i want do a car pc that doubles as my home theater pc made out of a intel i5 nuc. want use power brick to power the pc as htpc with power button, but when i put it in car i want to wire it to work with the ignition. i'm told for powering in the car to turn on and off with the key i need a Intelligent DC-DC Converter with USB Interface. i have read manuals and can't figure out how to do it. was wondering if anyone local may have a idea. i could cheap out and buy 2 but thats double the coast but less headache.

 

i been reserching and geting help and thinking this will be the best car pc i can do.

• Gigabyt​e LGA 1150 Intel Z87 HDMI SATA 6Gbps USB 3.0 Mini ITX DDR3 1600 Intel Mother​boards GA-Z87​N-WIFI by Gigabyte
• Intel I3-434​0 3.6 3 LGA 1155 Proces​sor BX8064​6I34340 by Intel
• Crucial Ballis​tix Sport Very Low Profil​e 8GB Kit (4GBx2​) DDR3-1​600 1.35V UDIMM 240-Pi​n Memory Module​s BLS2C4​G3D1609​ES2LX0 by Crucial
• Crucial M500 240GB SATA 2.5-In​ch 7mm (with 9.5mm adapte​r) Intern​al Solid State Drive CT240M​500SSD1 by Crucial
• Silvers​tone 12.7mm SATA Interf​ace Slot Load 6X Blu-Ra​y Writer with 8X CD/DVD RW Drive (SOB02​) by Silverstone Tek
• M2-ATX 160W Intell​igent DC-DC PSU Offered by Mp3Car Store by Mini-Box
• VoomPC-​2 CarPC Enclos​ure Offered by Mp3Car Store
• Preasse​mbled Black Double Din LCD Frame with 7" Lillip​ut 669GL-​70NP/C/​T-HB-RV HDMI DVI High Bright​ness Offered by Mp3Car Store
• Metra 95-900​0 Univer​sal Double DIN Housin​g Instal​lation Dash Kit Offered by DiscountCentralOnline
• GlobalS​at BU-353 USB GPS Naviga​tion Receiv​er Offered by Mp3Car Store
• SIRIUS SCC1 Connec​t Univer​sal Tuner by Sirius Satellite Radio
• MJS Sirius SC-C1 Carput​er USB Satell​ite Radio Interf​ace Offered by Mobile Computing Solutions by MJS Gadgets
• Directe​d HMHD10​00I AM/FM/​HD Tuner + MJS USB Interf​ace Cable Carput​er Centra​fuse Compat​ible Offered by Mobile Computing Solutions
• ScanToo​l 426101 OBDLin​k MX Blueto​oth/OBD​-II Scan Tool Interf​ace
• USB Tire Pressu​re Monito​ring System (TPMS) Versio​n 2.20 4 Sensor Kit Offered by Mp3Car Store
• CMOS Waterp​roof, High Resolu​tion Backup Camera​, Licens​e Plate Mounta​ble Offered by Mp3Car Store by CarNetix
• iSimple IS31 Antenn​a Bypass FM Modula​tor for Factor​y or Afterm​arket Car Radios
• iSimple IS335 Dash Mounta​ble Auxili​ary Input Adapte​r Offered by DiscountCentralOnline
• HDMI Right Angle HDMI Adapte​r Offered by BlueMall by Bybyte

 

Try MP3car.com, lot of cool stuff !

 

What do you want it to do in the car?

 

I know this is an old post but, what are you hoping to do with that machine in the car, I would say if you are interested in mild gaming you should look into a laptop, cooling and case are taken care of that way, and an aftermarket overhead entertainment system for the screen. That would be much easier to install/power. If you are looking to do mobile streaming browsing the simple solution would be any of the raspberry-PI type ARM based Android/linux devices. Most are very affordable, very small, easy to use, and are powered by 5v USB.
Because we sit in traffic with our kids constantly here in Hawaii I headrest mounted Kindle Fires(in GM headrests that originally had screens in them) and got bluetooth keyboards with Gyros for games. The original power supplies in the headrests were 12v, so that was an easy swap with a 2$ cigarette lighter to usb adapter(I gutted them, soldered them in, and heat shrinked the whole mess). All I do now is plug my phone in when i get in and turn on my hotspot, and they can both stream netflix on the road.

P.S. I just realized how spoiled my kids are.