I'm new to motor control, and I'm trying to create a circuit to control this motor: http://www.robotshop.com/en/banebots-rs-550-motor-12v-19300rpm.html
The key electrical characteristics for my application is that it uses a 12V supply, and at I need to be able to hit the operating point of 40A to get the resulting torque.
I am planning to use an Arduino microcontroller, and some googling led me to this schematic:
The particular motor they are driving is much lower power, it's 9V/100mA. So my question is if I can modify this circuit to use a larger power transistor for my application, and if so, how I should pick one. For example, I found this: http://www.digikey.ca/product-search/en/discrete-semiconductor-products/fets-single/1376381?k=power%20mosfet%2040%20amp and I don't know how to tell if a particular transistor would be appropriate or not.
After that, my next step is to add bidrectional control, and research tells me I need an H-Bridge. What does the circuit look like with an H-bridge added in? What sort of specifications do I need for the H-bridge? Does it have to handle similar current as the power transistor? For example, I found this: http://www.digikey.ca/product-detail/en/VNH7013XPTR-E/497-13076-1-ND/3455766 and have no idea if it's appropriate, or how to use it; to be honest all I know is that I want an H-bridge.
Some further background on my project: I am looking to build a relatively high powered robot actuator. The application is extremely price sensitive, so I'm looking to build out a circuit as inexpensive as possible as opposed to buying some pre-made motor controller, which I've seen can be >$50.