tag:blogger.com,1999:blog-6338993703407602171.post579680228404942272..comments2024-03-28T00:52:40.857-07:00Comments on Tahmid's blog: Output Inductor Calculation for SMPS Converters using the Forward, Push-Pull, Half-Bridge and Full-Bridge TopologiesTahmidhttp://www.blogger.com/profile/09117804893438710050noreply@blogger.comBlogger30125tag:blogger.com,1999:blog-6338993703407602171.post-84078546527951332052023-08-22T00:26:25.912-07:002023-08-22T00:26:25.912-07:00Great Work ThanksGreat Work ThanksAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-72591711867680322262020-11-20T21:18:36.458-08:002020-11-20T21:18:36.458-08:00Thank you so much for this information. Also Can y...Thank you so much for this information. Also Can you share the copper gauge calculation for 20A Current? G Suresh Kumarhttps://www.blogger.com/profile/11553247257810446265noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-50549206038832204762019-04-10T19:22:24.762-07:002019-04-10T19:22:24.762-07:00Alvaro.
Thank you so much for these formulas, and ...Alvaro.<br />Thank you so much for these formulas, and for the detailed explanation example. I really appreciate it, Now I'm feeling less lost than ever on SMPS .<br /><br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-5710638579150169812018-10-31T21:39:50.596-07:002018-10-31T21:39:50.596-07:00Very usefull informaton thanks for sharing this li...<br />Very usefull informaton thanks for sharing this link share for more about AC DC Full Load Current Calculation Formula <a href="https://www.techdoct.com/electrical/full-load-current-calculation-ac-dc-machine/" rel="nofollow">Click here </a>Ebloglineehttps://www.blogger.com/profile/13078375331531786950noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-54370552912014852012017-08-29T07:32:43.166-07:002017-08-29T07:32:43.166-07:00Hello Tahmid, How can we construct a LC filter wit...Hello Tahmid, How can we construct a LC filter with out using a transformer. I tried using LCR filter in between the full H bridge, but I'm not getting a clean sine wave. I need some help regards to that.<br />Thanks.Anonymoushttps://www.blogger.com/profile/06682811450702641535noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-63258604776489775352017-08-21T04:10:41.505-07:002017-08-21T04:10:41.505-07:00hi,
From where the constant value 1.4 comes to the...hi,<br />From where the constant value 1.4 comes to the denominator of Lmin equation.Anonymoushttps://www.blogger.com/profile/12384009016275124597noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-5987974523458669342017-07-17T00:25:34.918-07:002017-07-17T00:25:34.918-07:00sir
i want to design a high power dc supply and i ...sir<br />i want to design a high power dc supply and i intend to use toroid transformer,from 230 v ac input to 1000-1500 v dc output and about 200 mA current.i intend to rectify and switch the 230 v to high freq like 20 khz.is this feasible.want your help nishahttps://www.blogger.com/profile/12390082570482967936noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-69973804188634457382016-11-16T21:32:32.809-08:002016-11-16T21:32:32.809-08:00Interesting blog. It takes some time to understand...Interesting blog. It takes some time to understand but I must say you have described in very user friendly way which will be helpful for all to understand. Thanks for sharing. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-70837516774394900442016-01-01T10:26:23.262-08:002016-01-01T10:26:23.262-08:00This comment has been removed by the author.Anonymoushttps://www.blogger.com/profile/05996055127452940904noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-42144457796036269652015-10-13T01:08:56.161-07:002015-10-13T01:08:56.161-07:00Dear Tahmid i am new in this block i need your hel...Dear Tahmid i am new in this block i need your help i am doing a battery charger with halp brige topology its a 48v@12amp cahrger with pwm ic 33525 the output is able to deliverd 12amps but my probleum is coming when i am puting in cabnet (box alumunium) mens when i am going to coverd it than current going down from 12amps to 9 amps i am vary confused why its happen i am new in power electronics field Please help me <br />Anonymoushttps://www.blogger.com/profile/11366478025893320176noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-77566956964618876152015-07-10T08:12:54.288-07:002015-07-10T08:12:54.288-07:00congratulations on the blog, has been very useful....congratulations on the blog, has been very useful. I have a doubt in the calculation of capacitors for the H half bridge.<br /> Will could help me ?<br />greetings<br />José CamposAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-87833029918946306032015-07-04T03:11:46.006-07:002015-07-04T03:11:46.006-07:00pls tahmid can u tell me how to identify an ETD44 ...pls tahmid can u tell me how to identify an ETD44 using a metre rulerAnonymoushttps://www.blogger.com/profile/01940318423091558734noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-48707714683046082422014-06-18T21:13:31.944-07:002014-06-18T21:13:31.944-07:00yes...it is the answer...the frequence is too high...yes...it is the answer...the frequence is too high ( time period is small )...which makes the dc voltage a square wave...so now amplitude is not constant..it is varying w.r.t time...and hence voltage is induced in secondary winding.Anonymoushttps://www.blogger.com/profile/11815952314459247718noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-33728644033221693772014-06-09T13:04:39.171-07:002014-06-09T13:04:39.171-07:00Tahmid, I have one quick simple question.
