I am working on a school project for a line-following car. We are using 2 motors, which operate between 12-24 Volts. Link.
We use three 9 V batteries in series to get 27 V. When we connect this to the motor driver (L298N) and try to rotate the motors at the same speed using the same PWM value (writing values between 0 and 255) we get that one motor turns faster than the other.
We used a multimeter to measure the voltages between the terminals for both the motors. We noticed that one of the terminals gives lower voltages. For example:
If we write PWM signal of 150, one motor gets 18 V while the other gets 15 V (only if we use PMW signal of 255, the motors have the same speed and thus the same voltage about 23V). The motors aren't the problem, as we changed the motors to the other terminals. One terminal constantly gives a lower voltage.
We used two different motor drivers of the type L298N and also got the same result. Does anyone know why there is a different voltage drop at the 2 motorterminals?
Thanks in advance.