Larger motor control

Projects General Guidance
1

I am working on a project at my internship that involves controlling DC motors with an Arduino.
The motors typically operate at 11v but can operate are rated for 24v and they draw anywhere between .1A and .3A at a time.
There is already a power source for the old control system that I can tap into if I want, and this source is 24v and 10A.
I had the idea before of using one of the L298N Dual H-Bridge Motor Controllers, but I have some concerns.
The first is that these controllers seem to only output about 35mA and that is way to low for these motors, and also it seems that the max supply voltage is 2A and the source I have is 10A.
I believe that these could be powered from the Arduino 5v output, but I wasn't sure if that means that only 5V go to the motors or if there is sometime of voltage amplification that goes on inside of the controller.

Any help with these would be greatly appreciated, or if you have any other suggestions on how to control these motors it would be greatly appreciated.

Thanks.

2

There exist H-Bridge controller boards for various currents and voltages, no need to build your own.

How do you control the motors? On/off only or by PWM, one direction or forward/backward? PWM control typically requires feedback (RPM) from the motors, which can be delivered by the driver modules as well. Or the drivers stabilize the motor current themselves (internal feedback).

The required circuitry depends heavily on the intended operation of the motors - please describe.

3

. The first is that these controllers seem to only output about 35mA and that is way to low for these motors

I think you're reading the spec wrong...

..and also it seems that the max supply voltage is 2A and the source I have is 10A.

10A is the maximum power supply capability. Actual current is determined by the load ([u]Ohm's law[/u]).

For example, here in the U.S., we have 120VAC at the power outlet. If you plug-in a 100W light bulb a little less than 1A flows. Plug in a toaster and about 15A flows. Plug in two toasters and the breaker blows and now you're down to zero volts.

4

are rated for 24v and they draw anywhere between .1A and .3A at a time.

You need to determine the stall current for the motors, and size the motor driver accordingly.

The stall current, which is the motor power supply voltage divided by the winding resistance, is typically 5-10x the running current. The motor will briefly draw the stall current every time it starts up, and twice that if it is rapidly reversed.

5

Hi,

Welcome to the forum.

michaelsm:
I am working on a project at my internship that involves controlling DC motors with an Arduino.
The motors typically operate at 11v but can operate are rated for 24v and they draw anywhere between .1A and .3A at a time.
There is already a power source for the old control system that I can tap into if I want, and this source is 24v and 10A.
I had the idea before of using one of the L298N Dual H-Bridge Motor Controllers, but I have some concerns.
The first is that these controllers seem to only output about 35mA and that is way to low for these motors, and also it seems that the max supply voltage is 2A and the source I have is 10A.
I believe that these could be powered from the Arduino 5v output, but I wasn't sure if that means that only 5V go to the motors or if there is sometime of voltage amplification that goes on inside of the controller.

Any help with these would be greatly appreciated, or if you have any other suggestions on how to control these motors it would be greatly appreciated.

Thanks.

Sorry but it reads better and there are some forum members who don't read posts that are not structured to be read.
What is your electronics, programming, arduino, hardware experience?
Thanks.. Tom.. :slight_smile:

6

michaelsm:
The first is that these controllers seem to only output about 35mA

re-read the data sheet

the max supply voltage is 2A and the source I have is 10A.

re-read your post

I believe that these could be powered from the Arduino 5v output,

please do not use pronouns. 'these' refers to the what ? the L298 driver or your motors ?

if you think you can power EITHER from a 5v output from the Arduino, buy a LOT of Adruinos to replace the ones you burn up. or use a marker and write on the wall above your monitor NEVER POWER MOTORS FROM THE ARDUINO. you can CONTROL them all day. Great application, but POWER ? very bad thing to do.

