Transformer Definition and 787 Threads

What percentage of electrical energy is lost as heat by the transformer that supplies a house with 240V ac?

Hello All, I was wondering if someone could help me figure out how to calculate the induced voltage across each of the four windings on a toroidal transformer that I am going to make for a project (see attached sketch). The two black coils are the power in and out coils, and the two red...

Homework Statement In some places, insect "zappers," with their blue lights, are a familiar sight on a summer's night. These devices use a high voltage to electrocute insects. One such device uses an ac voltage of 4270 V, which is obtained from a standard 122.0 V outlet by means of a...

I may have a project in which I need approximately a 10 KVA transfomer. I've done a bit of research on-line and have some guidelines. Line/load regulation is of less than typical consequence. The turns ratio will probably be about 2:1, probably slightly less. My main questions are core...

According to ohm's law voltage is directly proportional to current that is if voltage get increased current also should get increased but in a transformer if voltage get increased current get decreased. so, Is a transformer is obeying ohm's law or not

I have a homework question that states: A transformer connected to a 120 V rms ac line is to supply 16800 V(rms) for a neon sign. To resuce shock hazard, a fuse is to be inserted in the primary circuit; the fuse is to blow when the current in the secondary circuit exceeds 10.0mA. a) What is the...

If a transformer has loose parts, then a hum is heard while there is current flowing through the primary coil. how do you explain this noise?

Hi there, I'm new here. I'm working on a project and I have a technical question regarding the wiring of the components. First, is wall power AC or DC? It seems that if there is a positive and negative terminal in the wall outlet, it would be DC (like a battery). But then again my...

:rolleyes: I'm curious if we use a direct wye connection instead of zigzag in case of earthing transformer.. i know that by merely looking if we use wye connection in earthing specially in medium voltage you have to have enough reactance for your exciting voltage.which will cost more in...

something i read from the textbook and i don't understand. "in an ideal transformer, no magnetizing current is required to produce the flux" so, where does the flux come from?

i want to design an isolation transformer A/C, with single phase and three phase input. How do i go about it?

I'm using a 460VAC/230VAC single phase transformer. My customer insists wanting to have 440VAC/220VAC one instead. The ratio between the two transformers are the same. How different are the two? Are they essentially the same ? Thank you,

I'm trying to understand what happens to a distribution transformer in relation to overvoltage conditions (in terms of saturation and current flow; not insulation failure). I understand that once the voltage has risen high enough to drive the magnetic core past the saturation point, that the...

Hello:smile: , I want to know about operate the auto transformer, if anyone could gimme the diagram about it and give explain about main function. Thanks a lot I appreciate it :rolleyes:

hi pf folks.. currently i am the electrical engineer incharge in a 152 hectares university campus in our place. commonly our transformer are rated 7620/240 volts, 1p with capacity of 25 KVA, 50 KVA and 100 KVA.. for our three phase loads we used to bank 3- 1p transformer wye delta...all in...

Hi, My Question: A model train transformer plugs into 120-V ac and draws 0.35A while supplying 7.5A to the train. (a)What voltage is present across the tracks? (b) is the transformer step-up or step down? Work Part A: I'V'=I"V" (0.25A)(120V)=(7.5A)(V") ((0.25A)(120V))/(7.5A)=V"...

Hi Guys! Well! I am studying transformer and i want to know about the following losses in a transformer: 1)Hysteresis Losses 2)Eddy Current Losses 3)Copper Losses 4)Stray Losses please explain me the right concept. I have studied so much but I am just not getting the right concepts...

I have a single phase transformer tutorial that I am struggling with, I was wondering if anyone could help. Attached is the equivalent circuit diagram I have values for all varables, and have a few questions, When the circuit is reduced to its approximate form (ie, secondary side referred...

dear all, When loading the secondary winding of a transformer, my textbook gives the following relationships: \frac{V_{sec}}{V_{pri}}=\frac{N_{sec}}{N_{pri}}\\ and \frac{I_{sec}}{I_{pri}}=\frac{N_{sec}}{N_{pri}}\\ Do these relationships hold also when the diameter of the windings are...

Hello All, I understand this is more of a question for electrical engineers however I have received only baffling replies from electrical engineers so I was hoping a physicist, or someone a little better versed in E&M than I am, could assist in finding an answer to this question. Long...

Hi, I have a 230V to 2x12V (2.3VA) transformer. There are 4 pins in the secondary coil 0(a)-12(a)-0(b)-12(b). When I measure the voltage across 0(a) and 12(a), I get about 23+VAC. I shorted 12(a) to 0(b) and measured 14VAC across 0(a) and 12(b). I connected a W05 bridge rectifier and...

If I have 2KVA transformer how do I determine the max. safe primary current.

I need a voltage multiplier to up DC voltage. Is there any household appliance that will have it that I can rip it out of?

For my project I need to transform the power from a 3000 watt, 120V AC generator to a high voltage DC, say 30,000V DC. Are such transformers easily made or of low cost? Bob Clark

Hi, I need to design a high-frequency, low power air core transformer implemented by conductors printed on PCB. Does anyone know about an application notes, free software or java applet which cam assist me in this case? Thanx in advance despair_eli :cry:

what makes one efficient? ie...does frequency have anything to do with it, operating temperature, number coils, core material, etc.

Hi! I just got to my last homework question and am not quite sure how to figure it out, it goes like this: Scott connects a transformer to a 24V source and measures 8.0V at the secondary. If the primary and secondary were reversed, what would the new output voltage be? I'm not sure...

Vs/Vp = Ns/Np This apply in transformer. But I have read the following statement : ' Uasally , voltage ratio is larger than the turns ratio. This is because not all field lines from primary coil cut the secondary coil.' Why? Is that mean some field lines 'go' to surroundings? :rolleyes:

In my car the OEM amplifier runs dual-voice coil subs. Its a SMT PCB with all ICs on even the outputs, no SMPS so its just 12V for the rails and the outputs are already bridged. Easy to see why many junk it and use an aftermarket amplifier come upgrade time. But I want to try to use it as is...

can you use a dc circuit in a transformer? will it work the same way?

I have obtained the approximate equivalent circuit of a transformer at its rated supply voltage having carried out the open circuit and short circuit tests on it. If I plot a graph of primary voltage against primary current for an open-circuited transformer I get a curve. If I use my...

Hello, I've been thinking about why (elementary) transformer efficiency drops drastically at very low frequencies. I know hysteresis effects play a major role in reducing efficiency at high frequencies, but why low? I realize that as we reduce the frequency of the emf, we're making the...

Hi Can anybody help me in getting technical information about core balance current transformers. Thanks Mahadev

okay, I Don't quite grasp this concept but!. Vo/Vi = No/Ni. And I have this problem. A Generator at a power plant produces AC at 24,000 V.A transformer steps this up to 345,000 V for transmission over power lines. IF there are 2000 turns of wire in the input coil of the transformer, how many...

Homework problem: A transformer on a pole near a factory steps the voltage down from 3900V to 220V. The transformer is to deliver 1180kW to the factory at 91% efficiency. Find the power delivered to the primary in kW. What I've done: Well, I thought that power in equals power out. So I...

how does a transformer work? Transformers could make 9v from a battery into say 250v but isn't that getting something for nothing? what about conconservation of energy? Does a capacitor with 9v potential discharge energy faster than a 9v battery? Can capacitors be replace with transformers...

Well, I didn't know where to post this...but it's here now:) I removed a flyback from my colour monitor and after removing it I succeeded in breaking what seems to be (or closely connected to) the ferrite core. It is a metallic (I think, it is cold to the touch) piece, black on mine, in the...