Patent Publication Number: US-5838559-A

Title: Host electronic equipment with internal power supply adapted for supplying power directly to peripherals

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 08/789,841, filed Jan. 29, 1997 now U.S. Pat. No. 5,777,397 which is a continuation-in-part of application Ser. No. 08/734,959 filed Oct. 23, 1996, now Pat. No. 5,753,979 issued May. 19, 1998. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to electronic equipment to which peripheral equipment is connected for cooperative system operations. 
     BACKGROUND OF THE INVENTION 
     The market is replete with electronic equipment to which peripheral equipment is connected for cooperative action. The personal computer is one example of equipment to which peripheral equipment such as a FAX/modem and a LABEL scanner are connected for communication purposes. Another example is the television set to which a video cassette recorder (VCR) is connected; another, a stereo system. A tape drive, which might be connected to any of the above hosts, is a particularly familiar peripheral. Each piece of peripheral equipment is connected separately to an in-the-wall socket for power, as well as to the host, leading to a tangle of cords characteristic of any PC installation, stereo system or video system. 
     The peripherals often require different voltage levels for operation. Thus, five volt, nine volt, and 12 volt requirements are not uncommon. Consequently, not only are the power cords common but they typically also require transformers. The transformers, in turn, not only further complicate the tangle of cords, but they also are expensive and not entirely reliable. Most individuals with systems of this type often find themselves complaining about the mess of wires providing further impetus for the significant effort now being expended to develop wireless communication links between components. But still the tangle of power cords and transformers remains. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The invention is based on the recognition that host equipment such as a personal computer, a television set or a stereo turner has an internal power supply and a voltage regulator which already provides low voltage requirements for internal components and can be adapted to permit the requisite low voltage power to be supplied for the peripheral equipment directly from the host equipment rather than separately through transformers to an in-the-wall supply. In this manner, the tangle of cords, characteristic of such systems, is considerably simplified. To this end, provision is made in the housing of the host to provide a socket, or sockets, to which a peripheral piece of equipment can be connected for receiving directly from the host the low voltage power it requires. The socket(s) are connected electrically to the outputs of the internal power supply (or regulator) of the host for providing the low voltage needed to power the peripheral. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a personal computer system with a plurality of peripherals and an internal power supply with sockets for direct supply of power to associated peripherals; 
     FIG. 2 is a schematic illustration of a portion of the computer of FIG. 1 showing sockets in the host computer housing for the direct supply of power to the peripherals in accordance with the principles of this invention; 
     FIG. 3 is a circuit diagram of a portion of the system of FIG. 1; 
     FIG. 4 is a schematic diagram of an alternative arrangement in accordance with this invention; 
     FIG. 5 is a schematic representation of a voltage expander for use with the arrangement of FIGS. 1, 2 and 4 in accordance with the principles of this invention. 
     FIG. 6 is a block diagram of a power supply of the type shown in FIG. 2 illustrating the provision of variable voltage at the sockets of FIG. 2; and 
     FIG. 7 is a circuit diagram showing a resistance network for the embodiment of FIG. 6. 
    
    
     DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT OF THIS INVENTION 
     FIG. 1 shows a personal computer 10 having a housing 11. A power supply 13 (with a voltage regulator (not shown) within the housing. The power supply is connected to an in-the-wall socket (or equivalent) as indicated by cord 19 and plug 20. Power supply 13 is connected electrically to components (not shown) within the housing which constitute typical components for a computer for supplying power to those components as shown by wires 21. Typical peripherals for a computer are, for example, a LABEL scanner 22, a FAX/MODEM 23, and a tape drive (or CD ROM) 25 shown also connected to internal power supply 13. 
     FIG. 2 shows a face of a typical power supply for a personal computer. The power supply typically is secured within housing 11 with face 30 visible at an aperture in the computer housing. 
     The power supply includes a fan which is secured behind the pattern of curved openings 32. Also, plugs 34 and 35 are available for connection to the computer monitor and to wall power respectively. Typical power supplies also include a switch 36 for switching between 110 volt and 220 volt house supplies for the U.S. and for the European markets respectively. 
     But, in accordance with the principles of this invention, additional sockets 40 are provided in the computer housing, or in the face of the internal power supply if exposed at the computer housing, for direct connection of wires 41, 42, and 43 connecting the LABEL scanner, FAX/MODEM and tape drive respectively of FIG. 1 for supplying the low voltage requirements for those peripherals in the absence of connection to in-the-wall sockets and in the absence of transformers. 
     Each of sockets 40, illustratively, is shown as circular with a central pin for conforming to popular connector shapes for the illustrative peripherals. Of course, other connector shapes could be provided for connection to cables of alternative configurations. What is necessary, in accordance with the principles of this invention, is that low voltage outputs from a host&#39;s internal power supply are connected to newly provided sockets at the housing face of the host. 
     FIG. 3 shows a portion of a circuit schematic for the output of an illustrative internal power supply. The power supply includes a network 50 which permits plus five volts and plus twelve (and/or nine) volts supplies, for example, to be connected to sockets 40 of FIG. 2 via lines 51 and 52 respectively. 
     Although the invention has been described in connection with a personal computer, FIG. 1 could just as well represent a stereo system with associated peripherals or a television system with a video cassette and the like. In each instance, additional sockets, or connectors, are provided at the housing face for external connection of peripherals for supplying power thereto. 
     FIG. 4 shows an &#34;internal&#34; power supply similar to that shown in FIG. 2 where the sockets are of several different configurations. The arrangement includes a socket 60 for connection to house power as well as a switch 61 for selecting 110 or 220 volts. But, the sockets shown are circular (63) rectangular (64) and diamond shaped (65) for connection to cables of whatever shape dictated by the peripheral connector. 
     If it is desirable for more auxiliary equipment to be powered from the host than there are receptacles, a voltage expander as shown in FIG. 5 may be used. Specifically, FIG. 5 shows an expander 70 with three receptacles 72, 73, and 74 each as shown, for example, at 40 in FIG. 2. The expander is configured to mate with one of the sockets (40), much in the manner of a triple plug mating with a wall socket, by a male plug on the reverse side (not shown) of the expander. 
     FIG. 6 illustrates an embodiment of this invention wherein a power supply configuration of the type shown in FIG. 2 or FIG. 4 except that the voltage at each socket is variable. Specifically, the power supply includes a fan which occupies a position behind the pattern of curved openings 82. Also, plugs or sockets 84 and 85 are available for connection for the computer monitor and to wall power respectively. As was the case with the embodiment of FIG. 2, the power supply includes a switch 86 for switching between 110 volt and 220 volt house supplies for the U.S. and for the European markets, respectively. 
     In the embodiment of FIG. 6, each of the sockets 87, 88, and 89, for the external connection of peripheral equipment, is associated with a variable voltage control 90, 91, and 92, respectively, for selecting an appropriate voltage at the associated socket. 
     FIG. 7 shows a resistor network 95 operable by switch 96 to select a voltage from voltage regulator 97 in a power supply 98 of the type shown in FIG. 2. Such a switch is exposed at the face of the power supply for user selection of the voltage at the sockets (87, 88, and 89) of FIG. 6 as represented by the double circle 99 in FIG. 7 there. In one specific embodiment, the voltage regulator is commercially available as PQ30RV31 from SHARP Corporation and the resistors, from top to bottom, as viewed, are 7.3K, 3.4K, 2.4K, 2K, 1.5K, 1.2K, and 560 Ohms, providing 24V, 12V, 9V, 7.5V, 6V, 5V, and 3V, respectively. The switch (96) is a 1R5H6 switch and resistor 100 is 390 Ohms.