Patent Publication Number: US-2002000789-A1

Title: Charger assembly

Description:
(1) FIELD OF THE INVENTION  
       [0001] This invention relates to a charger assembly and more particularly to an assembly which selectively communicates electrical power to a battery assembly effective to electrically charge the battery assembly.  
       (2) BACKGROUND OF THE INVENTION  
       [0002] Charger assemblies are generally used to allow electrical power to be communicated from an electrical power source to a battery assembly (i.e. one or more batteries), effective to allow the battery assembly to be electrically charged and to thereafter allow the charged battery assembly to provide the stored charge and power to many diverse types of devices and apparatuses in order to allow these devices and apparatuses to operate.  
       [0003] While it is desirable to fully and completely charge such a battery assembly, it is concomitantly and also highly desirable to substantially and automatically ensure that the battery assembly is not overcharged (i.e. that the battery assembly does not receive a voltage and/or an amount of electric charge exceeding the maximum threshold limit of the assembly) in order to avoid damage to the battery assembly and “out gassing” of the charge transport medium within the battery assembly. While many chargers do allow a battery assembly to be fully charged, they do not adequately prevent such overcharging or rely upon the user or the operator to determine whether a complete charge has been communicated to the battery assembly. These prior charges therefore fail to adequately ensure that such a complete charge has been communicated to the battery assembly while concomitantly and substantially preventing such undesirable overcharging.  
       [0004] It is also highly desirable to selectively provide either a “trickle charge” or a “float charge” to the battery assembly while the battery assembly is not “in use” (i.e., providing electrical power) and or to automatically “recharge” the battery assembly after a certain amount of time of “non-use” has expired in order to substantially prevent the battery from electrically discharging. The selective use of these “dual functions” (i.e., trickle charging and/or automatic recharging) allows the charger to remain operatively connected to the battery assembly during periods of non-use or to be later connected to the charger prior to the needed “recharge”, thereby allowing a single charger to be operatively used in combination with several battery assemblies while automatically “recharging” a previously charged battery assembly after a certain period of time has passed. Many prior charge assemblies do not adequately provide such a “float charge” and/or do not allow the selective use of such trickle charge or automatic “recharge” functionality.  
       [0005] It is also highly desirable to allow the charger to automatically “recognize” the amount and type of electrical power which it receives and to adapt the charger for operation with a wide variety of diverse types of voltages, currents, and power, thereby increasing its overall utility and substantially reducing the likelihood of operator error or operator induced malfunction.  
       [0006] Prior chargers do not typically operate with a wide variety of received and diverse voltages, currents, and/or electrical power and do not typically and automatically recognize such received voltages, currents, and power. Rather, these prior chargers require the operator to recognize the type and/or value of these received voltages, currents, and power and provide this information to the charger or to simply “not use” the charger with such improper input signals, thereby increasing the likelihood of operator error or operator induced malfunction and undesirably increasing the complexity of the overall electrical charging process.  
       [0007] There is therefore a need for a new and improved charger assembly which overcomes some or all of the previously delineated drawbacks of prior charger assemblies. Accordingly, as is more fully and completely delineated below, the present invention addresses these drawbacks and provides and/or constitutes a new and improved charger assembly which is relatively lightweight, relatively inexpensive, relatively compact, and relatively uncomplicated and which is adapted to be selectively and remotely queried.  
       SUMMARY OF THE INVENTION  
       [0008] It is a first object of the present invention to provide a charger assembly which overcomes some or all of the previously delineated drawbacks of prior charger assemblies.  
       [0009] It is a second object of the present invention to provide a charger assembly which overcomes some or all of the previously delineated drawbacks of prior charger assemblies and which substantially reduces the likelihood of overcharging a battery assembly while allowing the battery assembly to be substantially, fully, and electrically charged.  
       [0010] It is a third object of the present invention to provide a charger assembly which overcomes some or all of the previously delineated drawbacks of prior charger assemblies and which further and selectively provides a “trickle charge” to a battery assembly, thereby substantially preventing discharge of the battery assembly during non-use.  
