FrankenPower! Building a 12V Power Supply

[Road Builder]

Hey Mike, the one I got from you is still working perfect. If you guys don't like tinkering just get one from Mike. Awesome unit!

Jay

[Chris Puckett]

The one that started this thread still runs like a gem. Had it running my cube and two Thunder Power chargers going full bore.

[Road Builder]

I had mine doing my old Fromeco charger and my Sirius this summer. The thing didn't even grunt. To cool. Plus the red lights look really cool.

Jay

[Mike Bargman]

I need to find some more like that. I can't get those anymore...

[Road Builder]

Bummer. Did you try Fry's? They have all kinds of crap.

Jay

[captain ducman]

Mike,

This is a great project and Ive read start to finish hoping my feeble self could do something like this.
Ive been trying off and on to make this work for a couple of days now with no success. I have the same problem some others had with the fan starting for a second then stopping.

I have connected the:

Green (SW) to Black
Gray (PG) to Red (didnt work)
Gray to Orange (each of the 3 separately and none worked)
Gray to Black (didnt work)
Red to Orange (each of the 3 separately and none worked)

On the Orange wires, there are two that come out of a printed black square on the board and next to them is another orange in a circle printed on the board - looks like it is separate or something but very close to the other 2 orange wires. Any ideas?

Thanks,
Steve

[Cracky]

Did you put the sandbar resistor between I think it is the red and black? This puts load on the system and tells it to stay running.

I printed out Mike's directions and followed them to the "T" and it worked perfectly for me. The first thing that I did was cut away the colors that I didn't need and left three sets of yellow/black, a red/black and a green/black.

[Mike Bargman]

I'm wondering if one of the orange wires in a sense wire...somewhere in this thread, we found a power supply with a sense wire. On the ATX connector, there's a pin with two orange wires crimped together. Make sure that those wires STAY together or get jumped to each other.

[vsnap]

Thanks Mikey mine works perfect so far. I even did the 5volt side for working in the shop. Of course I will test it on non suspecting equipment.

[captain ducman]

Yep,

I'm about ready to eat a bullet over this ARRRGGGHHH. It's not even the PS I want to use, I just had it laying around and thought I see if I could get it to work before buying a bigger one.

Just PM'd Mike, I'm gonna leave the electronics and containment of the magic blue smoke to the professionals.

I wont say this project beat me, but like at the field when you see a crash..."it wasn't me, I was shot down" the PS must have had problems already

Thanks tho,
Steve

[Mike Bargman]

Glad to help, Steve.

[Uncle Brett]

	Quote: Originally Posted by Mike Bargman
	I'm wondering if one of the orange wires in a sense wire...somewhere in this thread, we found a power supply with a sense wire. On the ATX connector, there's a pin with two orange wires crimped together. Make sure that those wires STAY together or get jumped to each other.

Yep Mikey, the newer ATX PS will more than likely have a sensing wire, the last 3 that I've coverted have them. Here's an explaination on how to deal with this:
The +3.3 VDC remote sensing wire (brown or orange) is connected directly to the orange +3.3 VDC at pin 11 of the power connector (pin 13 if a 2x12). The sense wire will usually be of a lighter gauge (22 AWG) than the power wires (16 or 18 AWG) and its purpose is to monitor the voltage at the connector in order to provide feedback for voltage compensation by the supply.

If your PS has two wires attached to the same pin on the motherboard power connector, orange +3.3 VDC and a brown sense wire on Pin 11 for example, then these two wires should be joined when you make your conversion. Some power supplies may also have sense wires running to the +5 VDC and +12 VDC connector pins. If there are multiple sense wires, then they will usually be of the same color as the primary supply wire, but of a lighter wire gauge. These sense wires will also terminate in a different location on the PS printed circuit board than the heavier supply lines. As with the +3.3 sense wire, these additional wires should also be connected to the corresponding supply lines. Failure to complete these connections may result in your power supply not latching into a Power_On mode when switched on.
I've found that if I take an orange wire comming out of pin 11, and connect it to the brown wire (there's only one) then everything works perfectly. I've also found that if I use two 1 ohm 10W sandbar resistors in series, I can connect a charger while the PS is running without it shutting down, it will also increase the output voltage slightly.