Transformer Definition and 787 Threads

The two power transformer 69/22.9kV and 230/69kV are both rated 60/80/100MVA designed for 60 Hz operation. However it will be tested on test facility were the available supply is only 50 Hz. During short circuit test at the LV side the 60/80/100MVA rating will be tested for the lowest tap...

In transformer when voltage increases on secondry coil then current decreases but i am confuse here that how ohm law is obeyed here. as V is d.proportiona to Current. please advise...

Hi All, I am required to assume some parameters for my research, For a new transformer worth $100 million for a substation, what likely could be sensible for these parameters? Nominal Capacity? (Example 10^5 KW) Average Repair Cost? ($1 million ?) Unsupplied energy cost? ($3 kWh ?)...

Homework Statement For a transformer, I need to get the ratings on the meters (wattmeter, ammeter, voltmeter) when it is put through an open circuit test and a short circuit test. Primary 240/480 Secondary 120/240 1KVA 60Hz The Attempt at a Solution Now I am not sure what is...

Hello all, I am a layman who is interested in nuclear fusion via magnetic confinement (the Tokamak setup). I recently read in a book about how the (a) transformer in the device could operate only for some number of "volt-seconds" before it had to be "recharged". This requires an additional...

Homework Statement The transfromer equation is given by\frac{Vp}{Vs}=\frac{Np}{Ns} for an ideal transformer. This equation is correct only if there are perfect flux linkage, the resistance of both primary and secondary coil is small and carries negligible current. The notes mention here if the...

Hi all. I'm hoping someone can help me out on a (for me) tricky little issue. We are to use a communication module that we know will draw 5amp and must be supplied via a UPS. Tricky bit is that its 3.5km away so we need to step up the voltage at source and step down again at load. 400Vac is to...

Hi friends If I have three phase 250 kva Transformer, 440 input and 220 output then Can I say that it can bear 568.2 amp current or 1136.3 amps?

Weird Transformer Problem :( Homework Statement "In the transformer shown in the figure below, the load resistance RL is 44.0 Ω. The turns ratio N1/N2 is 2.10, and the rms source voltage is ΔVS = 77.0 V. If a voltmeter across the load resistance measures an rms voltage of 26.5 V, what is...

Hi guys, new here. I was wondering if anyone knew of a way to trick a 12 volt transformer into seeing more load. I have these lights http://www.lowes.com/pd_172832-24969-800CBL5N_0_?productId=1207073&Ntt=tiella&Ntk=i_products&pl=1&currentURL=/pl__0__s?newSearch=true$Ntt=tiella$y=0$x=0" and it...

Hello, I have some doubts in the following problem of a transformer, specially on parts 2 and 4. I would be very grateful if someone could please give me any ideas specially about those parts... Homework Statement The Attempt at a Solution 1) Applying KVL in each mesh...

how to convert dc voltage into higher dc voltage using transformer? i am tring to convert 9 volt dc into 120 volt dc , and i ve to use transformer ,,, the problem is the transformer must have input ac voltage as it work on flux variation . i think the solution is to convert the input dc into...

Does anyone know of a good link to basic transformer design? I keep seeing the standard equations but they don't seem like much help. I can't seem to find any good guides for designing the most basic transformer For example, I will see equations relating the ratio of turns to the ratio of...

Greetings physics gurus Im getting bogged down on conversion of the VA to A Homework Statement A small transformer used to power a laptop computer has the following characteristics printed on it: • input AC 220 V, 50 Hz, 15 VA. • output DC 5.0 V, 1.0 A. Is this transformer...

I have a question about impedance matching with transformers. If I have a source impedance of 20 K ohms, to step up the voltage does the primary have to match 20K ohms with a secondary of 40K ohms for a step up of 1:2. Or can I change it so the primary is 50 Ohms with a secondary of 40K ohms...

Homework Statement see attachment The Attempt at a Solution for part a): I tried to use the equation N2/N1= I1/I2 I got 12A, instead of the answer (24A) can someone please show me how to do this? I missed class one day, and now I'm lost

Current transmitted control by the input power from the generator or control by the resistance of the transmission cabel?

How small can I make a transformer and still get 1:30 or preferably higher step-up ratio ? I have been reading a lot about transformers and I know using higher frequency will reduce the size, and I need to use ferrite core for high frequency. I don't want to use really high frequency, probably...

Hi, http://en.wikipedia.org/wiki/Transformer related picture: Above link, says: "If the voltage is increased, then the current is decreased by the same factor." I didn't understand. Is this means, if I increase Vp, Ip will decrease? Or means Is will decrease? One more... Suppose...

Homework Statement A step up transformer is designed to operate from a 12V supply and to deliver energy at 240V. If the secondary winding is connected to a 60W, 240 V lamp, determine: a) the turns ratio of the transformer b) the primary current Homework Equations P primary = P...

Homework Statement I'm working with a stripped-out microwave oven transformer core. I've split off a stack of laminations 1.25" thick, and cut out the middle leg of the "E" lams. I want to build a hollow-core 1:1 isolation transformer, and input a slow (about 3 Hz) pulsed DC current...

Hey. I am currently doing a bit of revision for an exam and I am struggling on the following question: I understand the whole voltage/current/power/impedance ratio stuff, but can't seem to find any information on calculating efficiencies using the resistances or the transformer core losses...

Hello all, I am new to the forum and hope my question is appropriate for this section. My question is about per-unit notation and calculations. Basically I've been given the resistance, reactance at the primary and secondary windings of a transformer, core losses and inductance, etc. The...

