Page 5 of 5 FirstFirst ... 345
Results 41 to 47 of 47

Thread: SMPS with PFC

  1. #41
    diysmps Senior Member res_smps's Avatar
    Join Date
    Oct 2012
    Location
    bandung, indonesia
    Posts
    147
    I think I have to correct this statement
    Quote Originally Posted by res_smps View Post
    Sorry Silvio,
    With the presence of PFC, capacitor requirements can be smaller, I attach an excel file for PFC calculations (I downloaded from onsemi website) in post # 5
    I thought the PFC frequency determined the size of the capacitor, I was wrong
    from the worksheet, capacitor requirements are not determined by the PFC frequency, please check this formula (pic) below
    cbulk.jpg

    *for the same power, the higher the output voltage the smaller the capacitor needs
    Last edited by res_smps; 10-11-2019 at 02:13 PM.

  2. #42
    .... Silvio's Avatar
    Join Date
    Apr 2015
    Location
    Malta
    Posts
    890
    Blog Entries
    9
    *for the same power, the higher the output voltage the smaller the capacitor needs

    In the pfc circuit to my believe the value of the capacitor determines the hold time at load.

    Check this ( I sent you mail)

    NCP1653 Spread sheet Res.pdf
    Last edited by Silvio; 10-11-2019 at 09:56 PM.

  3. #43
    diysmps Senior Member res_smps's Avatar
    Join Date
    Oct 2012
    Location
    bandung, indonesia
    Posts
    147
    Quote Originally Posted by Silvio View Post
    *for the same power, the higher the output voltage the smaller the capacitor needs

    In the pfc circuit to my believe the value of the capacitor determines the hold time at load.

    Check this ( I sent you mail)

    NCP1653 Spread sheet Res.pdf
    Dear Silvio,

    yes, that also true. Thank you for the file, I also previously shared it here (zip files) in post #2

    please ignore the picture in post #41, there was an error
    cbulk.jpg
    cbulk value is determined from the highest results from the following 2 formulas :
    1) 10000*Pout/(0.01*Vripple*2*pi*Fac*Vout^2
    or
    2) 2000*Pout*Thold/(Vout^2-Voutmin^2)
    from the formula this parameter determines the cbulk
    1. Line frequency (Fac) 50/60Hz
    2. Pout
    3. Tholdup
    4. Vout
    5. Vripple
    Pout and Vout appear in both formula
    Last edited by res_smps; 10-11-2019 at 10:39 PM.

  4. #44
    switchmode-uc3844-2x100v-smps-circuit-schematic.jpg Hello, i think everything is ok about power supply , there is no errors, you can see on this one ..

  5. #45
    .... Silvio's Avatar
    Join Date
    Apr 2015
    Location
    Malta
    Posts
    890
    Blog Entries
    9
    Quote Originally Posted by Marshall View Post
    switchmode-uc3844-2x100v-smps-circuit-schematic.jpg Hello, i think everything is ok about power supply , there is no errors, you can see on this one ..
    I guess you want to check the schematic for any errors correct? If that is so please post a larger image of the schematic as it is too small to see it

  6. #46
    About this project , i checked separately every stage , NCP1653 in Data Sheet has same conections as on this schematic only inductor everywhere is 600uH, UC3845 is simple power supply, i share schematic here, connections are good , power stage with SG3525 is also ok , but, things that i dont understand, as i know , this configuration in half bridge main transformer has 13+13 turns in primary , same number of turns also here, i know that full bridge have less windings than half brigde , maybe 2 X 7.. that its not clear, also inductor 380uH vs. 600uH !? , number of turns on transformer on aux supply !? and windings on GDT !?.. PHOTO.jpg
    Attached Images Attached Images
    Last edited by Marshall; 12-05-2019 at 11:29 AM.

  7. #47
    diysmps Senior Member
    Join Date
    Dec 2010
    Location
    Kenya
    Posts
    498
    hi andrew . did you manage to make your smps work succesful with the pfc? please post photos and your experience on its power.

Posting Permissions

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