Patent ID: 7450356

Claim:
A rotation speed controller for fans, including three types of models for use in fans with the electrical current of 3 A, 8 A, or 12 A; the main difference between them being the specification of heat-dissipation plates and fuses are different from one another; the controller structure is comprised of: a printed circuit board 3 located between a heat-dissipation plate 1 and housing body 2 , on said printed circuit board 3 is disposed with a trimmer potentiometer 4 , a capacitor 5 , an inductance toroid 6 , a micro limit switch 7 , a TRIAC 8 , and a glass tube fuse 9 ; a cover board 10 added on top of said heat-dissipation plate 1 , a rotary knob 11 disposed on said heat-dissipation plate 1 , a cam 12 attached to one end of the main bearing of said rotary knob 11 , the rotation area of said cam 12 being next to said micro limit switch 7 , thus allowing a suspended fan or fixed fan to be precisely turned on and off by rotating said rotary knob 11 ; a variable resistor 13 attached on the main bearing of said rotary knob 11 for controlling the rotation speed of a suspended fan or a fixed fan without differentiation in rotation speed, after said rotary knob 11 is turned on; the rotation speed controller for fans of the invention has the following features: A TRIAC 8 and a micro limit switch 7 disposed on the circuit board for providing more precise control of the on/off status, and the rotation speed; a glass tube fuse 9 providing power-off protection in case power overload occurs in said controller to ensure safety.