Questions tagged [electrical]

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2
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0answers
27 views

Switchgear dielectric testing and impulse polarity

What is difference between negative and positive polarity impulse test? Why Negative only done for internal dielectric strength and positive polarity impulse only for external dielectric strength? ...
2
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1answer
159 views

Why does a turbine with PMSG and full converter system draws reactive power when turbine is stopped or there is no wind?

Our turbine has a permanent magnet synchronous generator and full converter system (rectifier diods for rectification and IGBTs for chopping dc link voltage and as inverters) which means its generator ...
2
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1answer
213 views

VA rating of Wall receptacle

What does VA rating of a wall receptacle means ? Just started using Revit for Electrical Design (120V/208V) and came across wall receptacle rated as 180 VA. Just trying to wrap my head around that ...
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0answers
28 views

LCD Dimmer with Variable Resistance Circuit

essentially I'm trying to make a very basic circuit where a 3.7 volt battery is wired to a liquid crystal display, (or LCD), and the brightness of said display is controlled by a pentiometer to ...
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1answer
57 views

Does these terms consider the same Voltage, electric potential, and potential difference

What are the differences between these terms ? do they are considered the same
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1answer
29 views

Gain of a Dual Gate MOSFET

simulate this circuit – Schematic created using CircuitLab This is the schematic of the circuit but tried to find the gain of this circuit, assuming 50 % of the Duty Cycle for the LO, and M2 ...
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1answer
30 views

The best way to test a solar panel generation

Is there any way to test how much a solar panel on a given position can generate for let say a day or few days. Like a multimeter that can automatically test the wattage days example? Or create a ...
1
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1answer
77 views

Torque in a 3-phase delta connected induction motor

I know the equation for torque is T=[m*(N2/N1)^2/2*pi*Ns]*[s*E1^2*R2/R2^2+(s*X2)^2] N2/N1 is the effecting rotor-stator turns ratio. I have it written ...
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1answer
81 views

How do I connect an LED with floating DC voltage?

I want to connected an LED at the output of 500V DC. This DC power supply is made by 3phase DC rectifier and is floating. I would like to have a display on the front panel of the supply which will ...
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1answer
60 views

What is the relationship between Ground Potential Rise (GPR) and Source Voltage?

I am looking at the results for an earth grid study for a 50Hz substation. Primary Voltage (Vp) = 11,000V Secondary Voltage (Vs) = 415V Secondary Fault Current (If)= 24kA Secondary Grid Current (...
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1answer
28 views

How to know if a motorcycle battery and power generator is enough to keep an device turned on without discharging the battery?

I have an arduino project in mind but I have some questions before I can start to make it. I need to plug an arduino Uno on my motorcycle, but I dont know if it will consume too much energy and lower ...
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0answers
98 views

What is the definition of hull voltage?

I'm studying the subject Electrical Safety in Engineering and a special term really drew my attention. When I tried to google it, no any option was suggested but hull protection. In the presentation ...
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0answers
97 views

Transparent Conductive Paint

Does anyone know of a transparent conductive paint? I am creating some home made electroluminescent panels and I need something what would work with water based polyurethane. Ive had some luck with ...
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0answers
97 views

Aluminium foil not blocking IR signal

I am using an IR sensor (vishay tsop32 series) but I want to ensure that it only sender directly ahead so I made blinders out of pla and covered them in aluminium foil. However it seems that despite ...
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1answer
55 views

Creating a small range, small baseline varying resistor

I am doing a design project on making a passive varying resistor device. I have a flex sensor that increases in resistance when you bend it. It has a 10k ohm nominal resistance and increase to 110k ...
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1answer
418 views

Calculating resistance for metal layer from LEF File

I have a .LEF File which has various metals description and their parasitics information. I am trying to calculate R. It is specified as RPERSQ = 0.278. In the File description it is written as ...
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1answer
111 views

Basic electric/wiring questions resources

I have a 12V DC motor that I want to power alongside a 40 Watt incandescent bulb (I might find an LED bulb that works aesthetically).  I need to run a single cord to power both.  Preferably with a ...
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1answer
452 views

