Power jack overheating - Arduino+battery


When I run the Arduino off the USB all works fine, but when I move the jumper to external and supply a 9.6 vdc from a battery (measured with a DMM before connecting), the power jack starts to overheat. Same thing happens when I connect a 12 volt battery. Could my jack be shorting only when I plug it in?

Any ideas?

Thanks -Migs

Maybe there is a short somewhere.

Does your arduino work in that case?

Remember that power regulator will heat up a bit (more for higher voltages) this is normal if you have a lot additional hardware.

Anything that gets too warm to be touched is signaling a problem.

Assuming you connected your battery to a plug, and when you plug it in the Arduino doesn't work, and only the socket gets hot . . .

  • You may have the wrong type of barrel plug connected to your battery.
  • (less likely) The switch that is built into the socket makes a short somehow when it is closed.

Another possibility is that the voltage regulator is faulty, or you have the jack power the wrong way round. In any event it is my guess that it is not the power jack that is getting hot but something close to it.

Hi all for the info:
With the same sources to the pin inputs Vin and Gnd the board works (led 13 blinks...) With the input as before, nothing. The barrel jack is the larger of the two versions right? It fits snug into the female on the board.

By the way, the Vin through the pin inputs is regulated as well right?

Thanks again for the ideas! -Migs

No! Vin through the pin inputs is not regulated! Do not give it > 5VDC.

If you have a meter check the polarity of your plug. Look for + in the center. Also check to make sure it's not AC.

And you say only the socket and not the reg. chip nearby is getting hot?

The barrel plug sounds like it's the right size.

According to the schematic here the Vin is in fact regulated. However, it does look like it is not protected from reverse polarity.

I think BroHogan is right that your power supply may not be a center positive model.

Hi guys:

I'm pretty certain of the polarity of the barrel jack and the Vin when I power it. My DMM is right there always before I plug anything in. At any rate, if Vin wasn't regulated I would have blown the board by now with a 13vdc input to the pins. (Pack is labeled 12vdc but freshly charged it measures 13+vdc) (I'm only using spare NiMh battery packs that I have from my other projects) Fortunately I ordered a couple more Diecimilas so I'll have something to compare to.
You all are very helpful so thanks-Migs