So I've got a mega 2560 that I'm using for controlling room automation from my phone. I've got my plan set and much of the programming finished along with my circuitry. I'm now trying to decide how I'd like to permanently power my device. I would like to power it through my desktop power supply from the 5VSB. The reasons for this is that i could hide the controller away in my tower and I want to use it to be able to start up and shutdown my desktop from my phone also and this would minimize the wiring needed to do so. My power supply is a NZXT HALE90 V2 1000W and at the +5VSB it is putting out 4 amps. I was wondering if this was far too much to even consider using to power my arduino. I realize that it is typically advised to just power the unit through USB but I'm trying to have it on while the computer is off for the utility of being able to turn the desktop on from the controller.
The +5VSB is 'putting out' what is required. If you require 150mA, it will deliver 150mA. If you require 4A, it will deliver 4A. If you require 100A, it will shut down or break.
Your normal household wall outlet is e.g. fused at 16A so can 'put out' 16A. If you connect a 60W bulb, it will just happily deliver around .5A or .25A (depending on the voltage).
Amperage doesn't work like that.
Devices pull what they need, they don't get it pushed into them.
You CAN'T pull 4A through the board, like hooking up several motors directly to the board.
Amperage is like a jar of mayonnaise and your device a spoon. Spoon scoops what it can, and that doesn't change regardless of how big the jar is. You don't put the spoon down and dump mayo onto it. (I'm guessing)
duinoNub91:
So I've got a mega 2560 that I'm using for controlling room automation from my phone. I've got my plan set and much of the programming finished along with my circuitry. I'm now trying to decide how I'd like to permanently power my device. I would like to power it through my desktop power supply from the 5VSB. The reasons for this is that i could hide the controller away in my tower and I want to use it to be able to start up and shutdown my desktop from my phone also and this would minimize the wiring needed to do so. My power supply is a NZXT HALE90 V2 1000W and at the +5VSB it is putting out 4 amps. I was wondering if this was far too much to even consider using to power my arduino. I realize that it is typically advised to just power the unit through USB but I'm trying to have it on while the computer is off for the utility of being able to turn the desktop on from the controller.
duinoNub91:
So I've got a mega 2560 that I'm using for controlling room automation from my phone. I've got my plan set and much of the programming finished along with my circuitry. I'm now trying to decide how I'd like to permanently power my device. I would like to power it through my desktop power supply from the 5VSB. The reasons for this is that i could hide the controller away in my tower and I want to use it to be able to start up and shutdown my desktop from my phone also and this would minimize the wiring needed to do so. My power supply is a NZXT HALE90 V2 1000W and at the +5VSB it is putting out 4 amps. I was wondering if this was far too much to even consider using to power my arduino. I realize that it is typically advised to just power the unit through USB but I'm trying to have it on while the computer is off for the utility of being able to turn the desktop on from the controller.
Yes, it is far too much. 5W / 1 A would be nicer on your pocketbook.
Do I get a star for answering the question without telling what kind of ice cream I like ?
Maybe I should add - post your full code?
Sorry, I just do like long winded / vining answers.
Call me crotchety OF.
Jim
I would like to power it through my desktop power supply from the 5VSB.
That is a fine idea.
julyjim:
Yes, it is far too much.
One of the most stupid replies I have seen in many months here.
Do I get a star for answering the question without telling what kind of ice cream I like ?
No.
sterretje:
The +5VSB is 'putting out' what is required. If you require 150mA, it will deliver 150mA. If you require 4A, it will deliver 4A. If you require 100A, it will shut down or break.
One caveat is that some power supplies specify a minimum load needed to maintain voltage regulation within the design limits. That's probably not going to be an issue in this case as I'm guessing the 5 V output is designed to USB limits, but I'd look at the power supply specification sheet to make sure.
INTP:
Amperage doesn't work like that.
You CAN'T pull 4A through the board, like hooking up several motors directly to the board.
Amperage is like a jar of mayonnaise and your device a spoon. Spoon scoops what it can, and that doesn't change regardless of how big the jar is. You don't put the spoon down and dump mayo onto it. (I'm guessing)
Wanna bet? If I take your spoon and put it across hot and ground of the device, I'm thinking I can get all 4 amps across the spoon.....
Just messin around.
A 4A supply is more than adequate to run several Mega's. In fact, you could use that supply to power additional sensors/motors/relays to avoid pulling too much power through the Mega's pins, as long as you stay under the 4A rating. As for efficiency....if the supply is going to be on for the computer anyhow, then why not use it?
I'm wondering why a 1KW power supply can only output 4 amps at 5V. That is only
20W. Where do the other 980 watts go. Even a maxed out graphics board doesn't
use that much or it would glow.
In general most devices rated to run at a specific voltage will only use as much current
as they need.
This isn't to say all devices are like that, a counter example is the LED light.
It is likely to be damaged by a constant voltage. We normally use them with a resistor
to limit the current.
Dwight
"+5VSB" is likely the 5volt standby pin. When the rest of the PSU is off.
Leo..
Dwight- the rest of the power is available for the main function of the supply- putting 12v/5v to the boards. Processors can use quite a lot of power, as evident by the huge cooled heat sinks.
Thanks a lot guys! Awesome, that is some good information and I learned something. Never a bad day when you've learned something. From my few electrical classes I remember that putting devices in parallel doesn't decrease voltage to each device but the amperage is divided (I think but I'll look it up for the math before hand.). Does this make it feasible to not only power my arduino from this standby voltage but also my LED strip that has 60 LED's at 20 mA? I believe this comes out to me needing 1.2 Amps total. This would eliminate any need to purchase battery packs or other power supplies.
tinman13kup:
Dwight- the rest of the power is available for the main function of the supply- putting 12v/5v to the boards. Processors can use quite a lot of power, as evident by the huge cooled heat sinks.
I see, SB, StandBy power.
Still, 1KW is a space heater.
As for running things. If it is rated at 4 amps, a 1.2 amp load should be fine.
Dwight
From my few electrical classes I remember that putting devices in parallel doesn't decrease voltage to each device but the amperage is divided
No, devices in parallel still take the same amount of current as they would if there were only one device. The total current is the ADDITION of the current from all devices.
dwightthinker:
I see, SB, StandBy power.
Still, 1KW is a space heater.
As for running things. If it is rated at 4 amps, a 1.2 amp load should be fine.
Dwight
Yea, I got a big one. I am using all but 2 plugs on it though so I'm getting some use. Some of it is certainly going to waste but I'm okay with that since I can now use it to power smaller projects like this so that I don't have to spend more money to go find solutions.
Thanks a lot Grumpy_Mike for the correction and thank you all for your input!