Transformer Definition and 787 Threads

Transformer efficiency/primary current (help!) Real transformers are not 100% efficient. That is, the efficiency, in percent, is represented by e = (100%) Ps/Pp. A step-down transformer has an efficiency of 92.5% is used to obtain 23.0 V from the 125 V household voltage. The current in the...

1. It is required to pass a current of between 6.0A and 6.5A through an impedance of (1.6 + 1.2i) ohms. With only a 230V supply available, it is proposed to use a transformer for impedance matching. A transformer is available with a turns ratio of 16:1. A laboratory test showed that with the...

I am trying to work out the BW of my transformer. My source resistance, Rs, is 50R. My load resistance, RL=50R. The windings ratio ,N, is 1:1. The magnetising current, Lmag=7.96uH. The data i have suggests that to find the lower -3dB point, you refer the secondary load to the primary. This...

just tell me how the p.d. increases in a step up transformer. (Please don't use formulas for this.) if we take a conductor of same length and thickness as the 1st one for the secondary coil, the voltage doesn't increase. but why does it,if we increase the length. I mean,how can that affect...

I have been trying to figure it out, but nothing seems to help. my question is simple, how are we able to derive a mathematical equation of a transformer for convesion of Delta connection to star or star to delta ?

Homework Statement Hi. Why does one conduct an open-circuit and a short-circuit test on a transformer to determine its equivalent circuit parameters? I've read that a) the open-circuit test determines the parallel parameters - the R and X equating to the core loss, and b) the short-circuit...

Hi All, I am building a circuit that i need to get a better understanding of before jumping in head first, it says it requires an Impedance Matching Transformer. I don't get this with the Attached Circuit, is it the whole Primary circuit has to match the whole Secondry Circuit Impedance...

Hi, I'm trying to perform a short circuit fault calculation on this transformer and load I have when a 3 phase bolted short (worse case) occurs. The transformer specs are below: Z(transformer)=5%, Z(cable)= .00306 + j.0027, Delta/Star 6.6kV/400V I can understand calculating the short circuit...

Hi all, I am looking for a transformer to convert the 115VAC from the wall to ~100VAC, 10-15A, and 1-1.5kW. Is something like this commercially available? Otherwise how difficult would it be to make? Thanks a lot.

what are the advantages and disadvantages of different types of transformer grounding -with regard to system protection and fault current reduction? we have the following grounding types YN - YN YN - Delta Delta - YN Delta - Delta where can i find a good resource that explains this?

Hi All, I have a step down Transformer 240v AC to 12v 100amp output. My question is, can i use this as a step up transformer as well by connecting to the other side of it? My supply voltage is of course 240v AC, this can be controlled with a 240v 10amp Variac to take it easy on things...

Hi, so I know that VI = P cos (theta), but during an experiment using a step up transformer, I got the primary voltage 7.42V, primary current 0.41A, and primary power 3.2W. How then should I calculate the angle theta. I can't use arcosine, 'cause that will give me undefined. Thanks a lot.

can we use step up transformer as step down without any change?

Hi Any body who can send me the link to a free low power sinewave transformer designing software and also of some free ebook on this subject.

what is the difference between direct coupled and transformer coupled?(mechanical configurations with the required turns ratios of 1:25 direct coupled and 1:1.79 transformer coupled)

I am electro-statically trapping particles for chemical and physical studies. I do not want to discuss the details of my research. AC Calibrators are very expensive and I don't need the precision. I did find a power amplifier that could step up my sine wave generator to the values I want...

Hello, I have a differential signal going into an instrumentation amplifier (AD620). I would like to employ galvanic isolation on the inputs of AD620. Would anyone be so kind and tell me how it shall be wired? I don't know much about signal isolation. Shall 1:1 or 1:1:1 transformer be used...

In the case of an open-circuit test of transformer, when I increase the supply voltage, i realize the magnetising reactance (Xm) decreases, why does this happen?

In a step-up transformer, since you can increase the voltage by increasing the number of turns on the second circut, where does this extra voltage come from? why does this not violate conservation of energy?

can u explain what hapens output circuit is open and no current is flowing through output coil? isn't it that a large current flows through the input?and the wire burns...i know it doesn't hapen...but why?when there is no back emf in primary?

Here is my question. It is rather simple quetion. But I am a beginer in this field so please help me. In the case of equivalent ciruit of the tranformer it is taken that the inductance and the capacitance in the primary coil of the transformer is taken parrallel and the inductance and...

Hello!I would like to ask about Electromagnetic induction in transformer.As we learn that an alternating voltage is connected to the primary coil,the alternating current in the primary coil produces a magnetic flux linkage with the secondary coil which constantly changes.\phi=magnetic flux...

I would like to know how to work out the turn ratio on a transformer from having just the input and output voltages.

Does the resistance in the secondary circuit connected to a transformer provide for a certain resistance in the primary circuit?

An average of 120 kW of electric power is sent to a small town from a power plant 10 km away. The transmission lines have a total resistance of 0.40 ohms. Calculate the power loss if the power is transmitted at 240 V. The solution is I=P/V=500 A, then the power loss in the lines...

