Why ferrite core is used in smps

For that reason, the smaller operating flux density of 2 kG will in most cases confine the core losses, consequently helping an affordable temperature increase in the core. Above 20 kHz, core losses maximize. In the feed forward circuit laid out in Figure 4A, the transformer executes in the 1st quadrant of the Hysteresis Loop. Fig 4B. Unipolar pulses implemented to the semiconductor device bring about the transformer core to be powered from its BR value near saturation.

As the pulses are downsized to zero, the core reverts to its BR rate. To be able to keep up a superior efficiency, the primary inductance is maintained high to help reduce magnetizing current and lessen wire drawdowns. This implies the core needs to have a zero or a bare minimum of air flow opening.

If you have any circuit related query, you may interact through comments, I'll be most happy to help! Your email:. Thank you sir. Lima, yes formulas can be confusing and difficult to solve because they usually involve a few complex parameters which may be difficult to identify in a given ferrite core design.

Presently I have no related article which I can recommend you, but may be I'll publish one soon and let know once it is posted. Thank you sir very much. By the way a cassettes player trafo will not be able to produce watt… not even watts.

Dear Swagatam, Thank you for your excellent informative posts as always. I was wondering if you have any suggestions with regards to a ferrite transformer that can output 50 kV p-p at 2 mA max current.

The switching frequency will be between 40 kHz to 75 kHz. I was thinking of an ETD core. I wanted to have your opinion before building a prototype. Thank you Dear NN, I have one article which explains how to design a ferrite core transformer, you can apply the specified formula for estimating the transformer details.

Since current is very low you can use a thinnest possible wire, may be a 0. So, before you roll your eyes at my comment, know that mine are stuck in the back of my head.

Consider that people seeking advice might not have a EE degree. Would it be a big problem to provide some simply and practical answers. Kids today. They want instant gratification. You can probably sense my frustration. If someone arrived here and found the info valuable, then great. Inner Dia. Rdc Ohms. Accuracy Class Select 0. Rd Ohms. Select 1 1 25 1 L mm MM. Dear Mr swagatam Sometimes i try to repair vfds or some other circuits wich smps section is completly destroyed.

Output includes different voltages with different watts. I have an idea.. I have tried this before with uc and 2sk…few success. Dear Ehsan, If the voltage, current and frequency are correctly matched then probably we can replace them, but without proper calculations it can be a lot risky to try this. In the other hand. It can be very difficult to provide a common clue, because SMPS have different topologies and transformer configurations, therefore along with the frequency, the configuration setting will also need to be matched.

Hello and thank you for your good website. Please make the watt inverter with pcb Please help me to make an inverter at home. Thank Farhad from Iran. Thank you, you can use any standard oscillator based inverter circuit and upgrade the MOSFET, transformer, battery appropriately to get watts. Hi thank you for your good website and perfect information. The area of the circular core should be equal to the Effective Cross-Sectional Area that is referred from the linked datasheet.

Nice article. Thanks for sharing. Hi, If you got the shown results through proper calculations then definitely it will provide you with the intended results. Can ferrite core be used instead of silisium wafer at low frequencies? If used, what are the benefits and harms? Dear sir, I have a switching transformer with a blown primary winding. I have the schematic that the SMPT came from. Please can you tell me if you can possibly rewind my transformer or give me a telephone number that I can call I live in the UK and would appreciate and help that you can give me.

Hello your article is very educating. I wonder how to choose the proper wire gauge with correspond to its current. Does wire gauge will not affect the number of turns? I think number of turn is depend on the current and wire gauge.

It will affect but not much…. This method allows compact winding and does not affect the number of turns. By the way thicker wire will also mean bigger bobbin, and therefore the cross-sectional area Ac will also change accordingly. I do design high end audio amps, and sinds short also do put a eye on class D where the multilevel is of mine interest, I have simulate some and the 5 level did has dB distortion at watts.

I did see your transformer calculations but are there also some for resonance smps what I do want, these does have low emi and this is good for aufio amps. I have some transformers but buying the bigger ones is difficult or I have chinese with wrong specs, much counterfeit there,.

I need to calaculate a transformer who give volts mA, 2 x volts mA, 1 x Hi, I appreciate your feedback, however at this moment I do not seem to have the calculation for resonance SMPS transformer, if I happen to find it will update it for you at an earliest.

So you mean to say Transformers for Full Bridge topology should have air gap. Please guide how to calculate Air gap for this type of transformer. For E-cores you will have to insert a paper gap between the surfaces of the cores that touch each other.

Just insert a layer of paper or a layer of insulation tape between the core end surfaces that clamp each other face to face. Can you please give any points to consider if I want to operate a standard halogen SMPS at a higher frequency with a view to applying gentle induction heating to embedded metal parts.

