Im just wondering of a couple of things with my new 12V mini-itx psu

**Plecto** · 10-09-2009, 12:33 PM

Hi. Just bought an http://cgi.ebay.co.uk/12V-Mini-ITX-A...d=p3286.c0.m14, the cheapest power supply I could find. After reading the manual (can be found in the link above) I think I figured out almost all the functions, but I'm left with two questions. The psu got a function which makes it shut down the computer automaticly after I have turned off the ignition. After a set amount of time after this (called "hardoff") it turnes off the power completely so that the computer doesnt drain power when it is not running. I tested this, I plugged out the power-sw cable, turned off the ignition and after the 45sek described in the manual, the computer shut completely down. The question I have is how come it is still sparkling when I tap the + or - cable from the computer on the + and - poles on the battery? If there is no power drained from the battery, there shoud be no sparks, right?

My second question is about the psu's function to automaticly turn on my amplifier when the computer starts. For this function there is two pins, the manual says that the pin on the left is for RMT (amp) and the one on the right is for GND. If I use my voltmeter, one part on the right pin and the other on the + pole it shows 12V! This means that it is a connection between the right pin and the minus pole, what then is the reason for hooking it up to ground? I'm also wondering about why there is two pins at all. The amplifiers remote just need a very week 12+ signal to start, shoudnt there be enough to just have a + output on the PSU which can be hooked up to the amp?

**soundman98** · 10-09-2009, 04:39 PM

1. amplifiers do this too-- while the are not turned on, they still draw a little amount of current.

2. just use the 12 volt lead, and don't think about the ground placed near it...

**Plecto** · 10-09-2009, 05:02 PM

1. amplifiers do this too-- while the are not turned on, they still draw a little amount of current.

May I ask why and how much current?

2. just use the 12 volt lead, and don't think about the ground placed near it...

Just figured out that this is not a 12V lead. It has no contact with the + pole and the voltage between this pin and the - pole is 0V. What am I missing? I could just try plugging this to the amplifier like the manual says, but if that worked I am still eager to find out how :O

**soundman98** · 10-10-2009, 04:09 PM

All electical devices that have a remote lead to turn on use a small amount of power when they are in standby- plugged in but not running. It has something to do with keeping the turn on circuit powered. I am not a electrical engineer, so that is about as much as I know.

I don't use the remote turn on feature, so I can't help you too much with that

**trader007** · 10-10-2009, 06:48 PM

are those just m2 clones made by a 3rd party? they look the same as the m2.

**Plecto** · 10-10-2009, 06:49 PM

I have absolutely no idea :P

**Mickz** · 10-10-2009, 07:40 PM

Originally Posted by Plecto

The question I have is how come it is still sparkling when I tap the + or - cable from the computer on the + and - poles on the battery? If there is no power drained from the battery, there shoud be no sparks, right?

The may be a momentary current draw as the electrolytic capacitors charge. You need to measure the constant current drawn after the momentary inrush current subsides to see how much power is actually been used in standby/off mode.