Abstract:
Apparatus for providing electrical power to signal conditioner circuitry inside a musical instrument having a signal output jack mounted thereon to carry a conditioned music signal via a signal cable to a remote location. The power source is a battery mounted inside a housing that is part of a signal plug on the signal cable plugged into the signal output jack. The battery powers the signal conditioner circuitry while the signal plug is in the jack. The housing provides access to the battery. Alternatively, a rechargeable power source is mounted inside or otherwise on the instrument and is connected to the jack. A power supply first plug is inserted into the signal output jack to charge the rechargeable power source. After charging the power source, the first plug is unplugged and a second plug of a signal cable is plugged into the jack to carry the conditioned signal to the remote location. When the second plug is plugged into the jack, the charged rechargeable power source provides power to the signal conditioner circuitry.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/558,624, filed Apr. 1, 2004 by Simona Ioffe for SYSTEM FOR POWERING A S IGNAL CONDITIONER CIRCUIT DISPOSED INSIDE A CONCEALED VOLUME, and U.S. Provisional Patent Application Ser. No. 60/558,623, filed Apr. 1, 2004 by Simona Ioffe for SYSTEM FOR POWERING A SIGNAL CONDITIONER CIRCUIT DISPOSED INSIDE A CONCEALED VOLUME. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     This invention relates in general to means for supplying power to signal conditioner circuitry inside musical instruments.  
         [0004]     2. Description of the Prior Art  
         [0005]     In the prior art, signal conditioner circuitry is often located inside musical instruments, such as stringed instruments. Such circuitry typically includes, but is not limited to, preamplifiers, buffers, equalizers and compressors. These circuits must have electrical power supplied thereto and energy sources, such as batteries, are mounted inside the musical instruments.  
         [0006]     A big disadvantage to locating batteries inside stringed instruments is that when it is time to remove and/or replace the batteries they are too often in a hard to reach place in the instruments. In addition, musicians generally remove batteries from their instrument(s) before transportation and they also usually replace the batteries before every performance. For too many stringed instruments the strings have to be loosened or removed to remove and/or replace the batteries.  
         [0007]     Thus, it is highly desirable to simplify the procedure of providing power to signal conditioner circuitry located inside musical instruments.  
         [0008]     In addition, there is a need in the art to provide electrical power to signal conditioner circuitry located inside musical instruments from outside the instruments so there is seldom any need to ever get inside the instruments to replace and/or remove batteries.  
         [0009]     Further, there is a need for providing electrical power to signal conditioner circuitry inside musical instruments without having to add more connectors or jacks on the instruments, and without having to add more wires connecting to the instruments via such additional connectors or jacks.  
       SUMMARY OF THE INVENTION  
       [0010]     The foregoing needs in the prior art are met by the present invention. Electrical power is externally provided to signal conditioner circuitry mounted inside musical instruments so the need to access the interior of such musical instruments to change or remove batteries is eliminated. Such external electrical power is provided to the signal conditioner circuitry mounted inside a musical instrument by using a conditioned signal output connector or jack mounted through the wall of the instrument, so no additional connectors or jacks are required.  
         [0011]     This is accomplished in two ways. In a first embodiment of the invention an electrical energy storage device is mounted on the musical instrument with the signal conditioner circuitry. Preferably, such energy storage device comprises a capacitor or a rechargeable battery that is electrically connected to the signal output connector or jack of the musical instrument. The energy storage device is charged by connecting a direct current (DC) power source that is external to the musical instrument to the connector or jack using a mating plug. When the energy storage device is charged the DC power source is unplugged from the connector or jack and one end of a signal cable is plugged into the jack. The other end of the signal cable is plugged into a remotely located amplifier, soundboard or other audio equipment in a manner known in the art. The signal from the musical instrument that has been processed by the signal conditioner circuitry is utilized by the amplifier, soundboard or other audio equipment in a manner known in the art.  
         [0012]     In a second embodiment of the invention, there is no electrical energy storage device mounted on the musical instrument along with the signal conditioner circuitry. Electrical power for the signal conditioner circuitry is input thereto from external to the musical instrument. A novel signal cable is plugged into the connector or jack of the musical instrument. This novel signal cable permits power from a DC power source external to the musical instrument to be input to the instrument via the connector or jack to provide electrical power to the signal conditioner circuitry. At the same time, the signal from the musical instrument that has been processed by the signal conditioner circuitry is output via the connector or jack and the same novel signal cable plugged therein, to be utilized by an amplifier, soundboard or other audio equipment.  
