Current flow through the motor is measured under two
conditions, i.e. with load and without load. The shaft of the
DC motor is attached with weight of 130 grams as a load. Fig.
7 shows the relationship between the driver output current
and duty cycle when there is a load attached. The results
showed that the driver managed to control the output current
linearly, and therefore the torque by using PWM control
signal. This enables the solar tracking system to work
properly later on when there is a need to mount more solar
panels on it. When there is no load mounted on the motor, the
driver only consume current maximum at 0.05A throughout
the duty cycle range as shown in Fig. 8. Most of the time,
solar tracking system is installed in a remote rural area where
power grid is nowhere to be found. This will be a very