Friday, September 28, 2012

Some of my SMPS circuits

Here are a few of the SMPS circuits I made, employing flyback, push-pull, half-bridge and full-bridge topologies.

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 Test setup on verroboard of half-bridge SMPS circuit with SG3525 and IR2110 for battery charging. See description below. This is the verroboard prototype of the circuit built on PCB below.
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Offline Half-bridge converter
Input: 160 to 240V AC 50/60Hz
Output: 14.5v 10A (max)
Final test circuit (on PCB) for battery charging. Successful. To be incorporated in SMPS inverter with charger.

The primary side PWM is controlled by SG3525 PWM chip. Frequency of operation is around 50kHz. The output signals of the SG3525 are fed into a IR2110 high-low side driver which drives the 2 MOSFETs (IRF840) configured for half-bridge topology. ETD39 core is used for the transformer. It was wound by hand at home by me. A primary side snubber is used. 2 bulk capacitors (470uF, 200V each) are used for the half-bridge converter.

An auxiliary 50Hz transformer (18V 100mA) is used to provide auxiliary low voltage output, which is rectified, filtered and regulated to 12V with a 7812 to power the SG3525, IR2110 and related circuitry. Since average current is low, voltage difference between 7812 input and output is not too great, the power dissipated by the 7812 is not too high and no heat sink is required.

The output of the ETD39-based transformer is rectified with schottky rectifier STPS3045 and an LC filter is used to filter to pure DC. The output voltage is kept regulated using a zener-optocoupler based voltage feedback loop. The STPS3045 is mounted on a heatsink. The output inductor is the large toroidal inductor beside the 50Hz transformer. It has not been mounted on the PCB.

NTC has been used at the input side to limit inrush current due to charging of the LARGE BULK capacitors at the primary side. A fuse has been used for protection in case of short-circuit.

A 200-ohm resistance is used at the output as "dummy load".

I have designed the PCB myself and have wound the transformer myself, at home.

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1A offline flyback power supply with UC3842
Input: 160 to 240V AC 50/60Hz
Output: 14.5v 1A (max)
Could be used as auxiliary power supply.

The primary side PWM is controlled by UC3842 chip. The UC3842 drives the high voltage MOSFET (IRF840) directly as it has a built-in MOSFET driver. 50k resistor is used for startup from the high voltage DC bus - the UC3842 has built-in zener diode that limits voltage, provided current is low enough.

EE25 core was used for the transformer. I wound the transformer myself.

The output of the transformer is rectified with ultrafast rectifier 31DF6 and capacitor is used to filter to pure DC. The output voltage is kept regulated using a zener-optocoupler based voltage feedback loop.

NTC has been used at the input side to limit inrush current due to charging of the capacitor at the primary side. A fuse has been used for protection in case of short-circuit.

This is one of the oldest SMPS circuits I had made. I made it sometime in 2008.

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2A flyback power supply with TOP-GX
Input: 160 to 240V AC 50/60Hz
Output: 14.5v 2A (max)

The power supply is based on the dedicated offline-switcher "TOPSwitch-GX" TOP245Y, which contains both the primary PWM controller and the high-voltage MOSFET.

EE25 core was used for the transformer. I wound the transformer myself.

The output of the transformer is rectified with ultrafast rectifier MUR420 and LC filter is used to filter to pure DC. The output voltage is kept regulated using a TL431-optocoupler based voltage feedback loop.

NTC has been used at the input side to limit inrush current due to charging of the capacitor at the primary side. A fuse has been used for protection in case of short-circuit.

This is one of the oldest SMPS circuits I had made. I made it sometime in 2008.


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 12VDC to 280VDC DC-DC converter for CFL inverter
Input: 11VDC to 14VDC
Output: 280VDC 60W
Was designed to drive four 15W CFL's from 12V battery.

The primary side PWM is controlled by SG3525 PWM chip. Frequency of operation is around 70kHz. The SG3525 drives the 2 MOSFETs (IRF3205) configured for push-pull topology. EI33 core is used for the transformer. It was wound by hand at home by me. The 2 MOSFETs are mounted on heatsinks.

The output of the transformer is rectified to DC with 4 ultrafast diodes (UF4007) configured as a bridge rectifier. LC filter is used to convert output to pure DC.

