United States Patent [19]
`Lee
`
`II ~1111111111111
`
`US005650771A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,650,771
`Jul. 22, 1997
`
`[54] ELECTRICAL SOCKET WITH
`MONITOIDNGUNITFORMONITOIDNG
`OPERATING CONDITIONS
`
`[76]
`
`Inventor: Chung-Cheng Lee. No. 16.
`Shing-Gong Rd .. Yung-Kang City.
`Tainan Hsien. Taiwan
`
`[21] Appl. No.: 427,766
`
`Apr. 25, 1995
`
`[22] Filed:
`Int. CI.6
`..................................................... GOSB 21/00
`[51]
`[52] U.S. Cl ..................... 340/656; 340/635; 340/310.08;
`364/483; 360/42
`[58] Field of Search ..................................... 340/635, 656.
`340/310.08. 538. 657, 660. 664; 364/483.
`482. 550; 361/42
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`5,003,486
`5,160,926
`5,332,993
`5,448,491
`
`3/1991 Herdel et al ............................ 340/656
`1111992 Schweitzer, ill ....................... 340/538
`7/1994 Ninomiya ................................ 340/636
`9/1995 Janke et al. ............................. 340/635
`
`Primary Examiner-Jeffery Hofsass
`Assistant Examiner-Edward Lefkowitz
`Attorney, Agent, or Finn-Skjerven. MorrilL MacPherson.
`Franklin and Friel; Alan H. MacPherson
`
`[57]
`
`ABSTRACT
`
`An electrical socket includes at least one socket receptacle
`adapted to connect electrically an electrical appliance to a
`line power source. and a monitoring unit connected electri(cid:173)
`cally across the socket receptacle for monitoring operating
`conditions, such as the ambient temperature. the line
`voltage. the line current and the line power supplied by the
`line power source, of the electrical socket.
`
`4,644,320
`
`2/1987 Corr et al.
`
`.. ....................... 340/310.08
`
`3 Claims, 5 Drawing Sheets
`
`12
`
`26
`
`31
`
`33
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`30
`
`13
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`11
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`11
`
`IPR Page 1
`
`Raritan v. Server Technology
`
`RARITAN EXHIBIT 1022
`
`

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`U.S. Patent
`
`Jul. 22, 1997
`
`Sheet 1 of 5
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`

`
`U.S. Patent
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`Jul. 22, 1997
`
`Sheet 2 of 5
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`5,650,771
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`IPR Page 4
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`

`
`U.S. Patent
`
`Jul. 22, 1997
`
`Sheet 4 of 5
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`5,650,771
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`IPR Page 5
`
`

`
`U.S. Patent
`
`Jul. 22, 1997
`
`Sheet 5 of 5
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`5,650,771
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`IPR Page 6
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`

