Hello! I am a student working on a portable laser project. The laser is going to be powered by two lithium-ion batteries at 3.4A capacity and 3.7 Nominal voltage (4.2 charging voltage cut-off and 2.5 discharging voltage cut-off). I'm using voltage regulators to step up or step down voltages for...
I've no political agenda. This is strictly a math question about optimization. Those addressing it should do so strictly from a mathematical perspective. Thank you!
If the world simply had one global currency, like Bitcoin, and everyone had an account, then the sum total of all accounts...
So I've done part a)
Primary current = 200000/415=481.9
Cos θ = -0.8
Sin θ = 0.6
Reg=(481.9 ( 0.014*-0.8 + 0.057*0.6))/415
= 0.0267
Reg% = 2.67%
Part b I simply used the same equation but for secondary:
@ unity p.f., cos θ =1, sin θ = 0
secondary current = 200000/11000 = 18.18...
I don't know much about biology but the following two questions have always puzzled me.
1: If each human body cell contains the same genes (from 20,000 to 25,000) then how different cells in different parts of body do different things. A liver cell, for example, does not have the same...
Hello I hope someone can help me, as i am kinda stuck for the moment.
As you can see, the assignment states that I need to find the poles from the closed loop transfer function.
I plan on doing so, by using block diagram reduction method.
This is as fare as I've come, and can't come...
If I had an object in an orbit around the Earth that I kept continually shaded from the sun, how cold would it get?
Assuming the shade device was not physically connected to and was sufficiently far away from the object to not radiate any heat to it.
And if I actively adjusted how much shade...
1. Homework Statement
A 415V to 11 kV transformer has a rating of 200 kVA. The winding resistance and leakage reactance when referred to the primary are 0.014 Ω and 0.057 Ω respectively.
(a) Determine the % regulation of the transformer at 0.8 power factor lagging.
(b) In designing a...
Two (not short) Science magazine articles on economic conflicts involving pharmaceutical companies (surprise, surprise!).
Payments to FDA advisors after drug approvals.
Pharmacology companies hire FDA staffers after successful drug reviews.
Hi, I was wondering if anybody would be willing to point me in the right direction for solving the following question.
The questions is as follows:
A 10000V RMS (primary) to 415V RMS (secondary) transformer rated 400kVA has the following resistance and reactance:
Rs = 3 ohms
Xs = 10 ohms
A...
Homework Statement
[/B]Homework Equations
I have used the Hughes electrical book for the equations to solve the above. I have very little notes from college to help. I have found these equations fit and am confident on it but not 100% can anyone who knows transformers please advise if they...
Hi! I am confused with the speed regulation for Isochronous control. In Droop control, we can surely solve for a value of speed regulation because droop allows the generator to have a varying frequency. However, in Isochronous control, the frequency and speed from no-load to full-load is the...
This particular question is for an assignment. However, I believe that I have the final (correct) answer, but want to check the understanding.
I am required to calculate the resistance of the secondary winding of a transformer. The transformer is a 415:11000 V step-up, rated at 200kVA but with...
Hi,
I want to calculate voltage regulation of a transfromer. I have learned that voltage regulation is (Vnl-Vfl)/Vfl.
While solving some problems for practice I came across multiple questions. In some of them where the load is given I understand how to solve them. I just find the No load...
Homework Statement
The whole image is at here http://imgur.com/a/Dcbvv , but I will try to elaborate more. I have a 12V fixed source with an RS of 220 Ohms with a 1N4733 zener diode model connected and a varying load parallel to the diode. Find the Source Current, Z current, Voltage at R1, and...
I am studying a particular gene whose expression decreases in certain types of cancer. I'm interested in finding out the mechanisms for this downregulation, specifically, which transcription factors and signalling pathways are involved. I have a hypothesis for the pathway involved, but in case...
Hi
I was wondering if someone could help me understand and explain to me how one can control the frequency of the grid from help of the active power (frequency -> power angle -> active power) and how reactive power can be used to control the voltage level.
My thoughts:
Voltage Control:
I don't...
I have been looking into different methods of regulating protein activity for a project. I think it is pretty interesting and I want to learn more about this. I want to learn about the different methods out there, if you know of any cool or helpful regulation techniques I would certainly...
