Ferrite Transformer Turns Calculation for High.docx

Ferrite Transformer Turns Calculation for High-Frequency/SMPS InverterOn different forums, I often find people asking for help in calculating the required turns for a ferrite transformer they are going to use in high-frequency/SMPS inverters. In a high- frequency/SMPS inverter, the ferrite transformer is used in the step-up/boost stage where the low voltage DC from the battery is stepped up to high voltage DC. In this situation, there are really only two choices when selecting topology – push-pull and full-bridge. For transformer design, the difference between a push-pull and a full-bridge transformer for same voltage and power will be that the push-pull transformer will require a center tap, meaning it will require twice the number of primary turns as the full-bridge transformer. Calculation of required turns is actually quite simple and I’ll explain this here. For explanation, I’ll use an example and go through the calculation process. Let’s say the ferrite transformer will be used in a 250W inverter. The selected topology is push- pull. The power source is a 12V battery. Output voltage of the DC-DC converter stage will be 310V. Switching frequency is 50kHz. The selected core is ETD39. Remember that the output of the transformer will be high frequency AC (50kHz square wave in this case). When I refer to an output of high voltage DC (eg 310VDC mentioned above), this is the DC output obtained after rectification (using ultrafast recovery diodes configured as bridge rectifier) and filtration (using LC filter). During operation, the battery voltage does not stay fixed at 12V. With high loads, the voltage will be less than 12V. With low loads and near-fully charged battery, the voltage may be higher than 13V. So, it must be kept in mind that the input voltage is not constant, but is variable. In inverters, the battery low-cut is usually set at 10.5V. So, we’ll take this as our lowest possible input voltage. Vinmin = 10.5V The formula for calculating the number of required primary turns is: For our push-pull transformer, this will be one-half the required number of turns. Npri means number of primary turns; Nsec means number of secondary turns; Naux means number of auxiliary turns and so on. But just N (with no subscript) refers to turns ratio. For calculating the required number of primary turns using the formula, the parameters or variables that need to be considered are:  Vin(nom) – Nominal Input Voltage. We’ll take this as 12V. So, Vin(nom) = 12.  f – The operating switching frequency in Hertz. Since our switching frequency is 50kHz, f = 50000.  Bmax – Maximum flux density in Gauss. If you’re used to using Tesla or milliTesla (T or mT) for flux density, just remember that 1T = 104 Gauss. Bmax really depends on the design and the transformer cores being used. In my designs, I usually take Bmax to be in the range 1300G to 2000G. This will be acceptable for most transformer cores. In this example, let’s start with 1500G. So Bmax = 1500. Remember that too high a Bmax will cause the transformer to saturate. Too low a Bmax will be under utilizing the core.  Ac – Effective Cross-Sectional Area in cm2. You will get this information from the datasheets of the ferrite cores. Ac is also sometimes referred to as Ae. For ETD39, the effective cross-sectional area given in the datasheet/specification sheet (I’m referring to TDK E141. You can download it from here: www.tdk.co.jp/tefe02/e141.pdf ), the effective cross-sectional area (in the specification sheet, it’s referred to as Ae but as I’ve said, it’s the same thing as Ac) is given as 125mm2. That is equal to 1.25cm2. So, Ac = 1.25 for ETD39. So now, we’ve obtained the values of all required parameters for calculation Npri – the number of required primary turns. Vin(nom) = 12 f = 50000 Bmax = 1500 Ac = 1.25 Plugging these values into the formula: Npri = 3.2 We won’t be using fractional windings, so we’ll round off Npri to the nearest whole number, in this case, rounded down to 3 turns. Now, before we finalize this and select Npri = 3, we better make sure that Bmax is still within acceptable bounds. As we’ve decreased the number of turns from the calculated figure (down to 3.0 from 3.2), Bmax will increase. We now need to figure out just how much Bmax has increased and if that is still an acceptable value. Vin(nom) = 12 f = 50000 Npri = 3 Ac = 1.25 Bmax = 1600 The new value of Bmax is well within acceptable bounds and so we can proceed with Npri = 3. So, we now know that for the primary, our transformer will require 3 turns + 3 turns. In any design, if you need to adjust the values, you can easily do so. But always remember to check that Bmax is acceptable.  For example, if for construction difficulties, winding 3 turns + 3 turns becomes difficult, you may use 2 turns + 2 turns or 4 turns + 4 turns. Increasing number of turns won’t hurt – you’ll just be under utilizing the core. However, decreasing number of turns increases Bmax, so just recheck to make sure Bmax is okay. The range I’ve stated for Bmax (1300G to 2000G) is just an estimate. It will work for most cores. However, with many cores, you can go higher to decrease the number of turns. Going lower will just be under utilizing the core, but may sometimes be required if number of turns is too low. you may have set Npri = 2 and calculated Bmax and decided that this was too high. You can also assign a value of Npri and then check if Bmax is okay. Feedback will just adjust the voltage required by changing the duty cycle of the PWM control signals.5V. The gap allows for dead-time. we’ll take maximum duty cycle to be 98%.5V to all the way down to 10. Thus duty cycle will be 98% when Vin = 10. a constant 310VDC output will be obtained throughout the entire input voltage range of 10. and repeat this process until you get a satisfactory result. in the MOSFETs. from all the way up from 13. At maximum duty cycle = 98%. So.5V.29V = 32.1 Since voltage ratio (secondary : primary) = 32. the headroom also compensates for some of the losses in the converter and thus compensates for the voltage drops at different stages – for example.98 * 10. Turns ratio is designated by N. output inductor.1 as turns ratio (secondary : primary) = voltage ratio (secondary : primary). If not.1. With proper implementation of feedback. Nsec = 96. you set Npri = 3 and calculated Bmax and decided it was okay. you set Npri = 3 and calculated Bmax and decided it was okay. in the transformer itself. For the PWM controller. some headroom must be left for feedback to work. you can then increase or decrease Npri as required and then check if Bmax is okay.5V = 10.5V and also input voltage equal to 13. Thus 96 turns are required for the secondary. Now it’s time to move on to the secondary. Besides feedback.5V to 13. duty cycle will be maximum. voltage ratio (secondary : primary) = 330V : 10. the transformer output must be 310V at all input voltages. So.1 (I’ve taken N as the ratio secondary : primary). etc. turns ratio (secondary : primary) must also be 32.1 * 3 = 96.5 = Vinmin. At minimum input voltage (when Vin = Vinmin). So.3 Round off to the nearest whole number. So. N = 32. voltage to transformer = 0. This means that the output must be capable of supplying 330V with input voltage equal to 10. we’ll design the transformer with secondary rated at 330V. Naturally. in our case. in the output rectifiers. The output of our DC-DC converter is 310V. feedback will be implemented to keep the output voltage fixed even with line and load variations – changes due to battery voltage change and also due to load change.29V. For example. So. Or you may have started with Npri = 4 and calculated Bmax and decided that it was too low.  I’ve started off with a set Bmax and gone on to calculate Npri from there. So.5V. So. Npri = 3 Nsec = N * Npri = 32. . 8V but needed more accuracy. if in our previous example. Let’s say we need an auxiliary winding to provide 19V. NA = Nsec / Naux = Vsec / (Vaux + Vd). instead of18. In the circuit. within the range initially specified (Vinmin to Vinmax – 10.Here. Here’s our transformer: .875V we had gotten 19. there we have it. so the duty cycle will be even lower.375V Vaux = 19.5V =15.0 (Vaux + Vd) = Vsec / NA = 310V / 16. a schottky rectifier with a Vd = 0.9 Nsec / Naux = NA Naux = Nsec / NA = 96 / 15.96 Let’s round off Naux to 6 and see what the output voltage is. Our transformer has 3 turns + 3 turns for primary. take Vaux as something higher and use a voltage regulator. the output will be 310V.0 = 19. I know that the output 310V will be regulated. If in your calculations you come to a voltage that is too far off the required target voltage and thus greater accuracy is required.375V – 0. So. Vsec / (Vaux + Vd) = NA = Nsec / Naux = 96 / 6 =16. the required turns can be easily calculated. maximum duty cycle in practice will be smaller since our transformer was calculated to provide 330V output. NA = 310V / 19. the advantage here is that you can be certain that the output will not drop below 330V even with heavy loads since a large enough headroom is provided for feedback to kick in and maintain the output voltage even at high loads.5V). whatever the input voltage may be. the turns ratio for the auxiliary winding can be calculated with respect to the secondary winding.9 = 5.875V (rounded off) I would say that’s great for an auxiliary supply. So. Let me show with an example. 96 turns for secondary and 6 turns for auxiliary.5V = 18. However. Vd is the output diode forward drop. we could've used 24V or thereabouts and used a voltage regulator to give 19V output. Let’s call this turns ratio (secondary : auxiliary) NA.5V to 13.5V is used. For example. one thing to note is that even though I took 98% as the maximum duty cycle. So. Let’s assume that in our application. If any auxiliary windings are required. Posted by Tahmid at 4:23 PM Email ThisBlogThis!Share to TwitterShare to FacebookShare to Pinterest 196 comments: 1. 2012 at 8:30 AM yes thamid it helps me very much. sandyDecember 24.Calculating required number of turns for a transformer is actually a simple task and I hope that I could help you understand how to do this. 2012 at 5:07 AM . I hope this tutorial helps you in your ferrite transformer designs.i have a dought generally ferrite transformers required high frequency to drive is 50khz enough to convert 12vdc to 310vdc? one more question home appliances required 230v then y we go for 310v ? Reply Replies 1. Do let me know your comments and feedback. AnonymousDecember 28. 310 = 230V RMS Reply 2. TahmidDecember 24, 2012 at 12:14 PM Hi sandy, I'm glad that my tutorial has helped you. 1) 50kHz is enough for use with ferrite transformer. Frequencies between 20kHz and 100kHz are usually used, with 30kHz, 50kHz, 75kHz and 100kHz being common frequencies. 2) I assumed 220V instead of 230V. I was thinking of sine wave inverter. So, to obtain a sine wave with RMS 220V, the peak must be 220V * sqrt(2) = 311V [sqrt(2) means square root 2, which is equal to 1.4142135....]. So, I took 310V since the DC bus voltage will be the peak voltage. When SPWM (sinusoidal pulse width modulation) is carried out, you will receive an output of 220V. If you are interested regarding SPWM, you may go through these: http://tahmidmc.blogspot.com/2011/01/generation-and-implementation-of-sine.html http://tahmidmc.blogspot.com/2012/10/smart-sine-software-to-generate-sine.html http://tahmidmc.blogspot.com/2012/10/generation-of-sine-wave-using-spwm-in_10.html http://tahmidmc.blogspot.com/2012/11/feedback-in-sine-wave-inverter-pic16f.html Hope this helps. Tahmid. Reply 3. sandyDecember 24, 2012 at 11:48 PM yes thamid i have a small request i am trying to develope a 150w inverter with smps transformer ,plz give your mail or send me a mail to this [email protected] .i will send my circuit diagram to your mail ,plz verify it for my satisfaction. Reply 4. veeraDecember 27, 2012 at 5:59 AM dear tahmid Its really helpful for me I was designing boost converter for my solar home ups. I need help from after reading the following link http://tahmidmc.blogspot.in/2012/09/some-of- my-smps-circuits.html I was in need of LCR Mere circuit can you post the firmware and circuit. Reply Replies 1. Rupali SdsMay 14, 2013 at 9:28 AM Thanks for sharing this info.Please visit my site also-design of transformer Reply 5. TahmidDecember 27, 2012 at 2:56 PM You can get it if you search on Google. A good design was, I think, the IronBark LC Meter. Do take a look. Reply 6. AnonymousDecember 30, 2012 at 12:50 AM Thanks for your reply...! regards veera Reply 7. Rony ChakrabortyJanuary 8, 2013 at 9:26 AM Dear Thamid I live in Chittagong. I'm also doing Power electronics research. Please contact me at [email protected], or my website is www.ekushebangla.com Reply 8. TahmidJanuary 8, 2013 at 1:03 PM Hi, If you are interested in contacting me, you can email me at inferno-rage (at) hotmail.com Reply Replies 1. AnonymousNovember 20, 2014 at 2:28 AM Hi Tahmid, It will be good if you post information about EMI filters for Inverters at the input. Reply 9. segarJanuary 20, 2013 at 8:35 AM hi, tahmid the circuits i have see its useful for any fast projects i have idea to build power inverter 6kw out put and input voltage is 48vdc the output voltage is 240vac, but in here i want to use SMPS transformer to built and the power mosfet ,can you help me to have any idea to guide me to help on it ,thanks so keep and touch Reply com/datasheets/1595842. Use SG3525 to feed into high-low side drivers that drive MOSFETs in full-bridge configuration. 2013 at 11:11 AM Hi. These MOSFETs will drive a ferrite transformer.farnell. I am planning on building a msps for a car amp.com/technical-info/refdesigns/iraudps1. For example in here:http://www. The amp requires a single 50v rail and 300watts.pdf they use a 29mm ring core for 500w(or even 1kw if i understood corectly). : 300w . THANKS BYE Reply 11. segarJanuary 20. I have this core witf 3F3 material http://www. YtsocJanuary 24. To be more precise how do i know how much power can a core handle? I know this varies with the frequency but have no idea how to determine it. 2013 at 8:41 AM hi. 12v to single 50v (regulated) . My hunch is that it's sine wave. Filter the output of the bridge and you have a sine wave output! Reply 12. That's the DC-DC stage done. So use microcontroller and high-low side drivers to generate SPWM and drive MOSFETs in bridge configuration.irf.com and also we can share many more on it TAHMID my name is SEGAR. I rather design the smps to be able to deliver this power continously rather than applying some music coeficient. Rectify and filter the output. you can directly email me via segarlinktech@gmail. most important being the desired otuput.TAHmid I forgot give you online email.10. TahmidJanuary 20.pdf . My big problem is choosing the transformer core. So. 2013 at 10:40 AM Hello tahmid. AC conversion stage will depend on a lot of things. Tahmid. etc. Reply 13. 2013 at 7:36 AM . 2013 at 7:17 AM hi i really love your tutorials but i would like to ask how i would go about when in comes to winding transformers for switch mode power supplies does the same rule apply and i would also like you to email me a h-bridge inverter circuit i would love to construct one for my final year project my email address is djultra0008@gmail. selected topology. Other factors that affect the power include operating frequency. TahmidFebruary 18. Will this core be able to handle the 300W continously? Also for this core . I will take a look at the core datasheets you have linked to and let you know more.com thanks Reply Replies 1. Regards. Bmax should be 100mT? Thank you ! Reply Replies 1. AnonymousFebruary 18. 2013 at 7:38 AM How much power a core can handle depends on the core itself and varies from manufacturer to manufacturer. A rough idea can be found in Abraham Pressman's "Switching Power Supply Design" book. TahmidFebruary 18. 2013 at 5:31 AM such a gr8 blog. Reply Replies 1.. 2.. I had in mind a low voltage to high voltage converter. 2013 at 2:33 AM how can we calculate b(max). Tahmid. djFebruary 23. I suggest you do some research and design the circuit. That shouldn't be a problem. Hi. although the same idea/principle can be applied for high voltage to low voltage converter. 2013 at 4:45 PM Choose something between 1300G and 2000G.... As for the H-bridge circuit.. How about starting with 1500G? Regards. The tutorial presented here is for switch mode power supplies. Reply 14. If you're stuck somewhere. Rupali SdsMay 2.?input voltage 12 volts dc.output 350 volts dc. I had the push-pull and full-bridge SMPS transformers in mind when designing it. then I can try to help. TahmidFebruary 23. Of course. Regards.. Tahmid..?? can u please tell me.flux density for E55 core.Potential Transformers Reply .please visit my site also. can u tell me how much gauss it will be?? and for e65 core also. TahmidFebruary 24. Tahmid.... Regards. 2013 at 1:26 AM dude. we're "playing it safe". Muhammad AbrarDecember 15. You choose what flux density the core is to be "operated".!!! how do we know that . Reply Replies 1. 2013 at 1:39 PM Hi Tahmid. by selecting an operating max flux density in the range 1300G to 2000G. This is usually quite a bit larger than 3000G. can we use 1300G to 2000G fulx density for 50 or 60 hz transformer if yes then what will be the turns fromula . This is done by selecting the number of turns with respect to the applied voltage. i found your articles very informative and helpful.specific core has specific gauss?? am using E55 core . A core has a limit up to which the flux density can be.. djFebruary 23. 2013 at 6:07 AM A core doesn't have a specific flux density.?? please tell me how much gauss it will be??reply me soon Reply 17.15. So. djFebruary 24. 2013 at 2:36 AM by using push pull topology Reply 16. Abrar Reply 18. AnonymousMarch 1. i seriously need them for my final year project.com thnks. plz reply me on my email muhammad. 2013 at 10:57 AM plz tahmid bro tell me calculations for full bridge same as u have explained push-pull here. Reply Replies 1.com or plz post it on your blog i will vist it sometime later. Reply 19. Regards. 