Abstract:
A device for generating a voltage comprises first and second plates spaced apart from each other, for being charged at respective different potentials. A third plate is placed at a first distance from the first plate so as to form a first capacitor, and a first semiconductor element is connected between the third plate and the second plate. This voltage generating device produces an output voltage having an amplitude that is dependent upon the first distance and taken between the third and second plates.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to electric power transformers. More specifically, the present invention is concerned with a static capacitor-effect based transformer that transforms electrical power from a higher voltage to a lower voltage. 
       BACKGROUND OF THE INVENTION 
       [0002]    Many types of electrical transformers may be found in patent literature. Conventional electrical transformers generally involve the use of magnetic fields to transform electric voltages and/or currents. 
       OBJECTS OF THE INVENTION 
       [0003]    An object of the present invention is therefore to provide a capacitor based electric transformer. 
       SUMMARY OF THE INVENTION 
       [0004]    More specifically, in accordance with a first aspect of the present invention, there is provided a device for generating a voltage comprising: first and second plates spaced apart from each other, for being charged at respective different potentials; a third plate placed at a first distance from the first plate so as to form a first capacitor; and a first semiconductor element connected between the third plate and the second plate. The voltage generating device produces an output voltage having an amplitude which is dependent upon the first distance and taken between the third and second plates. 
         [0005]    This device for generating a voltage may comprise a fourth plate placed at a second distance from the first plate so as to form a second capacitor; and a second semiconductor element connected between the fourth plate and the second plate. In this case, the voltage generating device produces an output voltage having an amplitude dependent upon the first and second distances and then taken between the third and fourth plates, instead of between the third and the second plates. 
         [0006]    According to a second aspect of the present invention, there is provided a device for generating an output voltage from an input voltage, the device comprising a first series circuit comprising a first capacitor having a first capacitance value and a semiconductor element connected in series with the first capacitor. The input voltage is applied across the first series circuit and the output voltage has an amplitude which is dependent upon the input voltage and the first capacitance value and is taken across the first semiconductor element. 
         [0007]    This device for generating an output voltage may further comprise a second series circuit connected in parallel with the first series circuit, the second series circuit comprising a second capacitor having a second capacitance value and a second semiconductor element connected in series with the second capacitor. In this case, the output voltage has an amplitude which is dependent upon the input voltage and the first and second capacitance values and is taken between a first point between the first capacitor and the first semiconductor element and a second point between the second capacitor and the second semiconductor element, instead of across the first semiconductor element. 
         [0008]    The foregoing and other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of illustrative embodiments thereof, given by way of example only with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    In the appended drawings: 
           [0010]      FIG. 1  is a schematic view of a capacitor based transformer according to a first illustrative embodiment of the present invention; 
           [0011]      FIG. 2  is a schematic view of a capacitor based transformer according to a second illustrative embodiment of the present invention; 
           [0012]      FIG. 3  is a schematic view of a capacitor based transformer according to a third illustrative embodiment of the present invention; 
           [0013]      FIG. 4  is a schematic view of a capacitor based transformer according to a fourth illustrative embodiment of the present invention; 
           [0014]      FIG. 5  is a schematic view of a capacitor based transformer according to a fifth illustrative embodiment of the present invention; 
           [0015]      FIG. 6  is a schematic view of a capacitor based transformer according to a sixth illustrative embodiment of the present invention; and 
           [0016]      FIG. 7  is a schematic view of a capacitor based transformer according to a seventh illustrative embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]      FIG. 1  of the appended drawings is a schematic view of a capacitor based transformer  10  according to a first illustrative embodiment of the present invention. 
         [0018]    As illustrated in  FIG. 1 , the capacitor based transformer  10  comprises a larger capacitor  12 . Two smaller plates P 1  and P 2  are each connected via respective semiconductor elements, for example diodes  14  and  16  to a same plate  18  of the larger capacitor  12 . Also, the smaller plates P 1  and P 2  can be positioned at respective, different distances d 1  and d 2  from the other plate  20  of the larger capacitor  12 . 
         [0019]    In  FIG. 1 :
       V 0  denotes the electric potential (in volts) of the plate  18  of the larger capacitor  12 ;   V 1  denotes the electric potential (in volts) of the plate P 1  connected to the plate  18  of the capacitor  12  through the diode  14 ;   V 2  denotes the electric potential (in volts) of the plate P 2  connected to the plate  18  of the capacitor  12  through the diode  16 ;   V 3  denotes the electric potential (in volts) of the plate  20  of the capacitor  12 ;   ΔV denotes the potential difference (in volts) V 1 -V 2  between the plates P 1  and P 2  and represents the output voltage of the transformer  10 ;   d 1  denotes the distance (in meters) between the plate P 1  and the plate  20  of the capacitor  12 ;   d 2  denotes the distance (in meters) between the plate P 2  and the plate  20  of the capacitor  12 ;   d L  denotes the distance (in meters) between the plates  18  and  20  of the capacitor  12 ;   C 1  denotes the capacitance (in farads) between the plates P 1  and  20  forming a first capacitor;   C 2  denotes the capacitance (in farads) between the plates P 2  and  20  forming a second capacitor;   A 1  is the surface area (in square meters) of the plate P 1 ; and   A 2  is the surface area (in square meters) of the plate P 2  (A 1  can be equal to A 2  but does not have to be).       
 
