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Questions tagged [electrical]

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1
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3answers
176 views

How to figure out what resistors are in the E12 and E24 series?

Is there a way, other then remembering, to figure out what resistors are in both of these series?
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3answers
91 views

MOSFET for revrerse voltage protection

I have used the following circuit to for the purpose of reverse voltage protection. But, I am a little bit confuse about the working of the zener diode in combination of the 100k resistor in this ...
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3answers
910 views

Why isn't line to line voltage zero?

If voltage is measured relative to something. For instance, voltage-meters measure voltage differences not individual voltage levels, or by analogy altitude is measured relative to somewhere. Mount ...
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1answer
116 views

can someone help with this question with capacitors

Please I need help solving this one, the book is Thomas Floyd 3rd edition Electric circuit fundamentals. The final answer is supposed to be \$ \text{0.0052 } \mu F\$ The ac source frequency \$f=...
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3answers
299 views

Help identify positive, negative and ground on a LCD screen PCB

Let's just say I know nothing about electronics, so please bare with me on improper terminology. I have a LCD screen that I have disassembled as I am trying to make a Touch screen mirror fit into a ...
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2answers
184 views

why does current like circulating?

why does the current in R2 remain always zero regardless the value of other parameters(V1,V2,R1,R3)?)
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1answer
313 views

How can I calculate Ampere Per Hour if Intensity has been given

Today I had an exam on Technology, and there was a question: If a nano robot has a battery of 2.15Ah(Amper per hour) , how much it will last without recharching , if the robot spends 1.8I(Ampere) ...
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5answers
99 views

How to determine which diode conducts in diode-OR application

Say I have two 12V power sources - 12V_A and 12V_B. What happens in the following scenarios: If 12_A = 12_B = 12V. Do both diodes conduct? If 12_A is slightly higher than 12V_B. Does the top diode ...
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3answers
85 views

Replacing Multimeters with Megaohmmeters

Standard Digital multimeters can measure up to the ranges of 20 Megaohms. Then why should we use Meggers at all?
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3answers
140 views

why is transformer not considered as an amplifier?

I know that in a transformer the power is conserved on both sides, and hence there's no power amplification as such. That's fine! But if I instead want only a voltage amplification, then choosing ...
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2answers
140 views

Can I harm my device doing these connections?

I was using a device (1) to intercept and read the SPI communication between a microcontroller and a LCD of another device (2). So, I did the conections as showed in the figure below. They use the ...
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3answers
688 views

Joining high current wires

I am trying to figure out the best way to join some 12 gauge wire that will be carrying very high DC current (about 100A) for about 2 seconds. When working with lower currents, soldering seems to be ...
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2answers
92 views

Does this look like a correct Bandpass filter?

A project task assigned me to make a simple series RLC bandpass filter with values B = 73kHz & freq center = 4.8MHz known. I use equations B=R/L and fc=1/(2pisqrt(LC)) to get the RLC values. ...
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3answers
938 views

Capacitors in parallel with voltage sources

Why can't capacitors be connected in parallel with ideal voltage sources? In various questions involving it we were asked to ignore the capacitors, by our teachers without valid explanations.
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1answer
404 views

Immersion water heater in a metal cup

I am creating a non-profit product for charity and I have a simple electrical question. I plan to place a small single cup immersion water heater inside a stainless steel cup. But I am going to have ...
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1answer
37 views

Graph theory for Networks

To use the formula, [Bf][Zb][Bf'][I] = [Bf][Zb][Is] - [Bf][Vs] for the concerned, or any tree, should [Vs] and [Is], be written with respect to the directed tree I've taken, or with respect to the ...
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3answers
105 views

Testing and safety requirements for selling homemade electricals

I am currently researching and designing electrical audio equipment, example devices: Tube and solid state guitar amplifiers Guitar effects pedals Mixing / filtering units Synthesizers Some of these ...
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2answers
346 views

Permanent magnet synchronous motor (PMSM) equivalent circuit

I am trying to model a PMSM (permanent magnet synchronous motor) in LTspice and in order to do so I need to form an equivalent circuit. Through some research I believe the circuit should be formed in ...
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1answer
288 views

How to design RF PCB to ensure the 50 ohm impedance

I do not have any experience designing RF circuits and I am finding many challenges for my project. One of them is to match the 50 ohm impedance that some components demand. In the input of my PCB I ...
1
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1answer
78 views

what is exactly 'gain and loss' is and how is it used?

