Please help for this SMPS circuit

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xyz9915

Joined: 14 May 2007
Posts: 42

24 May 2008 21:09 Please help for this SMPS circuit

Hi! The attached file is a schematic of 50KHz SMPS power supply which uses 325 VDC (after rectification of Mains 240 V). The required current is approx 15 Amperes. Please give comment if any modification in the circuit is required. Question

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FvM

Joined: 22 Jan 2008
Posts: 5161
Helped: 767
Location: Bochum, Germany

24 May 2008 22:39 Re: Please help for this SMPS circuit

The voltage feedback is missing. Using no current limit is dangerous to my opinion.

dian

Joined: 16 Apr 2006
Posts: 41
Helped: 7
Location: Indonesia

25 May 2008 4:02 Please help for this SMPS circuit

this design is very basic, there's no regulation/control because no feedback.

xyz9915

Joined: 14 May 2007
Posts: 42

25 May 2008 4:54 Re: Please help for this SMPS circuit

Please guide how do I add feedback circuit to limit the current.

darla1

Joined: 21 May 2008
Posts: 149
Helped: 11
Location: India

08 Jun 2008 16:18 Re: Please help for this SMPS circuit

hi xyz

your circuit it is based on push pull dc/dc converter, but this not good for your volatge range bcoz higher losses you can use half bridge/full bridge with same PWM ic.

did you regulation circuit if not, please tell i give you

ramesh

xyz9915

Joined: 14 May 2007
Posts: 42

09 Jun 2008 4:33 Re: Please help for this SMPS circuit

The changes/modification proposed by the friends, the modified circuit is attached herewith with Opto feedback control circuitry to keep the design stable. Opto is used for a simple current regulation. Please point out if any further modification is required.

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rajeevavr

Joined: 06 Sep 2009
Posts: 6
Location: india

18 Oct 2009 18:14 Re: Please help for this SMPS circuit

xyz9915 wrote:

The circuit you posted misses a choke on the O/P after SR560 which will surely blow your diodes after loading the SMPS. Also the push pull design on such a mainline is not safe.