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Topic: Ethernet Shield power problems (Read 849 times) previous topic - next topic

arduinotrev

Jan 02, 2012, 03:15 am Last Edit: Jan 03, 2012, 12:03 am by arduinotrev Reason: 1
Yesterday, i got my new Arduino Ethernet shield working with the Web Server code. I was running it off of USB power just fine but now it does not power on so i assume it is not a power problem. It works with only the arduino uno plugged to usb but when the ethernet shield is stacked it does not work. The power light goes on put fades away after about a second.

The power does work when plugged in with a wall adapter but the main board gets very hot around the capacitors and voltage regulator but the shield still fails to function.

EDIT: i should say that  the chip that says 509Z and the voltage regulator also get hot when wired to USB and wall power.

paracha3

I am having similar issues. let me ask you what is the DC voltage of your power adapter? what is the current rating on it?

sellonoid

#2
Mar 04, 2012, 02:59 am Last Edit: Mar 04, 2012, 08:06 pm by sellonoid Reason: 1
Mine gets pretty hot too with 12.0 VDC in, but it hasn't failed yet. I have 5.012 VDC and 3.295 VDC on the 5 and 3 volt pins with the Ethernet Shield connected.

zoomkat

When using an external power source to the arduino, measure the voltage between the arduino +5v pin and ground. My arduino/ethernet shield combo was outputting 8v+ when connected to an external 12v power supply.
Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

gelfling6


When using an external power source to the arduino, measure the voltage between the arduino +5v pin and ground. My arduino/ethernet shield combo was outputting 8v+ when connected to an external 12v power supply.


Now that is odd.. It sounds like the regulator is being overloaded/heat-failing if it's jumping that high, to say nothing of dangerous to anything connected to the +5V bus.(of being burned-out by running +3V over.)

I've had the same problem of the 5V regulator getting hot, and sometimes having the whole ethernet board stop working because of it.. I thought the board had it's own regulator? checking schematic... Yep, It's a 3.3V regulator, that appears to be drawing off the +5V bus for +VDD.  Which would explain the draw on the arduino's regulator.. the MC33269D-3.3 is supposed to have a maximum input voltage of 20V, which doesn't make sense why it's not drawing from the Vin (unless, as someone pointed out, and I accidentally shorted Vin to GND on a breadboard, the trace on the Arduino is not able to handle the draw.)

I've even had the 5V regulator run warm, even with just a 7.2V input. (i'm trying to make a robot, with power from a 7.2V RC car batteries.), and usually that's the low-end for the 5V's input. (which is still plenty for the ethernet router, which originally had a +9V, 1-Amp wall-wart, but it too, is only feeding to a 7805 regulator inside.)

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