This speed control is used to control 400W DC spindle.  it work like a variable DC to DC converter, if you turn the potentiometer, the voltage provided to the spindle increases and decreases accordingly.  This way the speed of the spindle can be controlled.

Specifications:

• Working voltage: 9-60V DC
• Maximum current: 10A
• Speed control range : 0-100%
• Control frequency : 25KHZ
• Speed control mode : Use potentiometer to regulate the current
• Module size : 92mm x 52mm x 36mm
• Weight : 135g