Hello All,
I am working on a project that requires my Arduino Mega 2560 to control a large motor and two linear actuators. The motor is a 750W brushed DC motor (48V with max current draw of 20A) and each linear actuator runs on 12V with max current draw of 4.6A. I've found drivers for the motor and actuators, but am wondering what kind of power supply should I use to power these things? I found a 1000W (48V 21A) AC-DC power supply, but I'm not sure if that is enough. Will the 21A from the PSU be split between the Motor and the Actuators if they are both connected, or will each driver get 21A?
As you can probably tell, I am fairly new at this. Any help with the power supply issue, or any other issue I may be over-looking, is greatly appreciated. Thanks!
Basically the power from the power supply is shared between everything connected to it. So if the motor is drawing 20A maximum (which is 960W not 750W) then there's effectively nothing left to run anything else.
So if the motor is going to be run at full power and both actuators need to run at the same time then you'll need a bigger power supply...or it might be easier to use that one just for the motor and add another separate 12V supply for the actuators otherwise you'll anyway need to find some way to reduce the voltage from 48V to 12V for them.
BTW you might get a better answer if you provide links to the things, motor/drivers/actuators etc, that you're talking about because sometimes the specifications aren't as clear as you might imagine.
Steve
"max current draw" is not a useful specification, as it could mean "maximum continuous current draw" or "stall current".
You need to know the stall current, and plan for that, as actuators and motors draw it every time they start up.
For a brushed D.C. motor the stall current is typically 5x to 10x the free running current and is always much higher than the maximum continuous current draw.
Here are the links to the parts I am planning on using. I already have one of the linear actuators so I hope it will work, but the motor could be swapped for a different one:
As for the specs, I was just looking at the part descriptions. I might look for a different motor, as this one seems to not have a whole ton of info on it. But the linear actuator does say "max current draw" so I'm not sure what that refers to.
For the power supply, I would ideally like everything on one as long as it isn't a huge inconvenience. I was planning on using something like this to power the 12V actuators off the 48V PSU:
Would this work? Also, does anyone know a place to get reliable, high-wattage power supplies for something like this? I'm having trouble finding many above 750W.
Again, your comments have already been extremely helpful and are greatly appreciated!
Not many people on the Arduino forum work with high current motors and power supplies like those, so you might look to other forums for advice.
Pololu makes high quality motor drivers and they support their products, but when dealing with Amazon/eBay/Alibaba etc. you are pretty much on your own. Note that two reviewers of the Kohree converter reported DOA devices.