Page 1 of 4 123 ... LastLast
Results 1 to 10 of 37

Thread: Car SMPS Project

  1. #1

    Car SMPS Project

    Hey Guys

    I'm working on a 800W Smps to drive my Amps in my car but I'd like to test it out fully before I use it in my car
    So I'm looking for a power supply to simulate car voltage to test and use the audio system at home (13.5 to 14.7V @ about 80A)

    Which solution do you guys recommend:

    1- Wind a 50Hz transformer
    2- Build a regulated SMPS

  2. #2
    diysmps Senior Member Silvio's Avatar
    Join Date
    Apr 2015
    Location
    Malta
    Posts
    495
    Blog Entries
    9
    Use a car battery and a charger

  3. #3
    Quote Originally Posted by Silvio View Post
    Use a car battery and a charger
    I have the car battery but about the charger, doesn't those only deliver about a couple of amps to charge the battery ?????
    I talking about 30 to maybe 80A here the doen't need the battery to deliver much of the current

    Maybe you mean different charger than what I have in mind.

    I honestly tempted to buy a 90A car alternator and a 1ph ElectroMotor Rated at 4HP @ 3000RPM but the only problem I have is with the size of this things.

  4. #4
    If its only short term then the small charger will be fine.. even a small lead acid battery will put out some serious amps short term

  5. #5
    Quote Originally Posted by noonehere View Post
    If its only short term then the small charger will be fine.. even a small lead acid battery will put out some serious amps short term
    actually no as I said I may wanna use this at home so it should be something to dilever 60A for an hour or 2 without any problem
    I can test the smps with the car battery that I have but without the altenator the voltage will drops and it will not be the case where I want this circuit to work(about 14V)
    so i'm looking for some method to keep the voltage on the battery around 14v when I drawing that many current (basically like what an altenator in a car does)
    I think a 50Hz transformer would be a good choice here but I don't know what output voltage and current my transformer should have? because after converting it to dc the level of voltage and current is different
    does anyone know a good and valid reference to calculate the ratings of the transformer

  6. #6
    diysmps Senior Member Silvio's Avatar
    Join Date
    Apr 2015
    Location
    Malta
    Posts
    495
    Blog Entries
    9
    I see if I understand well that you want a mains driven smps that can deliver 13v at 60 amps well that is a little less than 800w. If the load is going to continuous that is one thing but if the load is intermittent say 50% than that will be another.

    You can build an smps with half bridge like the 1000w smps and use thick secondary so that it can deliver current. You also need high current output diodes which have to be fast switching. feedback perhaps as well. You can use copper sheet for your secondary winding. If it is going to be for audio purpose then a current density of 5 amps per mm˛ will be ok.

    Taking some assumptions 60amps at 5amps per mm˛ = 60 / 5 = 12mm˛

    ETD 49 bobbin is around 30mm long so a 0.2mm thick copper sheet will be 30X0.2 = 6mm˛ this is only half so you need to parallel 2 sheets together. One other option is to make a center tap winding and use 0.2 sheet for each winding then use a common anode diode on the output.

    Regarding the size of an iron core transformer it should be the size of a microwave oven transformer more or less. The filtered secondary voltage will have to be larger so that it can be regulated to the desired output voltage. This will bring more complications to your setup and I think you should avoid it.

    I hope that helps Silvio
    Last edited by Silvio; 06-08-2018 at 09:41 PM.

  7. #7
    have you tried using a 2000va found in UPS
    Last edited by kegs; 06-11-2018 at 10:06 PM.

  8. #8
    Quote Originally Posted by kegs View Post
    have you tried using a 2000va found in UPS
    Actually as I haven't find the high speed & high current output diodes for the Smps in my area that my friend Silvio here suggested, I go for a powerful 2KW 50Hz transformer at it will be ready in a day or two
    I also bought car battery and a 3 Farad cap to minimize its ripple and 4*100A diodes so can handle this much current
    it cost about 300$ to gather this stuff but I think it will worth it

  9. #9
    diysmps Senior Member Silvio's Avatar
    Join Date
    Apr 2015
    Location
    Malta
    Posts
    495
    Blog Entries
    9
    Hi bad boy, I think you made a good choice as that kind of setup is more robust and more forgiving. What I am aware of is the 3 farad capacitor. This can easily destroy you rectifier diodes during start up. The transformer itself will also give surge in the mains and may blow your fuse during switch on.

    If you want an easy soft start to build you can find one in my blog posts. I made this for my isolation transformer which was around 1500w.

    One other option is to connect the battery first before switching on the supply so that the battery will charge the capacitor instead.
    Please also note that the battery itself will act as a capacitor and smoothing down the ripple.

    I would include the soft start as this will help things to tame down a little bit at start up.

    Regards Silvio
    Last edited by Silvio; 06-12-2018 at 07:11 PM.

  10. #10
    Quote Originally Posted by badboy_6120 View Post
    Actually as I haven't find the high speed & high current output diodes for the Smps in my area that my friend Silvio here suggested, I go for a powerful 2KW 50Hz transformer at it will be ready in a day or two
    I also bought car battery and a 3 Farad cap to minimize its ripple and 4*100A diodes so can handle this much current
    it cost about 300$ to gather this stuff but I think it will worth it
    For rectifier the best place is from a PC POWER supply as they are high speed and paralleling several is a good bargain

Similar Threads

  1. 500W Smps project
    By ludo3232 in forum diysmps
    Replies: 23
    Last Post: 12-07-2015, 08:11 PM
  2. 1 KW SMPS Project Discussion
    By MicrosiM in forum diysmps
    Replies: 24
    Last Post: 02-28-2014, 02:44 AM
  3. My first SMPS project - help needed please
    By Venture in forum diysmps
    Replies: 3
    Last Post: 11-14-2013, 12:41 AM
  4. Questions about smps project
    By jm-31000 in forum diysmps
    Replies: 0
    Last Post: 04-20-2013, 06:48 AM
  5. Open SMPS Project 1kW
    By Murilo in forum diysmps
    Replies: 5
    Last Post: 07-26-2011, 12:08 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •