SparkFun Forums 

Where electronics enthusiasts find answers.

General project discussion / help
Did you make a robotic coffee pot which implements HTCPCP and decafs unauthorized users? Show it off here!
By dtmacdonald76
#190527
I need a motor controller for 12VDC 3/4 HP motor to be used in a kids electric go-kart. most of the instructions I have found similar products are either designed far too large (144VDC 400AMP) or too small (hobby motors). Any one have any tips on where I might be able to find either DIY instructions, such as at instructables, or maybe pre-made or ready-to-assemble kits?
By jremington
#190528
The key determinant is the stall current, which the motor will draw every time it starts up. At 3/4 HP (12 V, 48 amperes maximum load), the startup current would probably be in the range 200-300 amps. The motor controller has to handle that, so a 400 amp controller would not be "far too large".

As an aside, you won't find many DIY projects that can safely handle that much current, and Instructables is the very last place to look. Most are written by people who DO NOT know what they are doing, and cause a lot of grief by posting their efforts.