DC Supply for Arduino Uno R3

Hi, I just recently bought Arduino Uno board. I have 2 adapters in front of me but with slightly different specifications. They are:

FIRST ADAPTER(AC/DC); Input: 220-240V~50/60 Hz 350mA
Output: 12V 1.5A

SECOND ADAPTER(AC/DC); Pri(I think it means Input): 240V~50Hz 135mA
Sec(I think it is Output): 12V 1A 12VA

Which adapter should I use to work at a maximum SAFE Voltage? And which one is suitable?

And also, have I made the right choice by buying Arduino Uno as I am new to Miro-controllers and a beginner to Electronics. I heard Mega board are quite popular too but is Uno enough for me? And the reason I got Uno was that I heard that if the Micro-controller got burnt, you could easily replace it whereas on Mega, you'd have to buy the whole thing again. Thanks.

Neither may be suitable if they output AC.

06awaism:
Hi, I just recently bought Arduino Uno board. I have 2 adapters in front of me but with slightly different specifications. They are:

FIRST ADAPTER(AC/DC); Input: 220-240V~50/60 Hz 350mA
Output: 12V 1.5A

SECOND ADAPTER(AC/DC); Pri(I think it means Input): 240V~50Hz 135mA
Sec(I think it is Output): 12V 1A 12VA

Which adapter should I use to work at a maximum SAFE Voltage? And which one is suitable?

And also, have I made the right choice by buying Arduino Uno as I am new to Miro-controllers and a beginner to Electronics. I heard Mega board are quite popular too but is Uno enough for me? And the reason I got Uno was that I heard that if the Micro-controller got burnt, you could easily replace it whereas on Mega, you'd have to buy the whole thing again. Thanks.

Sounds to me that either AC/DC adapter would work assuming they are both positive center pin, negative shell wired on their output connector.

As far as your Uno selection, that is the best board to start out with for several reasons, just start learning the basics of learning to write your sketches and acquiring the electronics knowledge to properly wire up external components to support your projects. Start simple and build up your experience before taking on complex projects.

Lefty

Oh, sorry as I forgot to mention that they both are positive centered and what AC/DC means it converts AC into DC. They both are adapters. Correct me if I am wrong please. The first adapter is a netgear adapter for my Wireless Router and second one I found laying around my house. Thanks.

Apologies, I missed the "AC/DC" in your description, though I know one of my older Netgear switches has an AC adapter.

AWOL:
Apologies, I missed the "AC/DC" in your description, though I know one of my older Netgear switches has an AC adapter.

You mean a AC/AC adapter? :wink:

Lefty

Thanks A lot guys for your quick answers but when I start out with complex projects, can I still use Uno? I am doing A-Level Electronics alongside Computer Science Maths and Physics so sketching won't be a problem but as you said, I do have to know where to mount external components on the board itself. And which adapter would you go for if you were in my shoes?

06awaism:
am doing A-Level Electronics which adapter would you go for if you were in my shoes?

Your A-level Electronics should be telling you that the only difference between these supplies is the power output. Both have more than you are ever likely to need, so just use the most convenient.
Note also that 12v is about the limit on the Arduino and the on-board regulators are working a bit hard up there. If you can find a 9v lying around the house, it might be preferable to use that

You can use both adapter nothing will happen...

I'd try to splice in a 9V voltage regulator in there. Or find a 9V power supply. Just to be safe.

NickPyner:

06awaism:
am doing A-Level Electronics which adapter would you go for if you were in my shoes?

Your A-level Electronics should be telling you that the only difference between these supplies is the power output. Both have more than you are ever likely to need, so just use the most convenient.
Note also that 12v is about the limit on the Arduino and the on-board regulators are working a bit hard up there. If you can find a 9v lying around the house, it might be preferable to use that

Hi, Thanks for the reply. When I plugged in my first adapter, my Arduino Board was a bit hot around the DC adapter port. Is that normal? and I didn't use the second adapter as it had a bigger current output which is more than enough and the minimum I need is 1A. Is that correct? Thanks

06awaism:

NickPyner:

06awaism:
am doing A-Level Electronics which adapter would you go for if you were in my shoes?

Note also that 12v is about the limit on the Arduino and the on-board regulators are working a bit hard up there. If you can find a 9v lying around the house, it might be preferable to use that

Hi, Thanks for the reply. When I plugged in my first adapter, my Arduino Board was a bit hot around the DC adapter port. Is that normal? and I didn't use the second adapter as it had a bigger current output which is more than enough and the minimum I need is 1A. Is that correct? Thanks

Sort of.
The heat is due to the regulators having to hold back 12v and let through 5, hence my comment. I was really concerned when I connected a 12v supply,. but things get hot even with a 9v supply. It won't make any difference in this matter, whichever supply you use. 12v is 12v, and a lot more than 5v. The extra current available only becomes relevant if the Arduino demands it, which is unlikely.

The heat is more disconcerting than dangerous. Although, a guy up the coast built a weather station, and rather foolishly had the ambient shade thermometer neatly enclosed in a weatherproof box with the Arduino. This resulted in a constant shade temperature of 47C, which is rather torrid for Newcastle.....