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Innoswitch3-EP 50W adapter design

Posted by: IKastantin on

I used online PI software to design adapter 230VAC/24VDC 50W power supply. I have bad heat results. the temperature on the the transformer is about 125 deg after 1 hout run time.
I used a closed enclosure without any cutout on it. my question is when we select adapter during the design that means using enclosure without any cutout like any adapter we use in all othe devices like mobile charger?

Comments

Submitted by PI-Spark on 01/11/2021

Hi IKastantin,
Thank you for using Power Integrations products.
Yes it is for enclosure without any cutout, similar to adapters in the market.
When the transformer temperature is too high, two typical factors are:
(1) flux density is too high, resulting in high core loss and increased temperature. you may check in PI Expert Software and ensure the Bpeak is within the core datasheet specifications (<3800 Gauss typical)
(2) the wires used are too thin and the wire cmil/A is too low, resulting in increased wire temperature
Is the high temperature the core or the winding? Can you also share the transformer temperature when operating at open frame for reference?

Regards,
PI-Spark

Submitted by IKastantin on 01/14/2021

Hi,

I implemented my design with online PI suite. I used EEL25 core for 50W design with INN3679C and it told me that the design passed. the peak flux density is 3699 Gauss in PI report. you can find attached the PI report.I tested it with open frame, the core temperature after 30 min,. run time is about 88 & the winding is about 96. This test is @ 22 deg ambient. another question: do we need any heatsink?
BR,
Imad

Submitted by IKastantin on 01/14/2021

Hi,
when you read the report from PI for 65W charger design reference, you can sea the thermal test in open frame and at 25 deg. the temperature is 81.2 @ 265VAC & 100.5 @ 90VAC. what do you think if you test @40 deg and adapter? which value we can get? do you have any idea about rating temperature for all components: transformer core, transformer winding, input rectifier, InnoSwitch3-EP, primary RCD snubber & output rectifier.
BR,
Imad

Submitted by PI-安德鲁 on 01/23/2021

Hi IKastantin, thank you very much for your questions. The flux density looks fine in your design, so should not be transformer core issue. No heat sink would be needed for open frame operation. How compact is this 50W design? Be careful that components may heat up each other if they are close on board, especially the hot ones, like a transformer sitting underneath IC. You would expect an additional 15C (estimated) increase in thermal when test under 40C ambient, and further temperature increase when test in case. This 65W design is designed for industrial/home appliance, so not tested in case (possibly another 10+ degree increase, as what I observed in one power adapter design for charger application). If in-case operation needed and the thermal in case tested very high, heat spreader/thermal pad would be recommended. Our InnoSwitch can operate up to at least 135C. Thermal characteristic of other components varies depending on the specific selection, and I could not give a general answer on it. Please feel free to add further comments here.

Submitted by IKastantin on 01/26/2021

Hi, Thank you.

I'm trying to put a new design with InnoSwitch3-EP online but it doesn't accept 24V/2A output. Why?

BR. Imad

Submitted by PI-安德鲁 on 01/26/2021

Hello IKastantin, the different family ICs are recommended for different applications and output levels (power, output voltage, etc.). For particular application and power/output level you selected, there might be some ICs not available for your design. If this happens, we would recommend to change the IC selection or modify the design. Please feel free to let us know if you have further questions on this.

Submitted by IKastantin on 01/26/2021

Hi,
But I made this design with the same outputs parameters with InnoSwich3-EP and it accepted it. is there any thing differed?
BR,
Imad

Submitted by PI-安德鲁 on 01/29/2021

Hello IKastantin, this might be a PI Expert issue. Previously it had some feature for high output voltage design, but there were some changes later on. I have talked to our PI Expert team, and they will come to answer this on more details. Kindly let me know if you do not hear from them by early next week.

Submitted by PI-Kenobi on 01/31/2021

Hello,
Thank you very much for your feedback - we will resolve this bug and revert back soon.

Submitted by IKastantin on 02/08/2021

Hello,

Please I need to set a new 50W adaptor design with InnoSwitch3-EP. 24V/18V outputs. I till couldn't yet.
Thanks

Submitted by PI-Kenobi on 02/09/2021

Hello,
You can still create your design by entering the 18V output first and then the 24V output in the design wizard screen. See the image attached.
Let me know if this helps.
Thanks.

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Submitted by IKastantin on 02/11/2021

Hi,
Yes, it works now. Thank you.
BR,

Submitted by IKastantin on 02/11/2021

Hi,

What can I do if I need only one output with 24V?
BR,

Submitted by PI-Kenobi on 02/15/2021

Hi,
The developers are expected to fix this issue prior to 2/19. Apologies for the inconvenience.
Regards.

Submitted by PI-Kenobi on 02/24/2021

Hi,
The issue was fixed - please let us know if you are able to create single output 24V designs.
Thanks.

Submitted by IKastantin on 02/24/2021

Hi,
Thanks. It works now and I can create single output 24V design.
Thanks & BR

Submitted by IKastantin on 02/25/2021

Hi,

You have to go to design support, then PI Expert online. before you have to register on PI website.
BR.

Submitted by IKastantin on 03/03/2021

Hi,
I have a new design with INN3679C-H606. my parameters:
- Universal input 85-265VAC.
- 2-isolated ouputs: 24V/2A, 18V/0.5A
The design passed except this message:

(The primary switch on-time is greater than 12.40 us. The switching frequencty will increase to maintain regulation. To reduce the primary switch on-time reduce VOR and/or increase FS)

when I define the minimum input voltage at 115VAC the design passed with no warrning.
my questions is:

- How can I reduce VOR?
- Is increasing or decreasing switching frequency is the solution?

BR,
Imad

Submitted by PI-Lupin the Third on 03/05/2021

Hi IKastantin,

Thanks for reaching out to us through this page. We are willing to help you on your concern but if may I request, can you please create a new ticket or thread for this one? We'll wait for your new post. If you think that this particular thread is related to your inquiry, then you may simply copy the link of this thread in your new post.

Thanks and regards,

PI-Lupin

Submitted by PI-Kenobi on 03/05/2021

Hi Imad,
To change the VOR and FS in PI Expert, go to the 'Design Results' tab and scroll down to the 'Transformer Construction Parameters' section.
Thanks.

Submitted by IKastantin on 09/13/2021

Hi,

I'm working now on a new design with ETD29/16/10 transformer, and I read your design reference RDK-747. it used AON6220 MOSFET and it is not exist in your online designer.

which replacement MOSFET we can use, AON6292 or 6290 or any other.

Thanks

Hi IKastantin,

Thanks for using PI products.

Can you please create a new post or thread for this inquiry? I'll wait for  your new post.

Thank you and regards,

PI-Lupin the Third