2013 at 11:15 PM Upload the files to a file storage site such as rapidshare and share the links here. 2013 at 6:13 AM hi tahmid i have some h-bridge circuits i would like to share with you how can i get it across to you one involves the popular tl494 and the other involves the use of the use of the 556 and cd4013 and another involve the ir2153 chip i would like you to have a look at them and i need a few explanation on some areas my email is djultra0008@gmail. thanx Reply . TahmidFebruary 28. Just remember to make the files public. AnonymousFebruary 28. thanks ragards M.mohiuddin@live. Tahmid. . You know what i mean. 2013 at 10:20 PM Hi Thamid . And thanks for a good artical Reply . Rony ChakrabortyMarch 5. ভভভ ভভভভভ ভভভ ভভভভ ভভভভ ভভ ভভভ ভভভভভ ভভভভভভ ভভভভ ভভভ ভভ ভভ ভভ ভভ ভভভভভভভভভভভ ভভভভভভ ভভভভভভ ভভভভ ভভভভভভ ভভ ভভ ভভভভভভ ভভভভভভ ভভভভভ ভভভ ভভভভ ভভভভ ভভভভ ভভভভ ভভভভভ ভভ ভভ ভভভভ ভভভভভভভভভ ভ ভভভভভভভভভভ ভভভভভ ভ ভভভভভভভ ভভ ভভভভভ ভভভ ভভভভ ভভভভ ভভভভভভ ভভ ভভভভ ভভভ ভভভভ ভভভভভ ভভভভভ ভভভভ ভভভভভভভ ভভভ ভভভভভভ ভভভভ ভভভভভ ভভভ ভভভভভ ভভভভভ ভভভভভ .no center tap. now how to calculate delivered power? Actually it will be very helpful for ur reader if you refer using to relation between area product. Can u please describe How to select a core for a certain power. you'll see that I've mentioned that the same calculation can be used for push-pull and full-bridge. ভ Reply 20. the full-bridge transformer will only have Npri turns for the primary . কককককJuly 31. 2. where in a push-pull transformer. Tahmid.. Regards.. and i also have Ac an Al values form core datasheet. TahmidMarch 1. The only difference will be that. 2014 at 2:43 AM ভভভ ভভভভভ ভভভভভ. 2013 at 11:50 AM If you go through this tutorial here. Replies 1. suppose i need 500w output power. the primary consists of Npri + Npri turns.. winding area and core area.. Tahmid. Reply 21. you could do some searching too! You might learn something interesting! Regards. In the mean time. 2. abmMarch 7. Thanks for the suggestion! Regards. please can this calculation work for torroidal cores as well? thanks Reply Replies 1. I'll research into it and let you know. Although. Tahmid. 2013 at 1:26 PM Hi Tahmid. TahmidMarch 6. I'll try to write an article on this topic and post it soon. It should work. TahmidMarch 11. 2013 at 3:44 PM .just take the appropriate values from the datasheet. Replies 1. I haven't thought of it before. 2013 at 7:47 AM Hi. But just to be sure. abmMarch 21. 2013 at 12:49 PM It should . It's intersting and it's good that you brought it up. eg for ETD39 or ETD49. 5. 3. 2013 at 12:00 PM . Tahmid. i will sure check them out more. 4. do you have experience with this pleae help out thanks.g etd39 or etd49 and so on. by matching the dimensions of your core against the datasheet figures you can identify which core. Common cores used in computer power supplies are EI33 (most popular) and ERL35. 2013 at 5:42 AM I think you should be able to get them quite easily. abmApril 12. Regards. TahmidApril 22. just another issue. I know that Farnell India. TahmidMarch 26. which I think is now element14. AnonymousMarch 11. Tahmid. Reply 22. thanks tahmid. i use to try salvaging the ones from computer psu please how can i identify the type of transformer they are e. 2013 at 5:29 AM Look for the datasheet. The number (eg 49 or 39) is dependent on the dimensions of the core. So. Regards. its not easy getting these ferrite transformer here let alone getting the datasheet. has quite a lot of them. 2013 at 9:46 PM thanks. The preceding letters (ETD) denote the "shape" and type of transformer. but please do you know where i could get this cores in india. blogspot.this transformer of any not found circuit diagram now me... Reply Replies 1. starMarch 16.. 2013 at 12:50 PM I'll see and let you know. Tahmid. .com/files/850668221/ir2153%20fill-bridge. I've written an article / tutorial regarding using the SG3525: http://tahmidmc. TahmidMarch 11.com/2013/01/using-sg3525-pwm-controller- explanation.plz sir tahmid needed me inverter circuit diagram of this ferrite core transformer. TahmidMarch 18. Regards..html Hope you find this helpful. 2013 at 12:16 PM You can design the circuit yourself using the SG3525 PWM controller...com i would post some later Reply Replies 1. 2013 at 12:50 PM sir plz given me inverter circuit diagram on this transformer...png my email is djultra0008@gmail. hi tamid could you pls check out this h-bridge circuit use this link https://rapidshare. Reply 23.. . 2013 at 11:54 PM hello Tahmid keep the good work going. Thank u 3.. Tahmid. Tahmid. Reply Replies 1. Regards. TahmidMarch 18. 2. You can use the calculation methodology for your own use in your own circuits. Reply 24. I am running into a lot of problems that only u can help me. 2013 at 1:00 PM or some circuit diagram received but the diagram in auxiliary winding not found. Regards. 2013 at 12:17 PM The transformer was calculated using an example. TahmidMarch 21.. AnonymousMarch 19. starMarch 16. I recalculated my primary turns for 24v transformer in the formular u gave but when I check I am getting nearly two times the secondary voltage i worked it out for Is there anything else to be changed in the formular other than the input nominal voltage from 12 to 24 v when working out the turns for the transformer. 2013 at 11:55 AM Recheck the calculations carefully to make sure you've done them correctly. .. Do let me know the results. 4. AnonymousMarch 23. Don't measure the output voltage without load. 2013 at 5:30 AM You're welcome. feedback or LC filter. 2013 at 1:04 PM sir your answer of waiting. Regards. Tahmid... TahmidMarch 26. Make sure you have an LC filter and a minimum load at the output. With no load. 2013 at 7:48 PM thank you Tahmid for your support I will do as u suggest because i was checking the voltage without load 5.. Reply 25.. starMarch 16. Without the load and LC filter. Reply Replies 1. 2013 at 12:17 PM . the output capacitor will charge to the peak voltage. TahmidMarch 18. Regards. you won't obtain the "averaging" desired and output will be too high. Tahmid. What about you? Reply 27. TahmidMarch 21. 2013 at 11:49 AM I live in Dhaka. I was very busy with school exams.i m only asking. we r working on 1KW inverter with below specs 12v-350v dc-dc converter with pushpull topology e65 core ferrite full bridge topology with igbt for ac-dc inversion we r planning to provide the isolated feedback with a transformer transformer specs are input will be from e65 core transformer and output must be scaled down to 5v dc to connect to sg3525... djMarch 19. ..... 2013 at 2:10 AM Hi Tahmid. Reply 26. Thanks for supporting designers.. Reply Replies 1. where do u live.. starMarch 18..? plz........dont your mind plz. Sorry for the late replies.... 2013 at 3:22 PM plz tell me.. starMarch 19.blogspot. Reply . Reply 28...if you are knowledge. TahmidMarch 21.. TahmidMarch 21. 2013 at 11:52 AM Go through this: http://tahmidmc. Tahmid. Reply Replies 1. 2013 at 11:50 AM You can calculate the transformer turns if you thoroughly go through this tutorial. plz provide us the details of the transforme like core to be used and no tunrs thanks in advance.. 2013 at 2:30 AM tahmid plz tell me inverter circuit diagram 12v to 220v step up on this trnasformer ferrite core.com/2013/01/using-sg3525-pwm- controller-explanation. Regards.html Regards. All steps have been covered. Reply Replies 1.. Tahmid. . 2013 at 12:08 PM Hi. 2. The 10^8 term comes due to conversion of the different units to "standard units". I hope that clears things up.25cm2 to give 330V but i dont know how you arrive at the 10 to the eighth power or the number 4 placed in the formula could you please give an explanation on it because i would truely appreciate it and secondly if i am going to calculate the number of primary and secondary turns for the transformer to work from 24VDC do i just have to put in 24 as the nominal voltage in or there is other things in the formula that will have to be adjusted or changed i truely have high regards for your work time and your answers to our questions thanks again please give an answer at anytime within your convenience thanks Reply Replies 1. TahmidMarch 21. You can eliminate the term 10^8 if you use m^2 instead of cm^2 and Tesla instead of Gauss. AnonymousMarch 20. You can just put in 24VDC there. Nothing else needs to be adjusted. That's where the 10^8 comes from. Wishing you success on your project. Thanks for the compliments. Tahmid.29. Remember that 1 m^2 = 10^4 cm^2 and that 1T = 10^4 G . 2013 at 1:24 AM hi tahmid thanks for your formula on calculating the primary and secondary turns for ferrite etd 39 core i understand the nominal voltage in which is 12 the switching frequency 50khz which is 50000 the bmax or flux density you choose to be 1500 and the core area 1. ie from cm^2 to m^2 and Gauss to Tesla. Feel free to ask if you have any further questions/queries. I chose 98% as a maximum to prevent cross-conduction. 2013 at 1:01 AM hi tahmid my project has been successful so far but i need to get something clear about "FEEDBACK" i plan to have 288VDC at the output of my dc-dc converter with lc filter. Tahmid..2. you'll need more turns on the transformers.96 so 13. There isn't a benefit to running it low. Instead. 