Abstract:
A capacitor module is utilized as part of a vehicle accessory system to accommodate the use of accessories that require high current power supplies on many different vehicles, thereby reducing the demands on the vehicle electrical systems. The capacitor module includes a plurality of ultracapacitors capable of maintaining relatively high charge levels and thereby accommodating the demands for short bursts of high current electrical power. Control circuitry is included to manage capacitor charging using lower current signals, thereby allowing for use of accessories on vehicles having lower capacity electrical systems. In one embodiment the accessories contemplated include a snow plow attached to a vehicle, with the snowplow having a hydraulic pump motor which requires high levels of electrical current for operation. Control circuitry manages charging using a relatively constant current electrical signal and discharging of the capacitors as necessary to operate the pump motor.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of previously filed U.S. Provisional application 61/154,157, filed Feb. 20, 2009 and entitled “A Low Current Snow Plow System or Other Vehicle Accessory System Operating on Trucks and ATVs”. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates to power supply systems which are capable of providing short bursts of high current electrical power. Certain variations of the power supply system are designed and configured to supply power to accessories carried on a vehicle, and to avoid the need for relatively high current electrical power demands which may strain the vehicle electrical system. 
       BACKGROUND 
       [0003]    Various accessories, such as snow plows, have been mounted on pickup and medium duty trucks for many years. The methods of operating these plows have progressed over the years, from manually raising and lowering the plow to the electric/hydraulic control methods which are almost universal used today. As these systems have become more sophisticated they have increased the demand on the vehicles electrical system. More specifically, these systems typically require short bursts of large electrical currents in order to properly operate. To accommodate this need, the vehicle electrical systems must have a large alternator and large capacity battery to operate the typical plow system. Such systems are often costly and may not be available on some vehicles. 
         [0004]    As vehicle fuel economy and engine efficiency become a primary factor in new vehicle design, many additional concerns come into play. Modern manufacturers are no longer equipping their vehicles with the necessary high output electrical systems. Thus, alternatives are necessary to operate these accessories which demand high levels of electrical current. 
       SUMMARY OF THE INVENTION 
       [0005]    One method of meeting the electrical needs of snow plows (or other accessories that use short bursts of high electrical current) is to incorporate a system that utilizes a relatively small continuous current signal to charge a storage device, instead of short bursts of a very high current. One more specific method of accomplishing this is to use a bank of capacitors or ultra capacitors to store a desired charge, which can thus discharged in the form of short bursts of high current. Significantly, the capacitors can be charged using a lower level continuous current signal, thereby reducing the demands on a vehicle&#39;s electrical system. 
         [0006]    Vehicles with low energy electrical systems, such as all-terrain vehicles, could also benefit from this type of application. With snow plows and bucket loaders of various types being installed on ATVs, a system using ultra capacitors is a more appropriate fit for the small output electrical systems typically included in these vehicles. 
     
    
     
       BRIEF SUMMARY OF THE DRAWINGS 
         [0007]    Further advantages of the present invention can be seen from the following detailed description of the preferred embodiments are, in conjunction with the attached drawings, in which: 
           [0008]      FIG. 1  is a block diagram showing one embodiment of a system supplying power to snow plows; 
           [0009]      FIG. 2  is a block diagram illustrating an alternative embodiment of a system supplying power to a snow plow; 
           [0010]      FIG. 3  is a block diagram illustrating more details of a capacitor module; and 
           [0011]      FIGS. 4-7  show a top side, perspective and front view, respectively, of a capacitor module contemplated to carry out the concepts of the invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0012]    In order to achieve the necessary power requirements for vehicle accessories, the various embodiments of the present invention utilize a capacitor module which is capable of storing energy for use at later times. The capacitors contained within the capacitor module can be charged using a more manageable current stream, thus avoiding unreasonable demands on the vehicle electrical system. As necessary for the operation of the desired accessory, control circuitry is then utilized to provide high current power signals using energy stored in these charged capacitors. In the description below, one example of an applicable accessory is a snow plow having hydraulic control systems to accommodate moving/positioning of the plow. Naturally, other alternative systems could be contemplated such as sprayers, material spreaders, painting systems, etc. 
         [0013]    Referring now to  FIG. 1 , a potential embodiment of the present invention is further illustrated. In this particular example, an accessory power/control system  10  is utilized to control and power a snowplow which is attached to the front of a vehicle (vehicle and plow not specifically illustrated). More specifically,  FIG. 1  is a block diagram illustrating the various electrical power/control components making up system  10 . In this particular example, certain components are housed on a vehicle side  12  while other components are housed on a plow side  14 . As can easily be anticipated by those familiar with plows, this type of separation is well known based upon the need to detach the plow mechanism. To provide coupling, a power connection  16  and a control connection  18  is utilized. 