Q: in f...Tahmid, I have one quick simple question.<br /><br />Q: in fly-back converters design, the transformer is connected to a DC voltage input but it only works with AC because of variable magnetic field which DC voltage can not provide. How did they achieve the induction of secondary voltage by the primary DC voltage?<br /><br />I know there is a MOSFET switch and it disconnects the DC voltage in a very short time (before di/dt becomes 0) but is it the answer?<br /><br />please provide your solution if you have it ^_^Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-23153301027765813752014-04-08T02:03:56.371-07:002014-04-08T02:03:56.371-07:00great blog, thxgreat blog, thxAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-21455636623350590892013-10-23T04:43:13.769-07:002013-10-23T04:43:13.769-07:00hello Tahmid
could give an example of calculation...hello Tahmid<br /><br />could give an example of calculation of a half-bridge smps with the following data:<br /><br />220Vac 310vdc<br />pri turns 32<br />sec 3 +3 turns<br />frequency 27kHz<br />secondary voltage 15v<br />70A output I<br />inductor with Al 100nH/esp ²<br /><br />very good blog<br />gratefulAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-58583958457286719352013-10-11T11:07:40.575-07:002013-10-11T11:07:40.575-07:00Hi Thamid, I found very helpful and interesting a...Hi Thamid, I found very helpful and interesting all your posts. Thanks to your explanation I have designed and built succesfully a push pull 300W dc/dc converter 12 V to 300V for use in geological survey. I am now at the calculus of the output inductor. Using the formula to determine Lmin if Vin(max) is less than Vout brings to a negative voltage value. How to overcome this problem?<br />RegardsFrannoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-75977614709904826302013-07-20T13:37:37.636-07:002013-07-20T13:37:37.636-07:00One obvious thing that would happen by reducing th...One obvious thing that would happen by reducing the turns is that it will increase the flux density. Now, if the flux density is increased too much, the core can saturate and there will be a short-circuit and you damage the circuit.Tahmidhttps://www.blogger.com/profile/09117804893438710050noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-89251487111139698832013-07-20T13:19:35.286-07:002013-07-20T13:19:35.286-07:00"Direction" is a flag that I used to det..."Direction" is a flag that I used to determine the direction of the bridge - to determine which MOSFETs will be on, when. Now, since it's a binary flag - taking only zero or one - it must be part of a register. So, I defined an 8-bit register FlagReg, of which bit 0 is the bit "Direction" which I use as a flag.<br /><br />I hope that answers your question.<br /><br />Regards,<br />Tahmid.Tahmidhttps://www.blogger.com/profile/09117804893438710050noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-3101621169439358992013-06-23T23:24:25.702-07:002013-06-23T23:24:25.702-07:00Hello Tahmid, what is the different in core design...Hello Tahmid, what is the different in core design method for dc-dc output filter inductor and dc-ac output low pass filter inductor for spwm inverters.<br />RegardsAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-50017889707592152272013-04-07T16:02:05.013-07:002013-04-07T16:02:05.013-07:00Hi, Tahmid. It's very interesting subject. I h...Hi, Tahmid. It's very interesting subject. I have a little question as I am a beginner in SMPS and very curious about it, here is my question, What would happen if we use output inductor that has smaller output inductor? For example from your above calculation, instead of using 84 turns, what would happen if we use only 40 turns? Is it going to heat up the switching transistor? Or maybe limiting the output current of the SMPS? Or what? <br /><br />Your explanation would be very helpful for me to make better understanding on this subject, Thanksmhtoxadhiehttps://www.blogger.com/profile/17769266417927605286noreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-26768803416269007952013-03-24T07:58:59.211-07:002013-03-24T07:58:59.211-07:00Dear Tahmid