2013 at 9:20 PM thanks tahmid i fully understand everything worked on my project and everything is working well but one more thing the 98% duty cycle you choose to calculate the number of secondary turns is it that you must use 98% or you can choose a lower duty cycle and whether the duty cycle is high or low what effect would it have on running home appliances thanks again you are the BOSS 3.. 5. so from pin 16 to pin 2 of the "SG3525" i put a 5k6 resistor thus voltage at pin 2 is 3.98*22.. In practice it'll be much lower due to feedback. AnonymousMarch 24.05. NOTE BRIEFLY i am operating from 24VDC i made my calculations for primary turns using the formula. checked b max and everything is in acceptable position i know i need some headroom for "FEEDBACK" to work so i took 98% duty cycle and calculate 0. . so 450:5 would give a 90:1 resistance ratio.77 rounded off to 98 to be my number of secondary turns do you think my calculations is right? i am looking forward for your reply thanks again in advance and remember you are the BOSS. TahmidMarch 26.5 minimum voltage which gives 22. AnonymousMarch 27. 2013 at 5:32 AM Thanks for the compliments.2 would be 288.96*7 which is my number of primary turns gives 97. from the output of the dc-dc converter i put a 450k resistor to pin 1 and 5k from pin 1 to ground so the voltage at pin 1 and 2 are equal.. so 90*3. 4.05=13. so i calculate my secondary turns by taking 308V:22. Regards.. feedback and a minimum load. Reply Replies 1. how about the diameter of wire? whether does not effect with the output voltage? thank you for your advise. The resistance ratio will be 91:1 and not 90:1 as you have mentioned. Regards. 2013 at 11:56 AM This will depend on the wire itself. . Tahmid. with no other resistor from pin 2 to ground. AnonymousMarch 22. Just Google for wire current rating tables or charts. 2013 at 11:21 PM Hi Tahmid. Regards. 2013 at 11:51 AM hi Tahmid. siktecMarch 21. 2013 at 1:27 PM If you put a 5k6 resistor from pin 16 to pin 2. how do i determine the current rating of wire for a particular transformer power. Reply 31. Tahmid. TahmidMarch 31. about the ferrite transformer above.2V as you have mentioned. You can get charts online. Reply 30. TahmidMarch 21. There are loads available. the voltage at pin 2 will be 5V and not 3. TahmidMarch 26. don't use thick wires. Please elaborate on wire sizing. 2013 at 1:09 AM Hi Tahmid. Reply 32. They'll suffer due to skin effect. Tahmid. Use multiple thin wires. 2013 at 5:33 AM Choose the wire such that it can carry the entire current without heating significantly. This is an excellent post. However. . AmruthMarch 23.htm Regards. BR Heri Reply Replies 1.com/Wire_Size.powerstream. is there any different wiring sizing for high frequency transformers ? Thanks Amruth Reply Replies 1. Take a look at this: http://www. Take a look at this: http://www. know that you need to choose the wire such that it can carry the entire current without heating significantly. I'll definitely write an article for wire selection.. They'll suffer due to skin effect. Reply 33. 2013 at 5:34 AM Hi. 2013 at 5:35 AM I'm glad you found it helpful. However. don't use thick wires. Udey RajMarch 23. TahmidMarch 26. TahmidMarch 26. Transformer turns ratio meter Reply Replies 1. Tahmid.powerstream. . Reply 34. Tahmid.com/Wire_Size. 2013 at 6:16 AM Thanks for sharing it is relevant beneficial information. Regards.htm Regards.. Use multiple thin wires.. For now. 2013 at 9:29 PM the 98% duty cycle you choose when calculating the number of secondary turns could you choose a lower duty cycle and what effect would it have when load is applied to the dc to dc converter Reply Replies 1. AnonymousMarch 24. TahmidMarch 31. off when there is no load ) ????? 2 My AC voltage increases with the amount of load I apply eg from 125 to 140v AC which stage could be giving me this problem I am using 556 and 4013 configuration Thank u for ur ususal support Reply Replies .I have three questions 1 with no AC load on my h bridge should i be getting my 5v drive voltage on the gates of the fets in the dc-dc converter I am using one of ur drive circuits ( My voltage only comes on when a load is connected and increase with added load. which would result in a short-circuit. 2013 at 11:15 AM 98% is the maximum duty cycle that I have taken to be allowable. AnonymousMarch 25. There isn't much of an advantage to using a lower duty cycle. Regards. I have been trying to put together an inverter over a year now and it since I saw ur blog I am getting some good results. 2013 at 10:54 PM Hi Tahmid I think this is the best pratical inverter building forum on the internet u are teaching the world. The actual duty cycle will be much lower than this in normal operation. Reply 35. due to the implementation of feedback. This has been done to prevent cross-conduction between switching devices. Tahmid. I hope to add more and make my blog even better. Without a diagram. If all's well. I am using a drive circuit similar to you figure 5 design the only difference is there is no 10k from base to ground on my circuit. It sounds like a problem in the driver circuit. Could u answer the other part of the question about the increase in AC voltage with increase load which stage could be giving me that problem . If you must test it. Testing without load can give erroneous readings. connect VS to ground and test the voltage and frequency at HO with respect to ground.1. Your ideas and suggestions are welcome. 2. TahmidMarch 26. Make sure that the driver circuit is working properly. You can upload your schematic to imageshack or photobucket or other such site. 1) There should always be a load at the H-bridge output. remove the MOSFETs. l youngMarch 27. all I'll be doing is guessing. TahmidMarch 31. Tahmid. I said I want to know if i should have the drive volt on the gate of the fet any at all with no load connected to the h bridge or only when a load is applied this voltage should come up on the gate. Regards. it'll be difficult to try to figure out where the problem lies without taking a look at the circuit diagram. Thank you for usual support 3. A circuit diagram will reveal where the problem may lie. 2013 at 5:54 AM Thanks man. Which driver are you using? Can you show the schematic? 2) It could be the drive stage. remove the short from VS to ground and then connect the MOSFETs. 2013 at 11:13 AM The drive voltage doesn't show properly on the high-side due to the "virtual ground". 2013 at 1:55 AM Thank u for your reply Thamid but i am not sure I got A Clear answer. Regarding voltage difference. . use SG3525. l youngApril 2. Regards. 4. Tahmid. even though nothing can be said with certainty without taking a look at the circuit. Tahmid. use two push-pull stages to drive both transformers. saiApril 1. However. I suggest that you. Regards. Regards. just feed the otuput of the SG3525 to the MOSFET high-low side drivers. you should use the converters in parallel and not the transformers themselves. Reply 36. For example. TahmidApril 5. both from the same input signal. Feel free to ask if you have any query or doubt. 2013 at 9:38 PM . Thank you for your support 5. Tahmid. One more question which design is better to handle heavier loads the paralell or series transformer configuration in the dc to dc converter. instead of using 556 and 4013. Then. with current limiting. 2013 at 8:58 AM I recommend using one transformer instead of multiple in series/parallel. if you're using push-pull topology and have two transformers. That will be better. 2013 at 11:12 PM Thank you Thamid for your reply I will check to see my drive circuit is working properly. I hope you have received the answer to your questions. You can connect the outputs in parallel. if you must use more than one transformer. 2013 at 8:47 PM thanks a lot for responding tahmid. saiApril 2. 2013 at 9:08 PM . Could you please mention which link (1kW SMPS inverter) you are talking about? You can choose one of the higher power ETD cores for this purpose. the only problem is that i am unable to find ft37-77 core.... ETD54. frequency. initially i thought of using ft37-77 core but later realized i cant find them in here. 2013 at 5:51 AM Hi.. Some cores you may be able to use are ETD49. 3. Hope this helps! Regards.. saiApril 2.thnks again... so could u please help me by suggesting an etd core as an alternative to toroid core and ways to wind it with copper wire. etc.i will be really thankful. etc.i know very little about winding an ETD core so i thought if u could help in selecting an ETD and procedure for winding it. Tahmid. Reply Replies 1.. at 50 khz. i am building a 1kw inverter based on push pull topology for the dc boost stage which is 12v to 32o v dc using ka3525 pwm chip as in ur link.. you need to keep in mind other factors such as winding. Of course.. 2. TahmidApril 2.hi tahmid... i have been following all your you-tube posts and blogs on eda board.. i am building a 1kw smps inverter according to the circuit diagram you gave in ur link....i am new to this smps stuff. .. as switching frequency increases.. you should look to use thinner wire.com/download/21937039/invertercircuit.html 4.. Reply Replies 1. at a switching frequency of 50 khz if i use 22 awg wire to wind the transformer.. Refer to this chart: http://www. TahmidApril 5. here is the link to the circuit diagram http://www. AnonymousApril 2.com/Wire_Size. but there is a few things i want to get more clearly.png. Reply 37.. Tahmid. 