Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Proximity effect causing significant losses in Flyback SMPS transformer

Status
Not open for further replies.
T

treez

Guest
Newbie level 1
Hello,
The following is a 150W offline Flyback ( abbreviated schem attached) with an output of 300V.
The three secondaries would each be spread across their own layer layer in the transformer. The three secondaries would be interleaved between the two primary halves to reduce leakage inductance.
-So, Given that the transformer has five layers of coils, to what degree do you believe that “Proximity Loss” would reduce the efficiency?
(it’s a constant off time flyback and switching frequency is around, but not exactly 90kHz.)
 

Attachments

  • Schem _Brief Flyback 300V 150W for efficiency test.pdf
    148.8 KB · Views: 130

Solid wire in the fringing field (near the gap) is almost always the main contributor to wire heating in a compact flyback Tx.

- - - Updated - - -

worse for Bpk = 280mT or similar, at 100kHz theoretical Bmax in a flyback is say 200mT (+/-100mT), lowering to 100mT gives lower wire loss at the fringing fields are less intense ...
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
The text description of winding geometry isn't very clear. Can you show a drawing?
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
and what wires do you use? TIW for secondary?
 
  • Like
Reactions: treez

    T

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top