Abstract:
Power supply equipment includes an adapter which converts power from a power source to DC power for powering an electronic device. The power supply equipment includes circuitry which produces a data signal for use by the electronic device to control power drawn by the electronic device. A cable, extends from the adapter. The power supply equipment further includes a tip which has an input side and an output side. The input side of the tip is detachable mateable to the cable. The output side of the tip is detachably mateable to the electronic device. The tip output side has a shape and size dependent on the shape and size of a power input opening of the electronic device. The tip provides the data signal, as well as the DC power, to the electronic device. Different tips may be used to provide appropriate data signals to different electronic devices.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a divisional of co-pending application Ser. No. 13/461,149, filed on May 1, 2012; which is a continuation-in-part of application Ser. No. 13/209,636, filed on Aug. 15, 2011, now U.S. Pat. No. 8,330,303, issued on Dec. 11, 2012; which is a continuation of application Ser. No. 12/840,952, filed on Jul. 21, 2010, now U.S. Pat. No. 7,999,412 issued on Aug. 16, 2011; which is a continuation of application Ser. No. 11/604,950, filed on Nov. 28, 2006, now U.S. Pat. No. 7,868,486 issued on Jan. 11, 2011; which is a continuation-in-part of application Ser. No. 10/758,933, filed on Jan. 15, 2004, now U.S. Pat. No. 7,453,171 issued on Nov. 18, 2008. Each of the preceding patents and applications is herein incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    This invention relates to DC power adapters for powering electronic devices. 
         [0004]    2. Description of the Related Arts 
         [0005]    There are power systems in the art which allow a user to hook up a DC/DC adapter to an automobile outlet, to supply regulated DC power to power an electronic device, such as a notebook computer. Automobile outlets typically provide a DC voltage in a range between 11.0 and 14.1 Volts. Some power systems also allow the user to hook up the DC/DC adapter to an airplane output such as the EMPOWER system. EMPOWER typically provides a DC voltage in a range between 14.5 and 15.5 Volts. 
         [0006]    Accordingly, some DC/DC adapters can be used with both an automobile outlet and the EMPOWER system to provide a regulated DC power to the electronic device such as the notebook computer. Notebook computers often contain lithium ion batteries. Such batteries can be recharged when the notebook computer is hooked up to the DC/DC adapter. For example, if the user is in a car, the user can couple a DC/DC adapter to the notebook computer and to the cigarette lighter outlet to power the notebook computer. The batteries in the notebook computer will draw some of the DC power supplied to recharge the batteries of the notebook computer if they are low in power. Accordingly, the user can simultaneously use the notebook computer and recharge the batteries therein. 
         [0007]    The user can also use the DC/DC adapter while on an airplane, by plugging the DC/DC adapter into the EMPOWER outlet. The EMPOWER outlet and the automobile outlets have different sizes and shapes. Accordingly, the user can directly plug the DC/DC adapter into the EMPOWER outlet, and can place a connector over the EMPOWER plug of the DC/DC adapter and then plug the connector into the automobile cigarette lighter outlet. When the user hooks the DC/DC adapter up to the EMPOWER outlet and then to the electronic device, the electronic device receives the regulated DC power. However, if the charging circuitry in the battery malfunctions, the battery can overheat or even catch on fire when recharging from an EMPOWER DC source. If the battery were to catch on fire while an airplane in which the emPlower outlet is located is flying, the fire would have the potential to cause the airplane to crash or cause substantial damage. 
         [0008]    To address this problem, one system in the art provides a connector to connect between the DC/DC adapter and the notebook computer to inform the notebook computer not to recharge the batteries.  FIG. 1  illustrates a power supply system according to the prior art. As shown, a DC power source  100  is coupled to a DC/DC adapter  105  via a cable  102 . The DC/DC adapter  105  receives power from the DC power source  100  and outputs regulated DC power to an electronic device  120 , via a cable  110  and a connector  115  coupled to the end of the cable  110 . 
         [0009]    The DC/DC adapter  105  can provide three output pins to the electronic device  120 , as shown in  FIGS. 2A and 2B  of the prior art. The first pin can provide the output voltage (i.e., Vout), the second pin can provide a ground reference (i.e., GND), and the third pin can provide a data line (i.e., Vdata) to instruct the notebook as to whether the batteries should be recharged or not. For example, as shown in  FIG. 2A , Vdata could be tied to GND to indicate that the DC power source  100  is the EMPOWER system and therefore the battery should not be recharged. Alternatively, as shown in  FIG. 2B , Vdata could also be left open (i.e., to provide a non-grounded floating voltage) when the DC power source  100  in a cigarette lighter outlet of an automobile. Accordingly, when using the DC/DC adapter  105  while in an automobile, the user would use a connector  115  having the Vdata line floating, and when using the DC/DC adapter  105  with the EMPOWER system of an airplane, the user would use a connector  115  having the Vdata line tied to GND. 