2013 at 8:48 PM hi again tahmid my project is more successful as i go along.powerstream. 2013 at 9:06 AM I have mentioned some ETD core names in the above post.ziddu. my questions to you now is..? next do i have to use a higher switching frequency for a higher wattage inverter or it does not matter as long as the calculations are right...... if i change my switching frequency to 75 khz do i need a smaller wire like about 26 awg to wind the transformer. 2013 at 9:01 AM Yes.htm . bmax and all that.. Regards. according to your blog on ferrite transformer turns calculation i now have a clear understanding on how to work it out with respect to voltage. TahmidApril 5... thanks again for your usual support. My antivirus and browser prevent the webpage (where you uploaded the circuit diagram) from loading due to a "suspected web attack". Please upload again or to another file storage site. frequency. which do you think works better. i have seen inverters with the transformers in parallel connection and some with the transformers in series connection.. Keep in mind that the higher the switching frequency. AnonymousApril 3.... Tahmid. the lower the required inductance. Reply 38. 2013 at 7:09 AM hi tamid i designed a 47kz push pull 12v to 310v converter but there is problem i seem to be getting close to 500vdc when rectified i am using an ei33 core ripped from a computer power supply though i have not yet implemented the feedback yet i did all the calculation for the transformer and got 3 + 3 turns for primary and 100 turns for secondary i am wondering if is bcos i winded the primary turns first b4 secondary i chose 1600g as flux pls any help would be appreciated.thanks again for your support. 2013 at 9:18 PM thanks tahmid all this really helps so to be more clear on all this you are saying its best to use a lower switching frequency for higher wattage inverters and one more thing.. AnonymousApril 5. but the higher the switching losses. Reply Replies 1.. Hope this helps. You can use a not too high frequency and just make sure that the calculations are correct. 2..... Regards. 2013 at 9:03 AM . capacitance and transformer turns.. TahmidApril 5. Thank you Reply 39. you'll be running at near 100% duty cycle which will mean very high voltages.20cm2 my question is : 1. You have to use feedback. Hope this helps. 2013 at 12:02 AM Hi Tahmid. The feedback circuitry is to regulate the output voltage depending on input line voltage and output load. This is the circuit I am having the gate voltage problem with.Please check to see if there is a circuit error. 2. 2013 at 8:04 PM Hello Tahmid I have attached the inverter circuit to an email and sent it to ur email address. what a good frequency for this application ? Thnks Regards Heri Reply Replies .com/prod/assets/ecores. can i produce 1500 Watt spms use this transformer at 38 kHz push pull? 3. assuming that proper feedback is in place. Regards. Without feedback. Remember that the calculations are done. L YoungApril 11.ferroxcube. The nominal operating duty cycle with correct feedback implementation will be quite a bit lower than 100%. i have ferrite core Type E55/28/28 http://www. i use TL394 for produce 38kHz for drive the push pull.htm with Ae 420mm2 = 4. Tahmid. herisetiawanApril 9. what the problem if i applied this transformer use push pull with frequency 38 kHz ? 2. Reply 40. Regards. No problems. TahmidJune 22. 2) I think you should increase the frequency. Tahmid. TahmidMay 2. 2013 at 5:44 AM 1) You can very easily use 38kHz. 1. 3) I would say 50kHz to 75kHz. Tahmid. Thanks for your valuble information about Ferrite Transformer you can give great help about transformer. 2013 at 2:50 PM . Luminous Inverter DelhiApril 11. 2013 at 6:33 AM Dear Sir. 2013 at 9:42 AM I'm extremely glad that you've found my blog helpful! Regards. AnonymousApril 14. Make sure you use good MOSFET drivers / driver circuits. Reply 41. Luminous Inverter Reply Replies 1. Reply 42.... 2013 at 5:25 PM hi again sir.html For the MOSFET driver. I hope to make my blog even better to reach out to help many more people like you. i really need this and thanks much again Reply Replies 1.. i have now managed to build a inverter using four dc-dc converters in parallel supplying 310vdc. TahmidApril 21.. I've written a tutorial covering the use of IR2110 for MOSFET drive in high-low side configurations (bridge configurations included).. I've written a tutorial covering the use of the popular PWM controller SG3525. For the PWM controller. you can use SG3525. is there any difference with the h bridge in a 12 volt inverter than that of a 24 volt or its just a standard circuit or the h bridge circuit is built according to the wattage of the inverter thanks. Check it out here: http://tahmidmc.. Set the frequency to 50Hz/60Hz as required.blogspot. 2013 at 9:10 AM I am extremely glad that my blog has helped you. Check it out here: http://tahmidmc. Tahmid. could u point me to a h bridge circiut that i could build with eight mosfets so i could get 230vac. you can use IR2110. AnonymousApril 14.html Hope this helps! Regards. hi tahmid your blog has helped me out the most sucessful way. .com/2013/01/using-sg3525-pwm-controller- explanation.com/2013/01/using-high-low-side-driver-ir2110- with.blogspot. you should be using the DC section of the voltmeter. 24V is preferred over 12V for higher powers due to the lower current (for the same power output). Regards. Place a sufficient load and use a feedback circuitry and then test again. 2013 at 9:13 AM Since your output is DC (you're using a DC-DC converter). . The AC section will give you incorrect reading. Tahmid. the principle is obviously the same. It sounds like you're measuring the output voltage with no feedback in place and with no load in place. AnonymousApril 15. TahmidApril 21. Reply Replies 1. Reply 43. 2013 at 9:06 AM No matter what voltage you use. This makes component selection and even wire selection easier and due to the lower current. TahmidApril 21. 2013 at 8:10 AM hi tamid here is a funny senario i built a 12v-310v dc-dc converter using an e-i33 core the funny thing here is when i read the ac output section with my meter it shows250v but when i read the dc section its giving me 500vdc is that the recovery diodes are recovering too fast or what ithe diodes i am using is mur460 pls if you have any solution it would be helpful thnks Reply Replies 1. places less "stress" on the components as they need to handle half the current. 2013 at 10:48 AM hi tamid i wound a transformer with with 1 primary turn and 3 sec turns for a push pull. Reply 44. TahmidApril 21. 2013 at 8:43 AM hi tamid do pls know how to manually calculate the area of an etd core . my bm is 2230 for 20khz 6 volt input 3. Regards. Tahmid. Reply 45.well since where i live it difficult to buy one so i usually come across so many core but with no labeling so i don't know the core type or its area if you any solutions it would be helpful thnks Reply Replies . 2013 at 10:11 AM How are you driving the transformer? What is the switching device you are using? Where do the drive signals come from? Your answering these questions will shed more light on the problem. Regards.35cm2 core area. jagadeshApril 16. Tahmid. but i dont get any output at transformer can u plz help me Reply Replies 1. AnonymousApril 17. A is one end that goes to a MOSFET "leg". Reply 46.A. Then attach the other end of the wire to another bobbin pin . .B. you can identify the core without needing to have labelling provided to you by your ferrite core supplier. That way. C is the other end that goes to another MOSFET "leg". B is the center tap that goes to the positive supply (since this is for a push-pull converter). 2013 at 7:27 AM when you say 3 turns + 3 turns. 2013 at 11:43 AM The transformer has a total of 6 turns primary. with a center tap.C. Hope this helps. Join one end to one of the bobbin pins . Then wind three turns and join the other end to another bobbin pin . 2013 at 9:04 AM You can measure the dimensions of the core and match the values against the values of a standard datasheet to identify which core you have. Take another piece of wire and join one end to the end B. okofisheApril 21. TahmidApril 28. Tahmid. Regards. Regards. Tahmid. TahmidApril 21.that is a number of 6 turns in the primary with 2 wires sticking out or what?please explain Reply Replies 1. wind three more turns. In the same direction (clockwise/anticlockwise) in which you wound the first three turns. You take a wire. 1. AnonymousApril 22. TahmidMay 2. Tahmid. AnonymousApril 22.. Reply 47.. Reply 48.....thanks again Reply .. the irfz46n is rated 50 amps so do i have to add more in parallel to my converter or do i need to purchase mosfets rated at higher amps for example irf3205 which is rated 110 amps and how much should i use. PLEASE i need your help or do you have a way to calculate and parallel mosfets to add up to a certain AMP for 600 WATTS ? PLEASE give me your most clear answer on this and keep up the good work thanks again BOSS . i need some help on selecting some mosfets for my dc-dc converter for a 600 watts inverter ( push pull topology } i use two irfz46n to drive my ferrite transformer but they heat and blow out in a short while. 