Full load current support of TOP switch
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
Comments
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
The power supply should regulate well without any load on the outputs; You can load the feedback supply to 10% (constant current) just as a check.
http://www.powerint.com/en/design-support/component-suppliers
http://www.powerint.com/en/design-support/rapid-transformer-samples
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
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
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.