Why do we use soft iron core in transformer

Table of Contents • • • • • • • • Why the coils are wound on a core made of iron? In real transformers, the two coils are wound onto the same iron core. The purpose of the iron core is to channel the magnetic flux generated by the current flowing around the primary coil, so that as much of it as possible also links the secondary coil. Why are transformer laminations insulated from each other? These laminations are insulated from each other by a coat of varnish or paper to increase the effective resistivity of the core thereby increasing the overall resistance to limit the flow of the eddy currents. Using laminations in a transformer construction reduces eddy current losses. What causes transformer core saturation? Magnetic saturation of a transformer core may be caused by excessive primary voltage, operation at too low of a frequency, and/or by the presence of a DC current in any of the windings. Physical forces causing winding vibration may also generate noise under conditions of heavy (high current) secondary winding load. What are the advantages of toroid over commercial transformer What are stray fields? Low Stray Field: Toroidal transformer with evenly wound primaries and secondaries have a very low stray field, best for audio equipment. Lower Off-load Power Consumption: Long term cost saving due to increased electrical efficiency. Why is iron used in transformers? The ability of iron or steel to carry magnetic flux is much greater than air. This ability to carry flux...

i am having some trouble with understanding the magnetic fields inside transformers and how they relate to back emf. My first query is: is the magnetic field produced inside the soft iron core aligned with the magnetic field produced in the primary coil, or does it oppose it? I think it has to oppose the magnetic field in the primary coil by Lenz's law because then the magnetic field in the core would induce a back emf in the primary could which would oppose the primary coil p.d, reducing the current in the primary coil and thus reducing the magnetic field around it so there is a smaller field in the core etc so it will oscillate between decreasing and increasing magnetic field. However my explanation above does not seem to fit when I consider the secondary coil as being part of a complete circuit and passing current. My text book says that 'when the secondary current is on, the magnetic field it creates is in the opposite direction to the magnetic field of the primary current. In this situation, the back emf in the primary coil is reduced so the primary current is larger than when the secondary current is off', but I am not sure I agree with the first part of that. I would think that the current induced in the secondary could would have to create a magnetic field that would oppose the magnetic field in the iron core by Lenz's law, so that means that both the primary and secondary coils have the same magnetic fields as both are opposing the core magnetic field. But then wh...

(Here's my understanding just in case if I misunderstood something) I understand that for order to induce a voltage on the other side of the transformer or in the secondary coil even though there's no battery over there, a varying magnetic field is needed to be cut repeatedly (lenz's law). This can be done using an AC generator which produces a varying current, both in direction and value. And since a current in a wire produces its own magnetic field and the current is varrying the magnetic field will be varrying too. Then these magnetic field travel through the soft iron core which, I guess, happens because the primary coil rotates around the core, they are touching, so it's basically touching a magnet and getting magnetised by induction (when a magnetic material touches a permanent magnet and becomes a magnet itself too my book call this magnetisation by induction). However the current doesn't travel through it too, even though iron must be a good conductor of electricity, because the coil must be coated with an insulator. My question is what will happen if the insulating coat of some wires fell off and current can travel through the soft iron core? The wires doesn't have to be next to each other because I know they may create a short circuit maybe they're separated by other wires which are still insulated. what will happen if the insulating coat of some wires fell off and current can travel through the soft iron core? If the core is ungrounded then the core will just be...

Hint: The capacity of a ferromagnetic material to tolerate an external magnetic field without getting demagnetized is measured by coercivity, also known as magnetic coercivity, coercive field, or coercive force. Electric coercivity, an equivalent quality in electrical engineering and materials science, is a ferroelectric material's capacity to tolerate an external electric field without becoming depolarized. Complete answer: In transformers, soft iron cores are utilised because they have excellent magnetic permeability, which focuses magnetic lines of force and reduces energy loss. Because soft iron has a high permeability, it allows full coupling of magnetic flux from the main coil to the secondary coil in the core of a transformer. It has a high coercivity and a low retentivity as a result. A solenoid is the simplest motion generator, consisting of a coil with a soft iron core (or armature) that glides easily in and out of the coil. Soft iron is utilised because it does not lose its magnetic field when the current is turned off; in other words, it does not get magnetised permanently. The transformer core offers a magnetic route via which flux can be channelled. Improved core building procedures, as well as the use of highly permeable material (which characterises the material's capacity to transmit flux), assist in producing a desired, low reluctance flux route and restrict lines of flux to the core. Low stray magnetic fields in Iron Core Coils help solve a variety of di...

