How Can  I protect my computer from overload

Hi all,
I am wondering if you have a good advice in how can I protect my computer from over current values, voltages, etc. etc
I am using usb interface,
and as you guys have experience, I make changes in the breadboard as still connected to the computer,
what will be the best way to protect my computer from overload of current, volatages comming from my electronics .
thanks in advance :smiley:

Using a resistor to limit the current to a value below the maximum would be a start. As to voltages, just be careful, you can damage/destroy chips quickly if you're not.

There is nowhere you can put a resistor to keep your arduino circuit from drawing too much current from the USB port.

Well designed USB hubs (including those built in to your computer) will monitor current on the port and remove power if the peripheral draws too much current. Unfortunately not all are well-designed, so it is possible to burn something by drawing too much.

If you are worried about overdrawing from your USB port, disconnect USB power and use a wall wart to power the Arduino. You can still communicate via USB this way, you just won't get power from USB. The Arduino NG requires a jumper move to do this; the newer model has an automatic switch.

-j

good advice in how can I protect my computer

I make changes in the breadboard as still connected to the computer

The best advice I can give you is don't do this, you are almost guaranteed to blow something up by connecting things in the wrong order sooner or later.

Always remove power before changing any wiring connections, and that probably means unplugging the USB cable.

thank you
in short
what I see the option are:

1 - connect the ardruino to external power
2- disconect to make changes in breadboard.

new questions?
what if ardruino sends power to the usb chip from external power
what if the components i the breadboard still bad place,

how do you guys work your projects then.

what if ardruino sends power to the usb chip from external power

I am not at all sure how this could happen. Have you anything more specific in mind?

what if the components i the breadboard still bad place,

Then bad things can still happen but not as many bad things.

thank you guys
to be more clear:
I am totaly newby in electronics,
I want to protect my computer from damages from ( bad circuits, over currnt, etc. etc.)
what do you recommed to minimized accidents.

what I am working in to have serial to computer so serial can be read in the computer, means ardruino needs direct connection to computer .
how would you protect the computer.

thank you.

The computer already has a lot of protection, there is very little extra you can do.

I know you are concerned about damaging it but it is a lot more difficult to do that you might imagine. Most things will withstand short circuits the main thing you have to avoid is putting mains on a signal line and your not going to do that are you.

Most things will withstand short circuits the main thing you have to avoid is putting mains on a signal line and your not going to do that are you.

/me

I am not shure what you mean?
every thing is going to be on the ardruino board.
the board gets power from usb from coputer
is that a good setting or should I use a external power supply @ all the times? for increasing protectin?
thank you.

Here are some ideas:

  1. Use an external powered hub between your computer's USB port and your Arduino. Possibly computer-damaging events at the arduino end of things SHOULD stop at the hub, rather than reaching your computer.
  2. Put an add-on USB card in your computer and use those USB ports for your experiments. If you DO manage to do something that damages the USB port, you're now talking about needing to replace a low-cost USB card instead of an expensive motherboard. (combine with (1) for extra security.)

As others have said, there is already a fair amount of protection on most computers' USB ports, but it's not REALLY aimed at people breaking out the wires and poking at them individually, as sort-of happens in an arduino environment. The above options are probably more than you need, but they are relatively cheap additional protection.

thank you so much
I will be only add a exteral powered usb ( I have a IMac)
when you mention external powered usb, you are saying - usb hub that has a external power adaptor?

when you mention external powered usb, you are saying - usb hub that has a external power adaptor?

Yes, exactly. That isolates power issues as well as signal issues.

thank you somuch guys
this is why I love open source
I use and have lots of knolage in other opensource staff and I help out when ever I can in the forums, I am new to ardruino, and I want to use it to make interactive art installations.
your help is the best. I hope that is post will be help full to some one with the same question.
:smiley:

Another couple of ideas:

  • use bluetooth version of arduino (not a very bright idea since you've already got an usb version, right)
  • use wireless USB (you'd have to use two dongles that transmits USB stuff over the air)
    Both ways you are concern free :). Assuming you don't use 1M voltage :wink:

thank you
I am thinking in geting this

it has overcurrent protection
what do you think ?