         [0013]     The external DC power source may be located with the amplifier, soundboard or other audio equipment and the DC power supplied via the novel signal cable, plug and jack to the signal conditioner circuitry inside or otherwise on the musical instrument. Preferably, a novel plug on the end of the signal cable that is plugged into the connector or jack through the wall of the musical instrument is used to provide the electrical power to the signal conditioner circuitry. The novel plug has a housing that is grasped to insert the plug into or remove it from the instrument jack. Inside the housing is a small, replaceable battery. The battery is wired to the plug. The housing is removed whenever the battery is to be removed or replaced. When the plug is inserted into the connector or jack of the musical instrument, DC electrical power from the battery is supplied to the signal conditioner circuitry of the musical instrument. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     Reference is made to the accompanying drawings in which are shown illustrative embodiments of the invention, from which its novel features and advantages will be apparent, and wherein:  
         [0015]      FIG. 1  is a block diagram schematic of a first embodiment of electronic circuitry mounted on a musical instrument that is powered by a power source that is external to the instrument;  
         [0016]      FIG. 2  is a block diagram schematic of a second embodiment of the electronic circuitry mounted on the musical instrument that is powered by a power source that is external to the instrument;  
         [0017]      FIG. 3  is a side cutaway view of a 1/4 inch jack showing a battery mounted therein;  
         [0018]      FIG. 4  is a block diagram schematic of a third embodiment of the electronic circuitry and a rechargeable power source located on the musical instrument, wherein the electronic circuitry is powered by the rechargeable power source that is charged by a power source external to the instrument; and  
         [0019]      FIG. 5  is a block diagram schematic of a fourth embodiment of the electronic circuitry and the rechargeable power source located on the musical instrument, wherein the electronic circuitry is powered by the rechargeable power source that is charged by a power source external to the instrument.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     In the following detailed description of the invention reference is made to use with a musical instrument such as a guitar. However, it should be understood by those skilled in the art that the invention may be utilized in any application where: (a) a signal is generated within a piece of equipment that includes electrical circuitry, (b) the signal is conditioned by the electrical circuitry before exiting the piece of equipment, (c) it is inconvenient and/or difficult to access the interior of the equipment to replace a power source in the form of a battery that powers the electrical circuitry, and (d) the conditioned signal is output from the equipment via a jack or connector.  
         [0021]     While a jack  18  and a mating plug  19  are mentioned in the following description, other types of connectors may be utilized. Preferably, the plug  19  is a standard 1/4 inch stereo plug that plugs into a standard 1/4 inch jack  18 . In addition, only a three terminal plug and jack are described herein, but four terminal plugs and jacks may also be utilized.  
         [0022]     In  FIG. 1  is shown a block diagram schematic of a first embodiment of the invention wherein electronic circuitry including a signal conditioner  14  is located on a circuit board  11  on a musical instrument  10 , but is powered by an electrical power source  20  that is external to the instrument. There is a jack  18  of the type described in the previous paragraph mounted on the musical instrument  10 . There is also a plug  19  of the type described in the previous paragraph mounted on the end of a signal cable  21  that carries the conditioned signal to remote equipment such as an amplifier, soundboard or other audio equipment (not shown).  
         [0023]     Briefly, the musical instrument  10  generates an electrical signal indicated as signal source  1  that is input to and processed by the signal conditioner  14  before being output from the instrument  10  via the jack  18 . There is no source of electrical power mounted inside the instrument  10  for powering circuitry on the circuit board  11 . The electronic circuitry mounted on the musical instrument  10  is powered solely by the electrical power source  20  that is external to the instrument  10 . This eliminates the prior art problem of getting inside a musical instrument to remove or replace a battery.  
         [0024]     The plug  19  with a housing  12  is mounted on one end of the signal cable  21 . Plug  19 , with the housing  12  attached thereto, is grasped to insert plug  19  into or to remove plug  19  from jack  18 . Housing  12  is easily removable and inside the housing is a small, replaceable battery  20 . Battery  20  is preferably a small coin type 1.5 volt or 3.0 volt battery readily available in drugstores and department stores. The battery  20  is wired to plug  19  as shown. Housing  12  is removed whenever battery  20  is to be removed or replaced. When plug  19  is inserted into jack  18 , DC electrical power from battery  20  is supplied to signal conditioner  14  inside musical instrument  10  via power conditioner circuitry  15 .  
