4. The 5V output port on the driver board prohibits connect external device. It is only applicable to the external potentiometer and switch of the board for speed regulation and reversal. 3. JYQD-V8.8 driver board is bare board without housing and heatsink. If the power of the motor below 60W ,it does not need to add heatsink, It only needs to normal ventilation and well insulation. If the power of the motor more than 60W, it must add heatsink like the diagram as below. 1. Confirm that the voltage and power parameters of the motor not exceed the range of the driver board as specified. 2. This driver board is used for 3-phase brushless sensorless motor, but not suit for all 3-phase brushless sensorless motors directly. If the driving effect is not good Customers can adjust the resistance and capacitance of the driver board according to the actual situation to achieve the best driving effect 5. The "M" terminal on the JYQD-V8.8 driver board is the motor speed pulse output signal (push-pull output), and the maximum output current is less than 5mA., Weight: 0.13448197982 Pounds, Manufacturer: Kueohse