`
`1
`ELECTRICAL SOCKET WITH
`MONITOIDNGUNITFORMONITOIDNG
`OPERATING CONDITIONS
`
`BACKGROUND OF THE INVENTION
`
`5,650,771
`
`5
`
`2
`voltage data and maximum operating-current data therein.
`The processing unit compares the ambient temperature data
`with the maximum operating-temperature data, the line
`voltage data with the maximum operating-voltage data, and
`the line current data with the maximum operating-current
`data to detect presence of a preset overload condition.
`The operating conditions may further include the line
`power supplied by the line power source. The processing
`unit computes the line power by multiplying the line voltage
`10 data with the line current data. The memory unit further
`stores maximum operating-power data therein, and the pro(cid:173)
`cessing unit compares the line power computed thereby with
`the maximum operating-power data to detect the presence of
`the preset overload condition.
`The monitoring unit further includes an alarm unit con-
`nected electrically to and activated by the processing unit
`upon detection of the overload condition. and function key
`means connected electrically to the processing unit and
`operable so as to control the processing unit to store the
`20 maximum operating-temperature data, the maximum
`operating-voltage data, the maximum operating-current data
`and the maximum operating-power data in the memory unit.
`
`1. Field of the Invention
`The invention relates to an electrical socket for connect(cid:173)
`ing electrically an electrical appliance to a line power
`source, more particularly to an electrical socket with a
`monitoring unit for monitoring operating conditions of the
`electrical socket.
`2. Description of the Related Art
`Short circuiting is a possible source of fire and usually 15
`arises when wearing of electrical cables occurs. Known
`electrical cables include a protective insulator layer that is
`wrapped around a conductor. The size of an electrical cable
`that is in use depends on the amount of voltage and current
`to be transmitted thereby. At high voltages and currents, an
`electrical cable must be capable of enduring relatively high
`operating temperatures. After a period of use, the insulator
`layer of the electrical cable deteriorates and eventually fails
`to provide adequate protection against short circuiting. Thus.
`frequent replacement of electrical cables is needed to mini- 25
`mize the possibility of short circuiting due to wearing of the
`electrical cables.
`Short circuiting also arises when electrical cables are used
`improperly. i.e. overloading. Electrical cables are designed
`to bear a maximum operating voltage and a maximum
`operating current However, in actual use. overloading hap(cid:173)
`pens when the current passing through the electrical cables
`exceeds the specified maximum value due to the use of
`electrical extensions for connecting a plurality of electrical
`appliances to a single electrical socket. Overloading dam- 35
`ages the fuses which are installed in the electrical appliances
`and causes overheating and short circuiting of the electrical
`cables.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`Other features and advantages of the present invention
`will become apparent in the following detailed description
`of the preferred embodiments, with reference to the accom(cid:173)
`panying drawings. of which:
`FIG. 1 is a schematic view of the first preferred embodi-
`30 ment of an electrical socket according to the present inven(cid:173)
`tion;
`FIG. 2 is a schematic circuit block diagram of the first
`preferred embodiment;
`FIG. 3 is a schematic electrical circuit diagram of the first
`preferred embodiment;
`FIG. 4 is a schematic circuit block diagram of a central
`processing unit of the first preferred embodiment; and
`FIG. 5 is a schematic view of the second preferred
`40 embodiment of an electrical socket according to the present
`invention.
`
`SUMMARY OF THE INVENTION
`
`Therefore, the object of the present invention is to provide
`an electrical socket with a monitoring unit that is capable of
`monitoring operating conditions of the electrical socket and
`that can be used to alert the user in the event that a preset 45
`overload condition has been detected to help avert actual
`occurrence of an overload.
`Accordingly. the electrical socket of the present invention
`comprises at least one socket receptacle adapted to connect
`electrically an electrical appliance to a line power source. a 50
`monitoring unit connected electrically across the socket
`receptacle for monitoring operating conditions of the elec(cid:173)
`trical socket. and a display unit connected electrically to the
`monitoring unit and controlled by the monitoring unit so as
`to display operating conditions of the electrical socket 55
`thereon.
`The operating conditions monitored by the monitoring
`unit include the ambient temperature, the line voltage and
`the line current. The monitoring unit includes a temperature
`sensor for sensing the ambient temperature. and a processing 60
`unit connected electrically to and receiving ambient tem(cid:173)
`perature data from the temperature sensor. The processing
`unit is further connected electrically to the socket receptacle
`and receives line voltage data and line current data there(cid:173)
`from. The monitoring unit further includes a memory unit 65
`connected electrically to the processing unit and storing
`maximum operating-temperature data, maximum operating-
`
`DETAilED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`Referring to the FIG. 1. the first preferred embodiment of
`an electrical socket according to the present invention is
`shown to comprise a housing 1 with a face plate 12 and at
`least one socket receptacle 11 mounted on the face plate 12.
`In this embodiment. there are three socket receptacles 11
`mounted on the face plate 12. Each of the socket receptacles
`11 serves to connect electrically an electrical appliance to a
`line power source. The socket receptacles 11 are conven(cid:173)
`tional in construction and will not be detailed herein. The
`face plate 12 further has a fuse unit 13. a display unit 26 and
`a function key set 30 mounted thereon. The function key set
`30 includes four function keys 31. 32. 33. 34. the purposes
`of which will be described in the succeeding paragraphs.
`Referring to FIGS. 2 and 3, the electrical socket further
`comprises a monitoring unit 2 disposed in the housing 1. The
`monitoring unit 2 is connected electrically across the socket
`receptacles 11 and serves to monitor the operating
`conditions, such as the ambient temperature, the line
`voltage, the line current and the line power supplied by the
`line power source, of the electrical socket. The monitoring
`unit 2 includes a power supplying circuit 21. a multiplexer
`unit 22. a temperature sensor 221. an attenuator 23. a central
`processing unit 25 and an alarm unit 27.
`
`IPR Page 7
`
`

