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[on:]

I'm sure this will not be as popular as the Sybian thread, but anyway, powering an Arduino while it's in a car from the standard 12v car battery, as we all know, is risky business. 'Dirty' DC power with the potential to both under and massively over-volt.

What surprised me, though, about the Arduino is that, while there are a good few threads on solderable together from cheap components (the usual array of diodes and varistors) to create a suitable power protection/voltage regulation circuit for the Arduino to use in a vehicle... there is nothing 'off the shelf' that you pick up for a few bucks that's proven to work, does what it says on the tin, as opposed to trusting the odd sketch suggested by a member on the Arduino forum that may/may not work.

Does such a thing exist? A simple, plug and play board that will provide suitable, even excessive protection for your Arduino in a vehicle-usage scenario?

[Reply #1 on:]

Hi
I´m not quite sure what you want to do but it sounds like you want connect a car battery to an Arduino. In that case just use a fuse to be save. But it´s very impracticle.

[Reply #2 on:]

Hi
I´m not quite sure what you want to do but it sounds like you want connect a car battery to an Arduino. In that case just use a fuse to be save. But it´s very impracticle.

You don't think you fully understand the question...  Car 12V rails can have destructive inductive spikes (well above the nominal 13.8V max) and will drop-out when the starter motors fires up.  Bad grounding connection or a dying battery can allow the alternator circuit to put out more higher voltages for extended periods of time too (bulbs tend to start failing then!)  The problem is to cheaply and simply protect an Arduino and associated circuitry in such an environment (brings peace of mind after you've spend 100's of hours on a project!)

OP:

Yes, it seems that most devices designed for vehicle use have to individually solve this problem, rather than a power-conditioning unit being provided to drive all the sensitive electronics in the vehicle on a separate 12V bus.  In the past there was nothing sensitive to worry about so it was never a feature of vehicle design.  There are in-car USB chargers which ought to provide a good regulated 5V (avoid the very cheap ones, of course), but if you want a nice regulated 12V as well its tricky. 

A combination of surge-protection circuit and a 10V regulator would be handy for some things (potentially little more than a series resistor, TVS diode and 10V regulator chip). 

12V low-drop-out regulator would also probably fare well most of the time (car batteries should be fully charged and more like 12.5V than 11.5V).

DC-DC converters, while somewhat electrically noisey, will isolate completely and not be affected by the battery voltage changing between charging and discharging.  A 12V -> 6V converter followed by low-drop-out 5V regulator could be a reasonable approach.  Go for the converters with a large input voltage range (8..24V or something like that).

[Reply #3 on:]

http://www.logicsupply.com/products/picopsu_80

Made for a computer motherboard, but hey for $25 at 80W of power the form factor isn't much of a hassle.

[Reply #4 on:]

You could just get a dc to ac power inverter. The http://www.powerbright.com/DX100-12.html is a cool one because it has both a usb and a ac port. I always find these great to leave in the car as they save you from having to by seperate dc chargers for things such as cellphones and iPods.