| microp |
Hi!
I want to create SMPS.
I have this schematics (pic)... and ETD49 core. I place of MTP75N06 will use four pairs BUZ11 or IRF 540.
Will it be enough with ETD49 for 500W?.... or how much power can produce this core?
If it is right ....how many turns and what kind of wires should I use?
Thanks! |
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| luka |
Hi
Buz11 would be ok, but I would go for irfz44.| quote: | | Will it be enough with ETD49 for 500W? |
It depends on what freq. you will go for....
You should go for minimum of 4 turns for primary. |
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| microp |
| could the core hold 400 to 500W? I will set any frequency needed by this core... as I heard ~50khz is good for this!? |
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| luka |
Hi
If you will go for 50kHz then core will probably be capable delivering ~900W, so I would go for around 30-35kHz so that you have minimum skin effect |
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| microp |
You are fast!
May be you could tell me what wire should I use in primary and secondary to produce 500W.
regards
microp |
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| luka |
Hi
Well I can't realy help you there, because I don't know what wire you have/can get. I have 0.5mm dia wire and make my own litz wire. cross section of those wires has to be as big as from single wire rated for that current. Assuming 500w and 13v input voltage there will be 40A going in each primary, so each pri must be rated for that current or more. Same with secondarys.
I have added a pdf, which has a table where you can see what wire can conduct what current. So I look for "single wire, open air". This is because I think you will be using this smps for audio, and the load is not 100% at all times, so you can afford this. So for 40A, wire has to be a bit less then AWG 12, or 0.08" in diameter. If EU this is 2mm. Whis wire has cross section of 3.25mm^2. So you should use xx wires in parallel to get this cross section. You do same for sec. I you will use ETD you will peobably put both PRI first and then both SEC. |
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| microp |
Wires I can get all diameters... its no problem... now I know all to build SMPS :)
Only problem is to figure out how to set it to more output voltage than 35... as I know SG3525 can operate not more than 35... but i don't want to remove feedback because I don't know will my amp hold the unload voltages... they are much more than 35 without feedback... or maybe I am wrong!? |
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| luka |
Hi
What are you tolking about. If you are building it for car, then SG will be powered from battery(12-14v). You can get any output voltge you want, even if a lot more then +/-35v. Transformer ratio will have to be changed, but that not a big deal.I would use feedback, so you can get high power without any sag in output voltage. Do you have any schema of what you are trying to build? |
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| microp |
I have read one thread about voltage... where the voltage is growing when lower load attached. I don't know... just gathering info...
You are the best of all informs because answers are correct and short!!!
Thanks! |
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| microp |
Here it is!
Power transistors will be four pairs of IRFZ44... think it would be enough!? Just find right resistor (RT input) to get 35khz
Please sorry for my stupidity... just starting with smps! |
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| microp |
| self created and fully working (DX schematics) |
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| luka |
Hi
Irfz's will be ok. For RT look in datashet, and try to find resistor closes to that you read.
Read here , the link I posted to get some idea what you need to look,... |
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| CHACALPOWERS |
Hello builders
I built the Rod Elliot design and it´s great. Look it. |
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| CHACALPOWERS |
This is the PWM controller (I have with SG3524, SG3524, TL494) and optozener regulation with 3 1N4755 zener diode (3X43V=129V or +64.5/-64.5 V output)
Bye |
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| luka |
HI
Did you make it work? If yes, at what power? |
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| CHACALPOWERS |
| Hi. Around 300W. Eficciency 86%. Input 13.8V. 2 inches toroidal transf., 12 FQP50N06 mosfets. No warm, fanless. I like it. |
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| luka |
Hi
Nice to hear this? Do you get any output voltage sag at this power? |
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| CHACALPOWERS |
The voltage fall with the zener regulator is around 2VDC because the transformer work with 80+80 and after regulation stay 62.5V.
Bye |
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| scrts |
| And finaly, maybe You have PCB ? Thanks. |
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| CHACALPOWERS |
| Yes, I have in my mind only. I will make some PCB bottom photos and post it. |
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