Speed Controller Design

The H-bridge speed controller will be based on an all N-channel MOSFET bridge. In order to control these MOSFETs, I have choosen upon using the Harris/Intersil HIP4081A Full Bridge FET driver. This driver will handle the high side FET gate charging as well as the low side FETs. It also has a few extra features such as a disable feature. If this pin is pulled high all of the outputs will be shut down until the pin is pulled low. This should interact with the failsafe that is sometimes required in competitions and is a great safety measure in keeping your robot from going haywire.

The interface to the HIP4081A will be a serial PWM chip that has direction and speed control via a serial communication to a microprocessor. I chose to use this to try and cut down on the components used in the design as well as making it a nifty feature for feature use.

Currently I'm not planning on using a current limiting circuit in this design as the motors will most likely not over power the speed controller's current handling capacity.