         [0014]    Referring now specifically to the vehicle side  12  of accessory power/control system  10 , a connection to a battery  22  (via a fuse  24 ) provides power to power connection  16 , and ultimately to the desired components on plow side  14 . Similarly, a controller connection  26  (to accommodate connection to a control mechanism which is typically housed within the vehicle cab for easy access by the operator) is also included. 
         [0015]    As illustrated in  FIG. 1 , plow side  14  includes a capacitor module  30  which is attached to control connections  18  and power connections  16 . As will be further discussed below, capacitor module  30  includes the necessary circuitry to provide power management and plow control operations based upon multiple inputs. Capacitor module  30  has a number of connections on plow side  14  to provide electrical power/signals to various components. More specifically, capacitor module  30  is connected to both a left light  32  and a right light  34 . As is well known, these are auxiliary headlights provided on the snow plow system. Capacitor module  30  also has an output to a valve body  36  to provide appropriate hydraulic controls to the various hydraulic components (not shown) which are typically included on a snow plow. Capacitor module  30  is also connected to a jack or attachment switch  38 . This jack or attachment switch is utilized to confirm attachment of the snow plow and appropriately switch over operating conditions to receive vehicle power. Lastly, capacitor module has a high current output provided to a pump motor  40 . As understood by those familiar with hydraulic technology, pump motor  40  operates for short periods of time while movements are being achieved. Additionally, pump motor  40  requires a fairly significant electrical power signal for operation, typically involving relatively large amounts of current. Motor  40  may include a switch reluctance motor, a three phase motor or any other well understood motor. 
         [0016]    Referring now to  FIG. 2 , an alternative snow plow system  50  is illustrated in block diagram format. Alternative snow plow system  50  utilizes a plow with additional capabilities and features, and consequently, the control/power connections are appropriately modified. Again, the accessory involved here is a snow plow attached to a vehicle. In this particular variation, both the vehicle side  52  and the plow side  54  make use of multiplexers to provide power and control signals as necessary. Referring to vehicle side  52 , an engine control module  60  is incorporated into this design. Engine control module  60  has connections to the same controller connection  26  and battery  22 . Engine module  60  also has connections to existing vehicle lighting systems including the vehicle right side lights  56  and vehicle left side lights  58 . 
         [0017]    Based upon control signals provided by controller  26 , engine module  60  will provide appropriate signals to either the existing vehicle lights (right side lights  56  and left side lights  58 ), or to various components provided on the plow side  54 , depending upon the particular mode of operation. For example, when the plow is detached, engine module  60  will simply provide power to existing lights, based upon control signals provided by the operator. 
         [0018]    Referring to plow side  54 , several additional sensors have been added, with each sensor being attached to capacitor module  70 . More specifically, these sensors include a pressure sensor  72 , and XYZ sensor  74 , a G sensor  76 , and a linear sensor  78 . Each of these sensors are capable of providing specific information to the capacitor module  70  thus allowing further enhanced operations. For example, a pressure sensor  72  will provide a signal indicative of the hydraulic pressure within the plow system. Having this information, the system will then be able to assess the operating characteristics of the various hydraulic components. Naturally, operation can be modified or halted if problems are detected. Similarly, XYZ sensor  74  will provide signals indicative of the plow orientation. XYZ sensor  74  could take many different forms, such as a magnetic sensor to detect positions, an optical sensor, etc. G sensor  76  (or accelerometer or physical force sensor) could be used to monitor plow down pressure being applied. Thus, in addition to monitoring and managing power, capacitor module is also capable of making adjustments to maintain relatively constant down pressure. Lastly, linear sensor  78  is utilized to measure linear movement forces encountered by the plow, which also indicate acceleration being achieved. Linear sensor  74  could also be an accelerometer, or any other type of sensor which is capable of detecting linear motion and/or acceleration. In addition to these sensors, other devices/components could be included to provide feedback regarding the operation of the plow. For example, it may be desirable to add cameras or optical sensors to detect the specific operation conditions. In many situations, the additional information provided may be helpful in determining whether adjustments are necessary. 
         [0019]    Also connected to capacitor module  70  are the same outputs/component discussed above in relation to  FIG. 1 . Generally speaking, these are all the outputs necessary to provide plow operation and unnecessary control movements. 
