Abstract:
The present invention provides a powered speaker, such as a subwoofer that may be turned on and off remotely by energizing the auxiliary AC power supply provided with an audio device or other source unit. The main power of the powered subwoofer is provided via a wall outlet or suitable power supply that may adequately supply the necessary power.

Description:
FIELD OF THE INVENTION 
     This invention relates to audio equipment, and more particularly to a powered speaker having a remote turn on function. 
     BACKGROUND OF THE INVENTION 
     In audio/visual equipment, powered subwoofers, the speakers dedicated to creating the low-frequency (bass) audio critical in multichannel movie soundtracks like Dolby Digital 5.1, 7. 1, and DTS 5.1, 6.1, and 7.1, as well as music, have become extremely popular. Such a subwoofer typically receives a line-level audio signal from a source unit, such as a receiver, preamplifier, processor, or a combination thereof, and amplifies it with an internal amplifier. As such, these powered subwoofers have an electrical cord that is plugged into a standard household electrical outlet that supplies the internal amplifier with electricity. 
     Additionally, powered loudspeakers, which operate in a similar fashion as powered subwoofers but use one or more internal amplifiers to power all audio frequencies including the mid-range and higher (treble) pitches, have similar power characteristics although they are not as popular in the consumer market. Collectively, the powered loudspeakers and subwoofers are referred to as powered speakers or devices. 
     Problems arise, though, when turning the devices on and off. Ideally, powered speakers should be energized when, and only when, the source unit is also energized. However, more typically, the user is expected to manually turn these devices on and off each time they want to use them. Because this can be burdensome in some situations, the device&#39;s settings are typically ignored by users once they are initially set up and the audio output is configured. 
     As powered speakers or devices are currently configured, they may be manually left on or off. If the device is left on at all times, unnecessary consumption of energy, unwanted ambient noise when the system is not being used, and potential damage to the electrical components within the device may result. Further, leaving the powered speaker on may emit excess heat resulting in discomfort to the user, or diminishing the performance of neighboring equipment. If the device is left off, the device will often be suboptimally used as owners will forget to turn it on. 
     Certain conventional devices also have an “auto” setting which will power the device upon receiving an audio input and will typically stay on until the input has ceased for a certain length of time. However, because a powered speaker or device requires a few seconds to warm up, it will not be able to reproduce the first few seconds of audio input and, in the case of a short duration sound input (such as a movie sound effect), the device will not reproduce it at all. Conversely, after being turned on by audio input, powered speakers and devices may remain on for a significant and unnecessary length of time, which, again, may lead to unwanted ambient noise, energy consumption and potential damage to the internal circuitry. 
     Therefore, powered speakers and devices that are immediately energized or de-energized at the same time as the source unit are desired. Since powering the device based on audio input is too late to be completely effective, it would be desirable to coordinate energizing the device with the energizing of the source unit. 
     U.S. Pat. No. 6,744,150 to Rendic, issued Jun. 1, 2004, discloses an “outlet strip controlled by PC using low voltage powertap.” Specifically, Rendic discloses a 110V AC power strip that will allow electrical current to any individual component plugged into it only upon receiving a 5V electrical input signal from a directing terminal via a low voltage connection such as a USB port. This device, however, is designed to use the low voltage conduits that are typical in computers as the input signal and would not be able to support a relatively high voltage input signal (typically 110V) that would come from a source device such as a stereo. Also, this reference is not designed to be internal to the powered speaker or device but is instead an external accessory with additional features such as a fuse or a circuit breaker, which would lead to potentially significant additional costs and less free space. Whatever the precise merits of this and other references, it does not achieve or fulfill the purposes of the present invention. 
     Therefore, a powered speaker that turns on only when the source unit is on is desired. Further, a powered speaker with reduced equipment wear and power consumption is desired. 
     SUMMARY OF THE INVENTION 
     The present invention provides a powered speaker, such as a subwoofer that may be turned on and off remotely by energizing the auxiliary AC power supply provided with an audio device or other source unit. The main power of the powered subwoofer is provided via a wall outlet or suitable power supply that may adequately supply the necessary power. 
