Patent Publication Number: US-7215526-B2

Title: Ion generator with open emitter and safety feature

Description:
FIELD OF THE INVENTION 
   This invention relates to ion generators, and more particularly, to negative ion generators where a high voltage power supply is connected to a sharp point to produce ions. 
   BACKGROUND OF THE INVENTION 
   It is well known that a high voltage, in the range of a few thousand volts, applied to a sharp point produces ions in the surrounding air. A lot of negative ion generators based on this principle exist in the marketplace. They generally consist of a high voltage power supply of which its negative terminal is connected to a sharp point, usually that of a needle, and its positive terminal is connected to an electrode, typically a ring (collector), in front of the needle. Sometimes this is duplicated a few times in a typical unit. Many negative ion generators of which I am aware, mainly for car use, are of this type. 
   Having the positive electrode, a ring, in front of the negative needle, a short path is made from the needle(s) to the ring(s). This causes two major problems. First, the ions coming out of the needle(s) get readily absorbed by the ring(s) (collectors) and much less ions get through the ring(s) to be of benefit, resulting in inefficient ion generation. Second, the proximity of the opposite collector electrode (ring(s)) to the emitter(s) creates a high differential voltage gradient which, due to the high velocity of the ions bombarding the oxygen molecules of the air between the electrodes, produces ozone. 
   SUMMARY OF THE INVENTION 
   It is one object of my invention to provide an ion generator that floods an interior with cleansing ions much more voluminously than heretofore. 
   It is another object to provide an ion generator that eliminates ozone generation. 
   It is another object to provide an ion generator that is safe to use. 
   It is a further object of the present invention to provide an ion generator comparatively inexpensive to manufacture suitable for mass distribution. 
   In accord with my invention, a very large gap is provided between the ion emitter and the opposing electrode of my ion generator. The emitter of the ion generator is exposed to the open space of an interior to be cleaned and the opposing electrode of the ion generator is provided by the electrical ground of the walls bounding the interior to be cleaned, such as the electrical ground of the walls of a house or chassis of a motor vehicle at least partially bounding the interior to be cleaned. All ions generated fly off the exposed and electrically unobstructed emitter and then spread out in all directions until they meet the walls of the house or the frame of the car, capturing dust and other particulates on the way, thereby removing the particulate matter from the interior to be cleaned in a highly efficient manner without producing ozone. 
   In further accord with my invention, I have devised safety circuitry preventing people from getting a shock if they touch or get near to the open exposed emitter. The safety circuit prevents people (or animals) from getting a shock if they touch or approach the point source ion emitter by sensing the extra current that flows through the exposed emitter because of the proximity to the hand and by shutting the high voltage off for a predetermined time, typically a few seconds, or until the hand (or other body part) is removed from proximity with the exposed electrode of my invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects, inventive aspects and advantageous features of my invention will become apparent as the invention becomes better understood by referring to the following, solely exemplary, detailed description of the presently preferred embodiments thereof, and to the drawings, wherein: 
       FIG. 1  shows a previous art ion generator where the ion emitter (needle) is near the collector (ring); 
       FIG. 2  is a block diagram of my invention, which shows an ion generator wherein the ion emitter is exposed and far away from the collector (ground) and including the proximity sensor; 
       FIG. 3  shows a variation of my invention where the ion emitter is attached to the air vent of a car; and 
       FIG. 4  is an electrical block diagram of the safety (proximity sensor) circuit in accord with my invention. 
   

   DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS 
   In  FIG. 1 , the numeral  1  designates an ionizing emitter, typically a needle, and the numeral  2  designates the collector ring (counter electrode) which is in proximity to the needle  1  of a prior art ion generator. Such prior art ion generators smell of ozone and represent an inefficient way to induce cleansing ions into the air of an environment to be cleaned. 
   High voltage power supply  3  provides high voltage to the ionizing needle  1  and to the collector ring  2 . Electrons designated at  4  coming out of the needle  1  are attracted by the opposite polarity of the ring  2  and are focused in the direction of the ring  2 ; some electrons are dissipated in the ring  2  and others get through to the outside. At the same time, because of the proximity of the counter electrode (the collector ring  2 ) to the ionizing needle  1 , the voltage gradient between the needle  1  and the counter electrode is high enough to accelerate the electrons to break the bonds of oxygen contained in the air between the needle  1  and the counter electrode, which generates ozone. 
     FIG. 2  shows an arrangement of my invention where the ion emitter  1  and the counter electrode  5  are far apart, where the numeral  5  designates a ground base or common ground which could be, for example, the wiring ground of a house or the chassis frame of a car or the electrical ground of some other interior in which it is desirable or advantageous to use my invention. Ions coming out of the exposed needle  1  have a long way to travel to reach the ground  5  and thus flood the interior space with a lot more cleansing ions than the prior art ion generator described above in connection with the description of  FIG. 1 , without producing ozone in the process. Proximity detector (safety circuit)  6  to be described is operatively connected to the high voltage supply  3  to prevent electrical shocks. Power may be supplied by any available or suitable AC or DC means. Depending on the implementation, the path from supply  3  to ground  5  may be by ground leakage currents or by conductor or some other means or mechanism. 
     FIG. 3  shows a car ionizer where the emitting electrode  7 , in this case a brush with conductive bristles, is connected to the suitably housed end of a conductive cord  8 . The brush emitting electrode  7  is attached by any suitable means such as a clip attached to or part of the housed end of the cord  8  to the car vent  9  so that the ions coming out of it will spread out better due to the air flow from the vent. Of course, the electrode  7  may be otherwise positioned in the car&#39;s interior to take advantage of the air flow or be differently positioned, arranged or provisioned. 
   The brush emitting electrode  7  and a connector  10  are electrically connected to a suitably housed power supply  10  adapted for attached or freestanding use inside a vehicle. The connector  10   a , adapted for connecting to the vehicle&#39;s cigarette lighter accessory or other plug, electrically connects the ion generator&#39;s power supply to the vehicle&#39;s chassis (electrical ground). 
   The electrode  7 , exposed at the car air vent  9  or other location exposed to the car&#39;s air stream or other advantageous location exposed into the open space of the car&#39;s interior, fills the interior space with cleansing ions. The ions, attracted towards electrical ground, efficiently remove dust, smoke or other particulate pollutants from the entirety of the car&#39;s interior as the ions move towards the vehicle&#39;s frame. A safety circuit to be described is provided to prevent electrical shock should a hand or other body member (or animal) touch or approach the exposed electrode  7 . 
     FIG. 4  shows the complete electronic arrangement of my invention in block diagram. An oscillator  11  coupled to the vehicle&#39;s accessory plug drives high turns ratio transformer  12 . The output of transformer  12  is connected to diode-capacitor multiplier  13 , which rectifies and multiplies the voltage from about one (1) KV to ten (10) KV direct current. One of the input leads of the diode-capacitor multiplier  13  is connected to transformer  12  via a resistor  14 . The current driving the diode-capacitor multiplier  13  passes through resistor  14 . 
   Resistor  14  develops a voltage across it which is proportional to the current going to the emitter  15 . If, for example, a hand comes near emitter  15 , because of the sudden increase of current in resistor  14 , a voltage surge appears across resistor  14 . This voltage increase passes through capacitor  16 . 
   A voltage comparator  17  is provided with threshold setting resistors  18  and  19 . If the voltage through the capacitor  16  exceeds the threshold, the comparator  17  gives a pulse to amplifier  20 . The output of amplifier  20  triggers monostable multivibrator  21 . 
   Monostable multivibrator  21  produces a pulse that is made to stop the oscillator  11  for preferably a few seconds and therefore the high voltage is interrupted during this time. After the pulse is gone, the oscillator starts again and if the hand is still there the process continues until the hand is moved away. 
   It is possible to connect more than one emitter in parallel on the high voltage power supply. The effect will be the same no matter which emitter is approached. 
   Many modifications of the presently disclosed invention will become apparent to those of skill in the art without departing from the scope and spirit of the present invention.