Questions tagged [electrical]

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2
votes
1answer
192 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 ...
0
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1answer
68 views

Can not recognise this piece of equipment. It is attached to the mains

It is normally quite noisy, but has gone silent.
1
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3answers
122 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 ...
0
votes
3answers
276 views

220V/1ph/60Hz equipment to operate on 208V/3ph/60Hz

Can an equipment built for 220V/1ph/60 Hz be connected to a 208V/3 ph/60Hz grid by using only two lines of the 110V each across the load?
0
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1answer
66 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 ...
0
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5answers
663 views

Voltage signal and Current Signal

Please give an intuitive explanation of difference between how a signal or data is carried using voltage and current? I'm wondering even though current and voltage inevitability co-exist, why do we ...
0
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2answers
39 views

Contact on substrate of a MOSFET

Why do we want to have an ohmic contact on a substrate terminal of mosfet? What would happen if we used schottky contact instead?
2
votes
3answers
610 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 ...
-1
votes
1answer
102 views

Can you connect transistors directly to high voltages or is there precautions neccesary?

I understand that the circuit above will simply work, but what if the voltage input from the battery is significantly higher and the necessary voltage for the motor is high as well? Can you still ...
1
vote
3answers
284 views

Dependent voltage/current sources

I'm so sorry for that questions, but we need to understand what's going on behind the concept/theoretical of using device "dependent voltage/current source"! My question: Yes, we are using dependent ...
0
votes
1answer
28 views

Choosing the appropriate power plug for a given fan motor

In a fan motor I have, the written specifications are as follow : "dual power: 110/230v 50/60Hz 22/20w". I would like to power the motor directly, without electronic parts between any 220V wall ...
1
vote
1answer
34 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 ...
2
votes
0answers
53 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? ...
0
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2answers
81 views

shorting method of current source and voltage source

I'm learning electronic circuit and sometimes we need to short just the current sources and sometimes we want to short source voltage. my question is: why if I want to short the current source then we ...
1
vote
1answer
233 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 ...
0
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2answers
723 views

Should startup torque be higher in value than full load torque in an induction motor?

I found out values of my 3 phase delta connected induction motor for full load torque, maximum torque and startup torque. My maximum torque was higher than my full load torque, but the thing I'm ...
1
vote
1answer
178 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 ...
1
vote
1answer
96 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 ...
0
votes
2answers
347 views

How to apply supermesh to this?

Since there is a current in the circuit, supermesh is much preferred. However, how do I do that as the current source is not in between 2 loops? Do I just open circuit at the current source and I will ...
0
votes
1answer
113 views

Soldering back the disconnected wires from the charger board [closed]

The attached link images are the front and back photo of the board inside my charger. This charger is used to charger my son's toy car. Unfortunately, the wire soldered on this chip got disconnected. ...
4
votes
5answers
418 views

If ground and neutral are bonded at main panel, why aren't all grounded device chassis energized?

I know this is a question with variants that have been asked countless times on the internet and on this site. Believe me that I have scoured through these questions and answers in search for a ...
2
votes
3answers
591 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?
8
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2answers
2k views

Phasing Order in IEC Color Codes

Currently, IEC 60445 international standard is used for conductor terminal color identifications. I've obtained different versions of the standard (2017 being the latest) and also IEC 60446, which was ...
0
votes
1answer
82 views

Impedance load matching

So I've done this so far, and know one of the components is a 50ohm resistor. However I dont know where to go from here. How do i decide if its an inductor or a capacitor? This is a past paper exam ...
1
vote
0answers
51 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 ...
0
votes
1answer
82 views

Styrofoam cooler/chest ok for electronics project?

I'm building a DIY power supply using 6 server power supplies. I've been looking for a case/enclosure to hold them and the necessary wiring and came across a styrofoam cooler that's the perfect size ...
2
votes
2answers
1k views

How current is steady after pinch off voltage?

I was studying the JFET. In the books and other material it is mentioned that when the voltage between the drain and source is increased then drain current is also increased. After a certain point (...
0
votes
1answer
159 views

Maximum safe working voltage of capacitors

The answer is 30kV. My method led to an answer of 41KV, where did I go wrong? I believe I cant just add the Vmax(s) at the end, but what would I do instead and why?
0
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0answers
59 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
1
vote
1answer
117 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=...
0
votes
2answers
58 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 ...
0
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0answers
43 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 ...
10
votes
2answers
2k views

What property of a BJT transistor makes it an amplifier?

I know how we can amplify a given signal using BJT transistors by biasing them. But I would like to know what is that crux property which enables BJT transistor to act like an amplifier. Is it the ...
-3
votes
1answer
57 views

what is the difference between active and reactive power?

What is active and reactive power ? does the active power means power flows from source to load and reactive power as its vice-versa?
0
votes
3answers
480 views

Using Thevenin's theorem, how do you find the Thevenin voltage?

The above image shows a circuit. It is required that we simplify the circuit using Thevenin's theorem to find the Thevenin voltage, current and resistance. I've done a countless number of problems ...
0
votes
1answer
63 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 ...
1
vote
2answers
242 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 ...
0
votes
0answers
69 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 ...
0
votes
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 ...
4
votes
1answer
713 views

Would the motor reverse if phases swapped for this case?

A servomotor power connection pins are given as follows: U V W are the three phase terminals. Would the motor reverse if I mistakenly swap phases U and V namely if I connect pin 1 to W and pin 3 to U?...
0
votes
1answer
96 views

How to know how much current is generated?

My input voltage is 4.5V. Based on this datasheet here, where do I reference in the datasheet to obtain the respective desired output current? Some background info: This is the schematic diagram of ...
5
votes
2answers
892 views

Bulding a physical calculator from scratch [duplicate]

As you can probably tell I am relatively new to the electronics scene and I'm rather stuck on a project I'm doing for school. I am on my second year of an Electrical engineering degree, tasked to do ...
1
vote
3answers
53 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 ...
1
vote
2answers
158 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 ...
1
vote
1answer
74 views

Problem with Network Topology based on circuits

I have started reading a book lately which covers an introduction to electric circuits. Currently, I'm trying to learn the basic network topology needed to solve exercises in a more efficient manner. ...
0
votes
1answer
81 views

LED lights with a dim light in open circuit [duplicate]

I was installing new LED lamps on my kitchen, which seemed to be functioning well. After turning off the lights, the newly installed lamps still had a dim light, that kept itself for quite long. I've ...
2
votes
1answer
779 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?
-1
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3answers
97 views

How is e=200sin(𝜔t+40)V equal to E=200∠40?

If we expand the first equation it goes like this: \$e = 200(\sin(\omega t)\cdot \cos(40) + \cos(\omega t)\cdot\sin(40))\$, Which means there is still \$\sin(\omega t) + \cos(\omega t)\$ remaining in ...
-4
votes
2answers
783 views

Earthing system on a mobile vehicle?

We have an electrical system which needs a low impedance earthing system below two ohms. We have provided a proper earthing system in our factory and it works well. Now my question is if the system is ...
0
votes
1answer
73 views

Burn In component testing

For pre and post electrical testing of burn in components under test: what is the best way to measure current and voltage through said burn in components before and after burn in to verify if the ...

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