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 Flyback circuit using TOP-GX

Input: 160 to 240V AC 50/60Hz
Output: 12V 3A (max)

The power supply is based on the dedicated offline-switcher "TOPSwitch-GX" TOP245Y, which contains both the primary PWM controller and the high-voltage MOSFET. ETD34 core was used for the transformer. I wound the transformer myself.
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12VDC to 220VAC Inverter (200 to 300W) using SG3525, IR2113 and PIC16F676 with features such as low-battery and overload protection
The primary side PWM is controlled by SG3525 PWM chip. It drives 2 MOSFETs (IRF3205) in push-pull configuration. The MOSFETs drive the transformer. ETD34 core was used for the transformer. The output of the transformer is converted to DC. The high-voltage DC is kept regulated by the SG3525 using direct resistive voltage-divider based feedback. This high-voltage DC is then converted to 50Hz AC using 4 MOSFETs (IRF840) in full-bridge configuration. The quasi-sine signal is generated by the 16F676. The output signals are fed into 2 IR2113 high-low side drivers that drive the MOSFET full-bridge. The 16F676 also monitors the battery voltage for low-voltage cut-out. It also monitors the load current for overload protection.

I made this circuit sometime in 2010 after lots of failure in design and implementation.

49 comments:

  1. Dear Tahmid,

    Its a very good initiative to put up all your efforts on the web and i also see a lot of contributions on eda boards and other sites...

    I am building an full bridge smps dc dc converter from ac rectified dc 230V to 200V DC at 10A (2kW). I am able to get PWM pulses from 3525. But when i connect the output to the high side, the circuit gets short circuited.

    Could you suggest the best way to use IR2110 ?

    ReplyDelete
    Replies
    1. Go through this: http://tahmidmc.blogspot.com/2013/01/using-high-low-side-driver-ir2110-with.html

      I'm sure you'll find that helpful.

      Regards,
      Tahmid.

      Delete
  2. Great Works! I arrived at an answer I was looking for on this page.

    ReplyDelete
  3. Umar, thanks. I'm glad you found your answer on this page.

    Sriram,
    There really is one way to use IR2110 when using it as a high-low side driver. Make sure you always have gate-to-source resistors for each MOSFET.

    ReplyDelete
    Replies
    1. Hi Tahmid,
      Great work... I have a few questions on the second figure (Offline Half-bridge converter).

      1) What's the role of the two diodes seen in the figure near the Mosfets?
      2) Which diode have you used at the output to handle this much current?
      3) At what frequency did you operate this circuit?
      4) What transformer turns ratio did you select?

      Regards,
      Prasanth.
      prasanthkumar77@gmail.com

      Delete
    2. 1) They are used to "bypass" the body diodes to reduce the switching losses. They can be omitted.
      2) STPS3045
      3) Approximately 40kHz - 50kHz
      4) I can't remember exactly. I think it was about 5:1 (primary:secondary).

      Regards,
      Tahmid.

      Delete
  4. Hi Tahmid,

    I found the article interesting, So i though of putting this questing in here. We have designed a circuit for controlling of led dimmer with 7805 and atmega32 microcontroller. It works fine with the lab power supply of 12VDC 300milliamps, but in actual the smps connected for led strips have very high current rating like 5amps and 10amps with 12V or 24V, when this supply is been given to my circuit the 7805 gets to much heated up. I tried using voltage divider LM317 and also switching transistor circuit, but it all failed. I am not able to find the exact problem. but i know its because of the excess amps provided to the circuit. If you can help me it would be great.

    ReplyDelete
    Replies
    1. No matter what the capacity of the power supply (1A, 5A, 10A or even 100A or more), as long as this is higher than that required, the current flowing through will depend on the load. So, if it works with the lab power supply of 12V 0.3A, it should work with any 12V power supply with supply capacity greater than 0.3A.

      The problem here could be that the output of the SMPS has "spikes" that cause the 7805 to heat up. Connect a diode between the output of the SMPS and the input of the 7805. At the input of the 7805 (after the diode), use a 1000uF capacitor with a 0.1uF capacitor in parallel with it. Try with this and let me know.

      Regards,
      Tahmid.

      Delete
  5. Hi Tahmid all of your post are really helpful for who really struck at hardware. I found lot of information on your post .I am designing a dc to dc converter 20V to 70V input 54V output for a 48V battery.i used inverting topology buck boost converter.I am using mosfet IRFP150N . PIC microcontroller for pwm pulse 5khz , and a3120 gate drive optocoupler to mosfet gate from microcontroller.
    design parameter are input voltage varies from 20V to 70V .fixed output 54V (including losses) . L=2mH, C=1.62mF . output current 5A.

    Problem is my capacitor burst for a input voltage of 25V and there is no boosting operation for duty cycle increment .
    Is this topology works fine with this power level.

    ReplyDelete
    Replies
    1. There might be a problem with the drive circuit or with the control algorithm. Without first seeing the schematic, not much can be said. So, you should upload your schematic first.

      Regards,
      Tahmid.

      Delete
  6. Dear sir,
    i have EI33 transformer bobbin can you help me to make 12v to 230v inverter
    i need to know what are the coil SWG value for need primary and secondary
    i see your blog post about primary and secondary turns calculation how we select Bmax value?
    please help me
    thanks .

    ReplyDelete
    Replies
    1. Without more information about the transformer core, I'd say that you should be able to select a Bmax value of 1000G to 1500G. That is a safe range for a typical core.