1. Two transformers T1 and T2 in parallel supply a common load at a lagging pf of 0.8, their per unit impedance are 0.04+j0.09 and 0.01+j0.07 at the same kva ratings of 3000KVA each and load power = 5500KVA Determine the kva output of each transfromer and power factor This is how i worked...

Hi, Does anyone knows how to prove that a potential transformer is a linear system or not? Can I use principle of superposition with time-domain impulse to prove it? Is there other ways other than the principle of superposition to prove linearity of a potential transformer? Is there a way to...

can anyone please help me, i want to know that whether 12v DC from a battery is same as 12v DC from a transformer ( after a 4 diode bridge has been fixed to it )... please help, because i want to expeiment something, i removed the 12v battery of my UPS and put in its place a 12v transformer, but...

For a while now I have been having some problems with ground loops that are due to the diagnostics (in this case thermometry) in the my measurement setup. Unfortunately there is no "easy" way to solve this problem without breaking the connection to Earth (=safety ground) and let some of the...

Regarding to physical size of national power systems, rate of power exchange and transmission lines capacity are increased by using of high voltage technology. Step up or generator transformers increase the produced voltage of power generators in great power plants. Therefore it seems the unique...

hi, May I know does anyone knows the industrial usage of the potential transformer and probably how it is connected? Thanks.

What happens if you connect the following in this order: 1) from a battery to the primary in 2) from the primary out to the secondary in 3) from the secondary out to a motor 4) from the motor to the battery I know that transformers usually step up or step down the voltage, but it shouldn't be...

I understand that according to Maxwell's equations time-varying EM fields cannot exist in a perfect conductor (but static magnetic fields can). Also if you have a time-varying magnetic field you also have time-varying electric field and vice versa. And this knowledge is used to solve EM wave...

I accidentally left a 220v transformer outside the house and somehow it flooded outside and left the transformer underwater, Would this thing still work if I let it under the sun for maybe 2-3 days and power it up again? any suggestions? the transformer I had is like this...

Hin Im Confuswed I Think...in A Traqnsformer The Current Drawn Is Decided By The Side Wirth The Highest Impedence?i Was To Be3lieve That I Was Am I Right To? Thnks For Aqny Clues ...l.

how does a transformer work?

urgent : single phase transformer Homework Statement A 2200/220 V, 500kVA, 50Hz distribytion transformer has been tested by means of the open circuit. the test data obtained is as follow: open circuit test: V(l)= 220V, I(l)= 85A, P(oc)= 1800W short circuit test V(h)=95V...

Hello, can someone please help me out here, i want to step up the voltage of a 1.5V battery to 300V, i know that to do so you need an oscilatro circuit consisting of a transformer a small capacitor and a transistor. so my question is, does the type of transistor/capacitor i use matter?

I conducted a transformer efficiency experiment using a 240/110V double wound transformer, first with one heater connected in series then with two connected in parallell. What I don't understand is why when both (identical) heaters are connected current almost doubles on the primary side. Why...

here's an idea i just came up with, it's to run DC into the primary of a tranformer and get a constant output: place a brush motor (like the ones in model airplanes/cars) in series with the primary coil, the motor will spin(obviously) and act as a switch(as the brushes swap contacts) so there...

Hi, I have two question about transformer and regulator: 1- When one refers to “isolation” with respect to a transformer, what does it mean? It related to the fact that the transformer blocks DC component of the signal? 2- this question is related to the electronic regulator 7812...

Hey, I am currently reading about transformers and one aspect of the equivalent circuit that I do not understand is why the leakage flux is represented by an inductor? Any help on this would be much appreciated. Thanks!

Hi I wondered if anyone could explain as to how actually the whole process of transformation of voltage happens. I know the equations involved but can't get them together to reach a conclusion. When a.c. is passed throught the primary, a flux is induced in the core, which travels to the...

Question: Can anyone tell me that Ohm law apply on Transformer or not? Thanx.

A power transformer manufacturer decided to decrease their production budget by reduction of material amount used in transformer construction. In that country, transformer core material is an expensive portion of power transformer because it shall be supplied by foreign companies. Therefore...

I'm building various current transformers for a project at work and having trouble finding out what the best core material is to generate the most power from a 7kV power line using inductance. I have seen that Silicon-Steel provides the greatest flux density saturation but have heard that some...

A power transformer manufacturer which was located in economical boycotted country met some problems in material provision. The core material and some other things shall be supplied by a foreign company that they work under its license. While boycotting duration they got to use inferior...

Hello , I have a ferrite core transformer with two separate windings. I was hoping if someone can tell me if I can locate the start of each winding relative to each other. I have a scope, and am comfortable with micro based circuits. Cheers Thomas

Need help to Design ferroresonant transformer I am traying to design 3kva /230v ferroresonant transformer for it I need help about following topics How deside resonant friquency? witch capacitor to use? how calculate winding inductans? whitch will...

I am using a Triad Magnetics CST206-3T Current Sensing Tranformer. How does it work? I need to find a resistor to measure the current, while getting the highest possible gain, and without losing performance at high frequencies. My question is how does the CT measure current?