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?
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.
Hi there, have you checked with amazon, there you can find " Motors Electric Pump Fan Speed Stepless Control Module with Reverse Polarity Protection High-Current Protection". This may help you and any kind of motors you want to run in future.
http://www.kb-controls.com/SCR-Chassis- … ol_c20.htm has controllers in your size range.