Combine AT and ATX power supplies to upgrade a system

[M. Shammout]

Hello,

I just found this nice forum, and I think it is the right place to help me through this.

I am struggling to upgrade a certain system  . The device I have contains an old motherboard which powered by an AT power supply.
My problem   is that the power supply board (which supplies the AT power) has other functions, and there's no way to be replaced (by an ATX PSU). I already bought the motherboard: http://www.ibase.com.tw/2009/MB970.html , with INTEL core i5 CPU   . I can't risk my power supply board in attempting to operate the new parts (motherboard, CPU, 4 Gb RAM, CPU fan, SATA harddisk, and DVD), I believe it won't stand that kind of power consumption. I know you'll say this won't work at all -I know, but I was thinking about using voltage regulators to generate the 3.3 v rail from the same AT power lines.
OMG I really need help about:
How I can connect the AT and ATX power supplies to this motherboard (and to the other parts), ensuring that I am not risking my AT power board at all?. Another headache is that the AT power board has to work at the same time with the motherboard. And in order for the system to work the AT power board has to work (you know that a feedback circuit should be completed) that's why it should be connected to the motherboard.

This really became a challenge for me. I can't stop thinking, planning, and dreaming about it   .
If you have any idea or any experience about this, I would like and hope to hear from you...

[notlist3d]

I think you might have found the wrong forum.  This is mining hardware, not medical hardware.

As far as PSU's we cannot really recommend what to use without knowing what type of connectors and the number of each,  you also need to know the amount in watts needed.

Is it a PC, a Server?  What is it your working on.  

[M. Shammout]

I think you might have found the wrong forum.  This is mining hardware, not medical hardware.

As far as PSU's we cannot really recommend what to use without knowing what type of connectors and the number of each,  you also need to know the amount in watts needed.

Is it a PC, a Server?  What is it your working on.  

Thank you for your quick reply .
Yeah I know but I am asking about PSU's, forget about the medical thing. I know there's some experts around here that can help me.
As you can see from the motherboard info's link, I believe an ordinary PSU will work fine with me. But what confusing me is the AT-ATX combination part..

[vm1990]

iv read this 3 times now and im still confused at what your trying to do. from what i can figure out your trying to run an AT board and a ATX PSU at the same time which would simply mean you wire the ATX up to the motherboard and wire the AT board into the 3.3v wire on the molex.

what voltage and ampage is the AT board?
what are you trying to do?

make it simple for us and we can help more

[M. Shammout]

iv read this 3 times now and im still confused at what your trying to do. from what i can figure out your trying to run an AT board and a ATX PSU at the same time which would simply mean you wire the ATX up to the motherboard and wire the AT board into the 3.3v wire on the molex.

what voltage and ampage is the AT board?
what are you trying to do?

make it simple for us and we can help more

Basically I am trying to upgrade a certain system. The system has an old motherboard which doesn't need the 3.3 V rail or simply it has regulators to generate it. I need to replace this motherboard with an advanced one (which I already bought "http://www.ibase.com.tw/2009/MB970.html". The thing is that the old AT-power source now can't be used to run this motherboard, at the same time I need the AT-power board as it has other functions (so I can't get rid of it).
I need a way to connect this AT power board with this motherboard  in a way that I take the lowest possible power of it (the AT-power board). So how can I combine the AT power supply board with the ATX PSU on the same motherboard??.


The following pictures of the power plug you see connected on the motherboard is for the old motherboard which I believe is customized (the motherboard) to work on AT-power (has inside regulators), so I can't use it with my new motherboard.

http://cdn.instructables.com/F2H/37I7/I1MQ5YDL/F2H37I7I1MQ5YDL.LARGE.jpg
http://www.instructables.com/files/orig/F6P/UV9E/I1MQ5YES/F6PUV9EI1MQ5YES.jpg

Some guys suggesting me only to wire the grounds of both PSU's?- okay.
Which PSU should I connect to the 20-pin ATX power connector??, also
which PSU is going to supply the harddisk, and DVD?.

Can I connect +12 V, and +5 V rails form the AT power supply to the ATX connector (as the power good signal is fed from them to the relays), while sharing its 4-COM's with the other ATX PSU on the same 20-pin connector. And filling all the other pins on the 20-pin connector from the ATX PSU??.

http://www.instructables.com/files/orig/F3G/7V66/I1MQ5YCE/F3G7V66I1MQ5YCE.jpg

For operating the motherboard with the AT-power board at the same time I only need to make a jumper to connect the PS_ON, along with one of the COM's on the ATX connector to the ON/OFF switch that starts the AT-power supply itself. Is that correct??.