      You should select the wire SWG depending on the current that the wire(s) must handle. But make sure you don't use too thick wires, to avoid losses due to skin effect. If necessary, connect multiple thin wires together, in parallel.

      Regards,
      Tahmid.

      Delete
  7. I am working on 1500 Watt inverter. What configuration of MOSFETs (each raed 100 W) should i use in the Full Bridge toplogy? How should i connect them and how many should i connect for this rating?

    ReplyDelete
    Replies
    1. Which MOSFETs are you using? What is the supply voltage you are using?

      You should connect multiple MOSFETs in parallel. The exact number should be set based on the current handling capacity of each MOSFET and the total power loss for a given number of paralleled MOSFETs.

      Regards,
      Tahmid.

      Delete
  8. I really like your post, this is what i was looking forward to know. your info was really very important for me and others to know too.
    Keep sharing more.
    inverter with charger

    ReplyDelete
  9. Hello,
    Can I ask for help in simple mobile chargers? The normal average mobile charger nowadays employs switch mode characteristics, but what I do not understand is how the DC signal (achieved after a full wave bridge rectifier from mains supply), is converted into a 100 khz signal and fed into a tiny pulse transformer. The circuitry hardly has a couple of resistors, diodes (zener ones too), and a BJT (some chanrger circuits have 2 BJT's). If you have any link or any knowledge on this please share, or if you have written a blog on it, please share the link. I require help in this topic.
    Thank you for all your efforts.

    ReplyDelete
    Replies
    1. Usually, the resistor-capacitor components and transistor(s) form an oscillator circuit employing an auxiliary winding on the main transformer that alternately switches the transistor on and off.

      Regards,
      Tahmid.

      Delete
  10. vaia ame sumon . ame dhakai thaki . electronic nea kaj kora shok coto bala thak a . ai shok ta ame puron korta parce na . ame khub e kom jani electronic sompor k . ame coto akta diploma o kor a ce. kintu tamon kecu shekta parini. apne jodi aktu somai detan ta hol a ame apner somai ar mullo detam. vai ame akta ips firm a ace but ips sompor k kecu janina maj a maj a khub bipod a por ta hoy. please vaia ama k aktu help koren.

    thank you.

    ReplyDelete
  11. slam tahmid sir i want to make switch mode power supply with output 380 volts plz help me best regards

    ReplyDelete
    Replies
    1. What are the other specifications, like input voltage, power output, etc?

      Delete
  12. hy,i appreciate your work.i'm also curious about it.can you send me the schematics of 15.5v,10A(max) circuit and pcb layout?my email is dowson.jack17@yahoo.com

    ReplyDelete
    Replies
    1. I'll try to write an article about it and then I'll link you to it.

      Regards,
      Tahmid.

      Delete
  13. I've written 15.5v instead 14.5v in above post..sorry for that... dowson.jack17@yahoo.com

    ReplyDelete
  14. Hy Tahmid,i hope you will be fine...
    i am having a problem in making inverter.i'm making inverter using tl494 and sg3524.i'm using push pull topology to drive transformer and tl494 to drive push pull mosfet and sg3524 to drive full bridge mosfet...but there is no feedback.its just a simple circuit.can you send me the tl494 and sg3524 circuit with proper feedback.i have shared the only tl494 circuit file.link is
    http://rapidshare.com/share/C59EB1590CB87009A651BB5C6251E3D8
    my email is dowson.jack17@yahoo.com

    ReplyDelete
  15. hi tahmid,

    nice tutorials and highly useful,
    I want to design single output.smps, input - 110-240v AC, output - DC - 24v 5A and also 24v 10A.
    Can u suggest a website where could i get these design...
    i want the flyback diode type of smps

    ReplyDelete
  16. oga tahmid i greet oo.

    ive tried this ferrite stuff mainly for Inverter application, but the moment i add load on it the heat my mosfets generates is enough to boil a bucket of water. im using ferrite core from tv power pack.

    my questions are :-

    1) does different ferrite cores work with different frequencies.


    2) is the winding pattern the problem?
    cos i made sure the coils were symetrical and very tight intact i used machine to wind it cos i no want story.


    i used 3-0-3 for primary then 80 for secondary turns. my snubber is 4.7 ohms and 470nf cap in series.

    please tell me where i went wrong.

    thanks in advance.

    ReplyDelete
    Replies
    1. Dear Sir,
      Really I am crazy about your article.

      Sir please kindly help me to design your 1A offline fly-back power supply with UC3843 , please send circuit and explanation to my mail, my mail id is colorboy007@gmail.com

      thanks to share your knowledge to other

      Delete
    2. You did not indicate your input voltage. 12V/24V?