Hi,
So I have been told on here that when you eliminate the leakage flux between coils it improves Voltage regulation, I have also read online that voltage regulation is related to inductance, but could anyone elaborate on these? 'why are these so?'
[I can sort of guess something like the...
Homework Statement
A 415V to 11 kV transformer has a rating of 200 kVA. The winding resistance and leakage reactance when referred to the primary are 0.014 Ω and 0.057 Ω respectively.
(b) In designing a particular 415V to 11 kV, 200 kVA transformer, the primary winding resistance is to be 10...
I am having confusion about the no load and full load speeds of a dc motor. What exactly does 'loading' stand for? How do we change the loading of a dc motor ?What is the relationship between loading and the speed of the motor?
Which situations does no load and full load refer to?
Homework Statement
The attachment depicts an active load (to the right is the equivalent circuit). It is called thus because this load (measured from TP27) changes its resistance according to the controlling signal connected to TP25. The load is switched “on” (minimum resistance) and “off”...
Hi,
I need to calculate the voltage regulation of the 3 ph Dzn transformer. I have knowledge of the current going into the primary winding of the transformer (Delta winding) and hence need to calculate the current in the secondary (load current) so that I can use this in the voltage...
Homework Statement
5. A 415V to 11 kV transformer has a rating of 200 kVA. The winding resistance and leakage reactance when referred to the primary are 0.014 Ω and 0.057 Ω respectively.
(a) Determine the % regulation of the transformer at 0.8 power factor lagging.
(b) In designing a...
Homework Statement
5. A 415V to 11 kV transformer has a rating of 200 kVA. The winding resistance and leakage reactance when referred to the primary are 0.014 Ω and 0.057 Ω respectively.
(a) Determine the % regulation of the transformer at 0.8 power factor lagging.
(b) In designing a...
Good evening everyone.
I have two questions to ask you guys.
1. Why voltage regulation of a synchronous motor is negative with a purely capacitive load? I mean why?
2. Why Reactive loss is higher than resistive loss in a power distribution line?
thank you and have a nice day...
I have a nokia N8 cell phone and it is very precise about what it will allow to charge it. Mostly it will only accept wall chargers, not car power in any way. There is no way it knows the car charger isn't in the wall so all I can guess is the power is "dirty" and therefore it denies it. My...
How can a transformer have negative voltage regulation?
A few texts state that a leading power factor can give rise to negative power factor, but I have not been able to figure out how this is possible.
One vague explanation in my mind is that capacitance across the secondary terminal will...
Are different electrical frequencies allocated to specific applications because of their properties or to regulate the spectrum so that each assigned frequency range is unique to one entity?
I guess a related question is: Are we going higher in frequency ranges for things like automobile...
Homework Statement
An 11kV to 415v transformer has a rating of 100kVA. The winding resistance and leakage reactance when referred to the secondary are 0.0142 ohms and 0.0569 ohms respectively. Determine the % regulation of the transformer for a 0.8 lagging power factor.
Homework Equations...
If I had a step down transformer of 300 VA in size at 45-0-45 Volts@3.3 Amps with a regulation of 10% could I do the following to calculate the internal resistance of the secondary winding for my power supply circuit?
Voltage * Regulation 10% to work out the voltage difference between noload...
How is the compressor speed controlled in a car air conditioner, in compressors driven by engine moved belts? Is temperature controlled just by on/of of the solenoid clutch?
Electric air conditioner (automotive), not driven by (directly) by engine, is widely used today?
Another question, not...
Hi,
I did an experiment, involving transformers. Where we did open circuit and short circuit tests then test with a resistor, capacitor and inductor.
For the last question it asks Calculate the load capacitance and inductance from the voltage regulation readings.
Voltage regulation...
Good day all!
I am new to this forum however i hear its great and full of good engineers. I want to convert 90-270 volts into either 88 volts or 112. I was thinking about a buck converter due to the efficiency however i cannot find one that can take my vin min and vin max. Then i though of a...
Hi everyone,
First post on this forum (!)