       [0011] It is a fourth object of the present invention to provide a charger assembly which overcomes the various and previously delineated drawbacks of prior charger assemblies and which selectively and periodically communicates electrical charge to a battery assembly while being relatively inexpensive, lightweight, uncomplicated, and relatively compact.  
       [0012] It is a fifth object of the present invention to provide a charger assembly which overcomes the various and previously delineated drawbacks of prior charger assemblies and which receives electrical current, voltage, and power of a certain type and which automatically recognizes the certain type and which provides a substantially constant output signal which is independent of the certain type of electrical current, voltage, and power which it has received.  
       [0013] According to a first aspect of the present invention a charger assembly is provided and is used in combination with a battery assembly having a certain maximum voltage threshold value. The charger assembly receives electrical voltage and communicates the received voltage to the battery assembly only if the electrical voltage is below the threshold value.  
       [0014] According to a second aspect of the present invention a charger assembly is provided and is used in combination with a battery assembly having a certain maximum charge threshold value. The charger assembly receives electrical charge and communicates the received electrical charge to the battery assembly only if the electrical charge of the battery assembly is below the maximum threshold valve.  
       [0015] According to a third aspect of the present invention a charger assembly is provided for use in combination with a battery assembly. The charger assembly charges the battery assembly and continues to provide electrical charge to the battery assembly after the battery has been charged.  
       [0016] According to a fourth aspect of the present invention a charger assembly is provided, and communicates voltage to a battery assembly, the voltage being dynamically modified to substantially prevent overcharging of the battery assembly.  
       [0017] These and other features, aspects, and advantages of the present invention will become apparent from a reading of the following detailed description of the preferred embodiment of the invention and by reference to the following drawings.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0018]FIG. 1 is a block diagram of a charger assembly which is made in accordance with the teachings of the preferred embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION  
     [0019] Referring now to FIG. 1, there is shown a charger assembly  10  which is made in accordance with the teachings of the preferred embodiment of the invention. As shown, charger assembly  10  includes an input module  12  which may, in one non-limiting embodiment, include a processor  13  operating under stored program control, and substantially identical direct current to direct current converters  14 ,  16 , and  18  which are physically and communicatively coupled to the input module by bus  20 . Converter  14  is selectively, removably, physically, and communicatively coupled to the positive terminal of the battery assembly  22  by use of bus  24  and converter  18  is selectively, removably, physically, and communicatively coupled to the negative terminal of the battery assembly  22  by bus  26 . Converter  14  is selectively, removably, physically and communicatively coupled to converter  16  by use of bus  28  and converter  16  is selectively, removably, physically, and communicatively coupled to the converter  18  by use of bus  30 . In one non-limiting embodiment of the invention, each converter  14 ,  16 , and  18  comprises a model PD300-300-48PC converter sold and/or produced by the Powercube Corporation. Other types of converters may be utilized. Module  12  may also include a memory module  80  and a transmitter and receiver or global communications network interface module  82  which are each physically, electrically and communicatively coupled to the processor  13  by use of bus  15 . Module  82  may comprise a radio frequency type transceiver, a power line carrier transceiver, or an Internet type interface.  
     [0020] The charger assembly  10  further includes a signal summation circuit member  32  which is physically and communicatively coupled to a signal comparator  34  by bus  36 . The signal comparator  34  is selectively, removably, physically, and communicatively coupled to converter  18  by use of bus  35  and receives and/or stores a reference signal of a certain threshold value. Summation circuit member  32  is selectively, removably, physically, and communicatively coupled to a temperature sensor  40  by use of bus  42 . In the preferred embodiment of the invention, the temperature sensor  40  is resident within the battery assembly  22  and accurately and periodically “reads” or determines the temperature within the battery assembly  22  and periodically provides and/or communicates this temperature information to the summation circuit member  32  by use of bus  42 .  