can you please explain what is this ...Dear Tahmid <br /><br />can you please explain what is this "unsigned char FlagReg; and sbit Direction at FlagReg.B0;" <br /><br />Regards <br />VeeraAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-70536799323253143972013-03-11T00:20:17.317-07:002013-03-11T00:20:17.317-07:00Hi Tahmid,
Thanks for supporting designers,
we r ...Hi Tahmid,<br />Thanks for supporting designers,<br /><br />we r working on 1KW inverter with below specs<br /><br />12v-350v dc-dc converter with pushpull topology<br /><br />e65 core ferrite <br /><br />full bridge topology with igbt for ac-dc inversion<br /><br />we r planning to provide the isolated feedback with a transformer<br /><br />transformer specs are input will be from e65 core transformer and output must be scaled down to 5v dc to connect to sg3525.<br /><br />plz provide us the details of the transforme like core to be used and no tunrs<br /><br />thanks in advance.ravitejahttp://www.neethainnovative.comnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-41483255299334401572013-03-09T15:20:22.095-08:002013-03-09T15:20:22.095-08:00Hi Tahmid,
One thing I can't find addressed i...Hi Tahmid,<br /><br />One thing I can't find addressed in your explanation is where the "1.4" figure comes from. I'm guessing it's related to the ripple current in the inductor, but could you elaborate on this for us here in the cheap seats? :)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6338993703407602171.post-89547822583934974582013-03-06T10:27:46.928-08:002013-03-06T10:27:46.928-08:00Tahmid, That was a very good write up on inductor ...Tahmid, That was a very good write up on inductor design for forward converters. It has more information than i have seen anyware.<br /><br />I slowly worked thru your method for calculating inductance and then i re-read all my literature on calculating inductors. Most methods were based on your formula with slight variations. Your comprehensive write up helped me understand the other variations of the formula.<br /><br />One of the differences in the formulas is what to use for I min. G Chryssis says .25Imax, M Brown does not say but used 10% in one example. Schmidt-walter says "L is chosen so that ΔIL=0,4 x Iout for >Vin_max". Pressman derivation of his formula says he uses 10% of I max.<br /><br />If I use 10% Imax in your formula “1.78A” (250W / 14vdc = 17.8A) then i get a L of 44.4uH.<br /><br />I used your numbers for the half bridge converter you designed and entered them in the other formulas.<br /><br />http://schmidt-walter.eit.h-da.de/sm...gw_smps_e.html<br /><br />gave an inductance of 9.32uH.<br /><br />G Chryssis book said 16uH at .25Imax. But at 10% was 39uH<br /><br />Tahmid method at 10% says 44.4uH<br /><br />Pressman’s book said 47uH. Based on 10%<br /><br />M Brown book said 57uH. Based on 10%<br /><br />If we throw out schmidt-walter, you ended up approximately in the middle of the other calculations, so i would say your write up has to be correct. M Brown’s value is a little high because he does something strange. He says that “Toff(est)” means “ON time” so that explains why his value is unexpectedly high.<br /><br />One last thing on Imin for these calculations. Imin does not mean that the power supply must not go below that current. It only means that the output goes into discontinuous mode after Imin and you loose the benefit of the inductor. If you have a regulated supply it will stay regulated. So you do not need to place a load resistor on the output to make Imin.<br />Anonymousnoreply@blogger.com