ATX power supply

[Freebird]

Well,  trying to power up my new SS hub, I thought for sure that I had the right power supply.  In fact I had 3 broken PC that I knew I could just pull the PS out and they would work.  However, when I pulled them out they were only the 20 pin rail.  A few questions.  Does anyone know the pinouts on the 24 pin so I can pick up a 24 pin from radio shack and just make it work? 

Or do you know if this adapter will work,  You are not allowed to view links. Register or Login

Thanks,

Okay  Found this photo.  If it matches up to the SS hub  What pins on the SS HUB are the final 4 at the bottom needing?

[rmp2917]

I believe the 20 pin connector should plug directly into the 24 pin connector. You just need to shift it to one side and leave the 4 pins on the other end empty. It should only fit on one side.

It should work fine as long as your power supply has enough Amps on the 12V line for your nodes.

[JoeFromOzarks]

That Radio Shack part is described: "This adapter cable turns your power supply's 24-pin male ATX connector into the 20-pin male ATX connector needed by most high-end motherboards"

The SSC Hub uses a 24pin.

joe

[Freebird]

Well here some other issues causing me to think this way.  With the ATX power supply P5, P6 and P7 in and the 20 pin of P1 out ( because it dosent fit) I can power up the board, even run the SSC Test Hex,  However  I can't program the SS HUB with my pickit 3.  I keep getting "Device not found" with the Pickit 3 utility.   I was thinkng that maybe it can't find the pic because power is not applied to the right spot via the 20 pin connector.

Now the P1 20 pin plug will not fit into the SS HUB connector.  If you look real close and Im sorry about the bad photos, but the rounded holes and square holes do not line up. 

ALso if you look close on the P1 plug you can see that pin 3 is missing a wire and pin  Is this normal?

Freebird

[JoeFromOzarks]

I do not know if the 20pin Power Supply is approved (by RJ) for use on the SSC Hub.

I've not built the hub yet, but it appears the "1" on the PCB is on the incorrect end of the 24pin connector.   Pin 1 is actually towards the bottom of the board, near to the GND +12 Optional connector.   (You want the power supply connector in the other direction in picture WP_000013.jpg, towards the bottom of the Hub PCB)

The 20pin or the 24pin power supply connector will fit only one way on the SSC Hub.

joe

[JoeFromOzarks]

The pin you've described as "PIN3" is actually PIN18 and it's okay if there isn't a wire there, it's for the (no longer used) -5VDC (minus 5VDC) and if I remember correctly, was used only for ISA slots.   PCI doesn't use -5VDC. 

Without the 20/24PIN power supply connected, the Hub isn't receiving the 3.3VDC which after a very quick peek looks like the PIC isn't being powered. 

joe

Well here some other issues causing me to think this way.  With the ATX power supply P5, P6 and P7 in and the 20 pin of P1 out ( because it dosent fit) I can power up the board, even run the SSC Test Hex,  However  I can't program the SS HUB with my pickit 3.  I keep getting "Device not found" with the Pickit 3 utility.   I was thinkng that maybe it can't find the pic because power is not applied to the right spot via the 20 pin connector.

Now the P1 20 pin plug will not fit into the SS HUB connector.  If you look real close and Im sorry about the bad photos, but the rounded holes and square holes do not line up. 

ALso if you look close on the P1 plug you can see that pin 3 is missing a wire and pin  Is this normal?

Freebird

[bcstuff]

Why not just use a 20 pin atx power supply adapter to 24 pin motherboard connector?

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Freebird, you had the right idea, but wrong connector.
I have used these with older power supplies on newer motherboards.
It replicates a 24 pin output on a 20 pin power supply.

[rm357]

Power should not be applied when programming the pic. The pickit 2 or 3 will provide power to the pic for programming.

RM

[rmp2917]

The 20 pin and 24 pin connectors were intentionally made to mate with each other. You just have to have it aligned correctly for it to plug in. It should be plugged in toward the bottom of the hub with the four pins at the top left empty. As Joe says pin 1 is actually towards the bottom of the board not the top as marked.

The four extra wires on the 24 pin connector simply add one additional 12V, 5V, 3.3V and GND wire for additional current capacity.

Adding an adapter does not add any additional benefit over simply plugging the 20 pin into the 24 pin connector. Since you are not adding any additional wires from the power supply to the 20 pin connector, you are not adding any additional current capacity.

As far as programming the PIC you shouldn't need any power connected at all to program it.