Flyback Power design

Jim -


You can use our products with higher input voltages although it might not be officially supported in the PI Expert software.


Two suggestions:
- Do a search on our website for "StackFET". This is the method we use in high-voltage input situations.
- Take a look at these reference designs for some ideas and starting points:
http://www.powerint.com/sites/default/files/PDFFiles/di124.pdf
http://www.powerint.com/sites/default/files/PDFFiles/der58.pdf


Please let me know if I can be of further assistance.

-The Traveler

Hello Sir,
Thank you very much for your message. I made a mistake. The output should be 1.5A
but not 1.5W. So the reference design would be not suitable for our application.
I will try to use your recommended method to look for some chipsets.

Best regards
Jim

jim2011 -


No problem. If you need further help, just come back to this forum question. I have it flagged so I get updated if you post anything additional.


If you can define your specs a bit better, I might be able to help further point you in the right direction when I have a little more time tomorrow.

-The Traveler

Hello Traveler,
Thanks again and again. Yes,we have following requirements:
1. Input voltage: 3 phase Delta connection
2. Voltage value: 600VAC/480VAC/240VAC/120VAC
2. Output:24VDC/1A or 1.5A
3. Output power: 24W to 30W
4. Isolation design
5. Temperature:-40° C to 85° C
6. Ripple and noise of output(max): 120mVpp
7. Efficiency: >76%
8. Vibration: 10-500Hz, 2G 10min/1cycle.
9. Size, as small as possible

Best regards
Jim

Jim -


Are you looking for a design that is super wide-range (ie 120-600 Vac)? Or are you looking for four different designs that have the same output specs but different input voltage ranges?


Regarding the efficiency spec, it might be difficult to achieve this as the StackFET implementation dissipates additional power to reduce voltage stress on our IC's MOSFET. If you're attempting a design that is super wide-range (120-600 Vac) this problem will be more pronounced.

-The Traveler

Hi Traveler,
Thank you very much for your help. Yes, I admit it. We will use transformer to reduce the voltage levels. This is one power supply that has to deal with different voltage input levels.

Thanks again and again.

Jim

Hello Sir,
I hope to know if there are some chips that support input voltage range from 120VAC to 340VAC.
Output Power: 20W
Output Voltage: 48VDC or 5VDC

This is a AC/DC converter.

Hope to get your help as soon as possible.

Best regards
Jim

Jim2011 -


From a design standpoint, your requirements are not too much different than some of the utility meter reference designs that we have listed in the design support section of our website. (I added links to a couple of them in an earlier post.)


You should be able to use these reference designs as a starting point. You will need to change your output voltages and output current accordingly...but pretty much everything is there for your to use. Also, this question regarding 600 Vac input has come up several times in the forum. You're likely to find some good explanations if you do a quick search.


Your efficiency requirement sounds a bit tough. You'll likely need to build a prototype and see what kind of efficiency you can get. As far as your temperature requirement, you will need to choose your output caps carefully as most electrolytics don't function as well at cold temperatures as they do at warmer temperatures.


Regarding the shake/shock/vibe requirement, I can't really help you with that.
You'll need to get your power supply up and working and then put it on a vibe table to conduct your testing. If your company has an environmental testing department, they can likely help you with this.

-The Traveler