     [0021] Charger assembly  10  further includes a first resistor  44  which is selectively, removably, physically, and communicatively coupled to the battery assembly  22  by use of bus  24  and to the summation circuit member  32  which couples the resistor  44  to a source of an electrical ground potential. In one non-limiting embodiment of the invention the resistor  44  has an electrical resistance value of about 0.1 ohms, although other resistance values may be used. In this manner, the voltage appearing “across” the resistor  44  is substantially representative of the voltage which is communicated to the battery assembly  22  by the charger assembly  10 . This voltage is periodically “read” by the summation circuit  32  and used in the “trimming” operation which is more fully delineated below.  
     [0022] Charger assembly  10  further includes a second resistor  48  which is physically and electrically coupled to a source of electrical ground potential and which is further physically and electrically coupled to bus  26  and to the summation circuit member  32 . In one non-limiting embodiment of the invention, resistor  48  has a resistance value of about 0.1 ohms although other values may be used. In this manner, the electrical current flowing through resistor  48  is substantially representative of and/or substantially equal to the amount of current which is provided to and/or communicated to the battery assembly  22  by the charger assembly  10 . This amount of electrical current is periodically measured and communicated to the summation circuit assembly  22  for use in the “trim” operation which is more fully delineated below.  
     [0023] As is further shown in FIG. 1, charger assembly  10  includes a conventional balanced “plug” or interface member  50  having three substantially identical protrusions  52 ,  54 , and  56  which are adapted to cooperatively allow the member  50  to be selectively and removably inserted into a conventional electrical power outlet or “wall plug” (not shown) and to receive electrical power (i.e., electrical voltage and current or charge) from such an electrical power outlet.  
     [0024] The protrusion  52  is typically physically and electrically coupled to a source of electrical ground potential while protrusion  56  is physically and communicatively coupled to a fuse  58 . In one non-limiting embodiment of the invention, fuse  58  is of the “20-ampere” type, although other fuses may be used. As should be appreciated by those of ordinary skill in the art, fuse  58  protects charger assembly  10  from relatively “high power” spikes which are communicated to the fuse  58  by the member  50  and which emanate from the electrical power wall outlet (not shown). Protrusion  56  is physically and electrically coupled to a switch  60  which is selectively moved between a first open position and a second closed position (shown in phantom in FIG. 1). Switch  60  and fuse  58  are physically and electrically coupled to the input module member  12  and selectively and cooperatively communicate the electrical power received by the member  50  to the module  12 . In one non-limiting embodiment of the invention, module  12  includes a commercially available model number UFM1K autoranging rectifier module which is sold and/or produced by the Powercube Corporation and which rectifies or converts the received electrical voltage to a direct current type of voltage.  
     [0025] The input module  12  is physically and electrically coupled to a pair of capacitors  62 ,  64  which are coupled or mutually configured in an electrical series arrangement. In one non-limiting embodiment of the invention, each of the capacitors  62 ,  64  is substantially identical and each capacitor  62 ,  64  comprises or commercially available “ESR” type high temperature aluminum electrolytic capacitor having a capacitance value of about 1500 micro-faruds. Capacitor  64  is further physically and electrically coupled to a source of electrical ground potential. Capacitor  62  is physically, electrically, and communicatively coupled to bus  20 . Charger assembly  10  further includes a third resistor  66  and a fourth resistor  68  which are connected or mutually configured in an electrical series arrangement. Resistor  68  is physically, communicatively, and electrically coupled to a source of electrical ground potential and resistor  66  is physically, electrically, and communicatively coupled to capacitor  62  and to bus  20 .  
