Movable target system in which power is inductively transformed to a target carrier

Abstract

An improved track-mounted movable target system is disclosed. Power is inductively transferred to a target carrier movable between first and second locations. The transferred power is used to power electrical equipment on board the target carrier. The electrical equipment may include electric motors, lights, solenoids, and control circuitry for the motors and solenoids. Preferred embodiments of the invention are implemented as track-based systems, as the track provides not only stability to the target carrier, but also protection from stray bullets to the conductive cable. For a first embodiment of the invention, power is transferred to a target carrier via a stationary inductor and a movable cable, which also provides motive force to the target carrier. For a second embodiment of the invention, power is transferred to a target carrier via a stationary cable and an inductor movable with the target carrier. For this second embodiment of the invention, electrical equipment on board the target carrier includes a drive motor for moving the carrier bidirectionally along the track. For both embodiments of the invention, communications with the target carrier may be achieved by modulating the frequency of the applied alternating current and demodulating it at the target carrier to provide control signals for control circuitry on board the target carrier.

What is claimed is:  
     
       1. A movable target system comprising: 
       a target carrier movable between first and second locations, said carrier having onboard electrical equipment;  
       a stationary power supply having first and second output connections ; and  
       a power transmission system for transferring electrical power from the stationary power supply to the on board electrical equipment via at least two mutually-coupled inductors, one of which is movable with respect to another.  
     
     
       2. The movable target system of  claim 1 , wherein power is transferable while one of said inductors is moving with respect to another. 
     
     
       3. The movable target system of  claim 2 , wherein said pair of inductors includes: 
       a first inductor, which is an electrically-conductive cable; and  
       a second inductor comprising:  
       a coil having at least one turn of wire, said wire having first and second ends which, respectively, form first and second leads; and  
       a ferromagnetic core which at least partially surrounds said cable and which magnifies the inductance of said coil.  
     
     
       4. The movable target system of  claim 2 , wherein said core is toroidally-shaped. 
     
     
       5. The movable target system of  claim 2 , wherein said core is substantially in the shape of geometric solid enclosed by the surface generated by rotating a rectangle 360 degrees about an axis that is outside the rectangle, parallel to one side of the rectangle, and equiplanar with the rectangle. 
     
     
       6. The movable target system of  claim 3 , which further comprises a track on which said target carrier is movably mounted, said track having a full-length channel within which said cable is positioned along substantially the entire length of said track; 
       first and second power input connections on said target carrier to which said electrical equipment is electrically coupled; and  
       wherein said cable is movable, having first and second ends respectively coupled to said first and second power input connections, said first and second ends each also being secured to said target carrier; and  
       wherein said second inductor is stationary, having first and second leads respectively coupled to said first and second connections of said stationary power supply.  
     
     
       7. The movable target system of  claim 6 , which further comprises: 
       a first idler pulley longitudinally aligned with said channel and positioned outboard of said first location; and  
       a drive pulley rotatably powered by a drive motor, said drive pulley aligned with said channel and positioned outboard of said second location; and  
       wherein said cable is looped between said idler pulley and said drive pulley.  
     
     
       8. The movable target system of  claim 7 , which further comprises a second idler pulley mounted between said second location and said drive pulley, said second idler pulley engaging said cable and serving to maintain said cable within said channel, and wherein said second inductor is positioned between said drive pulley and said second idler pulley. 
     
     
       9. The movable target system of  claim 8 , wherein said electrical equipment includes at least one electric motor for moving a target and control circuitry for controlling the operation of said electric motor. 
     
     
       10. The movable target system of  claim 9 , wherein said electrical equipment further includes frequency sampling and decoding circuitry, and wherein the frequency of an induced alternating current in said cable matches that of an alternating current applied to said second inductor by said stationary power supply, and wherein the frequency of the applied alternating current is modulated to provide decodable signals at the target carrier which are sampled by said frequency sampling circuitry and decoded by said decoding circuitry to produce control signals for said control circuitry. 
     
     
       11. The movable target system of  claim 10 , wherein said electric motor, said control circuitry, said sampling circuitry, and said decoding circuitry are powered by direct current produced by rectifying at least some of said induced alternating current. 
     
