I’ve got an interesting idea on one way to use the RB250GS.
We might use it as an inexpensive “4-port ethernet card” in an x86 MikroTik. Essentially, we would use VLANs between the RB250GS and a VLAN-capable single-port NIC. Obviously this wouldn’t be a bright idea if we were pushing a heap of traffic, but you get the idea.
Next, I came up with the idea of somehow mounting the RB250GS board in the rear of a 4U server rackmount or PC tower case and splicing the 12V DC line from a molex/IDE power connector into a DC jack that fits the RB250GS power jack.
Even though the PDF [link], that roc-noc.com posted, says “Jack: 9-28V DC,” I’m not sure that 12V would be enough to power it. Any thoughts?
Intriguing idea, I kinda thought it might work as a sort-of port expander for a 750G or such. I do wish it was a RB280GS, 8 ports if I understand naming convention right. As far as it running off of 12v, I don’t see why not if the specs say 9-28v, 12v is somewhere in the middle.
When Mikrotik publishes that it can be powered from 9-28vdc then it should run fine with a 9vdc supply, or a 12vdc supply, or a 28vdc supply, or anything in between. They often chose to ship RouterBoards with a 24vdc supply because their costs on the 24vdc supply are low from their purchasing volume.
I wouldn’t have any problem running the RB250GS or most other RouterBoard from a 12vdc supply. You just need to make sure that the supply has enough power to keep the RouterBoard running. The data sheet says the RB250GS takes up to 6W. That means a 12vdc 500mA supply or anything larger should work just fine.
A higher voltage supply is a better choice when running POE because there is a voltage drop associated with the length of the cable run.
A lower voltage supply will generally keep the RouterBoard running cooler (less waste heat) and probably extend its life.
9V and 28 are border values, if you want to run on these voltages, you should have very very stable PSU, since over the value or under and board will shut down due to overvoltage protection.
12V is fine. Power part of the board will turn that into what values needed for the board anyway.
