What is the best topology for an offline SMPS 330W?

90VAC to 140VAC INPUT, 33Vdc out 10A.

Half-Bridge Push-Pull Converter or two switch forward.

Reply to
Hammy
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How about: Multiphase Cuk converter.

Reply to
MooseFET

What is that?

2 Cuks with opposing ripple?

D from BC myrealaddress(at)comic(dot)com BC, Canada Posted to usenet sci.electronics.design

Reply to
D from BC

A real easy design is to take a cheap, off-the-shelf class D amp chip, and put an oscillator in front of it to drive your output stage with a nice sine wave. Put a feedback loop in to push the "volume control".

Make a super clean, low ripple linear fed by what is technically a switcher inside the amp chip. Even if you only run it at like 17kHz, the chip is at like 400kHz sample rate inside. This 'noise' can be detected in your output if not managed properly.

Reply to
Archimedes' Lever

[snip]

Don't too many Cuks spoil the broth ?:-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

I thought it was pronounced chewk. Rhymes with puke.

D from BC myrealaddress(at)comic(dot)com BC, Canada Posted to usenet sci.electronics.design

Reply to
D from BC

The reason I ask is that I'm taking a trip at the end of the month and where I'm going there will be a lot of places were I can get Ferrite cores. Who knows if I'm nice they may even wind up an ETD39 or 44 transformers for a half bridge. After some reading that is the best topology for the power range.

I can pick up an assortment of cores for 50 to 150W range while I'm at it.

Reply to
Hammy

Or perhaps 3, but yes running multiple Cuks out of step was what I was suggesting as another way to go.

The ideal transformer coupled Cuk converter can be made to have no input or output ripple. It is still useful to consider making more than one section and putting them in parallel.

Reply to
MooseFET

I've noticed that most controller ICs seem to be for non-cuk topologies. (Or perhaps it can be used but Cuk is not mentioned.) By any chance you know a nice controller chip for a Cuk supply? I need a supply that can vary from 10% to 80% duty.

D from BC myrealaddress(at)comic(dot)com BC, Canada Posted to usenet sci.electronics.design

Reply to
D from BC

I thought it rhymed with "buck", a la, one rev. higher than a Buck is a Cuk. ;-)

Cheers! Rich

Reply to
Rich Grise

I think I remember now.. I think Cuk is pronounced 'Chook'. Rhymes with book.

D from BC myrealaddress(at)comic(dot)com BC, Canada Posted to usenet sci.electronics.design

Reply to
D from BC

Sheeeesh! I was only trying to be a little funny ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
 Click to see the full signature
Reply to
Jim Thompson

Cuk-a-doodle-do.

Reply to
AnimalMagic

It appears that google lost my earlier reply Booster chips. Lets see if this works.

Reply to
MooseFET

Ok it worked.

Nearly any of the booster chips will work as the controller for a Cuk converter if you get the voltage feedback right.

Even an oldish design like an LT1246 will work.

Reply to
MooseFET

I'll check'm out. Thanks

D from BC myrealaddress(at)comic(dot)com BC, Canada Posted to usenet sci.electronics.design

Reply to
D from BC

Four higher is what you would like.

Reply to
Spehro Pefhany

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