Help! Transformer-less powersupply

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Could anybody help me on how to design a mosfet based powersupply,
naturally, requiring no transformer....

 

[petrus bitbyter]

Could anybody help me on how to design a mosfet based powersupply,
naturally, requiring no transformer....

Well... Err...

Get a box, put a MOSFET in it, lead the mains power cord through it and
you're done.

petrus bitbyter

 

[[email protected]]

Well... Err...

Get a box, put a MOSFET in it, lead the mains power cord through it and
you're done.

petrus bitbyter

And check your homeowners insurance policy very, very carefully...

;-)

 

[Pooh Bear]

Could anybody help me on how to design a mosfet based powersupply,
naturally, requiring no transformer....

Are you really sure that's what you mean ?

Graham

 

[kell]

Could anybody help me on how to design a mosfet based powersupply,
naturally, requiring no transformer....

What goes in, and what do you want to come out?
It's most likely going to have an inductor, at the very least.

 

[ehsjr]

Could anybody help me on how to design a mosfet based powersupply,
naturally, requiring no transformer....

Sure. Go to Radio Shack and buy a mosfet, a 9V battery,
and some epoxy. Stick the mosfet to the bottom of the
battery with the epoxy. When the epoxy is dry, stand
the battery up. Presto - a mosfet based powersupply.

 

[Jasen Betts]

Could anybody help me on how to design a mosfet based powersupply,
naturally, requiring no transformer....

sounds like you're after a switching powersupply. I've got bad news for you
they use transformers, only they are smaller ones operating at a higher
frequency. that you are unaware of this is somewhat worrying ans is
probably why you're getting so many unhelpful replies...

if you want to see how it's done pick your favourite MOSFET manufacturer
and download some of their application notes... or you could go to Linear
Technology's web site download LT-Spice/Switchercad III (circuit simulation
software) and play with some of the sample circuits that comes with.
Playing with these voltages in software is much safer too

Bye.
Jasen

 

[Pooh Bear]

sounds like you're after a switching powersupply. I've got bad news for you
they use transformers, only they are smaller ones operating at a higher
frequency. that you are unaware of this is somewhat worrying ans is
probably why you're getting so many unhelpful replies...

if you want to see how it's done pick your favourite MOSFET manufacturer
and download some of their application notes... or you could go to Linear
Technology's web site download LT-Spice/Switchercad III (circuit simulation
software) and play with some of the sample circuits that comes with.
Playing with these voltages in software is much safer too

I'll recommend Power Integration. They have a simple app that does 90% of the
tricky work ( including transformer design ) for you. They also have a wealth of
excellent application notes which should tell you everything you could ever
reasonably wish to know about switching supplies.
http://powerint.com/

Graham

 

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Gee thanx!

I'd never got that piece of info, as mosfet stuff needs a transformer!
Thanx folx for the help!

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