         [0010]    However, problems arise when the user forgets to change the connector  115  for use with the automobile when the user is in an airplane. Accordingly, if the user has the wrong connector  115  attached when using with the EMPOWER system, a battery of an electronic device  120  such as a notebook computer can charge the battery even when used with the EMPOWER system, and if the charging circuitry of the battery malfunctions, overheating or even a fire can occur, resulting in damage to the notebook computer. Also, if the connector  115  is damaged or flawed, then it may not provide the correct Vdata signal to the notebook computer, allowing the notebook computer to recharge the batteries in an airplane when they shouldn&#39;t be allowed to do so. 
         [0011]    Accordingly, current DC/DC power adapter systems are deficient because they are incapable of automatically and intelligently informing an electronic device  120  coupled thereto of the DC power source (i.e., the EMPOWER system or an automobile cigarette lighter outlet). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  illustrates a power supply system according to the prior art; 
           [0013]      FIG. 2A  illustrates a first connector to coupled a power supply system to an electronic device according to the prior art; 
           [0014]      FIG. 2B  illustrates a second connector to coupled a power supply system to an electronic device according to the prior art; 
           [0015]      FIG. 3  illustrates a power supply system according to an embodiment of the invention; 
           [0016]      FIG. 4A  illustrates a tip having digital control circuitry according to an embodiment of the invention; 
           [0017]      FIG. 4B  illustrates a tip having analog control circuitry according to an embodiment of the invention; 
           [0018]      FIG. 5A  illustrates comparison circuitry according to an embodiment of the invention; 
           [0019]      FIG. 5B  illustrates comparison circuitry according to an additional embodiment of the invention; 
           [0020]      FIG. 6  illustrates an electronic device according to an embodiment of the invention; 
           [0021]      FIG. 7A  illustrates a method of determining and outputting Vdata according to an embodiment of the invention; 
           [0022]      FIG. 7B  illustrates a method of receiving Vdata and allowing power to flow to devices within the electronic device based on Vdata according to an embodiment of the invention; and 
           [0023]      FIG. 8  illustrates a power supply system according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    An embodiment of the present invention is directed to a power supply system to determine a DC power source (e.g., an automobile cigarette lighter outlet or an EMPOWER airplane outlet) coupled thereto and send a signal indicative of the power source to an electronic device coupled thereto. The electronic device may be a notebook computer or other portable consumer electronic device, for example. Based on the signal sent to the electronic device, the electronic device may control the amount of power drawn to prevent overheating. For example, when a notebook computer is hooked up and the power source is the EMPOWER system, the electronic device may disable charging of the internal batteries of the notebook computer, in order to prevent damage or overheating of the batteries due to malfunction or failure. The DC power source may be determined by voltage comparison circuitry, such as a comparator, or by a voltage comparison device including a processor. 
         [0025]      FIG. 3  illustrates a power supply system  301  according to an embodiment of the invention. As shown, the adapter  340  may be used with an AC power source  300  or a DC power source  305 . In other embodiments, only a DC power source  305  may be utilized to supply power. The AC power source  300  may be coupled to an AC/DC adapter  310  via a cable  342 . The DC power source  305  may be coupled to both a DC/DC adapter  315  and comparison circuitry  320  via a cable  345 . The DC power source  305  may be an automobile&#39;s cigarette lighter outlet or an airplane&#39;s EMPOWER system outlet, for example. AC/DC adapter  310  may convert AC power from the AC power source  300  into regulated DC power, which is supplied to post-regulation circuitry  325 . The post-regulation circuitry  325  may provide an output voltage (Vout) and a ground reference (GND) to a tip  330  coupled to the adapter  340  via a cable  350 , as further explained below with respect to  FIGS. 4A and 4B . The tip  330  may be coupled to an electronic device  335  to provide the power thereto from the power supply system  301 . The tip  330  may be removable from the cable  350  and may be inserted into a power input opening of the electronic device. Tips  330  may have different shapes and sizes, depending up the shape and sizes of the power input openings of the respective electronic devices  335  being powered. The tip  330  may also include control circuitry  365  to provide a signal to control circuitry  370  of the adapter  340 . The signal may be sent to the control circuitry  370  via the cable  350 . In one embodiment, the control circuitry  365  of the tip  330  may include digital components to provide a digital signal to the control circuitry  370  of the adapter  340 . The digital signal may be utilized to set the magnitude of Vout and limit the amount of current which may be drawn from the adapter  340 . The post-regulation circuitry  325  regulates the voltage to what the tip  330  tells it to provide. 
