The shield contains two L293D motor drivers and one 74HC595 shift register. The shift register expands 3 pins of the Arduino to 8 pins to control the direction for the motor drivers. The output enable of the L293D is directly connected to PWM outputs of the Arduino.
To increase the maximum current, the L293D allows extra chips with "piggyback". Piggyback is soldering one or two or three extra L293D drivers on top of the L293D drivers on the board to increase the maximum current. The L293D allows parallel operation.
This kind of bipolar pulse width method has many advantages, such as the current continuous, or micro current vibration when motor stops, which as a lubrication effect. It can eliminate the dead zone of static friction when positive and negative.
Package included:
1 x Motor Drive Shield L293D
FEATURES:-
Two 5V hobby servos can be connected
Pull down resistors keep motors disabled during power-up
Arduino reset button brought up top
Dimensions: 69mm x 53mm x 14.3mm