2013 at 7:47 PM hi tahmid thumbs up again for your blog. 2013 at 5:49 AM How much load did you have at the output when the MOSFETs blew? Which PWM controller are you using? Describe the MOSFET drivers you are using. i have a ferrite torodial core the effective cross sectional area in cm2 is 0.. Regards.. Reply Replies 1...946 could i use it in the formula for my transformer calculations. 2013 at 8:51 PM hi again tahmid thanks for your continued help my question to you is... TahmidApril 28. Regards. Peak voltage in your cases seems to be 500V. you should be able to plug it in the formula for the calculation. Tahmid. 2013 at 11:53 AM Yes. 2013 at 11:35 AM Place any load that draws a current resulting in an output power of greater than minimum required power. AnonymousApril 24. the voltage rises to the peak voltage as the capacitor charges to the peak voltage. You might use 2 60W or 100W incandescent bulbs in series. Reply . TahmidApril 28. Tahmid. When you don't have sufficient load at the output. You can use 2 light bulbs in series. Reply 49. 2013 at 10:19 AM hi tamid in your replies on me getting about 500v dc you said i should place a load on the output and then implement feedback the question is how do i place a load on a 310vdc output and what kind of load are you talking about coz i dont have a load that will take such voltage i am buliding a small inverter and hope to build the circuit in sections thnks Reply Replies 1. Regards. Replies 1. Thanks for sharing this blog.50. 2013 at 6:44 AM This is very useful blog. Regards Heri Reply .20cm2 my question is : 1. what a good frequency for this application ? thank you very much.transformer suppliers Reply Replies 1. TahmidMay 2. Feel free to share any suggestions you may have. Reply 51. 2013 at 11:19 PM Hi Tahmid. Tahmid.ferroxcube.htm with Ae 420mm2 = 4. 2013 at 5:46 AM I'm extremely glad to hear that you've found the blog useful. Regards. i use TL394 for produce 38kHz for drive the push pull. herisetiawanMay 1. Rupali SdsApril 29. whether any problem if i applied this transformer use push pull with frequency 38 kHz ? 2. can i produce 1500 Watt spms use this transformer at 38 kHz push pull? 3.com/prod/assets/ecores. i have ferrite core Type E55/28/25 http://www.This blog is useful for construction. html Regards. Reply 52. 2) I think you should increase the frequency.com/2013/01/using-sg3525-pwm-controller- explanation. 2013 at 10:29 AM You will get your answer here if you go through it thoroughly: http://tahmidmc. 2013 at 5:44 AM 1) You can very easily use 38kHz. 2013 at 11:36 AM hi tamid in terms of feedback implementation how do i calculate my duty cycle for instance using the sg3535 setting pin 2 to 2. Tahmid. 3) I would say 50kHz to 75kHz.blogspot. No problems. TahmidMay 2. Tahmid. Regards. AnonymousMay 4. Reply . TahmidMay 17. Replies 1.5v as reference how do i calculate the resistor values for pin 1 for a lets say 90% duty cycle since these pins are responsible for the duty cycle thnks Reply Replies 1. Make sure you use good MOSFET drivers / driver circuits. it would be too difficult to understand what's causing the error. Reply 54.. bretMay 17. i red ur blog and lot of info in ur blog to me. SanjayMay 17.. Which controller are you using? Which driver are you using? Which topology are you using? Describe the feedback circuitry you're using. i turn on my project but switching mosfet are short- circuit . 2013 at 1:08 AM hi sir. TahmidMay 17. plz help me. Without more information. Reply Replies 1. 2013 at 2:50 PM . thank for u. my question is : my project's primary turns are 4.53. What are the input and output specifications? What frequency did you use? What did you select as the maximum duty cycle? Which MOSFETs are you using? Describe the transformer output section.. Tahmid. Regards. 2013 at 10:33 AM That could be due to a lot of things. Which transformer core are you using? What is your load? Your answering the above will help shed more light on to the problem. 2013 at 12:05 AM Hello. 2013 at 9:43 AM Take a look here: http://tahmidmc. my chager is to handle about 30Amps and 13. Pls i want you to tell me how to do the transformer turn calculation for an smps charger using the half bridge topology. keep the good work. 2013 at 9:41 AM . I. i really found your blog very useful since i discovered it.. hi Tamid.I found so many entertaining stuff in your blog.blogspot. The airticle "Ferrite Transformer Turns Calculation for High-Frequency/SMPS Inverter " is out standing. Tahmid. Reply 55. TahmidJune 22.com/2013/02/ferrite-transformer-turns- calculation_22.html I'm sure you'll get your answer there! Regards.m bret from nigeria. Trent PalmerJune 10.Thanks DC to AC power inverter Reply Replies 1. Reply Replies 1.8V output frm 220Vac input. TahmidJune 22. an LC filter with resonant frequency between 400Hz to 1500Hz should work well. AnonymousJune 23. I'm glad you've found it helpful! Regards. Don't use too high an inductance . Don't use too high a capacitance . Faruq Nigeria Reply Replies 1. I can use the method you post here for my high frequency low voltage DC to High voltage DC (20-400 VDC)tranformer design which works very well. BUT I am having problems with my SPWM wave input to Sine Wave output filter inductor.otherwise the output impedance will be very high. 2013 at 3:04 AM For LC filter. TahmidAugust 11. Tahmid. Then you need to size the inductor and capacitor.this will create rush currents. Tahmid. 2013 at 9:54 AM Hello Tahmid. Sorry for the long wind post. If your frequency is 50Hz. Regards. also for the 400v DC side filter inductor design I used the methods in Abraham pressman book and my filter works well. choose values such that the resonant frequency is close to your output frequency. Reply 56. Your help will be greatly appreciated. Reply . I am not sure if I should use the same method of low pass filter inductor core design method used in DC filtering or is there any special consideration you have to take into account in design of magnetic material for SPWM filter inductor (for pure sine wave output). Your Transformer calculation post has help me a lot in designing DC-DC converter but recently I moved to DC_AC inverter. We are also Manufacturer & Supplier SMPS transformer in India Reply 59. Tahmid. Reply 58. AnonymousAugust 4. Which way do you use to calculate it? Reply Replies 1.com/2013/03/output-inductance-calculation-for- smps. 2013 at 3:37 PM Hello Thamid. 2013 at 6:17 PM . Nilesh S. I actually have several formulas and all of them are no the same. Regards.blogspot.html I think you should find that helpful.VadharJuly 30.57. 2013 at 4:14 PM Take a look at this: http://tahmidmc. 2013 at 3:39 AM Nice post about SMPS transformers thanks for sharing nice information. AnonymousJune 26. TahmidJuly 20. I have a question about the equation to calculate an output inductor for a forward converter with a transformer (full bridge). Regards. AnonymousAugust 10.5V DC with 200mA . 2013 at 12:21 AM Did you go through the entire tutorial? Everything is covered in this article. Pls suggest design guideline. Bro i want to design push pull invertor . plz help me to design transformer. 2013 at 2:43 AM Dear. TahmidAugust 7. ?? Reply Replies 1. . Please read it carefully and then ask me if you have any specific questions. Reply Replies 1. input DC 40- 45 V. output 330-340 V and 500 W . I want to design transformer for 240V to 500V Input of AC supply and Output is 3. what turn ratio of transformer required . Reply 60. Tahmid. TahmidAugust 17. 2013 at 12:41 AM What kind of transformer are you designing? Are you using SMPS? What topology? 2. Reply 62. the secondary and primary is wound the in the same direction? Or can one just wound this bifilar style for primary. . We cannot think about current without transformer. they seem to wind sections side by side instead of 1 layer over the other. linking them. yes? Reason is. i would like some advice on winding high voltage secondaries. 2013 at 10:27 AM Hi. Reply 63. Firstly. Tahmid Do you still check your hotmail mailbox from time to time . and then to test it out. 2013 at 2:23 PM There is a big credit of transformer for getting us current constantly. AnonymousAugust 10. serving as CT. So it is better to know about transformer for every people. I`m trying to wind one. Say my calculations state 5 turns primary. yes? Lastly. Johan SagaertDecember 14. very informative. with the center two. 2013 at 3:53 AM Hi Tahmid!!! Very nice tutorials you have put up here. Thanks for sharing the information of transformer. From what i saw in microwave smps. so that means two wires on the primary side. need clarification on something. Reply 61. there is no guide on the internet that shows how to wind a ferrite toroid. Tahmid. over the many turns of secondary? In my circuit I need a step up. TransformerAugust 16. Servo Stabilizer Manufacturers. 