Looking for a creative solution: USB bus still powered after CPU is off

**archimense** · 08-23-2004, 03:39 AM

Originally Posted by rando

Yes, that's correct. Here's a schematic.

I just did this mod to my OPUS 150 and I can confirm that it works as described with my EPIA M10000.

Thanks again for the help Rando.

**rando** · 08-23-2004, 09:27 AM

Originally Posted by archimense

I just did this mod to my OPUS 150 and I can confirm that it works as described with my EPIA M10000.

Thanks again for the help Rando.

N/P. BTW, you didn't actually mod anything on your Opus, right? I just bought an ATX cable extension and did my splicing there.

**Ricky327** · 08-23-2004, 10:01 AM

Rando,

Just out of interest...from what I suggested earlier on the thread was it really neccessary to have the delay between the ACC and trigger for the OPUS to work reliably?

Im sure you mentioned somewhere that a delay may be needed from the result of your testing, or was it fine as it is?

**rando** · 08-23-2004, 10:19 AM

Originally Posted by Ricky327

Rando,

Just out of interest...from what I suggested earlier on the thread was it really neccessary to have the delay between the ACC and trigger for the OPUS to work reliably?

Im sure you mentioned somewhere that a delay may be needed from the result of your testing, or was it fine as it is?

Yes, I did confirm that the Opus intermittently failed to startup the computer when ACC is energized before the +12V input. See post #64 and your acknowledgement in post #65.

**Ricky327** · 08-23-2004, 10:26 AM

Ah ok...I did remembered it being mentioned, sorry I cant be bothered to read all the thread again...its too long.

Just made me wonder as I cant see any delay circuit on the schematic you posted...so I kinda assumed the delay was not needed.

Those guys following your circuit may have reliabilty problems?

or did I get it all confused now?

**savante** · 08-23-2004, 10:33 AM

Ricky327,
Doing it the original way, using relays to drive the opus power would require a delay to give the +12V to the Opus before the ACC.

The schematic is just using the relays to drive the PSON and +5VSB from between the Opus and the motherboard... which is not the way originally described.

Does that help?

**Ricky327** · 08-23-2004, 10:36 AM

Ah ok, thanks for the clarifications

I should have followed the thread all the way...oh well.

I think I better stay away from the thread as Im way out of line now

Good luck

**rando** · 08-23-2004, 10:55 AM

@Ricky: It's a different solution.
@savante: Correct!
@Ricky: LOL, you're welcome here...everyone has a bad day now and then.

**archimense** · 08-23-2004, 12:54 PM

Originally Posted by rando

N/P. BTW, you didn't actually mod anything on your Opus, right? I just bought an ATX cable extension and did my splicing there.

Correct. I didn't mod the power supply itself, just the ATX cable from the OPUS to the motherboard.

**djkriz** · 08-24-2004, 05:05 PM

since I am no electronics expert, i've got a question about the schematic by Rando.

Is it important which ground I take for the relay?
Since it uses two +12v inputs, 1 from the ACC and one from the +12v of the opus, can I take any of the black wires used in the ATX connector or just ground it directly on the car? Or doesn't it matter?

thanks!