         [0025]     In more detail, battery  20  inside housing  12  is connected to plug  19  such that its first terminal is connected to the ring (R) contact of the plug, and its second terminal is connected to the sleeve (S) contact of the plug. The conditioned signal from musical instrument  10  exits the instrument on the tip (T) contact of plug  19  to be carried via cable  21  to a remote amplifier, soundboard or other audio equipment (not shown) to be used in a manner well known in the art.  
         [0026]     When plug  19  is plugged into jack  18 , battery  20  is thereby connected between the R contact and the S contact of jack  18 . As seen in  FIG. 1 , this connects battery  20  to the power conditioner  15  on circuit board  11  inside instrument  10 . Power conditioner  15  is any type of DC-DC converter used to convert the voltage of battery  20  to a higher voltage as may be needed by signal conditioner  14  to operate properly. The higher voltage is output from power conditioner  15  on a lead  16  to provide the necessary operating power to signal conditioner  14 .  
         [0027]     In the event that signal conditioner  14  can operate using the output voltage directly from battery  20  inside housing  12 , power conditioner  15  may be eliminated and the R contact of plug  19  is connected directly to the power input of signal conditioner  14  on the lead  16 .  
         [0028]     The signal from musical instrument  10  on leads  13  is input to signal conditioner  14 . Signal conditioner  14  may be as simple as a pre-amplifier, or it may perform other types of signal processing known in the art. The conditioned signal output from signal conditioner  14  passes through capacitor C 1  and resistor R 1  and is connected to the T contact of plug  19 . The conditioned signal then passes to the T contact of plug  19  and on to signal cable  21 .  
         [0029]     In  FIG. 2  is shown a block diagram schematic of a second embodiment of the invention wherein electronic circuitry on circuit board  111  includes signal conditioner  14  and is located inside a musical instrument  10  but is powered from an electrical power source  20  external to the instrument. There are many similarities between the first and second embodiments of the invention, but there are some key differences. One similarity is that housing  12  with plug  19  contains a battery  20  that is easily accessed to remove or replace the battery. Another similarity is that power conditioner  15  is a DC-DC converter that is utilized if signal conditioner  14  needs a higher voltage to operate than is supplied by battery  20 . Also, power conditioner  15 , resistor R 3  and capacitor C 2  may be eliminated if signal conditioner  14  can operate using the voltage supplied by battery  20  inside housing  12 .  
         [0030]     The primary difference between the first embodiment of the invention shown in  FIG. 1  and the second embodiment of the invention shown in  FIG. 2  is that the latter can pass two signals from instrument  10 . To do this, plug  19  and jack  18  are wired differently. Battery  20  is connected between the T contact and S contact of plug  19  with the positive contact of battery  20  being connected to the T contact. With this configuration, both the conditioned audio signal output from signal conditioner  14  and DC power from battery  20  are passed via the T contact of plug  19  and jack  18 . Capacitor C 1  is used to isolate the battery voltage on the T contact of jack  18  from the output of signal conditioner  14 .  
         [0031]     The circuitry on circuit board  11  and plug  19  inside instrument  10  can concurrently pass two separate signals on leads  13  and  23  from instrument  10  through plug  19  but only one of the two signals is conditioned by signal conditioner  14 . The first signal on leads  13  from instrument  10  is processed by signal conditioner  14  and exits instrument  10  via the T contact of jack  18 . Signal conditioner  14  may be as simple as a pre-amplifier or it may perform other types of signal processing known in the art.  
         [0032]     The second signal on the leads  23  from instrument  10  are not processed in any manner and exit instrument  10  via the R contact of jack  18  and plug  19 . Although not shown, a second signal conditioner could be added on circuit board  11  to condition the second signals on leads  23 . The two separate signals on the leads of a signal cable  24  are input to a remote amplifier, soundboard or other audio equipment (not shown) to be used in a manner well known in the art.  
