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Topic: 12v DC Car Battery Power Supply - Off The Shelf (Read 3 times) previous topic - next topic

eobx

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?

otzi

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.

MarkT


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).




[ I won't respond to messages, use the forum please ]

Chagrin

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.

Carnyworld

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.
C program run. C program crash. C programmer quit.

ngourlay

I'm rather late to the game, but I was searching for in-car solutions, and found this:

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1953161_-1

Vin 9-18V, Vout = 12V

sonnyyu


I'm rather late to the game, but I was searching for in-car solutions, and found this:

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1953161_-1

Vin 9-18V, Vout = 12V

good find.

We have an other thread about improved power-supply rejection;-

http://forum.arduino.cc/index.php?topic=162326.msg1276774#msg1276774

cr0sh

I've seen inexpensive cigarette lighter things that plugged in, and provide a USB-style port for charging your phone; likely has some kind of DC-DC switcher inside, will generally give at least 500 mA (sometimes even 1 amp).
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

sonnyyu


zoomkat

Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

ricadam

I know i'm bringing up an old thread but it saves creating a new one.

I have a 1A USB charger and was wondering it this will safely power the Arduino Uno?

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