Hi all, i'm new to electro stuff but' a RC car fan..so one day i decided to make my very own RC car! but i faced some problem so any one can pls help me? i went out and brought a 8051 kit set and two stepper motor (after some reading and i found out its a bipolar motor) so happly i went home and tot i just plug the four stepper motor wire to the 8051 output port and was wrong...so i decided to test my motor and i gave +3 -3 +4 -4 to separate wire...(its a 7.5v/0.25A) and the motor won't move..so i read up more and saw the Hbridge...and i brought a l239d...and the problem now come ..i don't know how to connect the motor to l239d..do i need some external resistor/capacitor/transitor or such? i know i'm a newbie(or maybe can't even be a newbie) pls help me guys... help me get the motor going. using the stepper and l239d thanks a lot

 

If your motor is indeed a stepper motor it wont run without a stepper motor driver. The 4 wires have to be pulsed on in sequence to control the speed and direction it turns. The driver board does that, it converts your FWD, REV & speed inputs into the appropriate pulse sequence.

Its no good using a 'H' bridge for a stepper motor, these work with the ordinary, permanent magnet & brushes, DC motors.

To test your motor if it is definitely a stepper motor, short all 4 wires together then try to turn the shaft by hand. It should turn somewhat harder, and jerkingly, like there was grit in the bearings.
Go to Google and search for stepper motor driver schematics & theory to read more about how they work. They are great for robotic applications but I'm not so sure about RC cars 8)

 

evilsaint,

what brand and/or model of RC car have you played with so far?

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