Interface Submersible water pump with microcontroller using Contactor Relay

I am making a automatic water level controller for my home,I am new to Electrical Engineering and learning things. I am using a MCU to turn ON/OFF submersible water pumps using some float switch to ...
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3k views

Ultrasonic Sensor HC-SR04 without Arduino

I am trying to build a circuitry of obstacle detection. So, till now my research says, I need : ...
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2answers
92 views

PCB trace width

I am trying to design a PCB circuit in altium designer. My circuit consists of one ATmega8a, one NRF24l01 and three magnetic relays (mini relay 12V MPR-S-112-A.) I want to set the trace width to 0....
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27 views

How to develop Differential Conductance dI/dV measurement setup?

I have a Lock-in as sinusoidal Voltage source, DC Current source and Multimeter. Can you please help me to develop a functional setup for dI/dV measurements. How can I design the circuit? What ...
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38 views

Ballast Power Draw

I am trying to calculate the current draw for 6 florescent bulbs and ballasts. There is one ballast per 36W bulb. I know that the current draw for each bulb would be 36/240 =0.15A (0.6A total) How ...
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1answer
57 views

AC noise to electronic circuitry

I find some random issues that is still unknown. I'm using mean well SMPS 12v, 3A for supply and charging 2 cell battery 7.4v with a charging current 1.2A. The supplies are parallel which is switched ...
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1answer
54 views

Find rotor stator loss in a 3 phase delta connected induction motor?

I'm trying to work out stator input power of a 3 phase delta connected induction motor. I have the equation Stator Input Power (P1), where P1= Pm + rotor copper loss + rotor stator loss. I have Pm ...
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18 views

How does electrical noise affects signal and distribution power?

What is electrical noise and mechanical noise How does it interfere with power? - signal power - Power distribution/ transmission
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58 views

Help with determining the open circuit voltage

Can someone go through why Vxy= -84mV? Given the values off VB=180mv R1=22ohms R2=68ohms R3=150 ohms. Many thanks
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70 views

Relation between torque angle and power factor

What is the relationship between torque angle and power factor for a induction motor? Here is my understanding. Lets say a stator coil produces a magnetic field and the field induces voltage in a ...
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2answers
53 views

How VFD affects an isolated IOT system

To avoid noise from the external system I tried to isolate the internal completely. So I added DC-DC isolated converter with signal isolation. I have attached the picture. Still when reading data and ...
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2answers
136 views

Best way to power 120 VAC fog machine with DC?

OLD: I have a 120 VAC 400 W fog machine. I want to mount this on a robot that can supply 12 volts. Can I just reuse a $10 car inverter from Amazon or is there a better way to do this? UPDATE: So I ...
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0answers
42 views

Robotic tool changer functionality

Have you any idea how is a changeable end-of-arm tool powered when is interfaced with an ATI tool changer or something similar ? My first thought is that on both sides of parts is a F/M connectors ...
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12 views

TC-ER cable type for U/G installation

Can I use TC-ER type cable for Underground installation. Underground installation is in PVC conduits (schedule 40). PVC conduits are protected using lean concrete (sort of duct bank)
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1answer
58 views

Capacitor question - energy from pushing a baby stroller

I’m making a circuit that will be added to a stroller. With a 24 volt DC motor, I’m trying to power the capacitor by walking around & simulating a baby/mother experience and if I run into a hill ...
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0answers
63 views

Make Input and Output circuit really I/O

I currently have a self designed I/O board. I'm using the LPC1768FBD100 Microcontroller NXP 3V3 and created 20 inputs and 14 outputs. My design allows only inputs to be inputs and outputs to be ...
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1answer
50 views

Sensor with integrated ID

I'm looking for another solution to a problem. I have 4 of the same infrared sensors which detect if an object is close or not (pretty simple). The difficult part now is that they don't have an ...
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0answers
43 views