`
`5,650,771
`
`5
`
`3
`The power supplying circuit 21 includes a transformer
`211 and a bridge rectifier circuit 212 for converting an AC
`power signal from the line power source into a DC power
`signal for the monitoring unit 2. The socket receptacles 11
`are connected in parallel across an input winding of the
`transformer 211. The fuse unit 13 is connected in series to
`the input winding of the transformer 211 to prevent the flow
`of an excessive amount of current to the transformer 211.
`The temperature sensor 221 senses the ambient tempera(cid:173)
`ture and generates an electrical signal corresponding thereto. 10
`The multiplexer unit 22 is preferably a differential4-channel
`multiplexer-demultiplexer integrated circuit, such as
`CD4052B by RCA. The multiplexer unit 22 has signal
`inputs which are connected electrically to the temperature
`sensor 221, the input windings of the transformer 211 and 15
`the attenuator 23, signal outputs which are connected elec(cid:173)
`trically to the attenuator 23 and the central processing unit
`25, and control inputs which are connected electrically to the
`central processing unit 25.
`The central processing unit 25 receives operating condi- 20
`tion data, such as the ambient temperature, the line voltage
`and the line current, from the multiplexer unit 22 and
`monitors the operating conditions of the electrical socket to
`detect the presence of a preset overload condition. When
`monitoring the ambient temperature, the central processing 25
`unit 25 controls the multiplexer unit 22 to provide the output
`of the temperature sensor 221 thereto so as to receive
`ambient temperature data therefrom. When monitoring the
`line voltage, the central processing unit 25 controls the
`multiplexer unit 22 to connect the attenuator 23 to the input
`windings of the transformer 211. Line voltage data gener(cid:173)
`ated by the attenuator 23 is then received by the central
`processing unit 25 via the multiplexer unit 22. When moni(cid:173)
`toring the line current, the central processing unit 25 controls
`the multiplexer unit 22 to connect the attenuator 23 to a
`resistor 131 that is in series with the fuse unit 13 so that the
`attenuator 23 is able to detect a voltage drop across the
`resistor 131 due to the flow of the line current therethrough.
`Line current data that is generated by the attenuator 23 is
`then received by the central processing unit 25 via the 40
`multiplexer unit 22. When monitoring the line power sup(cid:173)
`plied by the line power source, the central processing unit 25
`simply multiplies the line voltage data with the line current
`data to obtain the line power.
`The display unit 26, which is preferably a liquid crystal
`display (LCD), is connected electrically to the central pro(cid:173)
`cessing unit 25 and is controlled by the latter so as to show
`the value of the line voltage, the line current, the ambient
`temperature or the line power thereon.
`The alarm unit 27 is preferably a buzzer which is con(cid:173)
`nected electrically to the central processing unit 25 and
`which is activated by the latter upon detection that the line
`voltage, the line current, the ambient temperature or the line
`power has exceeded preset limits.
`Referring to FIG. 4, the central processing unit 25 is a
`programmable integrated circuit which comprises a micro(cid:173)
`processor 251, an input/output (J/0) bus 252, a function
`select bus 253, an analog-to-digital (ND) converter 254, a
`data bus 255, a data latch 256, a display driver 257, a 60
`read-ouly memory (ROM) 258 and a random-access
`memory (RAM) 259. The alarm unit 27 and the control
`inputs of the multiplexer unit 22 are connected electrically
`to the microprocessor 251 via the J/0 bus 252. The function
`key set 30 is connected electrically to the microprocessor 65
`251 via the function select bus 253. The signal outputs of the
`multiplexer unit 22 are connected electrically to the micro-
`
`4
`processor 251 via the ND converter 254 and the data bus
`255. The ND converter 254 converts analog data from the
`multiplexer unit 22 into digital data for processing by the
`microprocessor 251. The display unit 26 is connected elec-
`trically to the microprocessor 251 via the data latch 256 and
`the display driver 257. The ROM 258 is used to store
`manufacturer-specified operating data, such as the maxi(cid:173)
`mum line voltage. the maximum line current, the maximum
`ambient temperature and the maximum line power, for the
`electrical socket therein. The RAM 259 is used to store
`user-specified operating data, such as the maximum line
`voltage, the maximum line current, the maximum ambient
`temperature and the maxinlum like power, for the electrical
`socket therein.
`The function key 31 serves as a select key for controlling
`the central processing unit 25 to control, in turn, the display
`unit 26 to show the value of a selected one of the line
`voltage, the line current, the ambient temperature and the
`line power thereon. The function key 32 serves as a setting
`key which is used in combination with the increment func(cid:173)
`tion key 33 and the decrement function key 34 to control the
`microprocessor 251 to store the user-specified operating data
`in the RAM 259.
`The microprocessor 251 refers to the user-specified oper(cid:173)
`ating data in the RAM 259 to detect the presence of the
`preset overload condition, and refers to the manufacturer(cid:173)
`specified operating data in the ROM 258 if the user-specified
`operating data has yet to be set by the user. The micropro(cid:173)
`cessor 251 does not permit setting of the user-specified
`operating data to values greater than those of the
`manufacturer-specified operating data
`In use, the housing 1 of the electrical socket may be
`mounted on a wall of a building structure. Alternatively, the
`electrical socket of the present invention may be modified so
`as to be in the form of an electrical extension, as shown in
`FIG. 5. The construction and operation of the embodiment
`shown in FIG. 5 are substantially similar to those of the
`previous embodiment and will not be detailed further.
`Initially, the display unit 26 shows the value of the line
`voltage thereon. The function key 31 is operated if the user
`wishes to see the value of the line current, the ambient
`temperature or the line power. The function keys 32, 33, 34
`are operated to set user -specified operating data in the RAM
`259. Upon detection by the central processing unit 25 of the
`presence of the preset overload condition, that is, when any
`of the line voltage, the line current, the ambient temperature
`and the line power exceeds the user-specified or the
`manufacturer-specified operating data, the central process(cid:173)
`ing unit 25 activates the alarm unit 27 to alert the user. Of
`50 course, if the line current exceeds that specified by the
`manufacturer, the fuse unit 13 breaks to prevent the occur(cid:173)
`rence of a short circuit
`Therefore, it has thus been shown that, unlike the con(cid:173)
`ventional electrical socket which provides inadequate pro-
`55 tection against short-circuiting, the electrical socket of the
`present invention incorporates a monitoring unit that is
`capable of alerting the user in the event that a preset
`overload condition has been detected to help avert actual
`occurrence of an overload. The objective of the present
`invention is thus attained.
`While the present invention has been described in con(cid:173)
`nection with what is considered the most practical and
`preferred embodiments, it is understood that this invention
`is not limited to the disclosed embodiments, but is intended
`to cover various arrangements included within the spirit and
`scope of the broadest interpretation so as to encompass all
`such modifications and equivalent arrangements.
`
`30
`
`35
`
`45
`
`IPR Page 8
`
`