         [0020]    Generally speaking, it should be noted that the second accessory power/control system  50  shown in  FIG. 2 , has only a single connection  62  between engine module  60  and capacitor module  70 . In this particular instance, both engine module  60  and capacitor module  70  will include appropriate multiplexers and communication logic to allow signals of multiple types to be transmitted via this single connection  62 . 
         [0021]      FIG. 3  illustrates a more detailed block diagram of capacitor module  70 . A primary component contained within capacitor module  70  is a capacitor bank  80  made up of multiple capacitors  82 . In this particular embodiment, it is contemplated that the capacitors used will be ultra capacitors or super capacitors, as they are known, which generally have very high energy densities when compared to “common” capacitors. References to capacitors however, can mean any form of capacitor or ultra capacitor or any other capacitor designation, so long as they meet the operational goals outlined herein. Also contained within capacitor module  70  is a microcontroller  90  and a motor control  100 , both including various control circuitry and logic necessary to carry out certain defined functions. 
         [0022]    As discussed above, capacitor module  70  has connections to the pump motor  40 , valve body  36 , light  32 , light  34 , and a power/control connection  62 . Additionally, connection jack or attachment switch  38 , and any number of additional optional input  66  could also be provided. For example, optional input  66  could include any one or number of the sensors discussed in connection with  FIG. 2  above. 
         [0023]    Contained within capacitor module  70 , a number of specific control and operating circuits are utilized to coordinate overall operation. Again, capacitor module  70  includes microcontroller  90  which will contain the primary control logic for overall operation. Various inputs are provided from connection  62 , via a multiplexer controller  92  to provide appropriate control and communication signals to microcontroller  90 . One primary function of capacitor module  70  is to contain the necessary stored energy for operation of pump motor  40  at a desired time. Consequently, the charging of capacitors  82  is one function coordinated by capacitor module  70 . 
         [0024]    As indicated in reference to  FIG. 2  above, connector  62  carries both power and control signals from vehicle side  52  to plow side  54 . This includes providing the necessary power for charging of capacitors  82 . Power is more specifically provided to capacitors via a current sensor  94  and a voltage controller  96 . As illustrated, both current sensor  94  and voltage controller  96  are also connected to microcontroller  90 , to help coordinate overall operation. Current sensor  94  will simply provide microcontroller  90  with information regarding current being supplied. Although  FIG. 3  indicates the use of an in-line current sensor, it is also contemplated that additional current sensor could be incorporated. For example, a hall effect current sensor could be added adjacent to the input connection, the motor connection or at the capacitor charging connection. In these instances, the specific current being provided to each of these components would provide valuable information to microcontroller  90 . Voltage controller  96  controls charging operations of capacitor bank  80  based upon provided control signals. In one exemplary situation, voltage controller  96  includes a boost circuit capable of boosting the voltage level of an output signal. In this case, 14 volt signal is received from the vehicle, and a 16 volt signal is provided to capacitor bank  80 . Naturally, other alternatives may exist. Also contained within capacitor module  70  is a balancing circuit  98  which more specifically coordinates the functioning of capacitor bank  80 . For example, balancing circuit  98  may be utilized to ensure the various capacitors within capacitor bank  80  are evenly charged. 
         [0025]    As also illustrated, microcontroller  90  is connected to motor control  100 . Although the primary function of motor control  100  is to coordinate operation of pump motor  40 , this control will also coordinate power signals which ultimately are provided to valve  36  and lights  32  and  34 . Specific drivers are utilized to coordinate operation of these components. More specifically, a valve driver  46  will coordinate operation of valve  36 , and a headlight driver  32  will coordinate operation of headlights  32  and  34 . Utilizing this connection, motor controller  100  is thus capable of managing the overall power distribution provided via capacitor bank  80  to the various systems involved. The circuitry involved in carrying out these particular features will likely include appropriate power transistors, or related analog circuit components. More specifically, these may include diode circuits, MOSFETS or several types of transistors. 
         [0026]    In addition to the functions provided above, the inherent inductance provided when a motor is part of the accessory can also be beneficial. This inductance can be used to produce a back EMF, which in turn could be used for further capacitor charging. Further, the back EMF generated could be used to monitor motor operation (such as speed and positioning). Along these lines, the back EMF could also be used to determine the overall number of rotations provided by the motor, thus indicating related plow cylinder position. Lastly, this capability also provides the ability to incorporate motor boost, thus further increasing efficiency. 
