Computer power connection device

Abstract

A computer power connection device 50 comprising: a three-way connection 54; a DC source cable 51 extending from a DC input plug P1 to the three-way connection; a DC output cable 52 extending from the

Description

22 04 Field of Invention The present invention relates to a computer power connection device. 5 Background Some computers are sold with a power supply which converts Mains AC electricity into DC electricity to be used by the computer, and which also supplies a verification signal to the computer on a third wire which indicates that the power supply meets certain technical standards relating, for example to the voltage of the power supply, to the earthing of the 10 power supply, to the maximum power that it can supply, and the like. The computer's performance is throttled if no verification signal is received in order to protect the computer and the power supply from damage in case the power supply is not compatible with the demands of the computer. While laptop computers with an integrated battery enable the use of a computer when not 15 connected to a Mains power source, there is a need for computers which are not laptops and which do not Include an integrated battery to be used when not connected to a Mains power source. Examples of this need Include computers mounted in wheeled computer workstations which are used in hospitals so that the computer can be moved to a patient, or in a factory so that the computer can be moved to a workstation or workpiece. There 20 are many reasons why a laptop is unsuitable, for example where a laptop screen is inappropriate for the computer's use, such as displaying high resolution or large images, or the keyboard is inappropriate for the computer's use, such as inputting data which cannot be entered In text form. An aim of the present invention is to enable an improved computing system in which non-25 laptop computers can be used, without being connected to a Mains power source, on battery power without being throttled. Summary of Invention According to a first aspect of the invention, a computer power connection device comprises: a 3-way connection; a DC source cable extending from a DC input plug to the 30 3-way connection; a DC output cable extending from the 3-way connection to a DC supply plug; a verification cable extending from the 3-way connection to a verification connector for connection to the power output of an unpowered power supply unit; a verification signal wire extending from the verification connector through the verification cable, through the 22 04 DC output cable to the DC supply plug; a DC power wire extending from the DC input plug through the DC source cable, and through the DC output cable to the DC supply plug; and a ground wire through the cables connecting the DC input plug and the DC supply plug. 5 The ground wire may additionally extend through the verification cable to the verification connector plug. According to a second aspect of the invention, a method of connecting a computer to a DC power source comprises: connecting a DC power wire and a ground wire between the DC 10 power source and the computer; and connecting a verification signal wire between a verification port of the computer and a port of an unpowered power supply unit of a type having circuitry to emit a verification signal on the verification signal wire when it has received a request to supply it. 15 Preferably, the method further comprises connecting the ground wire to the verification port of the unpowered power supply. Brief Description of the Drawings The present disclosure will now be described by way of example only with reference to the accompanying drawings in which: 20 Figure 1 is a schematic drawing of the electrical connection of devices of a wheeled computing workstation according to a first aspect of the invention; Figure 2 is a view of a power connection device of the wheeled computing workstation shown in Figure 1; and Figure 3 is a schematic electrical connection diagram for the power connection device 25 shown in Figure 2. Detailed Description: Figure 1 is a schematic drawing of a wheeled computing workstation 40 comprising a computer 44, a monitor 45 and a power supply unit 46 for the computer. Since the 30 workstation is wheeled, it needs to be able to operate whilst not plugged into a mains power supply. To permit this, the monitor 45 includes a battery 49 for powering the monitor 45 and for powering the computer 44. The battery 49 is preferably made up of three rechargeable batteries which can Individually be removed from the monitor for recharging. The power supply unit 46 is the standard power supply unit for converting 22 04 mains AC electricity into DC power for the computer 44. However, in this application, although the power supply is present, it is unpowered because it is not plugged into the mains power supply. 