MAKE A SKETCH - a schematic. make sure you have it in your head how things connect.

when you plug in your toaster, you have a potential of gigawatts of power, you are connected directly to the main turbines that produce enough power for a few cities. but, the LOAD can only use so much. there are lots of safeties between you and the power plant, but none are needed as your toaster can only use what it can use, not what is available.

you have a 10 amp power supply, connect a 1k ohm resistor and an LED and it will use a few milliAmps.

your L298 can deliver over an amp, and your motors are tiny, not sure where 'larger' comes in on from the subject line. what is troubling is that you have jumbled up some things. I would HIGHLY recommend you post links to your motors. there might be other things in those data sheets that would help to properly set things properly.

as a note, when you have a device, it alone will consume power. maybe a few microAmps, maybe a few watts... but it will consume power. the thing it drives will consume power.

in your case, you have an Arduino, an L298 and a motor. you really are only concerned about the motor, but... when calculating the total load, one has to include the tiny power consumed by the Arduino and the L298 board. the data sheet will note these things, you have to figure out what the data sheet is saying. if it is the chip power consumption or if it is the load power consumption.

7

DVDdoug:
I think you're reading the spec wrong...

Quote

..and also it seems that the max supply voltage is 2A and the source I have is 10A.

10A is the maximum power supply capability. Actual current is determined by the load (Ohm's law).

Doug, ??????

which is it ? is his supply :o voltage :o 2 amps or is his supply :o voltage :o 10 amp ?

8

It may help to understand the difference between voltage and current :wink:

9

Sorry but it reads better and there are some forum members who don't read posts that are not structured to be read.

Well, why should we? The carriage return key is not all that difficult to periodically tap, making paragraphs, instead of a big blob of text.

10

DrDiettrich:
There exist H-Bridge controller boards for various currents and voltages, no need to build your own.

How do you control the motors? On/off only or by PWM, one direction or forward/backward? PWM control typically requires feedback (RPM) from the motors, which can be delivered by the driver modules as well. Or the drivers stabilize the motor current themselves (internal feedback).

The required circuitry depends heavily on the intended operation of the motors - please describe.

Since I can't have variable voltage with this setup, I'll be controlling the speed via pwm, though for this specific project altering speed isn't a big deal. The motors are being used to control an automated blind system inside of the building that I work in, and they need to be able to adjust their angle, and raise and lower when commanded to do so. Both of these types of movements are controlled by one motor, with small changes for changing the angle, and much larger changes for raising and lowering the shades.

jremington:
You need to determine the stall current for the motors, and size the motor driver accordingly.

The stall current, which is the motor power supply voltage divided by the winding resistance, is typically 5-10x the running current. The motor will briefly draw the stall current every time it starts up, and twice that if it is rapidly reversed.

According to the online spec sheet I found for the motor, the stall current is 1.12A

jremington:
You need to determine the stall current for the motors, and size the motor driver accordingly.

dave-in-nj:
\re-read the data sheet

re-read your post

please do not use pronouns. 'these' refers to the what ? the L298 driver or your motors ?

if you think you can power EITHER from a 5v output from the Arduino, buy a LOT of Adruinos to replace the ones you burn up. or use a marker and write on the wall above your monitor NEVER POWER MOTORS FROM THE ARDUINO. you can CONTROL them all day. Great application, but POWER ? very bad thing to do.

MAKE A SKETCH - a schematic. make sure you have it in your head how things connect.

when you plug in your toaster, you have a potential of gigawatts of power, you are connected directly to the main turbines that produce enough power for a few cities. but, the LOAD can only use so much. there are lots of safeties between you and the power plant, but none are needed as your toaster can only use what it can use, not what is available.

you have a 10 amp power supply, connect a 1k ohm resistor and an LED and it will use a few milliAmps.

your L298 can deliver over an amp, and your motors are tiny, not sure where 'larger' comes in on from the subject line. what is troubling is that you have jumbled up some things. I would HIGHLY recommend you post links to your motors. there might be other things in those data sheets that would help to properly set things properly.

as a note, when you have a device, it alone will consume power. maybe a few microAmps, maybe a few watts... but it will consume power. the thing it drives will consume power.

in your case, you have an Arduino, an L298 and a motor. you really are only concerned about the motor, but... when calculating the total load, one has to include the tiny power consumed by the Arduino and the L298 board. the data sheet will note these things, you have to figure out what the data sheet is saying. if it is the chip power consumption or if it is the load power consumption.