         [0032]    Still referring to  FIG. 1 , the diodes  14  and  16  have respective cathodes connected to the plates P 1  and P 2 , respectively, and respective anodes both connected to the plate  18  of the capacitor  12 . The diodes  14  and  16  are selected as a function of the current to be drawn through them. The general purpose of the diodes  14  and  16  is to ensure a potential difference between the plates P 1  and P 2  and the plate  18  of the larger capacitor  12 . 
         [0033]      FIG. 1  also shows that the plates  18  and  20  of the larger capacitor  12  have been assigned an arbitrary charge (+ or −) for illustration purposes. 
         [0034]    For example, a magnetohydrodynamics (MHD) generator could be used to charge the plates  18  and  20  of the larger capacitor  12 . Since MHD technology is believed well known to those of ordinary skill in the art and is not particularly relevant to the present invention, it will not be further discussed in the present specification. 
         [0035]    As will easily be understood by one skilled in the art, other technologies could be used to charge the plates  18  and  20  of the larger capacitor  12  without departing from the spirit and nature of the present invention. 
         [0036]    The operation of the capacitor based transformer  10  of  FIG. 1  can be explained as follows. Generally, the voltage V (in volts) across a capacitor is given by: 
         [0000]    
       
         
           
             V 
             = 
             
               Q 
               C 
             
           
         
       
     
         [0037]    where Q is the charge (in coulombs); and 
         [0038]    where C is the capacitance (in farads). 
         [0039]    The capacitance C (in farads) across a capacitor is given by: 
         [0000]    
       
         
           
             C 
             = 
             
               
                 Σ 
                 o 
               
                
               
                 KA 
                 d 
               
             
           
         
       
       
         
           
             where Σ o  is the permittivity of vacuum (8.885×10 −12 ); 
             K is the relative permittivity of the dielectric material between the plates (K=1 for free space, K&gt;1 for all media, approximately =1 for air); 
             A is the area of the plates of the capacitor; and 
             d is the distance between the plates. 
           
         
       
     
         [0044]    Combining the above equations for V and C thus yields: 
         [0000]    
       
         
           
             V 
             = 
             
               
                 Q 
                 C 
               
               = 
               
                 Qd 
                 
                   
                     Σ 
                     o 
                   
                    
                   KA 
                 
               
             
           
         
       
     
         [0045]    And if the charge density is given by Q a =Q/A, then Q=Q a A, substituting and solving yields: 
         [0000]    
       
         
           
             V 
             = 
             
               
                 
                   Q 
                   a 
                 
                  
                 d 
               
               
                 
                   Σ 
                   o 
                 
                  
                 K 
               
             
           
         
       
     
         [0046]    Thus, from  FIG. 1 , the charge difference across the larger capacitor  12  forces a charge up to plate P 1  and up to plate P 2 . The diodes  14  and  16  respectively connecting the plates P 1  and P 2  to the plate  18  will ensure that a potential difference is produced between the plates P 1  and P 2  and the plate  18  of the larger capacitor  12 , since the distance d 1  is not equal to d 2 . Then, solving for the equations above, and assuming that A 1 =A 2 , yields: 
         [0000]    
       
         
           
             
               Δ 
                
               
                   
               
                
               V 
             
             = 
             
               
                 
                   V 
                   1 
                 
                 - 
                 
                   V 
                   2 
                 
               
               = 
               
                 
                   
                     
                       Q 
                       1 
                     
                     
                       C 
                       1 
                     
                   
                   - 
                   
                     
                       Q 
                       2 
                     
                     
                       C 
                       2 
                     
                   
                 
                 = 
                 
                   
                     
                       Q 
                       a 
                     
                      
                     
                       ( 
                       
                         
                           d 
                           1 
                         
                         - 
                         
                           d 
                           2 
                         
                       
                       ) 
                     
                   
                   
                     
                       Σ 
                       
                         o 
                          
                         
                             
                         
                       
                     
                      
                     K 
                   
                 
               
             
           
         
       
