multiple SMPS Voltages

[pol]

why i have to up the frequency till 2 mhz???

 

[goldsmith]

Pol , are you familiar with 2nd order filter basics ? e.g cut off frequency and .... ?
Oh i think i told you a thing wrong ! 3db is for first order filters , sorry , if you saw 6 db decreasing ,( because this is 2nd order filter ) you can say that is cut off frequency .
Respect
Goldsmith

 

[pol]

the output has generated the voltage,
but when i give the load, the voltage down until 3 volt from 13 v...

what cause it???

 

[goldsmith]

can you tell me the values of elements , or your attach your schematic ?

 

[muhammadali_16]

can anybody tel me about the relation between turns ratio, frequency and the size of the transformer???

guide me plzzzzzzzzz

 

[goldsmith]

Hi again
See below , please , you'll find answer of all of your questions here :
https://www.edaboard.com/threads/229615/
Best Wishes
Goldsmith

 

[muhammadali_16]

now i m planning to make a UPS based on switch mode power supply.

can anyone guide me in Auxiliary Power Supply for charger (AC TO DC)

 

[goldsmith]

Dear Muhammad
Hi
What was the result of your latest project ? successfully ?
Anywhere , Where is your problem , now ?
Best Wishes
Goldsmith

 

[muhammadali_16]

@goldsmith

My previous project is 100% working well. im very happy for that. becz on that, im planning for new project and for that purpose i need ur help

 

[goldsmith]

i'm very happy too , because you could do your project successfully .
Well , now , what is your problem , if you explain , your problem , i'll be happy to help you .
Best Luck
Goldsmith

 

[muhammadali_16]

there is not such problem. just plan to start new project of UPS. planning to make about 600W to 1KW UPS. dont have much such experience of making such things

 

[goldsmith]

Humm . no problem ! how much is your input voltage for UPS ? and how much is your out put voltage and current ?

 

[muhammadali_16]

my input voltage would be 12VDC and output will be 220 to 250 VAC. if i go for 600W, the current would be 2.5 - 2.7A and if go for 1KW, thn the current would be 4A

 

[goldsmith]

well , you can use an H bridge or push pull converter ( if your power was higher than this , you couldn't implement it with push pull , simply ) to increase your voltage , ( i think H bridge is good for your project ) ( increase it up to 311 VDC ) and then another H bridge , but without transformer , and then an LPF ( butter worth family ) and then a feed back loop from your out put to your first stage ( you should rectify and filter your feed back voltage ) . the command signal of 2nd stage will be an SPWM .
Best Wishes
Goldsmith

 

[muhammadali_16]

i hv studied the whole design of HOMEAGE. the boost section involve input center tap and output is simple with diode bridge. for inverter H bridge

---------- Post added at 22:26 ---------- Previous post was at 22:20 ----------

can u just tell me what frequency should i use to do this

 

[goldsmith]

For what ? for carrier of 2nd stage or first stage , ( Frequency of SMPS) ?
Kind Wishes
Goldsmith

 

[muhammadali_16]

ofcourse 1st part. step-up the voltage upto 311v as u said. i dont know what should be the appropriate frequency for this purpose. remember about the watt. i need upto 1000W.

Thx
Regard
Muhammad Ali

 

[pol]

my ferrit trafo has a nuosie like a clock walk....
what cause it?

i use the sg 3524 to make my konverter topologi flyback be automaticly for the output 13,8 v,and i= 0,5 A...
HELP ME....

 

[muhammadali_16]

@pol

u hv to use SNUBBER

 

[goldsmith]

Dear Muhammad
Hi
If you are using current mode topologies , you'de better to decrease your frequency e.g 100KHZ . and for carrier frequency of latest stage , i suggest you to use 50KHZ , triangle wave , as carrier .
Best Events
Goldsmith

---------- Post added at 17:59 ---------- Previous post was at 17:57 ----------

And dear pol
As muhammad suggested , you can use snubber network . but there are some other ways too , such as creating a littler gap space in your core or use a proper glue .
Best Wishes
Goldsmith