I'm sorry for my badly worded post; I wrote this right before I left work and was kind of rushing through it. Here is a spec sheet for the chip that is doing all the motor control on my module: http://www.st.com/content/ccc/resource/technical/document/datasheet/82/cc/3f/39/0a/29/4d/f0/CD00000240.pdf/files/CD00000240.pdf/jcr:content/translations/en.CD00000240.pdf. This is a link to my motor that I'm using which has the specifications listed on it: There was an error . I was mainly worried that this 10A supply would be too much for the controller, and was concerned because on the L298 spec sheet it talked about the logic current being around 36mA, but it seems that I was misinterpreting what it was actually referring to.

11

PaulS:
Well, why should we? The carriage return key is not all that difficult to periodically tap, making paragraphs, instead of a big blob of text.

to be fair, I have written many a post with tandem carriage returns. this would make a nice space between paragraphs. and the forum just eliminates them.

it is rather a pain to go back and edit to add them.

Also, at one time I used google voice on my tablet. worked great ! the micropone picked up sounds, the sounds were converted to words and the resut was... prbably a well written UNIX training manual or maybe a screen play for a dream sequence......

12

michaelsm:
Since I can't have variable voltage with this setup, I'll be controlling the speed via pwm, though for this specific project altering speed isn't a big deal. The motors are being used to control an automated blind system inside of the building that I work in, and they need to be able to adjust their angle, and raise and lower when commanded to do so. Both of these types of movements are controlled by one motor, with small changes for changing the angle, and much larger changes for raising and lowering the shades.

According to the online spec sheet I found for the motor, the stall current is 1.12A

I'm sorry for my badly worded post; I wrote this right before I left work and was kind of rushing through it. Here is a spec sheet for the chip that is doing all the motor control on my module: http://www.st.com/content/ccc/resource/technical/document/datasheet/82/cc/3f/39/0a/29/4d/f0/CD00000240.pdf/files/CD00000240.pdf/jcr:content/translations/en.CD00000240.pdf. This is a link to my motor that I'm using which has the specifications listed on it: There was an error . I was mainly worried that this 10A supply would be too much for the controller, and was concerned because on the L298 spec sheet it talked about the logic current being around 36mA, but it seems that I was misinterpreting what it was actually referring to.

dude... hit the carriage return !

13

@dave-in-nj:

pls be lenient with him, either the CR-keys on both keyboards are broken or he might have never detected them :slight_smile:

14

rpt007:
@dave-in-nj:

pls be lenient with him, either the CR-keys on both keyboards are broken or he might have never detected them :slight_smile:

I just realized that he may not even know what a carriage return is !

it is the large key to the right of the quote button. has a funnny arrow that points left.

15

michaelsm:
I'm sorry for my badly worded post; I wrote this right before I left work and was kind of rushing through it. Here is a spec sheet for the chip that is doing all the motor control on my module: http://www.st.com/content/ccc/resource/technical/document/datasheet/82/cc/3f/39/0a/29/4d/f0/CD00000240.pdf/files/CD00000240.pdf/jcr:content/translations/en.CD00000240.pdf. This is a link to my motor that I'm using which has the specifications listed on it: There was an error . I was mainly worried that this 10A supply would be too much for the controller, and was concerned because on the L298 spec sheet it talked about the logic current being around 36mA, but it seems that I was misinterpreting what it was actually referring to.

we are more than willing to help you, but a little courtesy on your part is in order.

post links as a link is easier for us, but at the minimum, post them on separate lines.
as you might know, we have spenp half the posts discussing the bad etiquette in posting.

the good news is you figured it out.

now you should be able to make it work without much problem

this is a MUCH better board for the L298 because it has the sense pins brought out.
L298 board

krazy expensive though.

16

dave-in-nj:
I just realized that he may not even know what a carriage return is !

it is the large key to the right of the quote button. has a funnny arrow that points left.

There is no such thing as a quote button; there is a button used for quotation marks if that is what you are referring to. Also my keyboard actually doesn't have an arrow on the carriage return key.