     
         [0047]    Thus, by increasing the difference (d 1 −d 2 ) between the distances d 1  and d 2  between the plates P 1  and P 2  and the plate  20  of the larger capacitor  12 , one can increase the output voltage ΔV, independently of the area of the plates P 1  and P 2 . In other words, adjusting the distances d 1  and d 2  will allow adjustment of the amplitude of the output voltage ΔV of the capacitor based transformer  10 . 
         [0048]    Therefore the arrangement of  FIG. 1  provides a means to transform electric power, without recourse to moving components, even when one does not have access to both poles of the source originally powering the larger capacitor  12 . The plates  18  and  20  of the larger capacitor  12  may be a solid, a liquid, a plasma or a combination thereof. 
         [0049]      FIG. 2  is a schematic view of a capacitor based transformer  100  according to a second illustrative embodiment of the present invention. 
         [0050]    The capacitor based transformer  100  illustrated in  FIG. 2  is very similar to the transformer  10  of  FIG. 1 . The main difference is that the plates P 1  and P 2  both include spikes  102  pointing toward the plate  20  of the larger capacitor  12 , in view of increasing the voltage of the transformer without changing any other parameter. Given that in a capacitor, the electric field E is given by E=Q a /d, placing numerous “spikes” such as  102  on the plates P 1  and P 2  as illustrated in  FIG. 2  will increase the electric field between each plate P 1  and P 2  and the plate  20  of the larger capacitor  12 . This increase in electric field E will increase the output voltage ΔV produced by the transformer  100 . 
         [0051]      FIG. 3  is a schematic view of a third illustrative embodiment of a capacitor based transformer  200 . As can be seen, the capacitor based transformer  200  is very similar to the capacitor based transformer  10  illustrated in  FIG. 1 . 
         [0052]    The main difference between the transformers  10  and  200  is concerned with the addition of a capacitor  201  interposed between the cathode of the diode  14  and the plate P 1  to form a series circuit with the diode  14  and the capacitor formed by the plates P 1  and  20  to thereby increase the amplitude of the output voltage ΔV of the transformer  200 , then taken between (a) the point between the diode  14  and the capacitor  201  and (b) the plate P 2 . The capacitor  201  can be a single physical capacitor or a group of capacitors connected in series and/or parallel. 
         [0053]    The resulting capacitance is given by: 
         [0000]    
       
         
           
             
               C 
               1 
             
             = 
             
               
                 
                   C 
                   11 
                 
                  
                 
                   C 
                   12 
                 
               
               
                 
                   C 
                   11 
                 
                 + 
                 
                   C 
                   12 
                 
               
             
           
         
       
     
         [0054]    In this equation:
       C 1  denotes the total capacitance (in farads) of the series circuit including the capacitor formed by the plates P 1  and  20  and the additional capacitor  201 ;   C 11  denotes the capacitance (in farads) of the capacitor formed by the plates P 1  and  20 ;   C 12  denotes the capacitance (in farads) of the additional capacitor  201 .       
 
         [0058]    By adding the capacitor  201  in series with the capacitor formed by the plates P 1  and  20 , the value of the capacitance C 1  is reduced and the value of ΔV, the output voltage of the transformer  200 , is therefore boosted, since V=Q/C. The added capacitor  201  can be of a fixed capacitance value (as illustrated) or be of the variable type (such as a varactor i  not shown). Although not illustrated that way, the capacitor  201  can also be itself composed of multiple capacitors in series/or parallel arrangement or a combination thereof. Each capacitor could be separated by semiconductor elements, for example, such as diodes. 
         [0059]    And so, combining this equation for the capacitance C 1  with the one for the output voltage ΔV yield: 
         [0000]    
       
         
           
             
               Δ 
                
               
                   
               
                
               V 
             
             = 
             
               
                 
                   V 
                   1 
                 
                 - 
                 
                   V 
                   2 
                 
               
               = 
               
                 
                   
                     
                       Q 
                       1 
                     
                     
                       C 
                       1 
                     
                   
                   - 
                   
                     
                       Q 
                       2 
                     
                     
                       C 
                       2 
                     
                   
                 
                 = 
                 
                   
                     
                       
                         Q 
                         a 
                       
                        
                       
                         A 
                         1 
                       
                     
                     
                       C 
                       
                         12 
                          
                         
                             
                         
                       
                     
                   
                   + 
                   
                     
                       
                         Q 
                         
                           a 
                            
                           
                               
                           
                         
                       
                        
                       
                         ( 
                         
                           
                             d 
                              
                             
                                 
                             
                              
                             1 
                           
                           - 
                           
                             d 
                              
                             
                                 
                             
                              
                             2 
                           
                         
                         ) 
                       
                     
                     
                       
                         Σ 
                         o 
                       
                        
                       K 
                     
                   
                 
               
             
           
         
       
     
         [0060]      FIG. 4  illustrates a capacitor based transformer  300  according to a fourth illustrative embodiment of the present invention. The transformer  300  is very similar to the transformer  200  but the added capacitor  301  is not in series with the diode  14  as in the transformer  200  but in parallel therewith. 
         [0061]    Turning now to  FIG. 5  of the appended drawings, a transformer  400  according to a fifth illustrative embodiment of the present invention will be described. The transformer  400  includes a single plate P 1  and the output voltage ΔV of the transformer  400  is taken between the plate P 1  and the plate  18  of the larger transformer  12 . Accordingly: 
         [0000]    
       