`
`5,650,771
`
`5
`
`I claim:
`1. An electrical socket. comprising:
`at least one socket receptacle adapted to connect electri(cid:173)
`cally an electrical appliance to a line power source; and
`a monitoring unit connected electrically across said socket
`receptacle for monitoring operating conditions of the
`electrical socket, said monitoring unit further includ(cid:173)
`ing;
`a temperature sensor for sensing the ambient tempera-
`ture;
`a processing unit connected electrically to and receiv(cid:173)
`ing ambient temperature data from said temperature
`sensor;
`a memory unit connected electrically to said processing
`unit and storing maximum operating-temperature
`data therein, said processing unit comparing said
`ambient temperature data with said maximum
`operating-temperature data to detect presence of a
`preset overload condition;
`wherein said operating conditions include ambient
`temperature, line voltage and line current, said process(cid:173)
`ing unit being connected electrically to said socket
`receptacle and receiving line voltage data and line
`current data therefrom;
`wherein said memory unit further stores maximum
`operating-voltage data and maximum operating-current
`
`5
`
`6
`data therein. said processing unit comparing said line
`voltage data with said maximum operating-current data
`to detect the presence of the preset overload condition;
`and
`wherein said operating conditions further include line
`power supplied by the line power source, said process(cid:173)
`ing unit computing the line power by multiplying said
`line voltage data with said line current data. said
`memory unit further storing maximum operating(cid:173)
`power data therein, said processing unit comparing the
`line power computed thereby with said maximum
`operating-power data to detect the presence of the
`preset overload condition.
`2. The electrical socket as claimed in claim 1, wherein
`said monitoring unit further includes an alarm unit con(cid:173)
`nected electrically to and activated by said processing unit
`upon detecting the presence of the preset overload condition.
`3. The electrical socket as claimed in claim 1. wherein
`20 said monitoring unit further includes function key means
`connected electrically to said processing unit and operable
`so as to control said processing unit to store said maximum
`operating-temperature data, said maximum operating(cid:173)
`voltage data. said maximum operating-current data and said
`25 maximum operating-power data in said memory unit.
`
`10
`
`15
`
`* * * * *
`
`IPR Page 9