I'm kinda confused by its definition. I know that gain is a measurement and gain and loss is the calculation (??). I'm still in 12th grade. Please guide me.
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2answers
168 views

Measuring individual Voltage of the connected solar panel in series using I2C Protocol having GND in common as this get short circuited

I was stuck in a situation when i was measuring solar panels connected in series using I2C communication protocol. The common ground between the system makes the panel disconnected making a short loop....
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2answers
790 views

Designing wig wag relay circuit

I have built the circuit below and am trying to get the lights to go into wig wag using the relay (wig-wag is often used in emergency response vehicles with red and blue lights flashing or orange ...
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2answers
175 views

I need a power source for my DBD (Dielectric Barrier Discharge) [closed]

I need to make a circuit which gives me ac voltage in the range of 5-20 kV and frequency above 1 khz. The ac voltage which my lab gets is 50 hz 240 v. I need to somehow step up the voltage and ...
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1answer
185 views

Electrical Engineering Prelab - Absolute value of gate voltage

A. In the circuit in the figure, the thermistor resistance is 50 kΩ. What is the absolute value of the gate voltage (voltage at node G) versus ground? B. How does your result change if the thermistor ...
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3answers
103 views

Is the electric current delayed

simulate this circuit – Schematic created using CircuitLab -Suppose that the distance between "D1" and "D2" is too large. -Does "D2" give a delayed response compared to "D1"?
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3answers
36 views

Connecting the Block AIM 5.0/2.0 auto-transformer to UK three-wire plug

I am not electrically very knowledgeable person. At the moment I am trying to connect a Block AIM 5.0/2.5 Auto-transformer to a piece of very sensitive medical equipment. The auto-transformer was ...
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2answers
131 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
160 views

Bjt circuits, “Vbe = 0.7 at edge of conduction”

could you explain what "eoc" and" eos" (edge of conduction and edge of saturation) is? The problem says "Vbe = 0.7 at edge of conduction" , is that in cutoff mode?
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1answer
94 views

Can ECG electrodes be used for EEG detection?

Im having financial limitation for purchasing EEG monitoring modules or electrodes. But so is not the case for ECG. I am doubtful whether I can use ECG electrodes for EEG since brainwaves are in the ...
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1answer
2k views

How can 400V & 690V on e-motors result in the same power

Forgive my ignorance, but how can two 3-phase ratings on the same motor result in the same output power? The one I have is rated for 0.7kW in triangle for both 400V and 690V.
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2answers
127 views

Laptop fried from spark while connected via USB to a battery system

EDIT 10/11 9:40am Central: I learned from my partner on this project I got the order of events wrong. I have edited the post accordingly. I am working on some custom electrical hardware for ...
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1answer
59 views

UPS for 1.1kW system [closed]

We have 3 motors each 0.37kW, they are now running on mains power, sometimes mains power cutoffs/fails, in that case we want the motors keep running. The motors are controlled by a PLC which do not ...
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1answer
864 views

Converting a NEMA 6-50p plug to NEMA 10-30p

I received a compressor recently that has a (I think) 6-50p plug on it but my dryer is currently plugged into a 10-30r receptacle and that's the only 240v I have available. I'm renting the house so I ...
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3answers
102 views

Heat and small appliances

I am in the middle of trying to wrap my head around basic electronics. I understand the concepts of voltage, amperage, and resistance, however I'm confused about how heat is generated and related to ...
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1answer
94 views

Why the shape of rotor-poles of salient pole synchronous machines are designed as sinusoidal in shape?

I knew that this is done to eliminate harmonics. But I couldn't get its reason. So I am confused whether my conclusion was right or wrong.
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1answer
38 views

Can I use per unit method for true, reactive, and apparent Power

I would like to show apparent power (S) in Cartesian coordinate system with a circle of radius 1, where x axis represents reactive power (Q), and y axis represents true power (P). There's the formula: ...
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1answer
92 views

Why AC is not used to excite synchronous machines?

In synchronous machines rotor is excited with DC and rotated so that due to change in mf falling on the conductors in stator an emf is generated.if we use Ac as an exciting means to excite rotor and ...
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2answers
232 views

Finding Current through element that offers some resistance and only permits current in one direction

Suppose An alternating voltage e=200sin(314t) is applied to a device that show a resistance of 20 ohm and only permits the current in only one direction and entirely preventing the current the flows ...
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5answers
7k views

LED lights wired in Series will not light

I have a pack of simple LED lights that I planned on wiring in my boat for cabin lights. I installed and wired them all in a simple series circuit. Power supply connected to switch, switch connected ...
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0answers
37 views

Can we use the Halbach array configuration in an electromagnet?

I tried asking this question in several forums but didn't find any answers as i expected. It's very hard to find information about halbach array in google, especially in the electromagnetic field. We ...
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0answers
72 views

Can a circuit have capacitors in both series and parallel?

From my understanding, two capacitors (or any electrical elements) are in series if the same current goes through them. Two capacitors are in parallel if they are connected to the same wires on both ...
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1answer
60 views

Please help guide if my understanding is correct

Please help check if my understanding is correct for the above circuits. As per my understanding the Voc=4v, since we have opened the circuit and there is no current flow. If that was not the case we ...
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0answers
31 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
79 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
39 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
31 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
104 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
79 views

Finding value of slip in an 3-phase delta connected induction motor

I know the equation for slip is s= (Ns-Nr/ns)x100 and that to find Ns is Ns= f/p. I have been given ...
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0answers
42 views

Maximum power transfer theorem [duplicate]

Im very stuck on where to go with this question. The examples in class used complex numbers, where as this doesn't seem to need them. Im aware that Zs = Zl, but does Zl=Cl+Rl? Any help with how to ...
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2answers
89 views

Use PNP sensor on NPN input

I want to use the IPOS3602 datasheet iPOS3602 this is a small motion controller. I have another datasheet which is protected so I can't share it. This datasheet states: The inputs are compatible with ...