Abstract:
A wireless sensor assembly that includes a battery pack and a wireless sensor. The battery pack is placed in spaced relation to the wireless sensor and inductively powers the wireless sensor utilizing primary and secondary resonant coils presented within the battery pack and wireless sensor. The wireless sensor additionally has super capacitors therein to continue to operate the wireless sensor during the changing of the battery pack.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to wireless sensors for construction and agricultural equipment. More specifically the present invention relates to a wireless sensor assembly that utilizes an inductive battery power transfer for powering the wireless sensor. 
     Sensors are used on agricultural and construction equipment for many different reasons. Typically, the sensor is placed on an agricultural or construction machine and the sensor is battery powered utilizing a battery that is physically in contact with the wireless sensor via contacts. Batteries with contacts are susceptible to dirt, debris, and other elements such as oxidization, short circuiting and wear and tear. There are many sources of these contaminants on a construction or agricultural job site that interfere with a good battery connection to the sensor including water, cement dust, dirt, diesel fuel, and the like. These batteries are exposed to these numerous contaminants when the batteries are swapped in the field with fully recharged batteries. Unfortunately, replacing these batteries in the field is required because of operation requirements of construction and agricultural projects and the wireless nature of these sensors. 
     Thus, a need in the art exists for eliminating the problems associated with utilizing a battery with physical contacts. Further, a need exists for a battery that can be quickly recharged and does not cause the wireless sensor to stop functioning as a result of the changing of the battery. 
     Thus, a principal object of the preset invention is to provide a wireless sensor assembly that is unaffected by dust and debris. 
     Yet another object of the present invention is to provide a wireless sensor assembly that is easy to handle, use and replace. 
     These and other objects, features, and advantages will become apparent from the specification and claims. 
     BRIEF SUMMARY OF THE INVENTION 
     A wireless sensor assembly comprising a battery pack having a primary resonant coil. The wireless sensor assembly additionally has a wireless sensor with a wireless sensor power receiver with a secondary resonant coil that is in electrical communication with the first primary resonant coil of the battery pack. The wireless sensor additionally has a super capacitor therein such that the wireless sensor is able to stay powered for a given amount of time after the battery pack has been removed. This allows the battery pack to be replaced without loss of power or function of the wireless sensor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a wireless sensor assembly; 
         FIG. 2  is a cut-away perspective view of a wireless sensor assembly; 
         FIG. 3  is a schematic diagram of a wireless sensor assembly; and 
         FIG. 4  is a schematic diagram of a wireless sensor assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The figures show a wireless sensor assembly  10  that includes a wireless sensor  12  that has a wireless sensor housing  14  that houses a wireless sensor power receiver  16 . The wireless sensor power receiver  16  includes a resonant coil  18 , synchronous rectifier or diode rectifier  20 , a buck boost regulator  22  and super capacitors  23 . The rotating element  24  is attached to a perma magnet (not shown) to create a magnetic field that the Hall Effect measures. The angle of turn correlates to the field intensity. The primary function of sensor is to measure an angle. The wireless sensor  12  is detachably placed on machinery  26  such as agricultural machinery or construction equipment and/or machinery for use. 
     A battery pack  28  is also part of the wireless sensor assembly  10  and is placed on the machinery  26  in spaced relation to the wireless sensor  12  to form a gap  30  there between. The battery pack  28  similar to the wireless sensor  14  has a battery pack housing  32  to prevent dust and dirt from entering the interior of the housing  32 . Sealed within the battery pack housing  32  are a plurality of batteries  34  and battery power/receiver electronics  36 . The battery power/receiver electronics  36  include an inverter  38 , a resonant coil  40  and a power management control  42 . In a preferred embodiment the resonant coil  40  of the battery pack  28  is considered a primary resonant coil while the resonant coil  18  of the wireless is a secondary resonant coil. 
     An actuating device  44  such as a switch or a button is also disposed within the battery pack housing  32  and when actuated the switch determines if a load is presented on the wireless sensor  12  and if so the battery pack  28  begins transmitting power to the wireless sensor  12 . If no load exists, power from the battery pack  28  is stopped. The battery pack is able to transmit the “state of charge of the battery” or “state of battery charge” to the wireless sensor  12  by providing an interrupted power transmission signal wherein the length of the interval is proportional to the state of the battery charge. 
     The battery pack and charger communicate using the bqTesla part that includes a charger and a receiver. The method is either phase shifting or amplitude keying. More specifically the battery pack  28  is placed on top of the battery charger  48 . In one embodiment the battery charger  48  is a wireless charging pad. The bqTesla charger detects the bqTesla receiver and charging occurs automatically. 
     In operation, the battery pack  28  is placed adjacent to but in spaced relation to the wireless sensor  12 , separated by space  30 . Power transfer to the wireless sensor  12  is initiated by pressing or actuating the actuating device  44  of the battery pack  28 . If the battery pack  28  senses a sensor load, the battery pack  28  begins to transmit power; otherwise the power transfer is to be stopped such as when in idle. The battery pack  28  transfers “state of battery charge” to the wireless sensor  12  by interrupting the power transfer signal to the wireless sensor  12 . The length of the power shutdown is proportional to the state of battery charge, but not long enough to drain the super caps. 
     The wireless sensor  12  has enough super capacitors  23  to temporarily power the wireless sensor  12  allowing the battery pack  28  to be replaced without interrupting sensor operation. The super capacitors  23  also power the sensor  12  when the battery pack  28  interrupts battery power during the transfer of “state of battery charge” data. 
     In an alternative embodiment, the wireless sensor  12  includes sensor circuitry  46  and second powering resonant coil circuitry  50 . The battery charger  48  includes a primary charging resonant coil circuitry  52 . The battery pack  32  includes a fuel gauge  54  connected to the batteries  34  and microcontroller  56 . The microcontroller is connected to a load detector  58  and the inverter  38 . The inverter  38 , which is connected to the batteries  34 , is also connected to primary powering resonant coil circuitry  60 . 
     Secondary charging resonant coil circuitry  62  is connected to a rectifier  64  that is connected to a battery charger  66 . The battery charger  66  is connected to the batteries  34 . 
     In operation the battery pack  32  is connected to battery charger  48 . Current is transferred from primary charging resonant coil circuitry  52  to the secondary charging resonant coil circuitry  62  on to the rectifier  64 , then to battery charger  66  and then to batteries  34 . Current is transferred from the primary powering resonant coil circuitry  60  to the secondary powering resonant coil circuitry based upon the load detected. If the current is too high or too low a signal is sent from the load detector  58  to the microcontroller  56  which prevents current from transferring. When the load detector  58  signal indicates that the current is within an acceptable range, current is transferred from the battery pack  32  to the wireless sensor  12 . 
     Thus provided is a wireless sensor assembly that provides inductive powering of the wireless sensor  12  from a contactless battery pack  28 . The contactless battery pack  28  is not affected by dirt of other contaminants on construction and agricultural sites as a result of the battery pack housing  32  and not having terminals or leads that must connect to the wireless sensor  12 . Load detection of the sensor  12  through use of the bqTesla part also provides improvement over the prior art. 
     Further, the wireless sensor assembly  10  transmits “state of charge” to the wireless sensor  12  from the battery pack  28  providing additional information not previously contemplated. Further, as a result of the use of the super capacitor  23  the battery pack  28  can be swapped out or changed without interrupting the operation of the wireless sensor. Thus, at the very least all of the stated objectives have been met. 
     It will be appreciated by those skilled in the art that other various modifications could be made to the device without departing from the spirit and scope of this invention. All such modifications and changes fall within the scope of the claims and are intended to be covered thereby.