I am really stuck here guys .... any help much appreciated.
Efficiency is not very important.
By universal .. it should operate on USA and European voltages

 

http://www.google.com/imgres?imgurl...0ahUKEwiooNf9kMXLAhUD8CYKHa0wClE4ZBAzCB0oGTAZ

 

Wow..... so much looking at step up IC's and circuits, there was a multivibrator in kermit's bag of tricks all along !

Thank you so so much... I have been at this for days and days trying to get and or find something like this.
Looks like I will have to bump up the the current on the Mosfet to get the required wattage out of it.
But this looks simple.... and cheap.... (like me .

I loved the regulation of the L6563 circuit ... I wonder how good this will be ?

Was thinking of putting a bunch of 50v zeners on the output of the 400volt setup L6563 so I could pick off the voltages I needed.
Still might if regulation is a problem on this circuit.

Cheers !!

Phill

 

Humm... just had a good look at it.
Supply frequency is going to be a problem ?
50Hz or 60Hz is going to change the output voltage.
Not constant current or voltage ?
BUT....
It has put me on the path to power mosfet control of the output.

 

Ok.. a picture is worth a thousand words as they say.

I Like this circuit .... I like it a lot.


Now how can I reduce it to 155VDC not 400 ... efficiently !

 

That is a boost converter. Based on the thread title and post #1, what you need is a buck/boost converter, something that will boost 127 Vp up to 155 Vdc and buck 340 Vp down to 155 Vdc. Buck/boost control chips are all the rage these days, but few (none?) are designed for your voltage levels so extending the app note circuits would be a challenge.

Also, the circuit in post #2 looks weird. There is no feedback so the output cannot be regulated. And why is there a monostable driving a shunt FET switch with no inductor?

ak

 

I now understand the difficulty's of forcing this boost converter down to a voltage below the input.

But .. you must be able to adjust the output with extra circuitry with discrete components.

here are a few more ideas I am thinking of attaching to the output of the boost converter.

This one is going to be inefficient as it will basically be a form of resister in series ? and will produce a lot of wasted heat ?



This is going to have a lot of zenner noise ? .... limited current ?


Inefficient
again ?

 

What I really need is a buck converter that will take 400vdc input ?