5 The computer 44 is one which will only operate if it is powered by an approved manufacturer's power supply unit, such as the power supply unit 46 plugged into the mains power supply. In this type of computer, the power supply cable which is normally connected between the computer 44 and the mains-powered power supply unit 46 includes a third wire for transmission of data between those devices. The computer 44 starts 10 communication with the mains-powered power supply unit 46 down the third wire, and circuitry within the mains-powered power supply unit 46 replies to the computer 44 in a verification signal through the third wire to identify characteristics of the mains-powered power supply unit 46. For example, it might identify charger characteristics such as maximum power, current, voltage and other appropriate things associated with the 15 operation of the mains-powered power supply unit 46. The computer will refuse to accept power from the mains-powered power supply unit 46 if it does not meet specified criteria, or will throttle its performance. Figure 2 is a drawing of the power connection device 50. The following text describes 20 Figures 1 and 2 together. A power connection device 50 is connected between the monitor 45, the computer 44 and the un-powered power supply unit 46 in order to power the computer 44 from the battery 49 of the monitor 45. To achieve this, the power connection device 50 comprises three cables, a DC source cable 51, a DC output cable 52 and a verification cable 53. The three cables are connected together at a three-way connection 25 54. The DC source cable 51 includes, at its end, a DC input plug 55 which can be plugged into a source port 48 in the monitor 45. This permits power from the battery 49 to be accessed by the power connection device 50. The DC input plug includes a shell 56, a tip 57 and a ring 58. 30 The DC output cable 52 includes at its end a DC supply plug 61 which can be plugged into a power port 47 in the computer 44 in order to power it. The DC supply plug 61 includes a shell 70, a tip 71 and a ring 72. The verification cable 53 includes at its end a verification connector 64 for connection to the power output of the unpowered power supply unit 46. The verification connector 64 of 35 the verification cable 53 includes a shell 65, a tip 66 and a ring 67. 22 04 As shown in Figures 1 and 3, a verification signal wire (shown with alternating long and short dashes) extends from the verification connector 64 to the DC supply plug 61 via the verification cable 53 and the DC output cable 52; a ground wire (shown with an unbroken line) connects the DC source plug 55 to the verification connector and to the DC supply 5 plug 61 via the DC source cable 51, the DC output cable 52 and the verification cable 53; and a DC power wire (shown with regular dashes) extends from the DC source plug 55 to the DC supply plug 61 via the DC source cable 51 and the DC output cable 52. This permits the computer 44 to be powered from the battery 49 of the monitor 45. However, since the computer will not operate unless it is powered by an approved manufacturer's power 10 supply unit, It communicates with the unpowered power supply unit 46 down the verification signal wire, and the circuitry within the unpowered power supply unit 46 replies to the computer 44 with a verification signal through the verification signal wire, receipt of which allows the computer to be fully operational, in that the computer 44 will accept the power from the monitor 45. This is achieved because the communication through the 15 verification signal wire between the computer and the unpowered power supply unit 46 occurs using a wired half duplex serial bus such as the 1-Wlre system. The unpowered power supply unit 46 includes a small capacitor to store charge which powers circuitry within the unit such that on receipt of the communication from the computer 44, it becomes active and is able to reply, sending the verification signal. This system Is not 20 described in any more detail here because it is well established in the art. Various further modifications to the above described examples, whether by way of addition, deletion or substitution, will be apparent to the skilled person to provide additional examples, any and all of which are intended to be encompassed by the appended claims.

Claims

1. A computer power connection device comprising:a 3-way connection;a DC source cable extending from a DC input plug to the 3-way connection;a DC output cable extending from the 3-way connection to a DC supply plug;a verification cable extending from the 3-way connection to a verification connector for connection to the power output of an unpowered power supply unit;a verification signal wire extending from the verification connector through the verification cable, through the DC output cable to the DC supply plug;a DC power wire extending from the DC input plug through the DC source cable, and through the DC output cable to the DC supply plug; anda ground wire through the cables connecting the DC input plug and the DC supply plug.2.. A computer power connection device according to claim 1, wherein the ground wire additionally extends through the verification cable to the verification connector.

3. A method of connecting a computer to a DC power source comprising:connecting a DC power wire and a ground wire between the DC power source and the computer; andconnecting a verification signal wire between a verification port of the computer and a port of an unpowered power supply unit of a type having circuitry to emit a verification signal on the verification signal wire when it has received a request to supply it.

4. A method according to claim 3, further comprising connecting the ground wire to the verification port of the unpowered power supply.

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