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

wide voltage range input high voltage power supply

Status
Not open for further replies.
francis29

francis29

Member level 5
Member level 5
Joined
Mar 22, 2016
Messages
90
Helped
2
Reputation
4
Reaction score
3
Trophy points
8
Location
India
Activity points
721
Hi,
I want to design a power supply with following specifications.
Input voltage = 250-750V
Output = 12V/2A
Isolation should be there.
What topology should i use?
is it feasible?
 

A typical specification of an auxiliary dc/dc converter of VFD inverters. Two-switch forward, or with restrictions, two-switch flyback converter is often used for maximal utilization of transistor voltage range.
 
Low wattage wide input power supply's are almost always single switch flybacks.

Search for "wide input flyback pdf" on the internet.
 
thanks to all. what about transformer?
Can you suggest some good books/application notes on flyback transformer design.
 

FlapJack said:
Low wattage wide input power supply's are almost always single switch flybacks.

Search for "wide input flyback pdf" on the internet.
Click to expand...
"Wide input" usually means for universal AC inputs, e.g. 90-265VAC, so your peak input voltage is far from 700V. At that high of a voltage even 1200V FETs don't have much headroom in a single switch flyback. I agree with FvM's recommendation of a two switch forward or flyback.
 
  • Like
Reactions: francis29

    V

    Points: 2
    Helpful Answer Positive Rating
    francis29

    francis29

    Points: 2
    Helpful Answer Positive Rating
Has anybody heard of single switch forward converter that uses rcd clamp for reseting the core instead of tertiary winding??
 

Has anybody heard of single switch forward converter that uses rcd clamp for reseting the core instead of tertiary winding?
Click to expand...
Guess I've seen it in designs. Implies that no stored inductor energy can be recovered. If the transformer main inductance is sufficiently high, this must not be a problem.
 
  • Like
Reactions: francis29

    V

    Points: 2
    Helpful Answer Positive Rating
    francis29

    francis29

    Points: 2
    Helpful Answer Positive Rating
If you use a RCD clamp to reset the core, then the energy stored in that core will be dissipated instead of recovered. The higher the magnetizing inductance, the less energy will be stored in it each cycle, and therefore the lower your losses in the RCD clamp.

But it's fairly uncommon to see this technique used in forward converters. And I would recommend against it for a high voltage design.
 
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top