     An embodiment of the invention comprises a powered speaker having an internal electrical relay. The relay includes an electromagnet in electrical communication with an actuation circuit. An actuation input is in electrical communication with the actuation circuit, wherein the actuation input is connectable to a switched output that is associated with an audio source unit. A manual switch selectively opens and closes the actuation circuit. A continuous power input is in electrical communication with an amplifier circuit, wherein the relay selectively opens and closes the amplifier circuit. An integral audio transducer is in electrical communication with the amplifier circuit. 
     Another embodiment of the present invention comprises a powered speaker, such as a subwoofer having an integral relay device for turning the powered speaker on and off. The integral relay device includes a pair of inputs. The device power input provides the power needed to energize the speaker and a plug means that plugs directly into a wall outlet or any suitable power source. The second input or the relay input comprises a plug means and plugs directly into the auxiliary power outlet provided on a device such as an audio receiver. The relay input utilizes the AC current provided from the auxiliary power output to energize the coil of the integral relay, thereby closing the relay and permitting the wall power to be feed directly to the powered speaker. Alternatively, the second input is in communication with a 12V DC remote turn-on lead and the relay utilizes the DC current to activate the relay. 
     The present invention operates by turning a powered speaker on and off, wherein said relay has a first input for receiving suitable AC power and a second input for actuating the contactor/relay. The method comprises the steps of plugging a first input into a wall AC outlet or suitable power supply, plugging a second input into the auxiliary power output of an audio receiver, energizing and de-energizing said audio receiver so that the auxiliary power source can turn on and off respectively, actuating and deactivating said relay/contactor, and turning the powered speaker on and off respectively. 
     An advantage of the present invention is a reduction in power consumption because the powered speaker turns on only when the source unit is on, and turns off immediately upon de-energizing the source unit thereby minimizing on time to time that the device is actually in use. Another advantage of the present invention is that the internal electronics of the powered speaker are powered up before any audio signals are sent to the unit. Therefore, the invention eliminates the delay of audio reproduction that occurs when a conventional unit is powering up after being actuated by the audio signal it is to reproduce. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is disclosed with reference to the accompanying drawings, wherein: 
         FIG. 1  is a schematic of the of the powered speaker of the present invention and other components in an audio system; and 
         FIG. 2  is a electrical schematic of the powered speaker of  FIG. 1 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The examples set out herein illustrate several embodiments of the invention but should not be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , there is shown the improved powered speaker  102  of the present invention and other components in an audio system  100 . In addition to the powered speaker  102 , the audio system  100  includes a source unit  114 . The figure also includes a household electrical outlet  112 , that serves to provide power to both the powered speaker  102  and the source unit  114 . For the purpose of this specification, the term powered speaker is to be understood to include powered subwoofers, powered loudspeakers, and other powered audio transducers. 
     The powered speaker  102 , shown schematically in  FIG. 2 , includes an input  104  for receiving an actuation current, an input  105  for receiving the continuous power necessary to power the powered speaker  102 , and the audio speaker input  106 . In the illustrated embodiment, the actuation input  104  is a AC power plug. The input line  108  includes a receptacle  118  for engaging the actuator input  104  and a AC plug  120  on the opposing end of the input line  108  to engage a 110V switched outlet receptacle  116  on the source unit  114  ( FIG. 1 ). An additional embodiment is contemplated wherein the input line  108  is hardwired to the powered speaker  102 . In the present invention, AC power is provided to the switched outlet receptacle  116  when the source unit  114  is turned on. Some source units  114 , especially high-end audio equipment, include a remote turn-on lead output  116 ′ that sends a 12VDC current over a remote lead line  108 ′ to an alternative actuation input  104 ′. The remote lead line  108 ′ engages the alternative actuation input  104 ′ and the remote turn-on lead output  116 ′ with ⅛ th -in jacks. According to the present embodiment, the powered speaker  102  may include the actuation input  104 , the alternative actuation input  104 ′, or both. 
     The power is supplied to the continuous power input  105  via a power cord  110  having a plug  122  that engages the household electrical outlet  112 . As shown in  FIG. 1 , the audio input  106  is in electrical communication with a audio output  124  on the source unit  114  via a line level cable  126 , which includes ⅛ th -in jacks. 
