The dual H Bridge L293D, in combination with an Arduino Uno, can drive the DAIWA APT-3DCP2-B Pan Tilt head, which is also described in this blog.
The PCB includes a 5V regulator to create the required logic voltage for the L293D.
In the photos below you can also see the 25 pin connector for the DAIWA pan tilt head.
For more information regarding the L293D: TI datasheet
In this application both enable pins of the L293D are connected to +5V.
This PCB/Circuit is a modified version of the schematics and code shown in Tom Igoe’s blog. Instead of one stepper motor, the two DC motors of the Pan-Tilt head are driven by this chip. For more information regarding H bridges, stepper motors, the L293D & Arduino visit the blog of Tom Igoe