I am simulating a distributed power generation system for which I need a current regulation on a buck converter (for load sharing between sources)...The model will be turned into a hardware solution so I need a practical solution, preferably...
Hi all,
I'm after a water system involving some sort of pressure valve (pressure regulator, relief valve etc - whichever gets the job done) where the inlet pressure is always OVER set-pressure, and the valve oscillates (opens and closes rapidly) in response. It is this oscillation that is...
Ok, so I have a variable DC voltage source that changes as due to outside factors. The voltage ranges between 9 and 18 volts with a current between 1 and 3 amps. I want the voltage source to charge a 12 volt battery continuously until it is full. Whent he battery is full, the circuit should shut...
theoretical modeling approach
PLoS Computational Biology article “A Tale of Two Stories: Astrocyte Regulation of Synaptic Depression and Facilitation” by Maurizio De Pittà, Vladislav Volman, Hugues Berry & Eshel Ben-Jacob
A transformer is rated at 2300/230 V, 15 kVA and 50 Hz. Assume that the transformer is operating at 80% p.f., leading and at rated output the secondary terminal voltage is 230 V. The following parameters for the transformer are given:
N1 = 1500 turns
N2 = 150 turns
r1 = 2.7 ohms
r2 = 0.024...
Labor Day and the Creation of “Free,” Anti-Feudalistic Labor Through Regulation
Interesting blogpost on the unfree state of free labor in the early industrial period
Edit by mod: We don't allow personal blogs as sources
more here
I'm still deciding on this student paper...
Hello, everyone
There is a control theory problem that i would like to ask for help here.
Suppose a very simple nonlinear system as follows
x' = u
y = (2-cosx)*(2-cosx)
how to find a control law u that makes the output y can track a constant asymptotically,
of course the x should...
This is more of a lab then a homework
Ok, so i had a full wave bridge rectifier w/capacitor hooked up to a power regulator. and i was attempting to perform line regulation- and for a Vmin i should have got around 10.5V but i got 2.4V. Why is that? I think the rectifier stopped rectifying but...
I'm an entry-level engineer, and I have a design question for the forum:
I'm designing a multiphase buck DC/DC converter which will convert roughly 65VDC to 52VDC at up to 150A. I'm using 4 phases, so inductors, etc will be designed to about 40A/phase, MOSFETS will be paralleled for less...
Am I the only person who gets really nitty-gritty about component selection? Well probably not, but I am having a bit of trouble picking out my power management ICs.
I am building a dual rail power supply. I guess you could call it that. It can do +/-12V and +/- 5V. It may be useful somewhere...
Not sure how to properly use the youtube tags.
https://www.youtube.com/watch?v=http://www.youtube.com/watch?v=ZR-H7CxhEZc
https://www.youtube.com/watch?v=http://www.youtube.com/watch?v=2iWPff2jEo0
https://www.youtube.com/watch?v=http://www.youtube.com/watch?v=TMfJGwngUAY...
Can someone please describe the different growth strategies that plants use in dark and light, and explain why these are important at different stages of growth in natural environments.
Homework Statement
when zener diode is used for voltage regulation,
voltage source is connected in series to zener diode and load resistance is connected parallel to zener diode.
when zener diode is reverse biased, it will enter zener breakdown region. when input voltage increases zener...
Homework Statement
Tests are performed on a 50Hz transformer which yield the following results:
Short circuit test: V1 = 40V, I1 = 10A, Power input = 20W
Open circuit test: V1 = 240V, I1 = 1.2A, Power input = 70W
Here are the equivalent circuit parameters from the above tests.
Rc = 823...
A 10 kVA, 2200/220 V, 50 Hz single phase transformer is tested and the following results are obtained.
Open circuit test (LV)
Short circuit test (HV)
Voc = 220 V
Vsc = 150 V
Ioc = 2.5 A
Isc = 4.55 A
Poc = 100 W
Psc = 215 W
Calculate:
(i)The transformer parameters and...
is it true that cooperativity is rare in enzymes with tertiary structure
and that Glycolysis is inefficient and therefore rarely found in present day organisms
i am not sure.. but iwas also wondering that a particular enzyme is likely subject to only a few forms of the regulation we...