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Why does the XBoard Relay get so hot?

PostPosted: Sat Jan 24, 2015 2:29 pm
by Al B
Hi everyone,

Today I received the XBoard Relay (RB-Dfr-216) and I noticed that after 5-10mins of being powered by an 9V power adapter, the board gets very very hot. There is absolutely nothing connected to it yet, except for the power adapter. It gets so hot, that you cannot keep the tip of your finger underneath the board for more than 3-5 seconds.

It also gets hot when it is connected to the laptop via the usb cable, but it doesn't get as hot as when it is connected to the power adapter. I guess the voltage level makes a different (usb 5v vs the 9v adapter) so I guess it will get even hotter when it is powered by the suggested 12V adapter.

Is this normal or I just got a defective board.

I'm really concerned that this can be a fire safety issue for my project so any comment or suggestion will be appreciated.

Re: Why does the XBoard Relay get so hot?

PostPosted: Sun Jan 25, 2015 10:14 pm
by support
We haven't experienced much "real" or "production" usage with the XBoard Relay, but in our experience, it didn't
get as hot as you seem to be describing it. You might want to contact DFRobot and ask them directly.

Best regards,

Re: Why does the XBoard Relay get so hot?

PostPosted: Wed Jan 28, 2015 8:27 am
by PTB
Mine gets pretty hot as well and it appears to be because of the wiznet chip for the Ethernet.

http://forum.arduino.cc/index.php?topic=68916.0

Cheers

PTB

Re: Why does the XBoard Relay get so hot?

PostPosted: Wed Jan 28, 2015 10:29 pm
by Al B
With mine, the chip labeled 78M05 FC (next to the XBee connector) is the one that gets extremely hot.

The vendor is sending me a replacement so I'll report back if the 2nd one doesn't get hot.

Re: Why does the XBoard Relay get so hot?

PostPosted: Sun Feb 15, 2015 5:40 am
by eredder
Al B wrote:With mine, the chip labeled 78M05 FC (next to the XBee connector) is the one that gets extremely hot.

The vendor is sending me a replacement so I'll report back if the 2nd one doesn't get hot.



Mine also gets very hot. Does the replacement board get as hot?

Re: Why does the XBoard Relay get so hot?

PostPosted: Sun Feb 15, 2015 1:37 pm
by Al B
Unfortunately, the 2nd board was getting very hot too. We determined that the heat was actually being generated by the Wiznet WS100 chip, which handles the Ethernet connector. The manufacturer suggested to install a Heat-Sink. However, that was not a good solution for my application either since the same amount of heat was generated thru it so I decided to return the 2nd board and use this board instead:

http://www.ebay.com/itm/221123947740?_t ... EBIDX%3AIT

That turned out to be a good solution for me since I didn't want to connect to board via the internet (neither WiFi or IoT). Instead, my app connects to it using a BLE module like this one:

http://www.ebay.com/itm/321392281915?_t ... EBIDX%3AIT

Re: Why does the XBoard Relay get so hot?

PostPosted: Mon Mar 16, 2015 1:35 pm
by z0ner
My infrared thermometer is clocking in on the Wiznet chip at a VERY concerning 79C! And this is with an ambient temp of only 23C. I can't imagine what the higher SoCal temps will bring.

I'm going to the manufacturer, but based on what I've read here I'm not getting my hopes up.

Re: Why does the XBoard Relay get so hot?

PostPosted: Sat Apr 11, 2015 8:18 am
by gio_dude
Before I purchased mine I emailed dfrobot about it. They said it doesn't get hot to a unsafe point. But if I was cornered he recommended a heat sink and acrylic base. Heat sink was one dollar.

Re: Why does the XBoard Relay get so hot?

PostPosted: Sat Apr 11, 2015 1:58 pm
by Al B
You can install a Heat-Sink, however, the same amount of heat will be generated thru it. Anyway, for our project the Heat-Sink was not good solution either. Good luck!

Re: Why does the XBoard Relay get so hot?

PostPosted: Fri Sep 11, 2015 10:05 pm
by johnt365
I just completed this project wanted to share my experience and possible solution. Using a laser thermometer, I was measuring 200* F on some chips. I was using a heat sync and a 9v adapter.

My solution so far is to use a USB power cable and adapter instead of the 9v adapter. This cut the heat almost in half to about 105* F. The unit works fine running off of the USB power.

Hope this helps.
john