Will this power supply work?

Forum 2005-2010 (read only) Hardware Interfacing
1

I have a Safety 1st power supply from an old baby monitor that has a connector that fits in the arduino jack. It is DC 9V 200mA and has the positive on the outside and negative on the inside. Does anyone know if that is the right configuration for the end? I assume the 9V 200ma is within the usable range. Thanks for the help.

2

Sounds fine to me.

3

Thanks. I would have hated to ruin a brand new board to find out!

4

:o Oh wait! Positive on the outside? I think that's wrong !
[edit]The center of the plug (hole) should be positive.
(Just going out for New Years - no time to double check, but 99% sure. happy New Year!) I think there is a diode for reverse voltage protection so you're probably OK if you plugged it in.[/edit]

5

Oh wait! Positive on the outside? I think that's wrong. !

Yes, I'm almost certain that the center pin should be positive and the outer sheath is negative. Totally backwards of the power supply the original poster has.

6

Oh wait! Positive on the outside? I think that's wrong. !

Can someone confirm for sure whether + or - should be on the outside?

7

Oh wait! Positive on the outside? I think that's wrong. !

Can someone confirm for sure whether + or - should be on the outside?

Sigh... You mean I have to get up and walk 20 feet to look at the plug? :wink:

I looked and it is positive center.

8

Totally shure now - don't plug it in.
(Wifes still getting ready.)

9

Ooops :-[

10

Thanks guys. You save me $35 in a ruined board! I will seek out another power supply. I have a box full of them form old devices.

11

Just for future record in case people search on this topic. Plugging a negative voltage source into Vin jack is never a good idea but damage will happen only if the board does not have a reverse voltage protection diode installed. If you review the schematic drawings you will see the the standard official Arduino USB board has such a diode (D1), however if you review the Nano schematic you will see that the Vin voltage wires directly to it's voltage regulator without such a protection diode.

So damage or not from reverse voltage depends on the specific brand and model.

Lefy