Newbie here looking for power suggestion for my setup

**erains** · 01-04-2004, 02:48 AM

Hello all,

I have been interested in a car pc for some time but have been leary due
to power sourcing issues meaning how fast will I be tearing down my battery while using the system and with the car running will the battery be charged enough? Also the heat generated with all the electronics confined to the trunk. In any case here is the gear I have so far:

1 VIA EPIA 800mhz board
1 custom plexi case made for the board
1 WD 40G HD
1 stick of 256 SDRAM memory
1 Sparkle 300W powersupply

On my shopping list:
Various long cables as I want to do a trunk installation
1 Liliput 7in TFT touch screen

System Goal: To funtion as MP3 player, GPS and Movie Player

So I'm confused on which way to go how big a power inverter do I need to run my system considering the equipment you see above? What is a good brand? Also if I go the inverter route I need to buy a shutdown board as well?

Or is a DC-DC supply the way to go? If so will a 90W be ok?

I'm tring to keep things as compact as possible but luckly have good room in trunk. Any help provided would be greatly appreciated.

I read the newbie faq and did do some searching but would like to get some experenced people with real world system experence to advise as they have been there and have bone that

-Eric

**Jackso** · 01-04-2004, 02:53 AM

I have the slightly larger EPIA board and run a 400 Watt inverter. The inverter runs everything listed below including the 14" LCD. The shutdown board is only needed if you want the computer to automagically start/stop when the car is started/turned off. I use a momentary push button to start up and shutdown my pc, and a toggle switch to apply/remove power to the inverter. All of the things you meantioned should run off of a 120 Watt or so power supply. They're usually the ones that go in e-machines. That is what I use.

**erains** · 01-04-2004, 10:58 PM

Thanks for the help Jackso Yeah I have a large 300W supply now I got for free but glad to hear I can use a smaller unit. Yeah I will probably install switches as well. I want to go the inverter route as it is least expensive and I don't care about reboot issues with startup or shutdown

-Eric

**LESLIEx317537** · 01-04-2004, 11:33 PM

You can try to use the ITPS combined with the PS that they make.

www.mini-box.com

**erains** · 01-05-2004, 11:40 AM

Hey the P70 looks great but will 70watts be enough to power everything?
Thanks for the suggestion Leslie

-Eric

**LESLIEx317537** · 01-05-2004, 12:24 PM

Eric, look at the power usage chart they have. It's interactive.

You check off how many fans hd's cd-roms you have etc...It tells you how many watts your drawing.

I have a keypower 250watt PS that runs off 12 volts. I'm planning on getting a EPIA setup soon. But I'm going to measure how many amps I'm drawing now with a meter, so I'll be sure that the 100watt P70A can handle the load I'm gonna be taxing from it.

Don;t forget you'll need the ITPS also, it regulates a steady 12 volts to the EPIA mini PS's. If not, they will not run correctly on a varying voltage.

**crosseye** · 01-05-2004, 12:56 PM

Quick related question:

If you use an inverter and an ATX power supply, you don't need to regulate voltage going into the inverter do you? When you start your car and the engine turns over, will your inverter shut off until the battery voltage returns near 12V? Seems like the inverter should handle this, right?

Also, I have a 250 watt ATX power supply... does that mean I have to use an inverter of at least 250 watts? Or can I use (for example) a 150 watt inverter with the 250 watt power supply? (I wouldnt expect to get 250 watts out of this tho)

Thanks.

**LESLIEx317537** · 01-05-2004, 01:02 PM

Q: If you use an inverter and an ATX power supply, you don't need to regulate voltage going into the inverter do you?
A: No.

Q: When you start your car and the engine turns over, will your inverter shut off until the battery voltage returns near 12V? Seems like the inverter should handle this, right?
A: A good inverter should handle it.

Q: Also, I have a 250 watt ATX power supply... does that mean I have to use an inverter of at least 250 watts? Or can I use (for example) a 150 watt inverter with the 250 watt power supply? (I wouldnt expect to get 250 watts out of this tho)
A: The PC will draw watts depending on how many things you have connected. If you go over 150 watts your ps will be fine, the inverrter will not.

**LESLIEx317537** · 01-05-2004, 01:04 PM

The main thing about inverters is that there is no reason to go from 12 volts dc to 110 vac and then back to 12 volts dc and lower.

It introduces line noise.

With EPIA setups, your better off without one, if you can get the new PS's and the ITPS module (Helps you press power etc...).

**erains** · 01-05-2004, 06:30 PM

Thanks Leslie

didn't even see the chart. Oh update to my setup turns out my VIA800mhz board was bad so I retuned it and upgraded to the VIAM1000
Hopefully power consumption will be the same or lower in any case thanks for the advise is is much appeciated

-Eric