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AC Adapter for the FEZ Cobra?


#1

If would be nice if you guys included an AC adapter for the Cobra in the bundle or separately. I have been using a 9V adapter from Sparkfun, but it looks like that 9V is too much for the Cobra.

Also, It would be nice if there was a bundle with the the 4.3" screen instead of the 3.5". Maybe this could be a bundle option.


#2

I second the 4.3" bundle option :slight_smile: :slight_smile: :slight_smile: :stuck_out_tongue: :stuck_out_tongue:

AC Adapter doesn’t stress me though, since I live in Australia I’ll need my own :slight_smile:


#3

This was requested before. The margins on the large display are little and so we can’t afford giving further discounts. If someone needs the 4.3" display then they can just buy the individual pieces they need. I mean just buy the cobra+display expansion+4.3" display.

We will even offer a 7" display and maybe other ones so making a package for each display we offer will be a nightmare. It is easier if you just pick what fits your project best.

As for the power pack, we have them in stock, but not on the website yet! I guess the guys are too busy to add them to the website :slight_smile:


#4

I see…

What’s the res on the 7" display? That’s going to be a beast.


#5

Funny I do not remember! Maybe 800x480 but I am not 100% sure


#6

Chis you should use 6v max. It’s also printed on the cobra.

Suggested the bundle before, but it’s GHI’s choice to either accept it or not :slight_smile:


#7

Yeah, I never saw it printed on the Cobra, but I stopped using that adapter as soon as I found out.


#8

By the way, 9V is okay for the regulators but the problem is that the display draws a lot of power which causes the regulators to heat up a lot. You can run the device for couple hours fine but do not leave it connected overnight or it may burn, or worse, catch on fire!

It is best if you just use 6V. Unregulated 6V is fine…or 7.5 if you have that. We tried 5V but that doesn’t work since there is already a 5V regulator online.


#9

seems it’s not possible to use 12V with this composition :

  • DOMINO
  • ETHERNET SHIELD
  • 2x16 LCD DISPLAY
    It seems that after 30-35 minutes, the regulators are too hot and the DOMINO reboot again and again… I now bring the power to the DOMINO via the USB plug… seems it s ok now :slight_smile:

btw i finished a network rfid clockwork with domino… it was very easy, i just had to do some modification in the old ethernet driver :wink: and few hours of coding, very easy !

The device is in test by my customer for the following days !


#10

Yeah, those LCDs pull a lot of current, so do the Ethernet shields. I use 9Vdc and have had no problems with overheating.


#11

I think wiznet draws a lot of power too.


#12

WIZnet withdraws about 170mA and I noticed it heats up. I guess this is normal according to WIZnet FAQ


#13

Wiznet heating up is a known issue. I am not too sure of the current silicon but the earlier releases heat up faster when the ethernet cable is not plugged in.


#14

Yeah, it really scared my when I first tried it thinking there is problem with FEZ but it turns out the problem is in WIZnet :o


#15

Don’t forget that a/c adapters are heavy and therefore cost a lot to ship. If you do offer it, make sure there is an option not to buy it. It would be useless for international customers most likely and just cost us more shipping.