Hi

I drive my motors with this layout. http://www.arduino.cc/playground/uploads/Learning/relays.pdf

I change the relay to a motor and it works perfekt. And i can use an external power supply/battery to drive the motors. (large transistor rekommended)

Maybe its different for servos but some usefull info.

You are still violating the specs of the motor, but if the motor does not get hot, it should not be a great problem.

If i can find a 3.3V voltage regulator somewhere i want to try that too. But 3.3V regulator seems to be not so often used.

Hi

Thx for the great help guys. Now i use a 7805 voltage regulator on a BIG heatsink and the motor doesnt get warm. Not so warm 

I dont plan to continous drive the motor.

thx both of you!

so with CD4051B i wont go wrong? as i like dip

that CD 4051 is actually called HEF4051BP (cmos, phillips)) and there is MC14051BCP, that HEF is actually the cheapest i find on ebay 24cents per piece.

is it ok, or bad?

http://www.ebay.de/itm/5-x-CMOS-4051-Multiplexer-8Kanal-analog-digital-DIP16-/310373781914?pt=Bauteile&hash=item4843b8119a

Hi

I used various "cd4051" dip type and they all functioning as same. But check and compare the datasheets for extra security.
This product is also useful: https://www.sparkfun.com/products/10680
You can get the IC in dip type too.

When i googled on it i find out the LM317 / LM338 / LM350 can use as a current regulator. Is this something for me? Im not an electric guru so i need some basic help. 

The L298 chip is just an H bridge without any kind of current limit control. Look better for some kind of chopper driver like this:
http://www.electrofunltd.com/2012/08/elfdrv1-stepper-motor-driver-coming-soon.html

or something based on a TB6560 or similar.

They even could be cheaper that your L298 based board and will allow you to keep the 18V voltage (obtaining the maximum torque of the motor). If you put a resistance in serie, it will need to be really really big (and expensive, therefore) and it will be a waste of energy ...  In this way your system will be more a stove than a motor system  

Thx for the info but i already have the L298. Can be a good thing if i power the L298 with a pwm power supply? I have some pwm supply for my modell train.

Something like this: http://www.electrokit.com/productFile/download/380

My arduino uno get 5V from the L298H-bridge board. The motor driver board 5V out to the arduino 5V out. Yes ist OUT on the arduino. Maybe its not a proper connection but working. 

1. The spec for your motor lists step angle as 7.5° so the steps per revolution should be 360/7.5=48, hence the code should be #define STEPS 48.

2. Secondly, the coil resistance is 5.5 ohms/phase.  You're driving it with 18V so the coil current will peak at 18/5.5=3.2 amps but the motor is only rated for surge current of 0.6amps, hence the overheading! The spec sheet applies if you're using a bipolar chopper driver which allows use of 24.0 V to overcome the effects of the winding inductance while limiting the surge current to 600ma (0.6amps).  Since you're using a simple L298H motor driver you should reduce the drive voltage to 0.6A * 5.5V=3.3 VDC.

3. With these new values in you code you may or may not be able to drive the motor at 100 RPM (stepper.setSpeed(100).  If you have problems at that setting try lower values to determine the max speed that you can drive it at.

Ok many thanks for the information. I was too fast to take a test with the motor. Can i serial connect a resistor/coil to sunk the current? ~25ohm and the current is 0,6A. This must be an effect resistor may i think.

You drive the motor with 18V and it gets hot - so what voltage is the motor meant for??

Its 24V i can upload the tech spec of the motor when i get home.  

The motor: http://www.nmbtc.com/pdf/motors/PM35S-048-HHC6.pdf

And my code:

Code:

#include <Stepper.h>

// change this to the number of steps on your motor
#define STEPS 300

// create an instance of the stepper class, specifying
// the number of steps of the motor and the pins it's
// attached to
 Stepper stepper(STEPS, 8, 9, 10, 11);

void setup()
{
   // set the speed of the motor to 30 RPMs
   stepper.setSpeed(100);
}

void loop()
{
   
   stepper.step(3000);
   
delay(1000);

 
   stepper.step(-3000);
   
delay(1000); 
}

Hi

I linked upp my arduino uno with an L298H motor driver board and use stepper library to get movments.
The motor functioning perfect forward and backward but get VERY hot. Its a stepper from a flatbadscanner. (Bipolar)
I drive the motor with 18V and the L298H does not be warm. (The heat sink)

Why does the motor???

Help me out pls! 

http://www.ebay.co.uk/itm/Dual-H-Bridge-Motor-Driver-L298N-Arduino-PIC-etc-DC-Stepper-L298-Board-/160831035879?pt=UK_Computing_Other_Computing_Networking&hash=item257246d9e7