Homework Statement A step down transformer has a primary to secondary ratio of 4:1. If the peak current in the secondary is 12 A, the peak current in the primary is what? Homework Equations Vp/Vs = Np/Ns The Attempt at a Solution (4/1) = (Ip/12 A) what is the relation...

I want to convert ac 50V, 1.8A into 100V, 1.8A. The voltage is doubling, while the current rating is required to be the same. How can I achieve this? A transformer action step ups the voltage, but does it lowers the current rating? Thanks

I am having a problem with the following problem: A step-up transformer increases 10V to 170V. What is the current in Amperes in the secondary as compared to the primary? Assume 100% effiiency. The only formula I can see that has Amps in it is the turn ration...

I've been wondering about this for a long time. The little black box that you plug into the wall so you can power your electronic devices contains a general run-of-the-mill transformer. But if the power is completely shut off to the device: not draining any current waiting for a power button...

1. A large power transformer has a turns ratio N1 / N2 of 1:5. When the primary voltage is 400v and it is connected to a resistive load its secondary current is 100A. Calculate the required value of source resistance of the supply to give a maximum power trnasfer 2. Vp = 400v, Ratio 1:5...

hey there.. how am i going to sketch a vector diagram of the given diagram? is it same like phasor diagram?

Hi guys, I don't understand why when one touches both the live wire and neutral wire in the secondary of an isolation transformer, the current in the live wire and the neutral wire in the primary will be the same. This is described in my book as the reason why a residual-current device in the...

Homework Statement A generator consists of a circular coil of radius 0.2 meters wrapped 10 times and is spun in a uniform magnetic field of 0.38 Tesla. It is connected (on the primary side) to a transformer with 7 turns on the primary side and 20 turns on the secondary side. If the secondary...

Hai all, How does an isolation transformer protects the circuit and the person from shock. Please explain in detail.

hi there, i'm trying to simulate a ETD core http://www.ferroxcube.com/prod/assets/etd29.pdf" transformer using FEMM free software but I'm not getting it...i've done some simulations with pot cores and had no problem with that, using the axissymmetric mode. bue this type of core is not...

Is it possible to build an adjustable transformer that can take 110/120 and dial it all the way down to 1 volt? I'd like to build one if possible to aid in physical development so it's very important to be able to take it as low as possible in the beginning. I'd like it to have 2 electrodes as...

Hi friends it is not ( problem or numerical) just i want know friends if i have 15kva transformer . then can i say it can carry 1500 watt 10 (split AIR conditioners) as a load. and what happened if i add 5 more (split AIR conditioners) in same case. just give me idea...

like in a car when electrons flow through the battery to the coil , the coil is like a transformer using coiled copper wire to up the voltage to give the spark plugs a hotter spark. I am not sure where this energy is coming from , so are we actually getting more electrons to flow per second...

Transformer questions - primary, secondary, gaaaah! Hello, I really need help with this. Much appreciated! Thank you so much in advance for any help!Homework Statement A step-up transformer has exactly 100 turns in the primary and exactly 200 turns in the secondary. If the voltage in the...

Homework Statement The primary coil of an ideal transformer is connected to a 120-V source and draws 1.0 A. The secondary coil has 600 turns and supplies an output current of 5.0 A to run an electrical device. A) What is the voltage across the secondary coil? B) How many turns are in the...

Homework Statement The specifications of a transformer for a small appliance read "Input: 110 V, 6.4 W" and "Output: 8.9 V, 270 mA". What is the efficiency of this transformer? Homework Equations P = I * V V = I * R The Attempt at a Solution 6.4 W / (8.9*(270*.001)) ---> I think this is...

Will an audio transformer pass multiple signals at the same time to the secondary winding. For example if there is 200Hz 300Hz and 1000Hz on the primary winding, will there be 200Hz 300Hz and 1000 Hz on the secondary. In my opinion it will but I just wanted to confirm this.

Homework Statement By trying a variety of values for L_{S} and L_{L} find a transformer for which the three relationships are satisfied while, a=10. Use smallest possible inductances you need to make the transformer work properly @ 1kHz and above. Print plot with the three ratios that...

Homework Statement Which is more dangerous: the electric shock caused by falling off of a transformer, or the impact when one falls, and why? Also, what would the voltage of a 12ft (meh. might as well go with 4m) transformer be about?Homework Equations V = IR U = mgh The Attempt at a Solution...

How transformer loss vary with load current?

Hi How do transformers get voltage in the secondary? I am after the boring details of the "magnetism" moving and dancing in/at/around/on the core to induce that voltage? thx

Hi Im building an energy meter and I have a doubt about the voltage channel I am using to measure voltage. Basically there is a transformer that is connected between line and neutral and on the secondary side, there is voltage dividing resistor circuit to step down the voltage to the levels...

Hello all, I'm currently working on a project and I have a question in regards to creating an efficient induction coil for our circuit. Without going into the specific details of the circuit(We aren't given the details anyways, just the circuit itself), it basically imitates a transformer...

Can intermediate frequency transformer be classified as a variable inductor ? What is its actual use in radio ?

Just out of curiosity : Consider a transformer with winding ratio of 1 : 10. What happens when AC 120 v is applied on primary and on secondary we apply DC voltage of 120 v from a battery source is series or in parallel? What will be the output in both cases?

Homework Statement Essentially, there are 4 separate windings that are not connected. Two windings are on the top (H) and two are on the bottom (X). It is given that the rated power of the entire transformer is 5 KVA. The rated voltage is 120/240: 120/240. It also notes that the colon (:) in...

Copper-wound Transformers were proven tested to be reliable and were used by utilities years ago, because of its low-cost and capabilities. However, with their high cost nowadays, we plan to use Aluminum-wound transformers. Based on facts, aluminum's characteristics in terms of its electrical...