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Full load current support of TOP switch

Posted by: sreekanthr on

Hi,

 

I am new to PI expert. I designed a circuit using Top Switch for the following Voltages

 

1. 24V @2A GND1

2. 24V@0.25A GND2

3. 15V@0.5A GND3

4. +12V@2A GND4

5. -12V@0.5A GND4

 

Feedback to TOP SWITCH is from +12V.

 

for reference i attachedPI expert file Also.

 

The circuit looks ok. and efficiency is about 92%.

 

Will it support for full loads on all supplies.

 

How reliable it is with full load.

 

What much be the components will get failure in future.

 

I want use this one in a VFD.

 

Plese clarify my doubts.

 

And suggest me the debugging procedure incase of failure.

 

regards

Sreekanth

Files

Attachment Size
TOPSwitch-JX_PIDesign2.uds 379 KB

Comments

Submitted by PI-Kenobi on 07/15/2013

All PI Expert designs are optimised based on the users design specifications, therefore, it will support full load on all supplies. As far as component failures are concerned, the electrolytic capacitors are known to fail first. I would recommend performing an accelerated lifetime/reliability test on your supply to evaluate any sources of failure.

Thanks for the reply given.

Is the circuit is correct in the attched.

What would be the minimum recommended load on feedback supply connected.

And can you recommend transformer manufacturers for this.

regards

Sreekanth

Submitted by sreekanthr on 12/18/2013

Hi,

I bought transformer from Rapid samples only,

Still i am facing problem with it and many of the voltages are not giving exact output.

regards

Sreekanth

Submitted by PI-Wesley on 12/20/2013

Hi.

 

A supply with 5 outputs, especially with multiple floating outputs will tend to have issues with output precision, particularly if the loads are operating at different energy levels (some fully loaded, some light loaded).

 

In your application, is there a possibilty to have a lot of load combinations, or are the loads constant?

 

The issue is that several of your outputs have no feedback whatsoever. So small changes between transformers (leakage, the way the wire is wound), and the output diodes will cause relatively large variations on the output voltages.

 

Typically it will help to fill the layers in the transformer, so that there is less part to part variation (since everything is packed together). You already have a deep continuous design, that should help. You may also have to tweak the number of turns for floating outputs. It is extremely hard for a software tool to predict the exact output voltage since this is dependent on the transformer construction

 

We have an application note for multiple output designs with examples of tolerance. Keep in mind that if all the outputs are tied to the same ground you will get tighter tolerance (just as a reference for when you read the application note). http://www.powerint.com/sites/default/files/product-docs/an22.pdf