     Referring to  FIG. 2 , the powered speaker  102  further includes a three-position switch  128 , a relay  130 , an amplifier  132  that is in electrical communication with the audio input  106 , and an audio transducer  134 . The switch  128  includes an off position  128   a , a remote position  128   b , and an on position  128   c . When the switch  128  is in the remote position  128   b , the actuation circuit is closed and the actuation input  104  is in electrical communication with an electromagnet side  131  of the relay  130  via a transformer  136   a , which converts a 110VAC current to a 12VDC current. The alternative 12VDC actuation input  104 ′ is also in electrical communication with the electromagnet side  131  of the relay  130  when the switch  128  is in the remote position  128   b , however, the alternative actuation input  104 ′ bypasses the transformer  136   a.    
     When the switch  128  is placed in the on position  128   c , the actuation bypass circuit is closed and the power input  105  is in electrical communication with the electromagnet side  131  of the relay  130 . The 110VAC current from the power input  105  is converted to a 12VDC current prior to being passed to the electromagnet side  131  of the relay  130  by a transformer  136   b . In this position, the relay  130  receives an actuation current regardless of whether the source unit  114  is activated as long as the power cord  110  is connected to power, such as by being plugged in to the electrical outlet  112 . 
     When a 12VDC current is passed through the electromagnet side  131  of the relay  130  from either the actuation circuit or the actuation bypass circuit, the electromagnet is energized, and an armature in the relay  130  closes the amplifier circuit, placing the power input  105  in electrical communication with the amplifier  132 . The amplifier  132  amplifies any signal from the audio input  106  and powers the transducer  134 . When the switch  128  is in the off position  128   a , the actuation circuit and the actuation bypass circuit are open and substantially no 110VAC power is supplied to the amplifier  132 . 
     In operation, the AC plug  120  is plugged into switched outlet receptacle  116  of the source unit  114 . The receptacle  118  on the opposing end of the contactor input line  108  is plugged into the actuator input  104 . This configuration serves to provide the power necessary to energize the relay  130  located within the powered speaker  102 . The AC power that is provided to the powered speaker  102  enters the powered speaker  102  through power cord  110 . The plug  122  is plugged into electrical outlet  112 , as illustrated in  FIG. 1 . 
     The user moves the switch  128  to the remote position  128   b  to allow the powered speaker  102  to be actuated by the source unit  114 . When a 110VAC current is provided to the switched outlet  116  by the source unit  114 , usually when the user turns on the source unit  114 , the current is carried to the actuation input  104  by the input line  108 . Since the actuation circuit is closed by the switch  128 , the current is converted to a 12VDC current by the transformer  136   a  and passes through the electromagnet side  131  of the relay  130 . Alternatively, a 12VDC actuation current is passed through the remote lead line  108 ′ to the alternative actuation input  104 ′, which is in electrical communication with the actuation circuit. The energized relay  130  closes the amplifier circuit, thereby providing power to the amplifier  132 . The line level or subwoofer audio signal from the source unit  114  is communicated to the amplifier  132  through the audio cable  126  and the amplifier  132  amplifies the audio signal using power supplied by the amplifier circuit. The current between the amplifier  132  and the audio transducer  134  is at speaker level voltage, such as 50VDC. Because the powered speaker  102  is energized before an audio signal is sent by the source unit  114 , performance is improved by assuring that a portion of the audio signal will not be lost due to a lag in turn on time. 
     Additionally the relay  132  is de-energized by removing or otherwise ceasing the flow of current to the actuation side  131 . This de-energizing step is achieved by selectively turning off the source unit  114 , and thereby removing power from the AC switched outlet  116 . The de-energized relay  132  opens the amplifier circuit thereby shutting off the powered speaker  102 . Therefore, when the switch  128  is in the remote position  128   b , the operator is not required to manually turn off the powered speaker  102 . Further, the speaker  102  does not remain on for several hours after it is no longer needed. The powered speaker  102  thereby avoids excessive power consumption and introduction of heat to the area where they are contained. Additionally, because the source unit  114  may include a remote control device that serves to turn the unit on and off, among other things, the powered speaker  102  used in the present invention may take advantage of the remote control device and be remotely turned on and off by the user. 
     While the invention has been described with reference to particular embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention. 
     Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims.