Arduino Motor Shield v3 getting very very hot

I have found some forum posts on this, but not really found the answer to what might be wrong, so hopefully there is somebody that can help.

I run a NEMA 17HS8430, 1.8 degrees, 1.8 A 12V on a Arduino Motor shield V3 and a Arduino Duemilanova I have an external powersource: 12V 0.8 A

It runs smoothly, but after a couple of hours the powersource quits. This happened two times, once to a 12V 0.8A, and a second time to a 12V 0.38A source.

Now i wanted to try a 12V 1.5A powersource, which would come closer to the 1.8A the motor needs, but now the Motor shield is getting really really hot, and smells like something is burning after a couple of seconds.

Too afraid to brake some of my board or arduino, i disconnected immediately of course.

Does anybody have an idea of what is wrong?

I run a NEMA 17HS8430, 1.8 degrees, 1.8 A 12V on a Arduino Motor shield V3 and a Arduino Duemilanova I have an external powersource: 12V 0.8 A

You have a power source that is not powerful enough for the load. You need to reduce the amount of power you are delivering to the motor by using PWM (analogWrite function) to match what the power supply can actually supply.

Now i wanted to try a 12V 1.5A powersource, which would come closer to the 1.8A the motor needs, but now the Motor shield is getting really really hot, and smells like something is burning after a couple of seconds.

1.8A x 2 --> 3.6A is too much for an L298-based motor driver like the Arduino Motor Shield. Here's why. Yes, the marketing literature says the L298 is a "2A driver" but that's just salesmanship.

Try using PWM with analogWrite to reduce the power output to your motor to about half (so analogWrite(128)).

-- The Rugged Audio Shield: Line In, Mic In, Headphone Out, microSD socket, potentiometer, play/record WAV files

Thanks RuggedCircuits,

well, i have fallen for the salesmanship! OK, so a 0.8 - 1A powersource and analogWrite(128) added in the script should do the trick. need to get a new powersource first then.

and in case i'd like to fall for you salesmanship and would like to purchase one of your motordrivers: where can i get them outside the USofA?

keep you posted

w

Don’t you already have a 12V 1.5A power source? You mentioned that that’s the one that caused the burning smell.

We don’t have any distributors outside the USA but we do ship internationally. First-Class Mail shipping is <$10 internationally.


The Flexible MIDI Shield: MIDI IN/OUT, stacking headers, your choice of I/O pins

Hi RuggedCircuits,

it works, thanks! at least here at my desk, without the boards to get hot tomorrow i will be implementing it in the installation in the gallery, hopefully it will be able to take he load there. w

I run a NEMA 17HS8430, 1.8 degrees, 1.8 A 12V on a Arduino Motor shield V3 and a Arduino Duemilanova I have an external powersource: 12V 0.8 A

Hang on, this is a NEMA 17 motor? about 1.5" square? And you claim it takes 22W (12 x 1.8)? Sounds very wrong to me, 5W would be more likely - what is the resistance per winding?

My googling seems to suggest its a 1.8A 1.8ohm bipolar motor (ie 5.8W) which sounds much more plausible. Measure those windings!