# Thread: Rookie Guide to CarPC's

1. ## Rookie Guide to CarPC's

I've put togeather many CarPc's. I've started out with just a laptop playing mp3's connected to an amp. Over the years my setups have progressed to some pretty fancy stuff.

What I will do here is try to recap what I've done and what I've learned in a guide form. Ultimatly, everyone could use this as a step by step guide to installing and learning about the computer in thier car.

I will cover the basics. Wirring, Hardware, and Software. You can grab this information by searching, however maybe this can be your one stop shop to a successful CarPC build. Throughout this guide, forgive me, if I cover things you may already know. Understand that I'm mentioning things that I've learned and that have saved me some trouble and that I'm mentioning it for the bebefit of all. Also if I am wrong on a fact or some advice please correct me, afterall success was built on lots of failure.

Wirring.
Looking thePC in your home you may wonder how to power the PC in your car? The first step to building a carpc is figuring out how to power it, and how much power you will need. There are two distincly different ways to acomplish this task. There are two ways, because there are two types of power, AC & DC. AC power, which is commonly found in your house WAS originally the first choice of power for carpc's. The idea was to use a DC to AC inverter, then plug your PC's power supply into the inverter. Below is an example of the different types of power.

2. Unless "DC" here is referring to digital signals, because that's what the pulses look like??? AC is a plain sine wave, and DC is a flat line, like purdoom said.

-psyrex

3. ## Ac/dc

Wirring Continued...

Above you can see the distinction between AC,DC and inverted DC. What a power inverter does is simply smooth out the edges of DC power to "trick" your computers power supply (the device that will actually power your pc). Focusing on the 3rd line of images or the Inverted DC. You'll notice a "cut-off" edge. On inverters you'll typically see a percentage range (ex. 85%-90%). This range means that each wave length will fall between 85-90% similiar to a real AC wave length. This number is important if you choose to power your carpc with an inverter. You'll want an inverter that is pushing 90-95% inverted power waves. The reason for this is because, your computer is actually a device that requires DC power. Your computers power supply, inverts AC power into DC power. Your probably thinking at this point "I'm going to convert DC power to AC, then AC back to DC?" YES! This is why this method is no longer preffered. If you still choose to power your pc with an inverter, make sure you choose a "SineWave" inverter that has a high efficiency (90-95%)

The newer way to power your CarPc hardware is with a dc-dc power supply. Basically, you need a 12v and ground line. Here's an example below:

4. ## image

here is the DC - DCATX Cable you may need.

Also if you look closly there are two holes in the PCB board. You can use standard Case Standoff to keep this above whatever surface you choose to mount this on. Typically you can mount this inside a pre-made case. Sometimes, depending on the case you may have to drill a bit. So if you don't own a drill consider buying one!

5. ## .

More Wirring.

lastly, you'll want to buy either an inverter or DC-DC power supply that will fit your hardware needs, if your unsure what you will need for hardware i'll go over this a bit later. For example, a 90w powersupply would probably not power just any old computer you have lying around the house. Use these Power Supply Calculators to figure out what kind of power your computer hardware will need to run stable.

A little advice, if your pushing the limit of your power supply it will run. It's not going to die out immediatly. What will most likely happen is that your system will become unstable and your power supply will run VERY HOT. Trouble shooting a power supply issue in a carpc can seriously be a pain. So I recommend you get a power supply that is a little bigger than what you need. Spend the extra 20.00, because honestly you'll wish you did after troubleshooting an under powered system. Also, this is a hobby and like most hobbies new things come out all the time. If some new devices comes out and you impliment it into your system that already has a pushed power supply. You may make your system become unstable. So try to build for expansion.

6. ## Finally.

Car Wirring.

Alright, so you've decided on what power and power supply you want to use. How do you actually wire the thing from your car to your power supply or inverter?

Well if you've ever installed an AMP before it's almost the same thing. Here are some accessories you may need. Take a look at them before you look at the wirring diagram it may shed some light on the project at hand.Connectors You may need.

7. While your efforts are appreciated, some of the information in there is just plain wrong; the last thing a true rookie needs is to be uninformed on the basics. I'm not trying to belittle you or discourage you from making this guide, I'm only trying to clear up some inaccuracies.
Originally Posted by IntellaWorks
Above you can see the distinction between AC,DC and inverted DC. What a power inverter does is simply smooth out the edges of DC power to "trick" your computers power supply (the device that will actually power your pc).
A power inverter takes DC power (which is inaccurately represented by your image) and turns it into AC power. There's no trickery or magic in the process.
Originally Posted by IntellaWorks
Focusing on the 3rd line of images or the Inverted DC. You'll notice a "cut-off" edge. On inverters you'll typically see a percentage range (ex. 85%-90%). This range means that each wave length will fall between 85-90% similiar to a real AC wave length. This number is important if you choose to power your carpc with an inverter. You'll want an inverter that is pushing 90-95% inverted power waves.
Those numbers represent the efficiency of the inverter. If you put 150 Watts of DC current into the inverter (calculated by multiplying the input voltage and current) and its efficiency is 90%, you'll get .9 * 150W = 135W of AC current out of the inverter (calculated by multiplying the RMS(Root Mean Square) voltage and the current). How closely the voltage / time wave matches a pure sine wave is a different matter entirely.
Originally Posted by IntellaWorks
The reason for this is because, your computer is actually a device that requires DC power. Your computers power supply, inverts AC power into DC power. Your probably thinking at this point "I'm going to convert DC power to AC, then AC back to DC?" YES! This is why this method is no longer preffered. If you still choose to power your pc with an inverter, make sure you choose a "SineWave" inverter that has a high efficiency (90-95%)
Good conclusion, poor way to come to it.

8. are you sure a sine wave inverter is 90-95% efficient????

are you sure a sine wave inverter is 90-95% efficient????
They can be

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