Power Supply Suggestions

Thread Starter

THRobinson

Joined Jun 7, 2018
55
Hey there, looking to order some parts for a guitar pickup winding machine and I think I have the list figured out, except power supply.

The main parts will be
- 12v DC Geared Motor (JGA25-370) with L298n controller
- Arduino either Uno r3, or Nano
- 2-line display lcd screen
- Maybe a 5v mini-stepper (28BYJ-48 with ULN2003)
- other stuff like switches and pots

I was looking at a 12v5a power adapter like laptops have with a y-splitter. I was also looking at the bigger ones used often for LED lighting but heard they're problematic with Arduino.

Any suggestions? Is 5a too much or too little? Just looking for a cheap 1 plug solution for the project. Would like to avoid using 2 adapters. If 5a is more than needed, how low can I go since lower amps means cheaper price.
 
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Ya’akov

Joined Jan 27, 2019
6,552
5A is a far more than is needed for the Arduino and associated parts. 2A should be more than enough but of course that doesn’t power the 12V motor.

This supply would do it, if you want a wall wart solution. How will you power the motor?
 

Thread Starter

THRobinson

Joined Jun 7, 2018
55
5A is a far more than is needed for the Arduino and associated parts. 2A should be more than enough but of course that doesn’t power the 12V motor.

This supply would do it, if you want a wall wart solution. How will you power the motor?
I think you missed part of my original post, or I was unclear. I was looking at the laptop style power adapter LIKE THIS and possible using a y-adapter LIKE THIS to run one to the Arduino and one to the motor (well, to the L298N controller which connects to the motor).

I originally looked at THIS TYPE of power supply, but on the Arduino forum they said those are problematic with Arduino's. They kept telling me what wouldn't work, but not what would. :) I figured a laptop style supply would be better because if it's good enough to run a laptop it should run an Arduino easy enough.

So... what I was wondering was, in order to power EVERYTHING from a SINGLE power supply, would 5A be enough? Would a lptop brick be good/bad?
 

Ya’akov

Joined Jan 27, 2019
6,552
I think you missed part of my original post, or I was unclear. I was looking at the laptop style power adapter LIKE THIS and possible using a y-adapter LIKE THIS to run one to the Arduino and one to the motor (well, to the L298N controller which connects to the motor).

I originally looked at THIS TYPE of power supply, but on the Arduino forum they said those are problematic with Arduino's. They kept telling me what wouldn't work, but not what would. :) I figured a laptop style supply would be better because if it's good enough to run a laptop it should run an Arduino easy enough.

So... what I was wondering was, in order to power EVERYTHING from a SINGLE power supply, would 5A be enough? Would a lptop brick be good/bad?
You’re right, I misread the 12V 5A as 5V. Sorry about that.

The L298N uses a maximum of 36mA at logic level (5V). The Arduino R3 uses a SPX1117M3-L-5 voltage regulator with the coaxial input jack and that can deliver a maximum of 1A. So, worst case you need 5V@1.36A, 2A gives you plenty of headroom for other random peripherals in the future. This would be 10W, ignoring the losses in the voltage regulator which aren’t significant in our case.

The motor has a stall current of 2.2A @ 12V. This is the most it could draw, nominally. Allowing 2.5A to make sure the supply isn‘t maxed out means you need an additional 30W from the supply. So, the 5V items will need 12V @ ~.5A, and the motor 12V @ 2.2A leaving us looking for a supply of at least 3.5A.

However, it is not a good idea to run a motor from the same supply as the Arduino because the motor will be very noisy and could easily cause unexpected results if the two are not galvanically isolated. It may seem “simpler” to use one supply but I wouldn’t do it.

If you want to avoid two separate physical supplies, you can get a LaCie external hard drive power supply which has both 12V and 5V outputs. This model is rated 12V @ 3A and 5V @ 4.5A (or it should be, thats the LaCie spec for the part number). You can cut off the connector and put your own, or possibly locate the compatible mini-DIN connector and wire to that.

If you do want to use this supply, contact the seller before you buy and double check the specs. There are at least two versions of this supply and the other one only provides 2.2A @ 12V which will certainly work until one day it doesn’t. I can’t read the label in the photo to see the output current.

You can use a 5V @ ≥2A wall wart supply (regulated) for the Arduino and the other sort of supply in your second link for the motor, you only need ~2.5A from it.
 

Thread Starter

THRobinson

Joined Jun 7, 2018
55
Holy cow, I came to the right place it seems for info.

How about a desktop computer power supply? They have 5v and 12v rails. Or would I still have the same issues with the 12v motor noise?

Must not bee too bad, I mean, my computer case has 2 fans, PSU has a fan, CPU has one and video card has 2, that's 6 motors running. Though no idea if noise issues or if the motherboard has built in stuff to fix that.
 
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Thread Starter

THRobinson

Joined Jun 7, 2018
55
Hey guys... parts all arrived from all sellers all at once this week. Kinda surprised, since ETA's were weeks from now. eBay China usually means months and at least 1 thing missing. :D

That said, 1 thing was broken. Motor control has a busted 5mm red LED. Luckily I ordered a bunch of 5mm LED's yesterday for another project. That said... is anyone familiar with this board? Maybe know what LED's it would be using? I was planning to de-solder the LED's and attach wires so I can run them to the case anyways but LED is snapped at the leads so, can't use it.

Resistors in the photo don't seem to match the board. What I have appear to be red-red-black-brown-brown. 2.2K Ohms 1%.

I ended up buying
- 12v3A AC/DC adapter
- 12v DC 1200rpm geared motor
- 5-digit digital counter w/proximity sensor
- 6-30v DC Motor Speed Controller with Reverse Switch

Figured for now, make a simple winder and start winding. I have the Arduino kit to learn from but a few large projects came up that needed done first. From what I've seen online, the parts should work for now.

Anyone happen to know the value of the LED's?

an/or what resistors I'll need because the red/green LED's on the board seem to all be the same value, but the LED's I bought show 2-2.2v for red and 3-3.2v for green, so assuming they'd need different resistors.

EDIT - Found this though not overly helpful for parts but may help someone recognize the schematic.

3circuit_diagram.jpg
 
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