     
       12. The movable target system of  claim 3 , which further comprises: 
       an electrically-conductive track on which said target carrier is movably mounted, said track having a full-length, upwardly-open channel within which said cable is positioned along substantially the entire length of said track;  
       a first cable anchoring device to which a first end of said cable is anchored, said first anchoring device being longitudinally aligned with said channel, positioned outboard of said first location, said first end of said cable anchoring device being coupled to said first power output connection via said track; and  
       a second cable anchoring device to which the opposite, or second, end of said cable is anchored, said second anchoring device being longitudinally aligned with said channel and positioned outboard of said second location; said second end of said cable anchoring device being electrically coupled to said second power output connection; and  
       wherein said second inductor is affixed to said target carrier and said power supply has first and second output connections, said first output connection being coupled to said track, and said second output connection being coupled to the second end of said cable.  
     
     
       13. The movable target system of  claim 12 , wherein said target carrier includes means for lifting a portion of said cable from said channel within the confines of said carrier as it moves along said track. 
     
     
       14. The movable target system of  claim 13 , wherein said means for lifting comprises: 
       first and second guide pulleys rotatably and rigidly affixed to said target carrier, said first and second guide pulleys being positioned at least partially within said channel; and  
       at least one other guide pulley rotatably and rigidly affixed to said carrier at a level above said first and second guide pulleys, said cable being routed from said first cable anchoring device, beneath said first guide pulley, out of said channel and over said at least one other guide pulley, into said channel and under said second guide pulley, then to said first power output terminal second cable anchoring device, said cable passing through said first inductor while said cable is out of said channel.  
     
     
       15. The movable target system of claim  14   12 , where said electrical equipment includes a drive motor for driving said target carrier along said track, at least one target movement motor, and control circuitry for controlling the operation of said drive motor and said at least one target movement motor. 
     
     
       16. The movable target system of  claim 15 , wherein said electrical equipment further includes frequency sampling and decoding circuitry, and wherein the frequency of the induced alternating current in the second inductor matches that of the a source alternating current output by said power supply, and wherein the frequency of the source alternating current is modulated to provide decodable signals at the target carrier which are sampled by said frequency sampling circuitry and decoded by said decoding circuitry to produce control signals for said control circuitry. 
     
     
       17. The movable target system of  claim 16 , wherein the source alternating current is modulated to provide a stream of serial binary data. 
     
     
       18. A movable target system comprising: 
       a track having a channel extending substantially the full length thereof;  
       a target carrier movably mounted on said track between first and second locations, said carrier having first and second power-input connections and onboard electrical equipment coupled to said first and second power-input connections;  
       a first idler pulley longitudinally aligned with said channel and positioned outboard of said first location;  
       a drive pulley rotatably powered by a drive motor, said drive pulley longitudinally aligned with said channel and positioned outboard of said second location;  
       a stationary power supply having first and second power output connections;  
       an electrically-conductive drive cable having a first end that is both electrically coupled to said first power-input connection and secured to said carrier, said drive cable also having a second end that is both electrically coupled to said second power-input connection and secured to said carrier, said cable being looped between said idler pulley and said drive pulley, said cable being positioned within said channel between first and second locations; and  
       an input inductance device that is stationary with respect to said track, said device having  
       a coil with at least one turn of wire, said wire having first and second ends respectively coupled to first and second power output connections; and  
       a ferromagnetic core which at least partially surrounds said cable and which magnifies the inductance of said coil.  
     
     
       19. The movable target system of  claim 18 , wherein said core is toroidally-shaped. 
     
     
       20. The movable target system of  claim 18 , wherein said core is substantially in the shape of geometric solid enclosed by the surface generated by rotating a rectangle 360 degrees about an axis that is outside the rectangle, parallel to one side of the rectangle, and equiplanar with the rectangle. 
     
     
       21. The movable target system of  claim 18 , which further comprises a second idler pulley mounted between said second location and said drive pulley, said second idler pulley engaging said cable and serving to maintain said cable within said channel. 
     