         [0033]     In  FIG. 3  is shown a side cutaway view of a 1/4 inch jack with a battery mounted therein. Plug  19  has a tip (T) contact, a ring (R) contact and a sleeve (S) contact as previously described with reference to  FIGS. 1 and 2 . Housing  12  screws onto the rear of plug  19  in a manner well known in the art. As previously described, housing  12  is grasped to either insert plug  19  into or remove it from jack  18 . At the rear of housing  12  is an opening  52  into which cable  21  ( FIG. 1 ) or  24  ( FIG. 2 ) is inserted to be fastened to the T, R, and S leads of plug  19  in a manner well known in the art. The novel aspect of plug  19  and housing  12  is that a small circuit board  51  is attached to the rear of plug  19 , and on board  51  is battery  20 , which is held in place by a battery holder  50 . As previously described, battery  20  is preferably a small coin type 1.5 volt or 3.0 volt battery readily available in drugstores and department stores. When battery  20  is to be removed or replaced, housing  12  is unscrewed from the rear of plug  19  to access the battery. Housing  12  is then replaced.  
         [0034]     In  FIG. 4  is shown a block diagram schematic of a third embodiment of the invention where a power source  32  external to an instrument  30  is used to provide power to circuitry on circuit board  31  inside musical instrument  30 . More particularly, the external power source  32  is used to charge an energy storage device  38 , preferably in the form of a capacitor or a rechargeable battery, located on the musical instrument  30 . The electronic circuitry on the board  31  is in turn powered by the charged rechargeable power source  38 . Thus, the prior art need to frequently get inside instrument  30  to replace a non-rechargeable battery is eliminated.  
         [0035]     With this configuration a main difference is that external power from charger  32  is not applied to instrument  30  while a plug  34  on the end of a signal cable  37  is plugged into a jack  33  to output the conditioned audio signal from musical instrument  30 .  
         [0036]     More particularly, to charge the rechargeable battery  38  inside instrument  30  a charger  32  with a plug  35  is utilized. Charger  32  may comprise batteries or be an AC-DC converter. The positive potential of charger  32  is connected to the R contact of the plug  35  and the negative potential is connected to the S contact. During charging mode, the signal cable  37  cannot be plugged into the jack  33 , but plug  35  is plugged into jack  33 . As shown in  FIG. 4 , when charger plug  35  is plugged into jack  33 , the negative terminal of charger  32  is connected to the negative terminal of rechargeable battery  38  and the positive terminal of charger  32  is connected via diode a D 1  and a lead  41  to the positive terminal of charger  32 . The diode D 1  is connected so that current can pass through it to charge battery  38 . However, when charger  32  is unplugged from jack  33  and the plug  34  of signal cable  37  is plugged into jack  33  to output the audio signal from musical instrument  30 , diode DI will prevent the discharge of battery  38  over this same path. Charged battery  38  is connected to provide power to a power conditioner  39 .  
         [0037]     The power conditioner  39  is any type of DC-DC converter used to convert the voltage of battery  38  to a higher voltage as may be needed by a signal conditioner  43  to operate properly. In the event that the signal conditioner  43  can operate using the voltage output directly from battery  38 , power conditioner  39  may be eliminated and the positive terminal of battery  38  may be connected directly to the power input of signal conditioner  43 .  
         [0038]     The signal from musical instrument  30  is input to signal conditioner  43 . Signal conditioner  43  may be as simple as a pre-amplifier or it may perform other types of signal processing known in the art. The conditioned signal output from signal conditioner  43  is connected to the T contact of jack  33 . The conditioned signal then passes to the T contact of plug  34  and on to signal cable  37 .  
         [0039]     When battery  38  needs recharging plug  34  of signal cable  37  is unplugged from jack  33  and plug  35  of charger  32  is plugged into jack  33  for a sufficient time to recharge battery  38  in the manner described above.  
         [0040]     In  FIG. 5  is shown a block diagram schematic of a fourth embodiment of the invention where an electrical power source  32  external to instrument  30  is used to provide electrical power to circuitry on circuit board  31  inside musical instrument  30 . More particularly, as previously described with reference to  FIG. 4 , external power source  32  is used to charge an electrical energy storage device  38  which is preferably a capacitor or a rechargeable battery  38  that is located on the musical instrument  30 . The electronic circuitry on circuit board  31  is, in turn, powered by the rechargeable power source  38 . Thus, the prior art need to frequently get inside the instrument to remove or replace the battery is eliminated.  
         [0041]     There are many similarities between the third and fourth embodiments of the invention, but there are some key differences. One similarity is that both embodiments utilize a charger  32  with a plug  35 . Another similarity is that power conditioner  39  is a DC-DC converter that is utilized if signal conditioner  43  needs a higher voltage to operate than is supplied by rechargeable battery  38 . Also, power conditioner  39  may be eliminated if signal conditioner  43  can operate using the voltage supplied by battery  38  inside instrument  30 .  
         [0042]     Another similarity is that the external electrical power from charger  32  is not applied to musical instrument  30  while plug  34  on the end of Signal cable  37  is plugged into jack  33  to output the conditioned audio signal from musical instrument  30 .  
         [0043]     The primary difference between the third embodiment of the invention shown in  FIG. 4  and the fourth embodiment shown in  FIG. 5  is that the latter can concurrently pass two signals from instrument  30 . To accomplish this, plugs  34  and  35  and jack  33  are wired differently. Charger  32  is connected between the T contact and S contact of plug  35  with the positive contact of charger  32  being connected to the T contact. The capacitor C 1  is still used to isolate the voltage on the T contact of jack  33  of charger  32  from the output of signal conditioner  43  when charger plug  35  is plugged into jack  33 .  
         [0044]     When it is desired to recharge the rechargeable battery  38  inside instrument  30  the charger  32  with the plug  35  is utilized. During charging mode, plug  34  of signal cable  37  cannot be plugged into jack  33  because charger plug  35  is plugged into jack  33 . As shown in  FIG. 5 , when plug  35  is plugged into jack  33 , the negative terminal of charger  32  is connected to ground which is connected to the negative terminal of rechargeable battery  38 , and the positive terminal of charger  32  is connected via the electronic switch  26  to the positive terminal of battery  38 . Charged battery  38  is connected to provide power to power conditioner  39  which, in turn, provides converted power marked as V c  to signal conditioner  43 .  
         [0045]     Power conditioner  39  is any type of DC-DC converter used to convert the voltage of battery  38  to a higher voltage as may be needed by signal conditioner  43  to operate properly. In the event that signal conditioner  43  can operate using the voltage output directly from battery  38 , power conditioner  39  may be eliminated and the positive terminal of battery  38  connected to an electronic switch  26  which, in turn, is connected to the T contact of plug  35  and jack  33  would be connected directly to the positive terminal of battery  38 .  
         [0046]     Electronic switch  26  serves the following purposes. It prevents battery  38  from discharging through resistors R 1  and R 2  at the output of signal conditioner  43 . It also prevents loading down of the conditioned signal output from signal conditioner  43  by battery  38 . When plug  35  of charger  32  is plugged into jack  33  the output voltage of charger  32  is greater than the sum of the voltage drops across a diode D 2 , a zener diode Z 1 , V be  of a transistor T 1  and the voltage of battery  38 . Thus, the transistor T 1  is turned on and charging current flows into battery  38 . When charger  32  plug  35  is unplugged from jack  33 , and plug  34  of signal cable  37  is plugged into jack  33 , transistor T 1  in electronic switch  26 , is not conducting and the positive terminal of internal rechargeable energy source  38  is not connected to the T contact of jack  33  and the conditioned signal now present from signal conditioner  43 .  
         [0047]     The first audio signal on lead  13  from musical instrument  30  is input to signal conditioner  43 . Signal conditioner  43  may be as simple as a pre-amplifier or it may perform other types of signal processing known in the art. The conditioned first signal output from signal conditioner  43  is connected to the T contact of jack  33  via capacitor C 1  and the resistor R 1 . The conditioned signal then passes to the T contact of plug  34  and on to signal cable  37  for use at a remote location as previously described.  
         [0048]     The second signal from instrument  30  on lead  23  is not conditioned in any manner and exits instrument  10  via the R contact of jack  33 . Although not shown, a second signal conditioner could be added to circuitry of board  31  to process the second signal on lead  23 . The two separate signals on leads  37  are input to a remote amplifier, soundboard or other audio equipment (not shown) to be used in a manner well known in the art.  
         [0049]     While what has been described herein are four embodiments of the invention, it will be obvious to those skilled in the art that numerous changes may be made without departing from the spirit and scope of the invention. For example, four contact plugs and jacks may be used in lieu of the three contact plugs and jacks described herein. Also, the unconditioned second signals in  FIGS. 2 and 5  may be conditioned by adding an additional signal conditioner. Further, in the drawings, the aforesaid first terminal is depicted as positive and the second terminal is depicted as negative; however, it will be apparent that the first terminal could be negative and the second terminal could be positive and the respective circuits modified accordingly, to obtain the same result.