         [0026]    Alternatively, the tip  330  may include analog components and may provide voltage programming and current programming voltages (V Vprogram  and V Iprogram , respectively) to the adapter  340 . V Vprogram  may be utilized to set the magnitude of Vout. For example, there may be a linear relationship between V Vprogram  and Vout where Vout is 3 times as large as V Vprogram . program. Accordingly, if V Vprogram  had a magnitude of 3.0 Volts, Vout would have a magnitude of 9.0 Volts, and if V Vprogram  had a magnitude of 2.0 Volts, Vout would have a magnitude of 6.0 Volts. The analog circuitry may contain passive or active components. 
         [0027]    Accordingly, regardless of whether the tip  330  has analog or digital control circuitry, a single adapter  340  may be used to supply power to a plurality of different electronic devices  335  having different power requirements. 
         [0028]    The adapter  340  may also include comparison circuitry  320 . The comparison circuitry  320  may compare a magnitude of a voltage received from the DC power source  305  with a reference voltage to determine whether the DC power source  305  is an automobile cigarette lighter outlet or an EMPOWER airplane outlet. As stated above, automobile cigarette lighter outlets typically provide a DC voltage having a magnitude within the range of 11.0 Volts and 14.1 Volts. An EMPOWER airplane outlet typically provides a DC voltage having a magnitude within the range of 14.5 and 15.5 Volts. Accordingly, the reference voltage may be set at a level between the high end of the automobile cigarette light outlet voltage (i.e., 14.1 Volts) and the low end of the EMPOWER airplane outlet voltage (i.e., 14.5 Volts). For example, the reference voltage may be set at 14.3 Volts. Accordingly, if the magnitude of the DC power source is greater than 14.3 Volts, then the comparison voltage may determine that the received DC voltage has a greater magnitude than the reference voltage and the DC power source  305  is therefore the EMPOWER airplane outlet. However, if the magnitude of the DC power source is less than 14.3 Volts, then the comparison voltage may determine that the received DC voltage has a smaller magnitude than the reference voltage and the DC power source  305  is therefore the automobile cigarette lighter outlet. 
         [0029]    The comparison circuitry  320  may output a signal Vdata based upon whether the DC power source is determined to be the automobile cigarette lighter outlet or the EMPOWER airplane outlet. For example, the comparison may output 5 Volts if the automobile cigarette lighter outlet is detected, and 0.0 Volts if the EMPOWER airplane outlet is detected. In alternative embodiments, different voltages for Vdata may be used. In additional embodiments, the comparison circuitry  320  may output a digital signal, such as a stream of bits, indicative of the DC power source  305 . Vdata may be sent via cable  350  to the tip  330 , and straight over to the electronic device  335 . The electronic device  335  may include a controller  360  which is responsive to Vdata. For example, if the electronic device  335  is a notebook computer and Vdata is indicative of the EMPOWER airplane outlet system, the controller  360  may disable battery charging circuitry  600 , thereby preventing recharging of the batteries. And if the Vdata is indicative of the automobile cigarette lighter outlet as the DC power source  305 , the controller  360  may enable battery charging circuitry to allow the batteries to be recharged. 
         [0030]    Although  FIG. 3  illustrates an adapter  340  which includes both a AC/DC adapter and a DC/DC adapter, other embodiments may include only a DC/DC adapter, and no AC/DC adapter. 
         [0031]      FIG. 4A  illustrates a tip  400  having digital control circuitry  402  according to an embodiment of the invention. As shown, the tip  400  receives Vdata, Vout and GND from the adapter  340  and allows them to all flow to the electronic device  335 . The digital control circuitry  402  may receive the Vout and GND signals and may output a control signal to the adapter  340  to set the magnitude of Vout and limit the current provided. The control signal may be sent to the adapter  340  via the cable  350  between the tip  400  and the adapter  340 . The digital control circuitry  402  may include a processor and a memory device, for example. In some embodiments, the tip  400  may be separable from cable  350 , and in other embodiments, the tip  400  may be physically part of the cable  350 . 
         [0032]      FIG. 4B  illustrates a tip  405  having analog control circuitry  410  according to an embodiment of the invention. As shown, the tip  405  receives Vdata, Vout and GND from the adapter  340  and allows them to all flow to the electronic device  335 . The analog control circuitry  410  may receive the Vout and GND signals and may output V Vprogram  and V Iprogram  to the adapter  340 . V Vprogram  and V Iprogram  may be sent to the adapter  340  via the cable  350  between the tip  405  and the adapter  340 . The analog control circuitry  400  may include passive or active components, for example. In some embodiments, the tip  400  may be separable from cable  350 , and in other embodiments, the tip  400  may be physically part of the cable  350 . 
