tabular alumina ...
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1answer
46 views

How effective are pancake motors as generators and why

Using a motor as a generator but looking to test something Why would or would they not be good generators thanks
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1answer
46 views

LPF Second Order use cascade

What is the minimum value of $R_2$ (in $R_1$) to minimize loading effect? Please explain the concept.
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2answers
42 views

Integrator OpAmp

Tell me how can the 's' in first equation described with the 'integration' in second equation?