      Delete
  17. hello tahmed hope you will fine. please send me your complete psu circuit diagram used ic 3525 i im trying to make a nice battery chargar and i hope this one is very nice my yahoo id is ihsan_electronics@yahoo.com
    i im waiting for your kindly reply please don't ignore my request .

    ReplyDelete
  18. hello tahmed hope you will fine. please send me your complete psu circuit diagram used ic 3525 i im trying to make a nice battery chargar and i hope this one is very nice my yahoo id is ihsan_electronics@yahoo.com
    i im waiting for your kindly reply please don't ignore my request .

    ReplyDelete
  19. hii tamid,
    nice work, and i got many information here, and i'm doing a project on mppt solar charge controller and there in inverter section i'm using sg3525 pwm controller, and i'm getting some confusion in design part, please can u send me the design of that circuit which u hv published here(Using the SG3525 PWM Controller - Explanation and Example: Circuit Diagram / Schematic of Push-Pull Converter)
    sudarshanms.bairy@gmail.com

    with regards,
    sudarshan ms

    ReplyDelete
  20. wow! great article.i always hont for this type of circuit.,i am collecting some smps circuit with uc3842. after collecting much knowledge i definitely tried to do it by myself....i need your help.

    ReplyDelete
  21. hai
    can you help me make a DC energy meter using pic16f88

    ReplyDelete
  22. Hi Tahmid,

    I am trying to design a battery charger using SG3525, half bridge and a TI microcontroller.. I am not able to achieve current regulation in the same. Trying to test it at 1.5amps but it keeps wobling up and down goes down till 1.16 and goes up till 1.8. Can you suggest something?

    ReplyDelete
  23. I WANT TO LEARN TRANSISTOR IN DETAIL?WHY IT'S SO POPULAR AS A SWITCH?
    AS WELL AS CAPACITOR AND INDUCTOR IMPORTANCE IN DC OR AC CIRCUIT WITH EXAMPLE.

    ReplyDelete
  24. hi tahmid,...
    can u give more information on full bridge configuration???
    How 4 mosfert drive in full bridge dc to dc converter??

    ReplyDelete
  25. much impressed with your knowledge..I want to design the battery charger of 24V,5A with input range of 180V ac to 300V ac..can u please send me relevant circuit diagram..If any other guy have it.Please send me...My Gmai is sagarpatel4506@gmail.com

    ReplyDelete
  26. Hello Tahmid, I just wanted to know is it will be possible to use the push pull topology for the Offline half bridge converter you did here with input 160vac to 240vac and output 14.5v @10A. If not why?

    ReplyDelete
  27. Tahmid hi,

    I am looking at the 1A offline flyback power supply with UC3842 and I have a question regarding transformer calculation. I am designing one PS using UC3842 and as a guide I use Philips AN AN1272, where the example on how to design a PS is given, but the calculation of the N ratio between primary, secondary and bias is strange.

    Do you have any resource that can help me?

    Kind regards, Sasa

    ReplyDelete
  28. Hello Tahmid,

    Could you please share the block diagram and circuit diagram of 12VDC to 220VAC Inverter and 16F676 c code. So that I can try to work on it.

    ReplyDelete
  29. Hello Tahmid,

    Could you please share the block diagram and circuit diagram of 12VDC to 220VAC Inverter and 16F676 c code. So that I can try to work on it, My Id asrappa.h@gmail.com

    ReplyDelete
  30. And Where I can get the ferrite core in india please suggest. I am hobbyist and i can not spend much on this.

    ReplyDelete
  31. Tahmid hello,

    I saw your push-pull converter for the CFL. I would like to know details of it from you. I want to have similar converter for my application.

    ReplyDelete
  32. Thanks for your community contribution, do you have the circuit diag for the "Offline Half-bridge converter Input: 160 to 240V AC 50/60Hz Output: 14.5v 10A (max)"
    THANKS

    ReplyDelete
  33. Thanks for your community contribution, do you have the circuit diag for the "Offline Half-bridge converter Input: 160 to 240V AC 50/60Hz Output: 14.5v 10A (max)"
    THANKS

    ReplyDelete
  34. Very nice circuits but no schematics :( ... I need them very much .. prince9561@gmail.com

    ReplyDelete
  35. Can you start a new topic for flyback SMPS design for universal input.

    ReplyDelete
  36. Hi Tahmid

    I have a few questions on the last figure (12VDC to 220VAC Inverter).

    1) Did you use the series capacitor on the transformer supply (center tap)?
    2) Did you use the bypass diodes near the mosfets (similar figure 2)?
    3) What is the effiency of the circuit?

    and

    Are the ETD type cores better than EE type cores (for push pull transformer)?

    Regards.

    ReplyDelete
  37. sir,
    I want to make a 48vdc to 12vdc converter with 2A output current using uc3845. How can i design the transformer using ee30 core? Please help me.

    ReplyDelete