2013 at 7:59 AM The voltage transformers are used in case of voltage fluctuations. TDAugust 28. tecmaxSeptember 2. You can confer the rigth flow of electricity to the electrical appliances inside your home and save the same from damages. Vin (nom) = 24v and it connect to 12v and out has a 40w bulb transformer sound like "trrrrr" why it is sound like trrrrr please help me Reply 65.keep on posting Inverter Manufacturer Reply 64. suki leeAugust 22. 2013 at 1:22 AM hi tahmid i have 2 qustion 1st is i make like you tarnsformer it work fine but it out 330v dc how i convert this to 230v 50hz sine wave Ac voltage ? 2nd is i make transformer to 12v-24v to 330v Vin min = 9v . thank you very very much that you are willing to share your knowledge. Isolation Transformer Manufacturers Reply 66. 2013 at 7:08 AM excellent blog about Inverter Manufacturing. Automatic Voltage Stabilizer Manufacturers. 2013 at 11:16 AM Hi really excellent blog. AnonymousOctober 1. not many do ! . 2013 at 3:29 AM hello sir. please solve my doubt how to calculate the gauge of the wire for your above given example of 3+3 turns & 96 turns xmer 50khz. 2013 at 12:30 PM hello tahmid sir. 2013 at 4:58 PM thank you this information was very helpful to me i'm designing smps to convert from 12vdc to 220vac 50hz I'm wondering about what are the stages I should follow with arrangement using also I don't know how to calculate the suitable frequency for the circuit what is the most important element of the power supply I should choose first Reply 69.i need to convert dc input range of 80v to 150v. Alaap JagdaleOctober 20.plz help me Reply 68. .and frequency range 160khz to 200khz. Thanks for the reply :) Reply 67.to 230v in ac. bareeza powerOctober 13. Here is a question. if I want to center tap the secondary to 96 + 96 turns. does the formulation change on the primary side to get the same output as with 1 secondary winding? Or will the 2 secondaries just divided the output power between them. ananth deepakOctober 8.using e65 core.and power of 1kw. can we apply P=VI & V=I(R+jXl) to find max ampere and accordingly the gauge or due to skin effect @ 50khz its better to use litz wire and if yes than of how many core wd respect to max current. thanks fmtech83 @yahoo. en este caso una celda tipo condensador de 1000uf Reply 71. 2013 at 12:10 PM Hi. llan perezNovember 6. However when I use the voltage (11V) coming from FET (bf245) I see 200mV on the output. I get 10-15times more voltage while testing signal generator. . fmtechDecember 5.com. Tahmid. Reply 70. Reply 73. 2013 at 7:35 AM hi. AnonymousNovember 22. I made my transformer with 8 primary and 100 secondary turn 33KHz ETD29 (76mm^2) with 11V input.what is the reason for that ? any help is appreciated Reply 72. 2013 at 2:16 PM hola mi pregunta es como se comporta una bobina bifilar en un transformador de ferrita tipo E. sin conectarlo de manera tradicional. si no en serie con la carga. pls can u help me with the code or connection for pic 16f72 sine-wave inverter to enable me make use of the normal off / on switch not the soft push reset type. yo le inyecto un voltaje de 24vcc a 10khz. My questions are 1.how do I make d calclation for: I have aaa ferrite core transformer with dis diamension 42mm*43mm*15mm. Can i follow your calculation for this rectifier?? 3. . (Transformer) how d i calculate Ac or Ae Reply 76. I am planning for design a high frequency rectifier for high current ranges with bridge rectifier construction. Vasu DevanDecember 15. I am an electronics engineer working in thyristor based high current rectifiers. Reply 74. Any book which guide me for designing this system?? thanks vasu Reply 75. 2014 at 10:23 AM Hi tahmid U r amasing pls i need ur assintance on how to calculte Ac or Ae of a ferrite transformer. can u please guide me and help to design the same. 2013 at 6:20 AM Hi this is really very helpful article. what is the maximum current i can get from high frequency rectifier?? 4. Distribution transformerDecember 6. I go through this site really very nice information. for low voltage high current DC output bridge rectifier is suitable?? 2. 2013 at 7:51 AM Dear Tahmid Nice to see ur blog. AnonymousJanuary 6.thank for sharing such a nice information. . with a EE4215 core. If no. In my country I can´t found a company that make that transformer. 2014 at 12:24 PM Hi tahmid! thanks a million for all your efforts. 2014 at 1:54 AM This comment has been removed by a blog administrator. Reply 77. CarliJanuary 28. 2014 at 11:58 PM Hi Tahmid. 2014 at 4:17 AM The isolation transformers are essentially devices that are used for the reduction of the power surges. thanks Reply 79. It has 2+2 turns in the primary and 56+56 in the secondary. then how do we calculate the relationship between input and output voltage?. Reply 78.pls assist. usama ja'afarJanuary 29. I have calculated a transformer for a Push-Pull SMPS that works with 12Vdc and the output is 410V.. Just got a question to ask: does the same principle apply to toroidal transformer(in smps). tecmaxFebruary 4. The safety and security of the devices can be accomplished by the installation of the devices. Zeebee RJanuary 15. Reply . Did you ever wound a transformer like this? Any suggestion? Thanks you very much and congratulations for your blog that is very useful. Runthala JaipurApril 10. 2014 at 7:20 PM how do you determine the b max value? there is not such a value on the datasheets. Very useful information regarding isolation transformer and its uses. Reply 83. 2014 at 8:28 AM Hi very nice post. 2014 at 5:48 AM . current and frequency will i get in secondary using ferrite core u type transformer.80. Reply 84. Wasim AhmedMarch 28. 2014 at 7:24 AM if i use primary of 21 turns and secondary of 3 turns and suppling 344volts dc then what voltage. 2014 at 6:02 AM hi dear can u share more article on this so that i can get more information on calculation transformer losses Reply 82. Reply 81. sergulen yenidoganMarch 21. Thanks for sharing this useful blog. niranjan tiadiApril 3. Nyza ShareefMarch 28. Reply 85. Vathi rajanApril 26. Pedro CockwellApril 15. 2014 at 4:29 AM hi can you tell me what should i understand from the ferrite transformer symbol given as below 1 ) (. Power transformers that will establish the service dependably with the web page.10 . Reply 87. 2014 at 7:37 AM Nice post about Power Transformers thanks for sharing nice information. 2014 at 4:17 AM how to calculate the seccion of de windings gracias Reply 86. Boguslaw BrandysApril 21. Many companies producing Power transformers in India. Cost-efficient along with secure through the entire ages. We are Power Transformers Manufacturer & Exporters in India Reply 88. Piyush JhaApril 30. 2014 at 11:08 AM This comment has been removed by the author. HkhurramMay 27.4shared.) (8 i want to indicate here primary and secondary side by using )( . I am afraid of 320V DC come out the inverter thru battery terminals. Pravin MagiyaMay 31. series lamp is ON and output is block. Please help me on this. 4. all components is ok FET is 7N60. 2014 at 1:01 AM how do you wind this transformer. is it 3+3 first and 100 turns or is it the other way . 2014 at 10:47 PM Hi Thahmid. I will be following your example circuit you mentioned with SG3525 for DC-DC conversion.jpg?lgfp=1000 Reply 91. 2014 at 8:45 AM Hi Thahmid. Also please suggest isolation for the feedback in the circuit. Rahees CMay 4. I learned more from you.5v please tell me what is meaning of 1. Now I am planning to design a Transformer-less Inverter using SG3525 in DC-DC and a PIC – PWM module for Sine wave production. i took this supply from junk yard for some experiment. Hope you are fine.com/download/bKbmAVCUce/PH_316. Your blog is really helpful for me.8 here . but let me know what should be the wire gauge for the DC-DC converter transformer windings to make an inverter of 800W capacity. i wound transformer as it is i opened but when i ON this supply is going heat too much but output voltage is ok then i put some load on it on series circuit on main. and 10. Reply 89. ***i want to wind this transformer can u help me***** supply picture is http://www. it is 2 w transformer and output is 7. i have a power supply (180W DC12V 15A LED Single Output Switching Power Supply). 4. Reply 90. you're using 10nF.. Pravin MagiyaMay 31. for example. is there any reference design you have.primary turns-3. what exactly do think could cause the problem. Reply 95..I pulled down the gate of the mosfets(IRF3205) with 1k resistor but still i am constantly having the mosfets burnt 5minutes after i connected it to the transformer although i did not implement feedback for now. 60KHz. please guide me. 100nF .. 47nF. firstly I congratulate you for doing such a nice sharing sg3525 What is the formula of compensation capacitors. Reply 94. yılmaz kemancıJuly 21. these values are chosen according to what? thanks . 2014 at 1:04 AM i have an ee42 core but i cant determine the bmax for it. I generated my signal from SG3525 and IR2110. 