On the website, it is said that the motor runs at 12V. But on the datasheet that has been delivered with the motor it is written 5V.
I use the L298N driver , when I supply it with 5V the motor doesn't work . So my guess is that the good voltage is 12V, and indeed with 12V the motor works fine, but it becames really hot (too hot that I can't even touch it) in a matter of few minutes. I'm afraid to burn it.
The Ebay web page says the motor is 12v and 0.4 amps. That means the coil resistance should be 12 / 0.4 = 30 ohms
Your datasheet that mentions 5v should also mention a current or a coil resistance - what does it say?
Measure the motor coil resistance with your multimeter and you should easily be able to verify which is correct. If you are unsure please tell what the measure resistance is.
An L298N is a very poor choice for driving a stepper motor. It is really designed for DC motors.
The nominal voltage for a stepper motor is largely irrelevant. They all work better with higher voltages but then you must use a specialised stepper driver that can limit the current to protect the motor.
Stepper motors are current driven, not voltage driven. Set the stepper driver module's current to the correct value before wiring up the motor to it. Always power down before changing motor connections or you'll burn
up the driver.
DRV8825 and A4988 are the popular stepper driver modules for small steppers.
Thank your for you replies.
I must admit I am a bit lost.. I just read again the datasheet and there is no mention of voltage (I must confuse with another datasheet I have found on internet )
It is only written :
AMPS/PHASE = 1
RESISTANCE/PHASE = 3,5 Ohms
Does it means I have to supply it with 3,5 V ?
Anyway I tested the impedance and there is 5 Ohms in each coils. I don't understand.
Are you saying that my motor is heating because the driver is not limiting the current ?
Thank you
tangoscar:
Thank your for you replies.
I must admit I am a bit lost.. I just read again the datasheet and there is no mention of voltage (I must confuse with another datasheet I have found on internet )
It is only written :
AMPS/PHASE = 1
RESISTANCE/PHASE = 3,5 Ohms
That'll be a 1 amp 3.5 ohm motor then. It also has an inductance, which is important.
Does it means I have to supply it with 3,5 V ?
No, stepper motors are not voltage driven, they are current driven, you supply 1A via a stepper
driver. The inductance of the motor winding is more important than the resistance, which can basically
be ignored.
Anyway I tested the impedance and there is 5 Ohms in each coils. I don't understand.
Then the datasheet lied or is the wrong one for the motor. This means you don't know the current
rating, only that its 5 ohms.
Are you saying that my motor is heating because the driver is not limiting the current ?
Thank you
All steppers will heat up, they are usually rated for 60C rise above ambient. If it rises more thant that
then perhaps you are using too high a current.
tangoscar:
I am sorry if the question seems idiot but how can I drive with current knowing I have only a transformer with different voltage output ?
You need to use a specialised stepper motor driver such as a DRV8825. They have a small preset potentiometer that you adjust to set the maximum current. IIRC the DRV8825 can work with voltages as high as 35v. The Pololu DRV8825 web page has lots of useful info.
Stepper drivers use the motor's inductance as part of a constant-current switch-mode circuit.
The setpoint current for each winding is changed every time a step (or microstep) is made.
The actual current will change to match the setpoint at a rate limited by the supply voltage and
motor inductance. Higher supply voltages and lower motor inductances mean the motor will be
able to spin faster.
All you have to worry about is setting the current level on the driver and providing step and
direction pulses.
tangoscar:
Ok but if my datasheet is not the correct one , how can I know the current level ?
I know your multimeter showed a resistance of 5 ohms but it would not surprise me if that is just an error and the actual value is 3.5 ohms as stated on the datasheet. Measuring small resistances accurately is not so easy.
Consequently I would assume that the stated 1 amp is the correct current for your motor.