We are building a controller using 3 stepper drivers and an Arduino UNO. Power comes from a 14.5A, Meanwell power supply with 3 outputs. 2 of the steppers require 3 amps (X and Y) the Z is 2.2, NEMA 23's Would like to connect the Arduino also to the same output as the Z, the unit has plenty of power but am I asking for electrical interference problems?? All wiring will be shielded and grounded cables. Any comments appreciated as were new to this.
a single output will suffice, but do research 'star grounding' and use it and also wire each driver seperately to the power supply (ie no daisy chaining) the arduino does not need to be connected to anything but the USB cable and step/dir pins of the drviers, and certainly not to the power supply.
That's an interesting comment, David. Mind explaining why you think it's not a good practice? I have my 4 drivers in two daisy chains.
a - the device at the end of the chain experiences more noise and voltage drop than the others because the others use power, or inject noise, along the way. This can lead to weird interference issues. By wiring direct from the PSU there is minimal voltage drop, and less noise because the PSU itself is the biggest filter around. b - the connections in the chain introduce resistance that causes more voltage drop (and heat in the connectors), and thus more noise for the last device. more weird interference. c - amateurs seldom use the correct size of wire for the combined current draw, but it is easy to get it right for a single driver (and cheap). d - I read it in an article on industrial wiring practice when I was building my OX and I did it and have never had any issues with EMI, so I figured it is good advice to pass along (-:
Thanks for responding: Wouldn't that only apply to steppers tied in series?? A single source tied to a distribution bus with the steppers then tied to the bus in parallel would receive equal voltage. You would, have to assure that the lead from the source to the bus had ample ampacity for the combined amperage load. We want to be able to power some circuitry with the Arduino independently without needing to connect to a laptop. thanks again.
Then I believe you need a 9v wallwart to power the arduino via its barrel connector socket. connecting the arduino to the stepper power supply is just asking for EMI problems. Let me expand a little: the step/dir inputs on the stepper drivers are optoisolated this is done so that the arduino is never connected to the stepper power side of the power supply. if you now power the arduino from the stepper psu, you are creating a loop that the optoisolators were supposed to prevent.
