Once Again, but this time adjustable OFF-LINE SMPS

[Shahriar]

Hi

I want to build a 150 Watt Off-line SMPS using TEA1507 Controller.
It seems that the output voltage just depends on the transformer windings turns ratio, in Flyback, Pushpull, Half-bridge Topologies. So there is no way out to build a High power variable Switching regulator. But I have seen Some 900W, 1.2 to 30V output smps that can give 30A@30V or 60A@15V on the web. So there is a solution!!!
I don't know which topology they have used or which Controller!
There are some adjustable Buck Controllers but none of them are Off-line. So I have to use a big transformer.(Not Good)
Do you know any way out how to convert usual SMPS to a Variable One?

The attached file is a TEA1507 75W Application used for monitors

ThanX in advance
Shahriar

Tea1507Design02.pdf

 

[Shahriar]

Here that Monster SMPS I talked about it!

HighPowerSMPS.pdf

 

[ante1]

Hi Shahriar,

Maybe the TEA1507 is not the best alternative for you?
Here is an example of a 550W+ of line PSU:

The description is here: http://ludens.cl/Electron/PS40/PS40.html
Even though this circuit has a fixed output voltage I am sure it will give you a good idea of how to build a similar circuit with your own specs. 8)

 

[Shahriar]

Dear ANTE

Thank you very much. I had searched the web a whole day, but didn't see the thing you posted? ???
It is very similar to this document I have attached. I have a question In this document:

how much voltage changes can we achieve at the output by varying the voltage divider at the TL494 Err Amplifier Input.
(Suppose that the Over protection circuit is disabled and the secondary Windings have been changed to proper number)

ThanX
Shahriar

AN983-D.PDF

 

[ante1]

Hi Shahriar,

The ratio of the transformer winding decides the maximum voltage. By adjusting the feedback voltage it might be possible to get the output voltage all the way down to 0Volts.