Power Supply Help

Hey,

I need to provide my arduino Uno with 12v and a step down board (12v-6v) with 12v too. Id like my setup to use a single plug. I was thinking of somehow splitting a laptop charger style 12v 2A power supply so that it was a dual supply, is this possible? Or is there an alternative way about this.

Would something like this work to split the power supply into two 12v supplies - http://www.dx.com/p/1-to-2-power-splitter-cable-for-cctv-security-system-camera-dc-12v-112982#.WJsLFDvyiUk

This is the step down board that i need to provide 12v to - https://www.pololu.com/product/2859 What is the easiest way to connect the second power wire to this board?

I have experience soldering if that helps.

Thanks in advance

A dual supply(*) is something else - you are talking about sharing a single supply I think. Or are you wanting isolation?

(*) For instance a +15/-15V dual supply for audio mixing desk, a 5V/12V supply for an old floppy drive.

MarkT: A dual supply(*) is something else - you are talking about sharing a single supply I think. Or are you wanting isolation?

(*) For instance a +15/-15V dual supply for audio mixing desk, a 5V/12V supply for an old floppy drive.

Sorry, im not sure on the terminology. I want a single plug in the wall and two 12v leads coming out of it so that i can plug one 12v supply into the arduino board and the other 12v supply into the step down board.

IF you want a plug, search for a 2,5mm (or 2,1mm or whatever it uses) splitter.

If you want an easy way you just grab scissors, cut the cable and solder it to the things you need without or with the plug you like...

septillion: IF you want a plug, search for a 2,5mm (or 2,1mm or whatever it uses) splitter.

If you want an easy way you just grab scissors, cut the cable and solder it to the things you need without or with the plug you like...

Is it okay to do that? I thought the wire that comes with the power supply (eg. http://ie.rs-online.com/web/p/desktop-power-supply/8157182/ ) would be designed to safely allow 12v x Amps to flow through it so splitting it in half and putting 12v x Amps through both thinner halves would be dangerous.

The supply CAN deliver x amps. If it needs to is up to you. All it does is give you 12V, the current is determent by what YOU connect to it.

A residential socket in a (Dutch) home is 230V 16A. But that does not mean a 5W led bulb gets 16A... It gets 230V and pulls it's 22mA share of the max 16A.

I would say, read a bit about voltage, current and ohms law a bit ;)

septillion: The supply CAN deliver x amps. If it needs to is up to you. All it does is give you 12V, the current is determent by what YOU connect to it.

A residential socket in a (Dutch) home is 230V 16A. But that does not mean a 5W led bulb gets 16A... It gets 230V and pulls it's 22mA share of the max 16A.

I would say, read a bit about voltage, current and ohms law a bit ;)

Is it safe to draw x Amps across a wire half the size of the one that came with the supply though? As in when i cut the wire and split it in two to solder it to both of the boards i want to power

Thanks for the reply

Kellji:
Would something like this work to split the power supply into two 12v supplies - http://www.dx.com/p/1-to-2-power-splitter-cable-for-cctv-security-system-camera-dc-12v-112982#.WJsLFDvyiUk

YES it would work. Just make sure your laptop charger DC Jack is the same as the mentioned product, that is 5.5 x 2.1mm which UNO uses.

also is 12V 2A sufficient to power both your projects??

Yes and no. It's a bit more complex then that. It's not directly dangerous to pass more current through a cable. It's not as precise as a fuse. Yes, it might get warmer but dangerous depends on the wire you start with, max operation temperature etc.

But you don't have to have the thickness... If you plus something into a power strip, do you check to see if the wire of the device is thicker or thinner then the cable of the power strip? Aka, your overthinking it ;)

But the current YOU draw is still leading. If one device draws 99% of the power you give that a thick. But if a device only draws a couple of mA it's (withing limits) not a problem to use a thinner wire for that.