Sir, good evening, this is a great article i enjoyed reading it several times. PLS let me know, bcoz i need to know how to calculate primary and secondary side current with prefect wire guage. Sorry for my english. Pls reply soon. Thank you srinivas, wire thickness decides how much current the wire can carry, or the current handling tolerance of the wire.

You can estimate the thickness with some experimentation or trial and error method, or you can refer to the charts and calculations as given in the following page:. Hello Sinu, core size will need to be verified practically, since it will strictly depend on the wire thickness and the number of turns it can accommodate.

Below hertz calculations are same. It is in a datasheets or via an experiment. It is very incorrect but — 40KHz at square centimetre Ni-ferrite Gauss can transform I am looking to charge a portable phone which requires 6VAC 60Hz from a normal wall adapter.

Problem is that I have a 12VDC power source only and it is impractical to run a conventional VAC inverter just for powering this wall adapter and just to keep a portable phone charged.

I think I could solve my problem with something more efficient using a into a perhaps isolation transformer phone line on portable phones is connected into power source which is another issue that drives the need for isolation transformer. Can you recommend a particular transformer or instructions with how to wind one which will serve a isolation purpose to attach to some of your example circuitry that performs efficiently at the lower Hz of 60cps?

I assume I could just reduce the power supply of to approach the 6VAC on the output rather than experimenting with winding and re-winding different ratios. And since 6VAC is not exact, just trying to make things simple. So I have a question… My husband wants to know if you take a V Distribution electrical Input to 12V 19W EI Ferrite Core Power Transformer Converter, with the 2 red wires on one side and the 2 blue wires on the other, is it possible to simply switch them?

Make them function opposite then their original state? No it is not possible to switch ferrite core transformers with 50 Hz or 60 Hz, unless the transformer has a huge ferrite core with a huge number of winding turns…. But is STRICTLY recommended to avoid the experiment — via over voltage of v red-red winding will be broken up in seconds to fire with splash of a melted copper e. Just connect colored wires in sequence: phase-red1.

Or phase hot -red1. Or phase-red1. Use AC-voltage meter and kiloohms watt resistor as load. Remind risc of electric shock with ALL autotransformators at all time!!!! The diameter of the wires will need to be selected with some trial and error or through online charts which tell you the wire thickness with respect to its current carrying capacity.

Diameters of a wire for all windings of all transformers are depends on load-regime. Also your converter must not be a source of an electromagnet notices — via set of frequency 50 x N hertz with correct primary filters with correct designed shields e.

Onyeka, the power will depend on how you accommodate the winding and the number of turns on the core. If you do it efficiently you would be able to get the maximum power output from it. I am so much happy for this topic you have explain.

I would like to ask if this will be possible in making Designing a SMPS transformer for a power supply and how to choose the proper wire size for the primary and secondary. Glad you found it useful! Yes, it is specifically intended for designing SMPS transformers.

Wire dimension will need to be confirmed from appropriate copper wire current charts. Your email address will not be published. Notify me via e-mail if anyone answers my comment. You'll also like: 1. Half bridge and full bridge both can work with two wire primary. Thank you my mentor for your expected response. Hello Kingsley, The formula results are dependent on the turn ratio between the primary and the secondary, and also the E core selection.

Thank you sir. Ok, My boss! I will consider doing it as you have said. Thank you dear. Is it safe to remove the capacitor? And if you did, will the circuit still work? Capacitor works like a series resonant circuit for optimal performance of the inverter. Hello, I think you can get a complete ferrite core based converter kit from ebay. Yes you can use it, just make sure to configure the output of the IC correctly. Ferrite cores are the best choice for high-frequency applications. For operation below KHz, most designers will use a core material with a permeability of to Permeability varies significantly with temperature rise and operating flux density.

In general, this will not affect operation of the converter as long as the core is not close to saturation as the inductance which controls the mode of operation is primarily determined by the air gap. However, temperature rise, and operating flux density will affect core losses, and this must be taken into account to ensure reliable operation.

The core shape and window configuration are important for high-frequency transformer design to minimize losses. The winding window area should be as wide as possible to maximize winding breadth and minimize the number of layers. This minimizes AC winding resistance. Determine the V-T value based upon the maximum allowable duty cycle and the frequency. Determine the minimum number of primary turns required to support the worst case V-T value. The smallest size and lowest cost transformer is achieved by fully utilizing the core.

In a specific application, optimum core utilization is associated with a specific optimum core gap length. The core gap will be determined by the number of primary turns and the inductance specification. The designer will verify that the gap is sufficient to prevent core saturation.

Note: Push-pull, forward, half-bridge, and full bridge converter topologies typically do not require an air gap, since it is actually true transformer action. Once all the winding turns are determined, the wire size should be properly chosen to minimize the winding conduction loss and leakage inductance.