Description: DC Motor Controller 10-30V with Adjustable Potentiometer, Positive and Negative Reversible Switch PWM DC Controller 120W.    Specifications: The resistance value of a resistor:B10K;  Cable length:approx. 20cm/7.87'';  Resistor mounting hole:8mm;  Voltage:DC 10V-30V( wide range);  Working voltage:12v*3A=36W/24V*3A=72W  Maximum up to 120W;  Rated current:3A(Maximum continuous output current);  Maximum current:4A;  Modulation range:5%-95%;  PWM frequency:500HZ;  Module size:approx.74*47*28mm/2.91*1.85*1.10''.    Features: Using PWM speed control technology, with high conversion efficiency, wide speed range, and stable performance.  Adopting imported semiconductor chips, and had tested the voltage, current, function etc. So the circuit is stable and reliable.  Overload short circuit protection and the current no more than 30 seconds.  Potentiometer is used to speed up the positive and negative switch for forward, reverse, and stop.    Note: 1. DC motor speed control input is DC, can not directly connect AC current (such as the 220V AC) otherwise it will burn.  2. The positive and negative poles of the DC power supply can not be reversed, Otherwise the governor will damage.  3. Motor can be divided into positive and negative, when the direction of operation and expectations are inconsistent, you can change the direction of the alignment.  4. The potentiometer knob can change the output duty cycle of the governor, thus changing the speed of the motor.  5. Please allow 1-3mm differs due to manual measurement.  6. Due to the different display and different light, the picture may not reflect the actual color of the item. Thanks for your understanding.    Package Included: 1 x Controller