2014 at 4:00 AM Hi tahmid i was designing a ferrite core transformer using push pull topology. can you tell me what is its value Reply 93. Reply 92. please help me out this mess. 2014 at 1:41 PM Tahmid Hi.sec-turns-120. Sohil SutharJune 7. AnonymousJune 16. other examples 220pF. 2014 at 8:41 AM i want to built power supply of 24Vdc input & 400Vdc output. primary winding is 3X0... Could you tell me what kind of things can be responsible of this loss of power? i feed 8A@12VDC primary and i can just get merely 30W.. my site http://picsimulatorideexample.wordpress.. But with no load i can reach 300-400Vac @60Khz. My core is 2+2 primary 60 secondary... Srini VasanAugust 20. AnonymousAugust 7. But I can't keep this voltage when a load is plugged i just can reach 60vac @ 30W.. AnonymousSeptember 9. 2014 at 9:33 PM I think you are very expert for transformer ^^ Reply 97. yılmaz kemancı I love sharing. push pull bridge can feed 10Amps.. 2014 at 7:39 PM . 2014 at 9:25 AM sir I need 12 v to 110v dc converter and pri/sec winding details and the inductance value of the transformer wattage is 300w Reply 99... B. Best regards. I'm working on a small inverter 200w.5mm² in parallel.H@FRA Reply 98..com/ Reply 96.. 2014 at 5:42 PM Hello Tahmid! good blog. sounds lots of work behind. power transformer philippinesJuly 21. Wich are the best ferrite to get 150W at 3Mhz? Reply 100.. ahmed elbannaSeptember 17.. i asked u this before but u dont answer. 2014 at 5:12 PM hii Tahmid! im so proud of your info . impresionant dear.i need to know which AWG wire in prim and sec wendings i can use to have output power 1000 watts . let me know. with turn ratio of voltage in transformer. AnonymousSeptember 16. so i'll be so happy to know what i can do to get 1000 watt from the same core u used thanks alot Tahmid :) Reply 102. i want to create pontential transformer for voltage measurement..can i turn couple or triple wires together to have higher current in prim turns (3 wires together 3 turns then another 3 for the other 3 turns) 3. 2014 at 10:36 PM hi tahmid. sigit kurniawanOctober 12. but now i got a question for you. your so good and helpfull thanks for all of your info 1. turns should i triple the wires as in the prim. am i can be used this technique for solving my problems? .(same core u used) 2. i need to know how can we decide the current carrying capacity of primary and secondary.what to do with the sec.i choose ferrit core because my objeck have frequency in 40 kHz. ? im still confused because i read all ur comments but didnt find what can help . ejaz abidi Reply 101...please if u dont want to answer. 2014 at 8:34 AM helo dear. Keep it up! Reply 105. Reply 103. 2014 at 10:32 AM Thanks in advance for the explanation but why did you divide the fromula by 4. Kutlu ZungurOctober 14. Abdur Rahman OwahidNovember 12. Path FinderOctober 27. 2014 at 7:59 PM .Where does this 4 come from? Best regards. 2014 at 11:31 PM Dear Tahmid. I am new in SMPS design. 2014 at 7:09 PM Thank you for explaining it very well. Kutlu Reply 104. is it possiable a pre simple circuit for working 220 volt AC for this module.I want make simple adjustable SMPS labrotory power supply 1-30 volt and max 3 ampere Ebay have very cheap LM2596 or LM2576 Modules. power transformer philippinesOctober 23.I mean it must cheap and small and suitable but it must without power transformer thanks for reply Regards Serhat Reply 106. Md . 6. your whole inductance values will change and most likely the over-all behavior of your coupled inductor as well. omarx646March 16. Reply . turns.5.9 what should I do? I need to know what to do with that number before calculate secundary winding. 2015 at 12:36 PM Sir thank you for your tutorial on ferite transformer . Here you showed 3+3 centre tap primary and 96 turns secondery.blogspot. AnonymousApril 1.2. 2015 at 11:33 AM It can work as long as it remains complete after the breakage. I've a question about this article. Reply 108. in case 3.html and http://easy-electronic-circuits.com/2012/09/making-200-watt- compact-pwm-inverter. 2015 at 2:34 PM Dear sir nice post I have a doubt about the winding primary formule that gives 3. Assala-mu-alaikum vai.com/2014/05/100-watt-compact-ferrite- inverter. 3.my question is if a my ferite core transformer core (ETD44) is broken can it be used still if i glue it back together Reply Replies 1.html Reply 107.blogspot. 3. If I need 3+3 centre tap primary and secondery also with centre tap than which modification required? Actually this question comes to see this two articles :http://homemadecircuitsandschematics. TroubleshooterJuly 24. If you loose even a small portion of the ferrite core. Rodrigo TechiApril 8. 2015 at 3:42 PM Hi I am using a E25*20*7 Ferrite core. Ifyou could provide me your email Id I will email you the schematics. But the output voltage is only 180 voltsWhat needs to be done Reply 110. but how do i chose the core. I would like to get 300-320 volts. 2015 at 7:45 AM hi Tahmid. The primary is 12 turns of 22 SWG. I am using UC3843 and 50 khz frequency. Reply 111. and what range is acceptable for the Bmax? Reply 112. i'm projecting a high frequency ferrite core. AkshadeepApril 10.109. 2015 at 3:09 AM Hi Jtrao. AkshadeepApril 5. . 2015 at 3:47 PM Hi Akshadeep! What is your input voltage and topology ? is 180V output is with load? do you have feedback control? Tirumala Rao Reply Replies 1. The secondary is 320 turns of 36 SWG. jtraoApril 7. 2015 at 6:02 PM Hi Tahmid. Reply 114. AnonymousJuly 10. 2015 at 11:44 PM how can I boost the current of a solar power laptop charger circuit using an Sg and a ferrite core transformer Reply 115. 2015 at 6:03 PM Yes but you must change Ac. ursulajudith19July 2. I need only 20mA to 80V to drive some leds. 2015 at 12:31 AM Dear Tahmid vai. The formula is the same or change? Vin*10^8 remain the same or change? .Can u please help me. 2015 at 11:01 AM can i use ETD44 Instead of ETD39 ? Reply Replies 1. I have to need a calculation of 300W toroidal auto transformer. Reply 113. AnonymousJuly 10. Sahadat JonyJune 9. Zeeshan AhmedApril 20. The baseband signal is 25kHz but the PWM frequency can be greater than 400 kHz. 2015 at 12:49 PM Hi Tahmid. I recently planned to develop ups for my home. parthiban kandasamyJuly 26.e. This chip allows you to set the PWM frequency between 400 kHz and 1. Please answer. Reply 117. The reactance of the ceramic element is tuned out by using a parallel inductor. Thank you in advance! Reply 116. It is the TPA3116D2. Switching) and i have doubt in transformer selection. . i learned concept ups from your post(MOSFET. I am trying to drive a high power ceramic transducer element using one of the latest TI class D chips. Using the equation in this blog. Good work with you tutoring. Any larger a cross section I get 1 turn or less for the primary. With that in mind. 2015 at 3:31 AM Hi tahmid your work so great-full.2 cm 2. One more request is to know about which types of transformer in push-pull stage and output stage as well as its different types and configuration Reply 118. but you cleared well. . the cross section becomes very small i.6 MHz. Your explanations are very will done and easy to understand. The core size should get quite a bit smaller. 2015 at 3:29 AM This comment has been removed by the author. My problem is making sure the impedance never falls below 1. The TI part will allow PBTL connection providing up to 100 watts output power. AnonymousJuly 27. parthiban kandasamyJuly 26.6 ohms. AnonymousAugust 4. 24kHz to obtain 50Hz 220VAC output. I am going to use 12V battery but the available information I can find concerns LF inverter transformers but with higher input voltages (24V.for 48V DC system to use transformer with primary 24-30V Following that recommendation I can calculate the primary for 12VDC system transformer to be app..5-14V DC (the inverter has feedback line which regulates the SPWM duty).5V? Please if you can to advise me how to calculate the needed transformer (EI or toroidal). Thanks in advance for support. It should maintain 220V all the way from 10. 6 to 7. The problem is how to calculate the 50Hz transformer (EI iron core). I assume the material should be suitable for operation above 400 kHz. Reply 119. do you have any suggestions for the core and the kind of material. Thanks. 2015 at 1:17 AM . Thank you for the detailed explanation of HF transformer calculations. I am trying to make the driver amplifier as small as possible and thus I need the smallest core that can handle the power but also present the reflected impedance greater than perhaps 2 ohms. 48V). But I would like to build LF (low frequency) inverter 1kW using full bridge & SPWM control signals with app. The recomendation is: . This application is just a variation of a SMPS but at higher frequencies than the 50 kHz circuits posted here.. smithlarryAugust 14. Reply 120. 2015 at 10:08 AM Hi Tahmid.. My question is. we could offer very competitive prices at the same time. . The 12v inverter basically produces the same type of power that is created by utility companies and generators. When we have the confidence on the high quality of our products.com.Shop 12v Converter Inverter at Dctodcpower.