     
       22. The movable target system of  claim 18 , wherein said electrical equipment includes control circuitry and at least one electric motor for moving a target, said control circuitry controlling the operation of said electric motor. 
     
     
       23. The movable target system of  claim 22 , wherein said electrical equipment further includes frequency sampling and decoding circuitry, and wherein the frequency of an induced alternating current in said cable matches that of a source alternating current, output by said power supply to first and second power output connections, and wherein the frequency of the source alternating current is modulated to provide decodable signals at the target carrier which are sampled by said frequency sampling circuitry and decoded by said decoding circuitry to produce control signals for said control circuitry. 
     
     
       24. The movable target system of  claim 23 , wherein said electric motor, said control circuitry, said sampling circuitry, and said decoding circuitry are powered by direct current produced by rectifying at least some of said induced alternating current. 
     
     
       25. A movable target system comprising: 
       an electrically-conductive track having an upwardly-open channel extending substantially the full length thereof;  
       a target carrier movably mounted on said track between first and second locations, said carrier having first and second input connections and onboard electrical equipment coupled to said input connections;  
       a stationary power supply having first and second power output connections;  
       an electrically-conductive cable having first and second ends, said cable being positioned within said channel between said first and second locations, except within the confines of said target carrier;  
       an output inductance device mounted on and stationary with respect to said target carrier, said device having  
       a coil with at least one turn of wire, said wire having first and second ends respectively coupled to first and second power output connections; and  
       a ferromagnetic core which at least partially surrounds said cable, and which magnifies the inductance of said coil,  
       a first cable anchoring device to which said first end of said cable is anchored, said first anchoring device being longitudinally aligned with said channel, positioned outboard of said first location, said first end of said cable anchoring device being coupled to said first power output connection via said track; and  
       a second cable anchoring device to which said second end of said cable is anchored, said second anchoring device being longitudinally aligned with said channel and positioned outboard of said second location; said second end of said cable anchoring device being electrically coupled to said second power output connection.  
     
     
       26. The movable target system of  claim 25 , wherein said core is toroidally-shaped. 
     
     
       27. The movable target system of  claim 25 , wherein said core is substantially in the shape of geometric solid enclosed by the surface generated by rotating a rectangle 360 degrees about an axis that is outside the rectangle, parallel to one side of the rectangle, and equiplanar with the rectangle. 
     
     
       28. The movable target system of  claim 25 , wherein said first cable anchoring device incorporates a cable tensioner. 
     
     
       29. The movable target system of  claim 25 , wherein said target carrier includes means for lifting a portion of said cable from said channel within the confines of said carrier as it moves along said track. 
     
     
       30. The movable target system of  claim 29 , wherein said means for lifting comprises: 
       first and second guide pulleys rotatably and rigidly affixed to said target carrier, said first and second guide pulleys being positioned at least partially within said channel; and  
       at least one other guide pulley rotatably and rigidly affixed to said carrier at a level above said first and second guide pulleys, said cable being routed from said first cable anchoring device, beneath said first guide pulley, out of said channel and over said at least one other guide pulley, into said channel and under said second guide pulley, then to said second cable anchoring device, said cable passing through said output inductance device ferromagnetic core while said cable is out of said channel.  
     
     
       31. The movable target system of  claim 25 , where said electrical equipment includes a drive motor for driving said target carrier along said track, at least one target movement motor, and control circuitry for controlling the operation of said drive motor and said at least one target movement motor. 
     
     
       32. The movable target system of  claim 31 , wherein said electrical equipment further includes frequency sampling and decoding circuitry, and wherein the frequency of an induced alternating current in said output inductance device matches that of a source alternating current output by said power supply to first and second power output connections, and wherein the frequency of said source alternating current is modulated to provide decodable signals at the target carrier which are sampled by said frequency sampling circuitry and decoded by said decoding circuitry to produce control signals for said control circuitry. 
     
     
       33. The movable target system of  claim 32 , wherein said source alternating current is modulated to provide a stream of serial binary data. 
     
     
       34. The movable target system of  claim 25 , wherein at least a portion of said induced alternating current is rectified to direct current and used to power at least a portion of said electrical equipment.