Need help for 200 watt power supply, Source is 12 volts DC

[pcmaker.dude]

guys i need help cause im not much of an electronics engineer and im more in computers and i need help on making a 200 watt power supply but without 220-240 voltage source but instead i need a 200 watt power supply that uses 12 volts DC.? really need help

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Guys i recommend detailin gyour comments cause im a noob in electronics! Tnks

 

[sky_123]

Re: This is th estupidest question in the whole world?

Is this for your vehicle? You may want to investigate something like raspberry pi, which can operate from 5v.
Otherwise, I'd suggest that it is quite hard for someone new to electronics to develop a PC power supply that operates from
12V.
There is the inverter option to take 12V and convert to 220 so that you can power a conventional 220V PC power supply.
It becomes unattractive and takes up a lot of space. Hence you may want to evaluate if a smaller computing platform (e.g.
rasp-pi, or something else) is a better choice.

 

[godfreyl]

Re: This is th estupidest question in the whole world?

I understand you want a computer PSU that runs off 12V DC instead of 230V AC, but where does the 12V DC come from? Is it a nice clean regulated 12V, or is it something like a car battery, which can vary anywhere between 11V to 14V or worse?

Uh i just would like to take out the 120-220 to 12 volts dc converter on this schematic...

That's not how it works. First the 115V or 230V AC is converted to about 320V DC. Then the 320V DC is converted down to the various voltages you need (+12V, +5V, -12V, -5V and +3.3V).

You'd need something totally different.

...i want to take out the converter cause if i dont take it out and use a converter there will be tons of heat bilding up when it's on for a while and takes more power!

You sure about that? Most computer PSUs are pretty efficient, so the heat produced by the PSU is much less than the heat produced by the rest of the computer it's powering.

 

[sky_123]

No offence, but unless you're going to invest time learning about circuits and troubleshooting circuits,
and hundreds of dollars in equipment and test gear, you're going to find it hard to assemble such a power
supply no matter how much help people give you over the internet.
As Godfrey mentioned, it is not possible to "adapt" an existing 220V PSU to your needs. Also, you're
presuming you need to now generate 320V, which is an incorrect presumption which no-one actually suggested
you do.
You could seek existing DC-DC converter modules that will supply DC 12V and DC 5V from an unregulated 12V source,
but they are going to be expensive - it may cost a few hundred dollars, depending on how much current
you need on the 12V and 5V rails.
You could try seeking some lower-cost DC-DC converters from ebay and experiment, but at least use a multimeter
and a dummy resistor to check all is well before connecting up your motherboard.
Why does someone need an atom server (!) to operate from 12V? If it is not from a battery, then just go the
easy route and buy a 12V->220V inverter. It is cheap and will work.

 

[godfreyl]

Re: This is th estupidest question in the whole world?

So just summarizing i need 320 volts DC?

No, you don't. When the input is 230V AC, that's the easiest way to do it. If the input is 12V, there's no point converting to 320V.

You forgot about this:

...where does the 12V DC come from? Is it a nice clean regulated 12V, or is it something like a car battery, which can vary anywhere between 11V to 14V or worse?

It's pretty important. Most of the power in a typical computer is drawn from the +12V line. If your input is clean, regulated 12V, you can use it directly and only have to worry about generating the other voltages (with relatively low power). If the input is dirty/unregulated/not exactly 12V, then you have to convert "dirty" 12V to "clean" 12V as well (at relatively high power).

 

[godfreyl]

Aaargh!The forum software's being flakey again - at least two posts disappeared and one duplicated. :sad: