my smps project help

[zerohead_ak47]

i have no oscilloscope

i think frequency is not important just wanna know that the value of
resistance rd ?

 

[zerohead_ak47]

some photos

An externally hosted image should be here but it was not working when we last tested it.

and pcb , another photos
http://rapidshare.com/files/65575247/yap__305_lan.rar

 

[luka]

Hi

What/where is this rd resistance?

 

[zerohead_ak47]

Hi

What/where is this rd resistance?

7. pin - 380r (dead time)

 

[luka]

Hi

I think you don't need it that high, I have 33 ohme I think, you can check that...100 would be still fine, but if you don't have any problems leave it as it is.

 

[zerohead_ak47]

now i put 33ohm instead of 380ohm rd and then effeciency rised from%65 to %75 and the frequency rised to 70khz from 60khz

 

[luka]

Hi

Which core do you use? I use 50k which should be enough for 800w+, so I don't think you will need 70k, but it all depends on type of core that you use

 

[zerohead_ak47]

my transformer

http://www.epcos.com/inf/80/db/fer_01/04970499.pdf

 

[luka]

Hi

Uff ETD59, lower freq. At 20K you still would get 1kw. And skin effect will be much smaller.

See here
http://sziget.mine.nu/~danko/letoltes/Magnetics_design_application_notes.pdf

 

[zerohead_ak47]

using gold palted copper wire

 

[luka]

Hi

Ok, but still skin effect is present... So how does it work, do you get 800W out of it? And why do you need such power with only +/-42?

 

[zerohead_ak47]

only test

 

[luka]

hi

What did you use as test load?

 

[zerohead_ak47]

220v 100w lamb 2x parelel

%80 eff at 50k now (rt15k)

 

[luka]

Hi

That is not that much power, won't you use something bigger?
Try using even lower freq., say 30k, I would be happy with that...

 

[zerohead_ak47]

updated schema

 

[zerohead_ak47]

this transistor catalog found ?

H9840
40n60b3d

 

[zerohead_ak47]

900watt version symetrical 70 volts

using epcos 1.0 transformer (high gauss)

47khz at 900w

 

[inductionMotor]

is that possible to convert this project to adjustable power supply. for example 0-100V 10A power supply?

 

[inductionMotor]

is that true?

if i change the zener diode (connected between output voltage+ and 4N25), i can set up the output voltage. Than if i replace the zener diode by adjustuble zener diode , i can control the output voltage. Thus this project cab be converted the adjustable output voltage smps.

but in here. do i have to change ETD59 transformer?