         [0033]      FIG. 5A  illustrates comparison circuitry  320  according to an embodiment of the invention. As shown, the comparison circuitry  320  includes a comparator  500 . The comparator  500  receives (a) the DC power signal from the DC power source  305 , and (b) a reference voltage, Vref. The comparator outputs Vdata based on whether the magnitude of the DC power from the DC power source exceeds Vref, as described above with respect to  FIG. 3 . 
         [0034]      FIG. 5B  illustrates comparison circuitry  320  according to an additional embodiment of the invention. As shown, the comparison circuitry  320  includes a processor  505 . The processor  505  receives (a) the DC power signal from the DC power source  305 , and (b) value of a reference voltage stored in memory. The processor  505  then outputs Vdata based on whether the magnitude of the DC power from the DC power source exceeds Vref, as described above with respect to  FIG. 3 . The processor  505  may output a single high or low voltage (e.g., 5.0 Volts or 0.0 Volts) based on the detected DC power source. Alternatively, the processor  505  may output a stream of bits to indicate the DC power source. 
         [0035]      FIG. 6  illustrates an electronic device  335  according to an embodiment of the invention. As shown, the electronic device  335  may receive GND, Vout and Vdata from the tip  330 . Vdata may be received by a controller  360 . The controller  360  may disable battery charging circuitry  600  of the electronic device  335  from charging batteries when Vdata is indicative of the EMPOWER outlet. Alternatively, the controller  360  enables battery charging circuitry  600  so that the batteries of the electronic device may be charged based on the value of Vdata. 
         [0036]      FIG. 7A  illustrates a method of determining and outputting Vdata according to an embodiment of the invention. The processing shown in  FIG. 7A  may be implemented by the adapter  340 . First, DC power is received  700  from the DC power source  305 . Next, the comparison circuitry determines  705  whether the magnitude of the voltage of the DC power received is greater than Vref. If “no,” the comparison circuitry determines the DC power source  305  to be an automobile cigarette lighter outlet, and processing proceeds to operation  710 , where Vdata is output with a signal/voltage magnitude indicating that the DC power source  305  is the automobile cigarette lighter outlet. Processing then returns to operation  700 . If “yes,” at operation  705 , processing proceeds to operation  715 , where Vdata is output with a signal/voltage magnitude indicating that the DC power source  305  is the EMPOWER airplane outlet. 
         [0037]      FIG. 7B  illustrates a method of receiving Vdata and allowing power to flow to devices within the electronic device  335  based on Vdata according to an embodiment of the invention. First, the electronic device  335  receives  720  the Vdata signal. As discussed above, the Vdata signal is sent from the adapter  340  through the tip  330  and over to the control circuitry  365  of the electronic device  335 . Next, based on the Vdata signal, a first set of predetermined devices may be prevented  725  from receiving power. For example, if the electronic device  335  is a notebook computer, the control circuitry  365  may prevent batteries from recharging if Vdata indicates that the DC power source is the EMPOWER airplane outlet. Other devices/components in the electronic device  335  may also be prevented from receiving power or from functioning in a certain way. 
         [0038]    At operation  730 , a second set of predetermined devices may be allowed to receive power based on the Vdata signal. For example, if Vdata indicates that the DC power source is an automobile cigarette lighter outlet, then power may be available to batteries of the electronic device  335  to allow recharging. Other devices/components in the electronic device  335  may also be allowed to receive power or function in a particular way. 
         [0039]    In embodiments described above, the Vdata signal may be used to send a signal to the control circuitry  365  indicating the DC power source. This signaling may be done via a discrete bit, an analog signal, a data signal line, an analog voltage, or via any other suitable manner. The Vdata signal may be transmitted from the adapter  340  to the tip  330  and electronic device  335  via a single signaling line or multiple signaling lines. 
         [0040]      FIG. 8  illustrates a power supply system  800  according to an embodiment of the invention. The power supply system  800  is similar to the power supply system  301  shown in  FIG. 3 . However, unlike the power supply system  301 , in which the adapter  340  itself contains comparison circuitry  370 , the adapter  340  of power supply system  800  does not contain the comparison circuitry  805 . Instead, a regular adapter  340  may be used and the electronic device  335  itself includes the comparison circuitry  805  for determining the DC power source. The electronic device  335  may be a notebook computer and may implement the methods shown in  FIGS. 7A and 7B . 
         [0041]    While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.