Find force pull solenoid

Sorry for the previous post that was wrong. I want to knowF=(NI)^2*μ0*A/2L^2 A What is the cross-sectional area? NewRef.https://www.researchgate.net/publication/...
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1answer
16 views

Two port network z parameter determination

I would like to know how it is solved in book as I found that it is way quicker than the way I solved. Any detailed explanation will be appreciated.
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1answer
37 views

The differential protection relay

The differential protection relay may lose its stability through fault due to the saturation of a CT magnetic circuit during a short circuit condition. To overcome this, which type of relay should be ...
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0answers
19 views

why the stator magnetomotive force lags behind stator armature current in salient pole alternator

https://circuitglobe.com/two-reaction-theory-salient-pole-synchronous-machine.html?fbclid=IwAR1ODRDONC27LIL83Lvb3WohPaSrIG4BRZ8l-ATyeloZEqrZ6juKw__jNMQ] Hello guys in two reaction theory of salient ...
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72 views

Arc Flash carbonized particles initiation

Ok. I'm investigating an arc flash accident. In the above image. The breakers encountered a first short which deposited carbon into the plastic enclosure and lugs. During a second event. The ...
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1answer
67 views

Assemble Peltier Cooler to Li-poly Rc Battery

I have procured a thermoelectric cooler (TEC, this one) and my purpose of the TEC is to produce current for the Li-poly RC battery to increase its battery life. The Li-poly RC battery has 7.4V stated ...
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1answer
78 views

How do I convert 1/3 to signed float 8 bit?

The formula is as follows: (-1)^[signed bit] * (1.[significant bit]) * (2^[excess bit -3]) or (-1)^[s] * (1.[f]) * (2^[x-3]) It is a question posed by my signals and systems instructor, hence the ...
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0answers
62 views

PI or PID vs Manual Controller design using Control theory

Why should we design a controller manually using Bode plots and control theory instead of using PI or PID controllers and tune them? Or more specifically when should I design a controller and when ...
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0answers
26 views

Gauss' Law for Electric fields

Is Gauss' law valid for space varying electric field? Gauss' law: Flux = Charge enclosed/Epsilon For same field E, flux = line integral of E.ds, ds- small area element What happens when E is ...
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2answers
161 views

\$pV/\sqrt {Hz}\$ in Power Spectral Density

I am trying to plot a Noise Spectral Density from 10 kHz to 1 MHz. The Graph shows a cure which at 1 MHz the noise is 76 pV/rootHz. I am unable to understand that unit definition here. Becuase the ...
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1answer
156 views

Synchronous Motor Power and Frequency Relationships

I'm having a difficult time trying to understand what effect the frequency of a power supply has on the power of a synchronous motor. For example, if the supply frequency were to increase from 50Hz ...
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1answer
24 views

How to get the Forward voltage of a tachometer?

I am currently in the process of building a circuit board for components that I am going to use on a lathe. I want to use this tachometer. https://www.amazon.com/dp/B00VKAT8A2/ref=...
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2answers
102 views

OpAmp Comparator Circuit Design for High/Low voltage measurement

I am new to this. I want to make a circuit to measure the voltage from (0 ~12 V), which can have 2 op-amps as comparator to give the output positive, when the voltage goes from 8 V to 12 V and give ...
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0answers
52 views

Behavior of a pin that, initially is configured as output, but, inevitably is configured as input when it should not be

Helo, all !! I have a doubt, I'm using a MC9S12DP512 microcontroller to read another microcontroller, that I will name it as A. But I'm having some problems. Here, I will present you a image of a log ...
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1answer
64 views

Ideal Energy/Battery Source for a Battery Powered Lamppost

​Hello everyone, Relatively new to electrical engineering (my background is more in coding), so, thank you ahead of time for all your help! Project: I was tasked with creating an outdoor lamppost ...
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1answer
51 views

Finding Magnetic Flux

I'm hoping someone can verify an answer I have found for the following problem: A helmholtz coil consists of two identical circular wire loops placed coaxially. If each loop has radius a and carries ...