         
           
             
               Δ 
                
               
                   
               
                
               V 
             
             = 
             
               
                 
                   V 
                   1 
                 
                 - 
                 
                   V 
                   0 
                 
               
               = 
               
                 
                   
                     
                       Q 
                       1 
                     
                     
                       
                         C 
                         1 
                       
                        
                       
                           
                       
                     
                   
                   - 
                   
                     V 
                     0 
                   
                 
                 = 
                 
                   
                     
                       
                         Q 
                         a 
                       
                        
                       
                         d 
                         1 
                       
                     
                     
                       
                         Σ 
                         
                           o 
                            
                           
                               
                           
                         
                       
                        
                       K 
                     
                   
                   - 
                   
                     V 
                     0 
                   
                 
               
             
           
         
       
     
         [0062]    It is to be noted that the transformer  400  of  FIG. 5  could be provided with an additional, smaller capacitor (not shown) to increase the output voltage ΔV. This capacitor could be connected as illustrated in  FIG. 3  or  4 , in which cases: 
         [0000]    
       
         
           
             
               Δ 
                
               
                   
               
                
               V 
             
             = 
             
               
                 
                   V 
                   1 
                 
                 - 
                 
                   V 
                   0 
                 
               
               = 
               
                 
                   
                     
                       Q 
                       1 
                     
                     
                       C 
                       1 
                     
                   
                   - 
                   
                     V 
                     0 
                   
                 
                 = 
                 
                   
                     
                       
                         Q 
                         a 
                       
                        
                       
                         A 
                         1 
                       
                     
                     
                       C 
                       12 
                     
                   
                   + 
                   
                     
                       
                         Q 
                         a 
                       
                        
                       
                         d 
                         1 
                       
                     
                     
                       
                         Σ 
                         o 
                       
                        
                       K 
                     
                   
                   - 
                   
                     V 
                     
                       0 
                        
                       
                           
                       
                     
                   
                 
               
             
           
         
       
     
         [0063]      FIG. 6  illustrates a transformer  500  according to a sixth illustrative embodiment of the present invention. The main difference between the capacitor based transformer  500  of  FIG. 6  and the capacitor based transformer  10  of  FIG. 1  is that the larger capacitor  12  and plates P 1  and P 2  arrangement of the capacitor based transformer  10  has been replaced in transformer  500  by conventional capacitors C 1  and C 2  that can be fixed or variable capacitors having different values. 
         [0064]    It is to be noted that the transformer  500  could be provided with an additional smaller capacitor (not shown) to increase its output voltage ΔV. This latter capacitor could be connected as illustrated in  FIG. 3  or  4 . 
         [0065]    Finally,  FIG. 7  illustrates a transformer  600  according to a seventh illustrative embodiment of the present invention. The transformer  600  is very similar to the transformer  500  of  FIG. 6 , but the capacitor C 2  has been removed. 
         [0066]    It is to be noted that the transformer  600  could be provided with an additional smaller capacitor (not shown) to increase its output voltage. This capacitor could be connected as illustrated in  FIG. 3  or  4 . 
         [0067]    It is also to be noted that the output of the transformers illustrated herein may be supplied to conditioning and/or regulating circuits, for example to achieve a specific DC or AC voltage and/or a specific AC or DC current. 
         [0068]    Transformers according to the non-restrictive illustrative embodiments of the present invention may be used as DC-DC or DC-AC transformers in a wide range of uses including, but not limited to:
       Power supplies in electrical equipment;   Power generation and transmission equipments;   Homes, buildings, transportation, military, factories;   Applications where there is a need for adjusting the electric voltage and/or the power;   Applications where one of the plates of the larger capacitor such as  12  may be a solid, a liquid, a gas, a plasma or a combination thereof, such as, for example, the exhaust of a MHD generator;   Applications where a magnetic field may be undesirable, such as, for example, in the vicinity of IC chips, microprocessors, etc.       
 
         [0075]    The non-restrictive illustrative embodiments of the present invention present many advantages over the current magnetic transformers such as, for example:
       Ease to manufacture;   Low cost to manufacture;   In some cases, it may be the only way to built a transformer, for example when one of the plates of the larger capacitor such as  12  is a gas or a plasma; and   Operation at potentially lower temperatures than existing transformers since there is no heat generating coils such as those found in conventional transformers.       
 
         [0080]    Although the present invention has been described hereinabove by way of non-restrictive illustrative embodiments thereof, these embodiments can be modified at will within the scope of the appended claims, without departing from the spirit and nature of the subject invention.