     [0026] In operation, member  50  is selectively inserted into a conventional electrical power outlet or “wall plug” (not shown). Switch  60  is selectively moved to a closed position and electrical power (i.e. electrical voltage and electrical current or charge) is communicated to the input module  12  from the electrical power wall outlet (not shown) and through the cooperative arrangement of switch  60  and fuse  58 . The received electrical power is rectified by and communicated by module  12  to the capacitors  62 ,  64  where it is temporally stored until used. The capacitors  62 ,  64  cooperatively allow diverse types of electrical power to be communicated to and allows the charger assembly  10  the input module  12  and allow the charger assembly  10  to have a relatively wide applicability and use within a relatively wide variety of electrical power environments. That is, direct current type of received electrical voltage may be directly communicated, for storage, to the capacitors  62 ,  64  through the module  12 , while an alternating type of received voltage is first rectified by module  12  before being communicated to the capacitors  62 ,  64 . Module  12  (i.e., processor  13 ) automatically recognizes the type and amount of the received electrical voltage and either causes it to be rectified to a certain level required by the capacitors  62 ,  64  or the received voltage to be directly communicated, without rectifications to the capacitors  62 ,  64 , is the previously delineated manner. Processor  13  may also selectively “pad” or reduce the amplitude of direct current type voltage before communicating the received voltage to the capacitors  62 ,  64  in the event that the amount of received voltage exceeds the current storage capacity of the capacitors  62 ,  64 .  
     [0027] Typically the electrical voltage which is communicated to the input module  12  is of the alternating current type and has a root mean square voltage value of about 90 to about 250 volts. The input module, in this one non-limiting embodiment, provides and/or communicates about 300 volts of direct current type voltage upon bus  20  to the capacitors  62 ,  64 . The stored electrical power is provided to the converters  14 ,  16 ,  18  by use of resistors  66 ,  68 . Converters  14 ,  16 , and  18  which, in one non-limiting embodiment of the invention, are “synchronized in phase” cooperatively provide as is more fully delineated below, a single, isolated, regulated, and protected and “dynamically modifiable” output of electrical power to the battery assembly  22 , effective to allow the battery assembly  22  to be substantially and fully charged while concomitantly reducing the likelihood of overcharging. The amount of provided electrical power is regulated or dynamically modifiable by use of a “trimming control” signal which is placed onto bus  35  by the comparator  34  as is more fully delineated below and may be made substantially constant and independent of the type or amount of changes while occur to the signal emanating from the wall plug outlet.  
     [0028] That is, about eight ampere, of electrical current is typically provided to the battery assembly  22  in order to initially charge a substantially and previously discharged battery assembly  22 . The initially “sourced” or provided voltage is varied depending upon the temperature output signal from the sensor  40 . That is, in one non-limiting embodiment of the invention, if the sensed temperature is equal to or less than about zero degrees centigrade, the voltage which is communicated to the battery assembly  22  is made to equal about 152.8 volts of direct current type voltage. If the sensed temperature is equal to about twenty degrees centigrade, the voltage which is communicated to the battery assembly  22  is made to equal about 148 volts of direct current type voltage. If the sensed temperature is equal to about seventy degrees centigrade, the voltage which is communicated to the battery assembly  22  is made to equal about 136 volts of direct current. If the sensed temperature is between zero degrees centigrade and twenty degrees centigrade, the voltage which is communicated to the battery assembly  22  is made substantially equal an amount which is equal to the difference between 142.8 and a second number. The second number is equal to the product of 4.2 and a fraction having a numerator equal to the currently sensed temperature and a denominator equal to twenty. If the sensed temperature is between about twenty degrees centigrade and about seventy degrees centigrade, the voltage which is communicated to the battery assembly  22  is made substantially equal to the difference between 138 and a third number. The third number is equal to the product of 12 and a second fraction having a numerator equal to the currently sensed temperature and a denominator equal to about fifty. If the temperature is over about ninety degrees centigrade, no electrical power is provided and/or communicated to the battery assembly  22 . If the temperature is between about seventy degrees centigrade and about ninety degrees centigrade, the voltage which is communicated to the battery assembly  22  is made substantially equal to the difference between 126 and a fourth number. The fourth number is equal to the product of 21 and a third fraction having a numerator equal to the currently sensed temperature and a denominator equal to about twenty. In this manner, the provided electrical power is automatically and “temperature” regulated according to the measured temperature of the battery assembly  22 , thereby reducing the likelihood of battery overcharge and undesirable battery damage.  
