Patent Publication Number: US-2007104575-A1

Title: Touch control system for a fan

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims priority benefit of Chinese application No. 200510115589.0filed on Nov. 9, 2005, the content of which is hereby incorporated by reference in its entirety.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates to a touch control system for a fan, particularly to one able to turn on and off a fan, and change its speed by touching a protective net of the fan without need of pressing the switch, easy to operate the fan.  
      2. Description of the Prior Art  
      Most conventional fans generally have a switch for turning on and off the fan or additionally provided with a wireless remote controller to control the switch.  
     SUMMARY OF THE INVENTION  
      This invention has been devised to offer a touch control system for a fan to turn on and off the fan and change its speed by physically touching a protective net of the fan without pressing a switch. The invention has the following features.  
      1. It generates a control signal of micro capacity alteration caused by a user&#39;s physical touch on a protective net of a fan.  
      2. It has a touch input circuit for converting the control signals of micro capacity alteration into digital signals to be fed to a microprocessor.  
      3. It has a microprocessor for receiving the digital signals coming from the touch input circuit, and coding the signals into a coded program signal, which is to be fed to a driving circuit.  
      4. It has a drive circuit to operate the fan according to the coded program signal for turning on and off the fan, change its speed etc, without need of pressing a switch but by physically touching the protective net,  
      5. It uses the drive circuit having a conductor connected to the protective net, which is coated with an insulating material such as plastic, paint or lacquer, so a user&#39;s physical touch on any place of the protective net can activate the touch control system to operate the fan. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
      This invention will be better understood by referring to the accompanying drawings, wherein:  
       FIG. 1  is a block diagram of a touch control system for a fan in the present invention;  
       FIG. 2  is a diagram of the electric connections of the touch control system for a fan in the present invention;  
       FIG. 3  is a side view of the fan with its protective net being touched by a person for controlling the fan in the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      A preferred embodiment of a touch control system for a fan in the present invention, as shown in  FIGS. 1 and 2 , includes a touch input circuit  1 , a micro processing circuit, a drive circuit  3 , and a current rectifying and voltage lowering and stabilizing circuit  4  as main components combined together.  
      The touch input circuit  1  includes an integrated circuit (IC) U 2 , a resistor R 8 , a capacitor C 2 , and a conductor  10 . The IC U 2  is connected to the resistor R 8  and the capacitor C 2  in parallel and receives a touch signal of a micro capacity alteration caused by a user&#39;s physical touch on the metal protective net  50  of the fan  5 , and then converts the touch signal into a digital signal. The conductor  10  is connected to the metal protective net  50  of the fan  5  and also connected to the IC U 2 . The metal protective net  50  has its surface coated with a layer of insulating material such as plastic, paint or lacquer of a proper thickness. The plastic, or the like does not affect the touch signal to be interfered. The invention is illustrated with a standing fan as shown in  FIG. 3  in spite of the fact that this invention can be applied to various kinds of fans. The drive circuit  3  can be properly modified in its size according to the power of the fan motor. Then the touch input circuit  1  transmits the digital signal to a microprocessor U 1  of the micro processing circuit.  
      The micro processing circuit includes a microprocessor U 1  and an oscillating circuit  2 . The oscillating circuit  2  supplies oscillation signals needed to the microprocessor U 1 , which receives the digital signal coming from the touch input circuit  1 , and properly processes it into a coded program signal. Then the coded program signal is transmitted to the subsequent drive circuit  3 .  
      The drive circuit  3  can be designed in accordance with an operational mode of a fan, controlling the fan motor to turn on and off, and its speed based on the coded program signal from the microprocessor U 1 . The drive circuit  3  includes three triacs , TRC 1 . TRC 2  and TRC 3 , as shown in  FIG. 2  for altering the fan speed in three levels, fast, medium and slow. It should be noted that the components and elements of the drive circuit  3  must be selected according to the power of the fan, The drive circuit shown in  FIG. 2  is exemplary, and various modifications and variations can be made.  
      The current rectifying and voltage lowering and stabilizing circuit  4  is to rectify AC into DC, and then lower the voltage and stabilize the voltage.  
      Symbols shown in  FIG. 2  have the following meanings R 1 -R 11  are resistors. U 1  is an integrated circuit, and PA 3 , PA 2 , PA 1 , PA 0 , PB 2 , PB 1 , PB 0 , VSS, PC 0 , PA 4 , PA 5 , PA 6 , PA 7 , OSC 1 , OSC 2 , VCC, RES, and PC 1  are connecting points of U 1 . VCC is connected to a positive point of the power input. X 1  is an oscillator. EC 2  is a capacitor. C 1 -C 2  are capacitors.  
      The invention can be applied to various kinds of electric fans, to turn on and off and change the speed of the fan motor by a user&#39;s physical touch on the protective net of the fan instead of pressing a switch, renovating the handling method of an electric fan.  
      While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.