Hello, today I received my motorshield, the one that is shown here.
So now I immediately wanted to try out this new gadget and pluged in my motor, it is a RS-540/SH.
I am using a Arduino UNO plugged into USB and a strong 5 Volt power supply for the motor, that is connected to EXT_PWR of the motor shield, I removed the "Ext Power Jumper", hopefully I was doing right with that?
However, it all works fine, the motor runs as expected forward and backward, but the motor shield, especially IC1, becomes very hot very fast, after 2 or 3 seconds.
I cannot imagine the motor is too strong for the shield, is it? Please could anyone have a look at the specs of the motor and the ones of the shield, because I am not sure if I understand that right or if I am doing something wrong? Thanks a lot, Martin...
Yes, the motor is too "strong" for the motor shield. The motor shield is rated at 0.6 A and your motor draws >1.6 A with no load (I couldn't tell exactly which motor from the spec sheet). You will definitely need a more powerful driver.
Those are some pretty heavy duty motors and will require a stout motor controller to adequately drive them.
The thing to look at on motor spec sheets is the stall current. This is the maximum current that motor will draw under stall conditions. If the motor driver isn't rated for at least that much current, you risk overloading the motor driver. In your case, the motor driver isn't even close to being able to handle those motor's stall currents.
Hell! A more powerful driver? Hmmmmm... But that is THE motorshield, no? So I should try a weaker motor first. I read the specs too, but since I am a beginner I thought I was maybe misinterpreting them. I could not imagine that such small motor already is to strong...
Sorry for asking again, but I was looking at the "stall" column in the spec sheet. There it is written "32.0" A. That cannot be true, no? That would mean that the motor draws more that 25 times more than the shield can supply? What kind of motor should it be then? Is it true, that only very, very small motors can be driven by the shield? Hmmm... I was hoping to use a stepper motor with the shield, but on that it is written "0.95A". I suppose that means that even my stepper motor can´t be driven by the shield, yes? Hack!
clockdivider:
Sorry for asking again, but I was looking at the "stall" column in the spec sheet. There it is written "32.0" A. That cannot be true, no? That would mean that the motor draws more that 25 times more than the shield can supply? What kind of motor should it be then? Is it true, that only very, very small motors can be driven by the shield? Hmmm... I was hoping to use a stepper motor with the shield, but on that it is written "0.95A". I suppose that means that even my stepper motor can´t be driven by the shield, yes? Hack!
Yeah - I think a 540 motor could have a stall current of 32 amps; I have a PowerWheels H2 ride-on that uses two of these motors (well, likely similar motors - perhaps wound different) to drive the rear wheels - I think the main fuse is a 25 amp fuse to the 12 volt gel-cell. You need a much smaller motor (ie, a cheap 25 cent 6VDC "hobby" motor) - or a much larger driver h-bridge (prepare to spend a bit of money on it).
Hello, thanks for your reply. Actually I wanted to go on with my Arduino for testing, and I remebered that I have an old CD-Drive here, that didn´t work anymore...
The stepmotor ist already working fine, the other one, which I don´t know what kind of motor it is, not. However, I have some stuff to try with... Thanks a lot!
To control that motor you want a RC-model ESC for a brushed motor (2-wire)...
Certainly you need to be driving it from a beefy MOSFET-based controller since it is low voltage and high current - you can't afford to waste power in the Vsat of a bipolar output stage (let alone the Darlington outputs of a L293D!!!).