WIERD ps problem

**Slitha** · 09-13-2004, 12:33 AM

This is realllly wierd. First, some background. I'm usin a 400 watt power invertor to run my 300 watt power supply comp.

I have my BIOS set up to turn on on ac power return or whatever that option is. So when i turn on my power inverter, the computer starts booting and everything's great. I look at the fan for the power supply and it's on and whirring like new. I go turn on m LCD to see that it's getting no VGA signal. THen i realize that my motherboard isn't on casue i didnt' hear the boot "beep". but the fan on the power supply is still on. So i'm like wtf mate?

Now being the smart guy i am, I checked all my connections inside my computer and they are all on perfectly. So i go away for a couple hours cause i had to do somethin. I come back, and it works again. AHHHH. I get all excited and think i'm godly.

Next day, same problem arises. What the hell is going on? It has happened on and off for four to five days now.

Please noone give me the 'suggestion' of gettin an OPUS because i honestly cannot afford an opus because i can't get one to power my whole computer, and would like to just buy a whole new computer with power supply for under 250 if that's possible.

Anyways, please help me.

**Change** · 09-13-2004, 03:06 AM

Does the system work with the power supply plugged into a wall socket? If so, maybe your inverter isn't providing enough inrush current to let the system boot. If not, start looking elsewhere.

Oh, verifying the "boot on AC mains restore" setup inside would be good too...plugging it into the wall alone should make it start up then.

**Slitha** · 09-13-2004, 04:18 PM

Well, i tried it and it seems you were right about it not giving enough power.
So, i went to talk to someone at the road shop at Circuit City to see if i had fat enough cables. He suggests using a bigger relay than a 30 amp auto relay from radio shack or making a parallel circuit with two 30 amp relays. If i get a bigger relay, i'd like to get a time delay relay as i do it, to solve other problems i'm having. does anyone know if this is the right relay for me? I mean does the voltage, amp rating, wattage and all that make sense for me? I'm sorry to be asking such newbie questions, but i haven't taken any electronics courses and am just learning this stuff. Thanks in advance.

**Slitha** · 09-13-2004, 11:25 PM

bump, i edited my previous post, but noone will read it if it's at the bottom.

**Tidder** · 09-13-2004, 11:28 PM

Man, I feel for you. I wish I could help. From the sound of it, everything is ok... I would try the parallel relay setup though.

Time delay relays are good to have as well...

**choyak** · 09-14-2004, 12:28 AM

Perhaps the inverter has insufficient input voltage. I have the xantrex 400w, and whenever you switch off the key, the inverter starts to whistle because the voltage is too low. The inverter will dump if it is running with the key off for about 10 minutes or so. I think that the inverter needs more than 13 volts to operate properly.

**archimense** · 09-14-2004, 02:38 PM

You have a 400 watt inverter.

Watts = Amps x Volts.

Your car battery is between 12 and 13 volts. Most automotive circuits/relays etc are designed to be 30 amps.

400 watts = 33.3 amps x 12 volts OR 400 watts = 30.76 amps x 13 volts.

I would think that the inverter you have is only designed to be on when the car is running.

I would see if you could get a smaller power supply, maybe a 200 watt? That is the cheapest thing I think you could do. Or else maybe try a 300 watt inverter.

**MatrixPC** · 09-14-2004, 03:07 PM

How do you wire the inverter?
Are you wiring the inverter (+) to the relay then to the battery (+)? If so, you should change the wiring. The inverter (+) should go directly to the battery (+). The cable should be at least 8GA (4GA is better). Use the relay to control the inverter's ON/OFF switch.

**Slitha** · 09-14-2004, 04:28 PM

Originally Posted by MatrixPC

How do you wire the inverter?
Are you wiring the inverter (+) to the relay then to the battery (+)? If so, you should change the wiring. The inverter (+) should go directly to the battery (+). The cable should be at least 8GA (4GA is better). Use the relay to control the inverter's ON/OFF switch.

Yes, that is how i am wiring my invertor. If i want to wire it to the inverter's on/off switch, i would need to open up my invertor and mess with stuff inside that i don't know how to mess with. I'll try it though. Also, if i do decide to wire to the on/off switch, the relay i put a link to should work, right?

**MatrixPC** · 09-14-2004, 04:49 PM

The inverter's ON/OFF switch is just a 2 wires/terminal toggle switch.
Any automobile type relay will work, so use what you aleady have and you don't need more than 1Amp relay to drive the switch.
To connect (parallel with switch is easier).
One wire from 1 leg of the switch to Pin 30 of the relay. The other leg of the switch go to Pin 78 of the relay. Pin 85 and 86 connect to ground and IGN switch signal.
Operation: The inverter's switch should left in the OFF possition.
Ignition ON which turn on the relay and which simulate the inverter switching to ON.
Does it make sense?