         [0027]    While the components of one embodiment are illustrated in  FIG. 3  above, it is understood that certain variations are easily achieved and contemplated without departing from the overall spirit of the present invention. For example,  FIG. 3  illustrates a voltage controller  96  utilized to coordinate charging of capacitor bank  80 . Voltage controller  96  may include a voltage regulator, a current regulator, or both, as desired in a particular system. Alternatively, this component could be portrayed as a current controller as opposed to a voltage controller. Additionally, the discussion above contemplates multiplexed communication between the vehicle side and the plow side. Variations may include the use of wireless communication of control signals, a separate two-wire communication bus, optical communication or any possible communication scheme. 
         [0028]    As generally discussed above, microcontroller  90  may be connected to several different inputs and sensors (e.g. pressure sensor  72 , XYZ sensor  74 , g-sensor  76 , linear sensor  78 , etc.). Microcontroller  90  can use all information received from these various sources to most efficiently manage energy use. This will include efficiently managing the way capacitor bank  80  is charged and the way energy is used by the plow system. For example, sensors can be used to monitor plow positions and avoid overrun when the plow reaches stops. As is well understood, these overrun conditions can strain the electrical system, using high levels of power for unnecessary operations. Microcontroller  90  could also monitor movements to determine if more efficient operating steps could be used. As an example, microcontroller  90  could monitor movement of the vehicle and utilize a slower raising rate for the plow when the vehicle is operating in reverse. Additionally, microcontroller  90  could monitor the operating characteristics and create an operating history to determine if changes in a user&#39;s habits could more efficiently manage power usage. 
         [0029]    Although not specifically shown in  FIG. 3 , it is possible for the capacitor module to include an internal battery, such as a lithium battery. In this particular embodiment, microcontroller  90  would include appropriate controls to coordinate the charging of the battery, and its use as an additional supplemental energy source. 
         [0030]    Certain components have been shown above to be housed or carried in particular locations (i.e. vehicle side versus plow side). It is contemplated that the locations of these systems could be easily modified depending upon other considerations. For example, depending upon the availability of space, an overall control module could be housed within the vehicle engine compartment, which contains both the engine module and the capacitor module. In this variation, each of these components would be contained within a single housing. Additional variations will be readily apparent to those skilled in the art. 
         [0031]    Referring now to  FIG. 4-7 , the physical layout of one embodiment of capacitor module  70  is illustrated. In these various figures, a front plate  110  and a back plate  112  are both illustrated. As shown, front plate  110  and back plate  112  are connected to each other via a plurality of standoffs or connecting posts  114 . Also contained between front plate  110  and back plate  112  is a circuit board  116 . As best illustrated in  FIG. 7 , capacitor module  70  includes a plurality of individual capacitors  82 , as generally discussed above. Individual capacitors  82  are connected to circuit board  116  using a multifunction bracketing system  118  which provides both physical and electrical connections. Bracketing system  118  allows for the specific connection of capacitors  82  to the designated portions of circuitry contained on circuit board  116 . In this manner, it is possible for the bracketing system  118  to operate as a buss bar, while also allowing for the appropriate connections to balancing circuit  98 . By having bracketing system  118  connected directly to circuit board  116  also keeps the overall package size relatively small and compact. Also illustrated in  FIG. 4-7  are a pair of high current output connections  120  and two connector ports  122 . It is contemplated that high current output connections  120  would be attached to pump motor  40 , while connector ports  122  are utilized for connection to engine module  60  and/or any other optional connections. 
         [0032]    As mentioned above, capacitor module  70  includes circuit board  116 . In this particular embodiment, circuit board  116  would include necessarily control circuitry generally discussed above, in conjunction with appropriate power connections to coordinate the desired capacitor operations. This will likely include appropriate traces on the circuit board to achieve current sensing, and heat management during the various capacitor charging and discharging operations. These traces (most likely copper traces on circuit board  116 ) can also provide a safety discharge for the capacitors. Additionally, certain other concerns may be addressed by the design of components contained on the circuit board. For example, appropriate isolation between control circuitry (i.e. micro controller  90 ) and the related power management circuitry may be necessary. This could be achieved by using appropriate opto-iosolators as necessary. Clearly, the actual design of circuit board  116  will likely vary depending on the overall concerns of the designers involved in creating the particular system. 
         [0033]    Although various embodiments have been discussed and described above, it is contemplated that many variations in the actual design of products could certainly exist. The above described embodiments are meant to be illustrative in nature, and not intended to be limiting in any way. The applicant contends that the present invention includes all modifications and variations coming within the scope and spirit of the following claims.