HELP on Using Inverter and UPS to power carpc

**davidbudi** · 04-25-2005, 09:14 PM

I'm a newbie in building car pc. I was planning to use an 500 watt inverter connected to UPS then to car pc. I built my own shut down and power on relay my self. My plan is use 12 V DC relay (normally Open) that is connected to ignition key. So if the key is in the ACC position the relay will turn on the Inverter that supply power to the UPS, then to the car pc. For the car pc i use 12 V DC (normally close) relay that connect to ACC position on car ignition key and an 12 V DC (normally open) relay that connect to on position on car ignition key. Both of the relay is use to control the power button on the ATX power supply on the car PC. The reason i use UPS is that it will allow continous power after the car pc is shut down and also to survice cranking voltage drop. The UPS will always be recharge when the car in running, so the battery will not be drain out. The other reason i use UPS is i can start the car PC without draining power from the car battery.

My question is... Does this settup will work? Please help me with this issue. Any comment and help is greatly appreciate it.

Thanks

David Budiatmaja

**xdjxklusivex** · 04-25-2005, 10:13 PM

i heard if u use ups's u get engine noise or something but for crank stuff i got a normal stupid 90watt psu that came with my pc and a 400/800 watt colman inverter it survives crank and shutdown just wired it str8 to my battery i paid like 25 bucks for it

**greenman100** · 04-25-2005, 10:16 PM

too complicated and too expensive.

use a battery and a relay.

**davidbudi** · 04-25-2005, 10:54 PM

Thank you for your reply.

Is there any more reason why the UPS and the relay can not work? I dont know much about how the UPS work, but i was planning to buy one with the automatic voltage regulator. Can it reduce the noise?

Would you please explain more about the noise cause by using UPS?

If there anyway i can built delay relay that will enable the car pc to shutdown properly. If i can built the delay relay i will not need to use the UPS.

The 12 V DC relay is quite simple, i'll give more detail explenation if your interested. The cost of the relay is very VERY cheap. I use 3pcs 12 V DC relay that only cost me about $3

**greenman100** · 04-25-2005, 11:35 PM

New shutdown controller - software

the UPS is too bulky, expensive, nut I don't htink it will introduce noise.

**davidbudi** · 04-26-2005, 09:13 PM

thank you for your eply greenman, i already read your link. Thanks for your info.

IS there anyone else that ever us UPS in their car pc setup? Please shrare your experience. Thanks

**Vchat20** · 04-26-2005, 09:41 PM

for one, iirc, most UPS's have problems running off inverters. something about them not being true sine waves. feel free to correct me on this though.

**davidbudi** · 04-27-2005, 05:06 AM

Thanks for the info. what kind of a problem Warren? Could you explain it to me in more detail?

Could anybody tell me what the common problem cause bu using UPS to power car PC?

Thanks

**stevieg** · 04-27-2005, 11:03 AM

Sorry but what is the point of all this?

12V battery > Invertor 240v > UPS Down to 12v > UPS back upto 240V > 240V PSU > 12V Car PC

( above applies in some circumstances, not all, btw)

And Relays too!!!!!!!!!!!!!!!!!!!!!

*****s sake m8, you're making it WAY to complicated, much to inefficient and your worrying about running down the battery!??!?!

Yes, people used to do this **** years ago before 'clue' was distibuted to mp3car'ers.

The UPS IS a battery. If you *NEED* backup power, then look into a tank circuit, NOT a standard UPS.

If you *need* an inverter, fair enough, but you may wish to look at an inexpensive shutdown controller to go with that setup.

If your system will be low-power enough, say ~2ghz ATX/512MB and below, or Epia Mini-ITX have a look into the in car DC-DC solutions which survive cranking, and protect the batery from going plat, and because they don't waste power, they can run the PC for HOURS with the computer switched on and the engine off.

I could go on for ages and ages about diffeent options, disadvantages of this athat and the other, best to let you have a little search around, take a look at some installs and wiring diagrams etc and then ask a few more questions so you can get some specific advice as you never know a UPS might be your only option. But I doubt it

**davidbudi** · 04-27-2005, 11:24 AM

Thanks for your comment stevieg, your car pc is excelent and the dash is awesome. After this i will try to built the shut down controler. Its more efficient.

What do you think about using an inverter stevieg? The reason i want to use an inverter is because the dc to dc power supply is a very hard thing to find in my country.

My car pc will be built using micro ATX mother board and intel celeron 2 ghz. I use 500 watt inverter. Do you think it will survive the crank, if not is there any other solution about this matter (one that include the use of inverter).

Thanks