Amazon.com: PWM DC Motor Speed Controller, DC10-55V/40A Max 60A Stepless DC Motor Speed Controller with Forward-Brake-Reverse Switch Adjustable Potentiometer and LED Display,Continuous Current 40A : Industrial & Scientific
80A 24V DC Motor Speed Controller Power Controller Solid State Relay Regulator 0-5V 0-10V SSR - China SSR, SSR Relay | Made-in-China.com
Cebek R-20 | AC Motor Speed Control DC Signal/Pot 230V 750W | Quasar Electronics Limited