     [0029] Fans, such as fans  70 ,  72  may be placed within the charger assembly  10  and selectively and physically, and electrically coupled to busses  74 ,  76  by the selective activation of respective switches  74 , 76  by the input module  12  or by a thermostat  77  (i.e. a device to monitor the temperature of the charger assembly  10  and to provide a first output signal onto bus  79  should the temperature exceed a first dynamically configurable value and to provide a second signal onto bus  79  should the temperature fall below a second dynamically configurable value) in order to cool the charger assembly  10  should the monitored temperature of the charger assembly  10  exceed over seventy degrees centigrade. These fans  70 ,  72  may be selectively deactivated (i.e. respective switches  74 ,  76  may be physically and electrically opened) should the temperature within the battery charger  10  fall below about sixty degrees centigrade (i.e., the first signal from thermostat  77  “closes” switches  74 ,  76  and the second signal “opens” these switches  74 ,  76 ).  
     [0030] After the initial amount of electrical power begins to be communicated to the battery assembly  22 , the supplied electrical voltage and current is “read” or periodically monitored in the manner which has been previously delineated. The monitored amount of supplied electrical voltage, the monitored temperature within the battery assembly  22 , and the monitored amount of supplied electrical current are summed and compared with the value of the reference signal by comparator  34 . Should the summation of these three received signals exceed the value of the reference signal, a signal is produced on bus  35  and communicated to the converter  18 , effective to dynamically modify or dynamically and automatically reduce the amount of supplied voltage and current or electrical charge to the battery assembly  22 , thereby substantially preventing undesired overcharging and outgassing from occurring. In one non-limiting embodiment of the invention, a substantially constant charging voltage is supplied until the periodically monitored and sensed electrical current “drops” or falls below about two amperes. By way of example and without limitation, should the battery assembly  22  contain about sixty separate battery cells (although other numbers of battery cells are possible), a charging voltage of about 148 volts is communicated by the charger assembly  10  to the battery assembly  22 . At a sensed battery assembly temperature of about twenty degrees centigrade, the supplied charging current is made to equal about eight amperes. Should the sensed or monitored amount of charging current drop to about two amperes, the summed signal will fall below the reference signal and the signal on bus  35  will cause the communicated voltage to be automatically reduced to about 138 volts or about 2.3 volts per cell at about twenty degrees centigrade, thereby automatically providing a “float” type charge and substantially preventing or substantially reducing the likelihood of battery discharge.  
     [0031] Alternatively, the input module  12  contains a timer  84  which is coupled to processor  13  by bus  86  and which begins to operate upon the occurrence of such a “drop” of charging current. Once a predetermined interval of time has lapsed (i.e. about four hours), the module  12  may cause the battery assembly  22  to be “recharged” in the foregoing manner provided that the charger assembly  10  be connected to the battery assembly  22  in the manner shown and previously described with respect to FIG. 1. Alternatively, memory module  82  may be selectively provided with the identity and charging time of battery assembly  22  by use of a transmitter  90  which is resident within the battery assembly  22  and which is of the radio frequency, or a power line carrier, or global communications network type), thereby enabling the transmitter to store identifications and timing data and to communicate with the interface  82 , thereby enabling the charger assembly  10  to be used with other battery assemblies while “remembering” or automatically notifying a user of the lapse of the predetermined time interval and the need to “re-charge” the battery assembly  22 .  
     [0032] Global communications network interface module or Internet interface module  82 , allows the contents of the memory  82  to be selectively accessed by computers, individuals, and/or entities which are remotely located from the charger assembly  10 , thereby allowing a user or remotely located computer to dynamically acquire historical data associated with the use of the charger assembly  10  (i.e., the identity of all of the battery assemblies  22  unit have been charged together with all of the respective charge levels, charging time, and the time that the assemblies were respectively charged).  
     [0033] It is to be understood that the invention is not to be limited to the exact construction and method which has been illustrated and discussed above but that various changes may be made without departing from the spirit and the scope of the inventions as described within the following claims. It should be further realized that charger assembly  22  is relatively compact, inexpensive, and uncomplicated architectural design and that charger assembly  22  obviates the need for a user to “remember” to utilize the assembly  22  only with a certain type of received voltage and/or power signal.