So I need to power an arduino and a 6v motor with a non-load current of 100ma. I have a 12v Mean Well switching power supply to use, but I need to drop the 12v to 6v's. I was looking at using an LM317 to drop the voltage for the motor, is that a reasonable way to do that?

Second, I'm trying to figure out what type of a connector this is, anyone have any ideas? It looks similar to a Dell latch type fan connector, but I can't be sure.

 

For the connector, go to DigiKey's or Mouser's website and look under connectors. By using their search features you can probably narrow things down pretty quickly.

As for the use of the LM-317, you only talk about the no-load current draw. Why are you designing a system around the no-load current? Is this motor never going to be loaded?

 

I was going off the specs from where I purchased it, that's all. I haven't had a chance to test the load current yet as I don't have anything thats 6 volts.

 

Until you know how much current you will need, you will not be in a position to determine whether an LM-317 will suffice and, even if it will, whether and how much heat sinking you will need.

One thing to keep in mind is that if you drop from 12 V to 6 V with a linear regulator, then your system will be 50% efficient, meaning that you will be wasting as heat an amount of power equal to whatever power is actually delivered to the load. That may or may not be acceptable for your application.

 

Ok, I got it working, under load its between 360-400milliamps.

I'm starting to think it would be easier to use a 5v, 750ma - 1amp power supply to power the motor and the arduino and the motor will run a bit slower, which isn't an issue. Thoughts?

Maybe something like this?
https://power.sager.com/gs06u-1p1j-2525076.html

 

You don't really need SMPS or regulation for a DC motor, a simple 6v transformer secondary with a bridge will do.
No cap required.
Max.

 

Ok, I got it working, under load its between 360-400milliamps.

I'm starting to think it would be easier to use a 5v, 750ma - 1amp power supply to power the motor and the arduino and the motor will run a bit slower, which isn't an issue. Thoughts?

Maybe something like this?
https://power.sager.com/gs06u-1p1j-2525076.html

It all depends on what is important to YOU for THIS project. Your first post sounded like you wanted/needed to use a power supply that you had on hand. Now it seems like you are willing to buy one. So if you would like 6V at somewhere around an amp of current, then why not get one of those. If 5V will do, then go for it. At $10 you don't have a lot to lose. You can get one quickly by going just about anyplace such as Radio Shack, Best Buy, Walmart, dozens of other places. And if you can find a second hand store for electronic (or perhaps even a run of the mill pawn shop) you can get it for next to nothing.

 

You don't really need SMPS or regulation for a DC motor, a simple 6v transformer secondary with a bridge will do.
No cap required.
Max.

I agree. But it is better to use SMPS to increase efficiency as dissipates little power and also include smaller size and lighter weight from the elimination of heavy line-frequency transformers.

 

I appreciate the advice.