What is Transformer Core Saturation? Before to know about transformer core saturation you must know about reluctance, magnetic flux, flux density, and mmf (ampere turn). Simply we can compare with the analog electrical quantity. In electrical circuit, Resistance, current and voltage (EMF). The same quantity in magnetic circuits are in the same order reluctance, magnetic flux and ampere turn (mmf). Lets see Resistance => oppose the flow of electrical current Reluctance => oppose the flow of magnetic flux Current => flow of electron Magnetic flux => the electric energy expands in to magnetic field. The field force is called magnetic flux. EMF => electro motive force typically voltage MMF => Magneto motive force. Typically, ampere turns Simple understanding about magnetic saturation: i.e in analog circuit copper or aluminium conductor carries the current, it has own internal resistance… this resistance opposes the flow of current and results line losses and the cable gets warm. Further If you increase the flow of current in the same conductor, the conductor may get damaged. The same principle is used in magnetic circuits. In magnetic circuit, the conductor as core, resistance as reluctance, current as flux density. In normal condition, we apply the voltage, the flux produced, the flux pass through the core and reaches the secondary or primary winding and produce counter induced voltage in the secondary or primary. Here The reluctance of the core is normally less. If the appli...

Table of Contents • • • • • Why is soft iron is chosen as the material for the core of the transformer? The reason for having a soft iron core is that it is capable of producing internal magnetic flux densities some 10,000 (relative permeability) times stronger than in air. This is the basic principle of induction where, as engineers, we exploit the magnetic properties of the soft iron core material. What are the advantages of iron core in the transformer? The magnetic reluctance of iron is less so that it allows more flux through it. Heat losses are less. It is used for low frequencies (<10KHz). Why iron is chosen as the material for the core of the transformer why not we use Aluminium? The ability of iron or steel to carry magnetic flux is much greater than air. This ability to carry flux is called permeability. Thus iron core is used in transformer in place air core. This means that the ability of a steel core to carry magnetic flux is 1500 times that of air. What is produced in the iron core of a transformer? A basic transformer is made from two coils of wire, a primary coil from the alternating current (ac) input and a secondary coil leading to the ac output. The primary coil current produces a magnetic field, which changes as the current changes. The iron core increases the strength of the magnetic field. Why is soft iron preferred? Soft iron core is used in electromagnets because they get easily magnetised/demagnetised when current is flowing or not flowing along th...

Table of Contents • • • • • Why does an electromagnet need an iron core? An iron core makes a temporary electromagnet. It loses its magnetism as soon as the switch is opened and the current is switched off. A steel core makes a more permanent magnet. It does not lose its magnetism quickly when the current is switched off. Why does adding an iron core make an electromagnet stronger? Putting a piece of iron or steel inside the coil makes the magnet strong enough to attract objects. The strength of an electromagnet can be increased by increasing the number of loops of wire around the iron core and by increasing the current or voltage. Why is an iron core used? The purpose of the iron core is to channel the magnetic flux generated by the current flowing around the primary coil, so that as much of it as possible also links the secondary coil. Which iron core is used in electromagnet? Soft iron Hint: Soft iron acts as a magnetic core for the electromagnet in case of an electric bell. When current passes through it, it magnetizes and produces a strong magnetic field and also increases its strength. Why do we prefer soft iron for the core of transformer? In transformers, soft iron cores are utilised because they have excellent magnetic permeability, which focuses magnetic lines of force and reduces energy loss. Is core magnetic? In a sense, yes. The Earth is composed of layers having different chemical compositions and different physical properties. The crust of the Earth has some...

What is the difference between schematics for air core and iron core transformers? The advantages of an air gap TransformerHigher values of mmf can be tolerated before saturation takes placeReduced core losses.The flux is less sensitive to changes in current and temperature.Cores can be obtained in adjustable versions.The disadvantages of the air gap are -More turns are required to obtain a given inductance.Increased losses in the windings.Increased leakage inductance.Increased radiated field.Increased susceptibility to external fields.AnswerThe schematic symbol for an iron-core transformer is a pair of parallel inductors separated by a pair of solid lines; for an air-core transformer, the parallel lines are omitted. Air-core transformers are used for high-frequency applications such as radio circuits. How does Lenz's Law explain power loss in transformers? It doesn't, really. The power loss in transformers is broken down into copper loss and iron loss. The copper loss comes from the resistance of the windings in the transformer and depends on the load current, while the iron loss in the magnetic core depends on the magnetic flux density and is constant if the supply voltage is constant.

We usually see induction produced by two coils wound around a transformer core: [ ] Can you please specify if there is induction if we eliminate the core? Do we have to arrange the coils one inside the other? If the core can increase induction, to what extent can we increase it? What happens if, in the above transformer, we connect an appliance to both windings, do they both get half power or only the appliance connected to the second winding will work? Also, can we get induction with straight wires? $\begingroup$ I don't think your question is very clear. Without a complete circuit/closed path, no current can flow, although an emf may exist. As such perfectly straight wires are impossible for induction to take place. However this is not the case if you take into account the thickness of the wires. $\endgroup$ $\begingroup$ What you need is flux linkage between the primary and secondary circuit. The "soft iron" increases the linkage as does increasing the number of turns. If you have a primary circuit with a vertical bit of wire which is parallel to the vertical bit of wire which is part of the secondary circuit you would get an emf induced in the secondary circuit provided the current in the primary circuit is changing. However the magnitude of the induced emf would be much smaller than for the circuit shown in your diagram. $\endgroup$ To answer the questions • Yes, there is still induction even if you remove the core of the transformer. • No, you do not need to arrange ...