Thread: M2-ATX(-HV) 160 watt Intelligent DC-DC PSU

Good idea.. I'll try that tomorrow.. Thanks for the help.

Originally Posted by Mickz

I don’t want to lead you down the garden path here but if I was having this problem and I had eliminated the rest of the wiring then I would run a small temporary wire (run it outside the car and through the window for the test) directly from the battery to the control wire and see what happens when the car is turned off with that line connected.

If the PC runs ok and does not immediately power down when the motor is shut down then you know for sure that it’s the control line that is the source of the problem. At Least you then have a place to start.

On second thought.. How exactly do you mean to do this? Should I start the vehicle and then connect another 12v constant directly from the battery to the switched pin of the M2, wait for it to power on completely, and then turn the vehicle off?

Yes, it's not the ideal way to do it because it may be a combination of the power down signal and the engine shutdown, but the idea is to see if the cause of the sudden PC switch off is that control line or some other connection to the PC/PSU. Then a more correct test can be carried out.

Originally Posted by WuNgUn

Without shutting of the IGN, remove the wire from the IGN leading to the M2 and see what happends...
Also, what do you mean the 'ground is to ground'? It's attached to the chassis of the car?

Ok, I started the car with the IGN wire disconnected.. With the car running I then applied the IGN wire to the M2.. It powered up correctly after 5 seconds.. I let it run for a minute or so and then removed the IGN wire from the M2..

It began the hibernation process.. While it was still in the process I turned off the car.. It didn't shut down and continued hibernating correctly..

So, it has to be something going on with the IGN wire only when the car is shut off because it works fine when I manually remove the IGN wire from the M2..

How can I fix this?

Thanks

Just one more test, this time don’t set the PC to hibernate, just cut the ignition. Want to make sure the PC keeps running fine.

Yea, it does..

Ok, so you have now eliminated the rest of the installation and were down to something going on with the PSU control line.

Now there are elegant solutions to the problem BUT for now we want to keep it SIMPLE and almost NO COST until were 100% sure we have a fix.

So, with that in mind you could try a couple of quick fixes.

1. Try a quick filter on the control line.
Go to an electrical hobby store and buy a 47ohm ½ or 1 watt resistor and a 10uf 25 volt electrolytic cap. Place the resistor in line with the control line, mount it near the PSU, and then connect the (+) side of the cap from the PSU side of the resistor and the (–) side of the cap to a ground point on the PSU. See if it solves the problem.

2. Solution two.
Get a very small 12v relay. Power the relay coil from the IGN wire. Connect one of the relay “normally open” contacts to the PSU control line and the other to the “always on” 12v line going to the PSU. This “almost” completely isolates the IGN wire from the PSU control line.

Once again NO guarantee that this will work first time, but I am pretty sure we can get it to work one way or another. Again the point of the exercise is not to get technically cute, just to get it working first.

I seen one member use the liliput egg / filter before.. Could I try that? If so, how would I wire that up?

Yep, I mentioned that earlier, didn’t know if you had one though. That is most likely just a DC filter; connect it the same way, between the IGN and the PSU control line. He may have used his in a different location but we know that your problem appears to be coming down the control line. The filter I described will de-bounce the ignition line a lot more, but that should not be the problem anyway.