So you’ve decided to build your own Carputer. Great! Where to start?
The best place is to think about whether you’re going to build a PC from scratch, or try and modify an existing PC for use in a car. I would seriously recommend the former, but if you’re on a budget or you already have a PC to hand then you may want to re-purpose a machine which was originally designed for a home or office. However, for reasons that will become clear over the current pages, I really don’t recommend this.
This decision is going to affect your fabrication straight away, the primary problem is power.
Power
All “traditional” home or office PC’s or laptops run on mains electricity, which uses Alternating Current (AC), whereas your car uses Direct Current (DC).
Without going too far into the technicalities of this, it’s not a simple case of connecting your home PC to the battery or cigar lighter, you’re going to need to convert the battery DC power to AC power that the computer can use.
Ironically, the internal components of all PC’s use DC, but because all homes are fed with AC the PC’s power supply converts the mains electricity to DC. So, in effect, if you’re using an existing PC then you’re going to be converting the car’s DC power into AC, and then the PC’s power supply will convert the AC back in to DC so that it can power the components. Complex, huh?
The only way you’re going to convert your cars power to DC is to use a device called an inverter
You’d need to connect this device to your car’s battery (via a fuse), it would then convert the batteries DC power into AC power that the computer can use.
This ad’s another level of complexity to your build, and is the primary reason why using an existing PC is a really bad idea (if you want a professional looking result).
A much better solution is to take advantage of the fact that both your car’s battery and PC components use DC electricity. In other words, bypass the traditional power supply all together.
Mini-Box.com produce a product known as the M2-ATX, which is a power supply board for PC’s designed for places like cars and boats.
This power supply differs from a traditional PC power supply as it doesn’t convert AC power into DC. Instead, this focuses on taking the DC power from your cars battery and regulating it properly so that it’s suitable for the components in a PC.
This nifty little box also has another neat little trick: When properly wired it can tell when you start and stop the car and control whether the computer is on or off. That way you can automate your Carputer so that it turns on when the engine is started, and turn off when the engine is stopped. You can also set a timer so that it doesn’t turn off the PC straight away, but waits a few seconds (or minutes), just in case you’ve stalled or your car has a stop/start system for traffic.
I’ve used this power supply before and it works flawlessly, I’d personally recommend it for anyone who’s building a Carputer.