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Topic: How to wire up 5 stepper motors using 1 power supply? (Read 227 times) previous topic - next topic

nyxraia

Hi everyone,

I'm trying to use the A4988 drivers to drive my Nema 17 Stepper motors however I have no idea how to wire the electronics when it comes to the power supply.

I am using this image to wire 1 motor:


My power supply is 12V 30A, so it should have enough power to drive it.

My questions are:
-Can I use this power supply as shown above in the picture for just one motor? Wouldn't all the 30A go through just one motor?
-Say I had 5 Drivers and Stepper motors, how would I go about wiring them? (there is only one Vdd pin in the Arduino and only one cable out of the powersupply in power and ground)

Thank you!

Robin2

Wouldn't all the 30A go through just one motor?
It does not matter if you have "too many" amps. Each device will only take what it needs.

Under NO CIRCUMSTANCES should you draw power for your motors from the Arduino board.

Just connect all your motor drivers in parallel to the power supply. You can also draw power for the Arduino from the power supply.

You have not provided a link to the datasheet for your stepper motors. You may find that a voltage higher than 12v would be better for driving the motors.

...R
Stepper Motor Basics
Simple Stepper Code
Two or three hours spent thinking and reading documentation solves most programming problems.

dougp

Just connect all your motor drivers in parallel to the power supply. You can also draw power for the Arduino from the power supply.
Pardon me if you already know this, but it seems you may not. Pardon the analogy, too. If you hang all your socks (ie, motor drivers or other loads) on a clothesline (power supply) to dry they're all in parallel connected to the line. Think of the clothesline as Vdd. As long as the clothesline is strong enough to support the load (current capacity) without snapping you're OK.

On the other hand, if you connected one sock to the line and another to the free end of that one and so on, they'd be connected in series.

nyxraia

It does not matter if you have "too many" amps. Each device will only take what it needs.

Under NO CIRCUMSTANCES should you draw power for your motors from the Arduino board.

Just connect all your motor drivers in parallel to the power supply. You can also draw power for the Arduino from the power supply.

You have not provided a link to the datasheet for your stepper motors. You may find that a voltage higher than 12v would be better for driving the motors.

...R
Stepper Motor Basics
Simple Stepper Code
Pardon me if you already know this, but it seems you may not. Pardon the analogy, too. If you hang all your socks (ie, motor drivers or other loads) on a clothesline (power supply) to dry they're all in parallel connected to the line. Think of the clothesline as Vdd. As long as the clothesline is strong enough to support the load (current capacity) without snapping you're OK.

On the other hand, if you connected one sock to the line and another to the free end of that one and so on, they'd be connected in series.
Thank you for your replies, they are very insightful :).

I'm more of a software guy which is why I'm clueless when it comes to this :p.

The motor specs are as follows:
4942Q-T032409
3.2V  1.2A  1.8/step
...

The power supply I have is 12V 30A.

Am I understanding you correctly in that this is how I should wire the PS?
Shouldn't there be a 12V -> 5V converter before going to the Arduino?

https://imgur.com/VjmBNOA
(the ground wire on one of the drivers is missing, but is there in reality AND there is no red wire from the PS into the 5V pin on the arduino, excuse me)
Thanks :)

Robin2

Image from Reply #3. See this  Image Guide





Yes, That is the correct way to connect the drivers in parallel. But UNDER NO CIRCUMSTANCES connect 12v to the Arduino 5v pin. Either connect the 12v to the barrel connector or use a regulator such as a 7805 to provide a suitable 5v power supply for the 5v pin.

Also NOTE that in the diagram in your Original Post there is a large capacitor at the motor driver input pins - you don't have them in you diagram.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

nyxraia

Image from Reply #3. See this  Image Guide



Yes, That is the correct way to connect the drivers in parallel. But UNDER NO CIRCUMSTANCES connect 12v to the Arduino 5v pin. Either connect the 12v to the barrel connector or use a regulator such as a 7805 to provide a suitable 5v power supply for the 5v pin.

Also NOTE that in the diagram in your Original Post there is a large capacitor at the motor driver input pins - you don't have them in you diagram.

...R
I have tried to put a capacitor in parallel between each driver's VMOT and GND input but it has blown so I have stayed away from them since. They are:
47uF 16V 105C Radial Electrolytic Capacitor 5x11mm
And look like this:


I read somewhere that they are polarity restricted, but have been too scared to use them since that loud explosion/pop. Can you help me with wiring them? One side has a '-' symbol, as seen in the picture (the white stripe).
Can this model handle the 12V30A?
Should I have one in parallel between each driver, and one between the Arduino's Vin and GND pin?

Thank you so much for your help, I just want to make sure I don't fry anything. :)

Robin2

Electrolytic capacitors are very clearly marked with a minus sign on the side with the negative terminal. Make sure to get capacitors with a voltage rating that is 2 or 3 times higher than your power supply voltage.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

jremington

#7
Sep 19, 2017, 05:24 pm Last Edit: Sep 19, 2017, 05:27 pm by jremington
Quote
47uF 16V 105C Radial Electrolytic Capacitor 5x11mm
Both the capacitance and the voltage rating are too small. Use 100 uF (or higher) and 35V (or higher).

Connect one capacitor to each motor controller, as close to each controller board as possible.

nyxraia

Electrolytic capacitors are very clearly marked with a minus sign on the side with the negative terminal. Make sure to get capacitors with a voltage rating that is 2 or 3 times higher than your power supply voltage.

...R
Negative is ground? (the black wire)

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