US3843949A - Electrical relay - Google Patents

Electrical relay Download PDF

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Publication number
US3843949A
US3843949A US00293323A US29332372A US3843949A US 3843949 A US3843949 A US 3843949A US 00293323 A US00293323 A US 00293323A US 29332372 A US29332372 A US 29332372A US 3843949 A US3843949 A US 3843949A
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United States
Prior art keywords
electrical
substrate
temperature sensitive
relay according
sensitive material
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Expired - Lifetime
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US00293323A
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English (en)
Inventor
C Plough
M Arts
M Leitner
W Russel
F Marman
K Eastwood
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MARSMAN F
MARSMAN F US
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MARSMAN F
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/78—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used using opto-electronic devices, i.e. light-emitting and photoelectric devices electrically- or optically-coupled
    • H03K17/79—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used using opto-electronic devices, i.e. light-emitting and photoelectric devices electrically- or optically-coupled controlling bipolar semiconductor switches with more than two PN-junctions, or more than three electrodes, or more than one electrode connected to the same conductivity region
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/04—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having negative temperature coefficient
    • H01C7/041—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having negative temperature coefficient formed as one or more layers or coatings

Definitions

  • An electrical relay comprises: a plate-like substrate of electrically insulating material; spaced electrical contacts on one face of said substrate; a layer of selected material bridging said spaced contacts; and an electrical device provided on said substrate arranged to develop Joule heat; and in which said selected material satisfied the following criteria: (i) contains elements whose atoms when in chemical combination with other elements have an incompletely filled d-shell or an incompletely filled f-shell; (ii) contains a substance effective to remove sand pelectrons from the conduction bands of said atoms; and (iii) exhibits a sharp change in conductivity between an insulating condition and a conducting condition at a definite critical temperature.
  • An object of the present invention is the provision of an electrical relay which, while the same order of size as a semiconductor switch or relay of similar rating, can provide virtually complete high voltage electrical isolation, for practical purposes, between its control elements and its current carrying electrodes.
  • an electrical relay comprises: a plate-like substrate of electrically insulating material; spaced electrical contacts on one face of said substrate; a layer of selected material bridging said spaced contacts; and an electrical device provided on said substrate arranged to develop Joule heat; and in which said selected material satisfied the following criteria;
  • ii. contains a substance effective to remove sand p electrons from the conduction bands of said atoms
  • FIG. 1 is a side elevation of a very small relay device, and is not drawn to scale;
  • FIG. 2 is a sectional upwards view taken on the line II-II of FIG. 1;
  • FIG. 3 is a perspective drawing of the device of FIGS. 1 and 2 mounted on a T header, the cap of which is omitted and shown in dashed outline only;
  • FIG. 4 is a graph showing the temperature/resistance characteristic of material used in the relay of FIGS. 1 to 3;
  • FIG. 5 is a perspective drawing similar to FIG. 3 and showing a modified device providing the control circuit of FIG. 9;
  • FIG. 6 through 9 are circuit diagrams illustrating typical uses of the device shown in FIGS. 1 to 3;
  • FIGS. 10 and 11 are diagrams which illustrate the different action of this device when subjected to alternating and to direct currents.
  • a rectangular single crystal sapphire chip 1 having a width of 0.01 7 inch, a length of 0.030 inch and a thickness of 0.006 inch is provided, on one face only, towards its two ends with a film 3 of a nickel-chromium alloy, and on top of each film 3 is provided a gold layer 5 of smaller size than the film 3, and which serves as a terminal.
  • the space between the two films 3 is bridged by a thin layer 4 of vanadium dioxide VO which extends up onto the film 3 but stops short of the gold layer 5.
  • a resistor 7 made of a nickel-chromium alloy, which acts as a heater, of the thin film type, each end of the resistor having applied to it a gold layer 8 which again serves as a terminal.
  • a ceramic plate 9 which is shown most clearly in FIG. 3.
  • the size of this plate is not critical except that as shown in FIG. 3 it is to be mounted in a standard T05 header 11, consisting of a metal base 13 and four contact pins l5, 17, 19 and 21 extending respectively through four insulating plugs 25, 27, 29 and 31 extending through base 13.
  • Plate 9 is formed, in the example shown, of alumina (A1 0 Formed on the upper surface of plate 9 are four metallic contact areas 35, 37, 39 and 41 connected respectively by leads 45, 47, 49 and 51 to the the pins 15, 17, 19 and 21.
  • the gold layers 5 are each provided with a solder ball 53, suitably of a germanium-gold alloy or a tin-gold alloy, by which the sapphire chip 1 and the parts carried by it are. mounted on the ceramic plate 9, the two solder balls engaging respectively contact areas 35 and 37. Leads 55 and 57 respectively connect the two gold layers 8 to the two contacts areas 39 and 41.
  • FIG. 3 In FIG. 3 is shown the complete assembly, a standard encapsulating top cap 59 being shown in dashed outline only.
  • the sapphire chip 1 alternative materials are quartz and other forms of glass, while Beryllium oxide (BeO) or alumina (A1 0 can be used. It is important that the chip be an electrical insulator of high dielectric strength, and that it has good thermal conductivity. A nickel-chromium alloy is used as a contact material since it provides a good bond to sapphire, and for other materials for the chip it may be desirable to use a different material for the film 3. The gold is used to provide a satisfactory terminal material.
  • BeO Beryllium oxide
  • A1 0 alumina
  • the film of vanadium oxide is very important, since this material is one of a class of materials which, as they are heated through a critical temperature, suffer a very large change in resistance, of the order of l,000: l. The characteristics of this material, and of materials falling in this class, are discussed in detail below.
  • the chip 1 is first coated over its whole face with the nichrome films by an evaporation technique, known in itself, in a suitable inert atmosphere.
  • the film typically has a thickness in the range 500 to 1000 AU (Angstrom units).
  • the film of gold is then applied by a similar technique to a thickness of say 2,000 AU.
  • the gold is first etched back from the central part of the chip, and then by a further photoresist process the nichrome is also etched back, but
  • This film has a thickness of between 1500 and 2500 AU, and it is most important that the vanadium oxide shall be in the polycrystalline, and not in the amorphous condition.
  • This film will cover the central part of the sapphire chip 1, the two shoulders of the nickel-chromium layer, and two contact layers of gold 5. The film is then backetched to expose the gold contact layers.
  • any change in any one of the materials mentioned may require a change in the technique used, and particular care is needed toensure that no damage is caused to any of the films by excessive diffusion of the other materials which are in close proximity to it.
  • ii. contains a substance effective to remove sand pelectrons from the conduction bands of said atoms
  • the graph of FIG. 4 shows how the resistance of a body of such a material changes as its temperature is raised and lowered through a critical temperature T
  • T critical temperature
  • the metal can be present, as in the example given above, in the form of its oxide.
  • Other compounds can be used, for example the nitride, the sulfate, the sulphide or the phosphide, or any other compound of the metal which will act in the specified manner, to remove the sand pelectrons from the conduction bands of the said atoms.
  • transition-se'ries elements and rare earths have incomplete dor f-shells. Therefore, where a number of atoms of such materials are placed in close proximity, an electron can move from, one dor fshell to another. If the normal valence electrons are present and uncombined (these are the sand p-electrons), the device would be useless because a strong electrical field can no longer be applied.
  • the valence electrons are rendered inoperative by chemical combination of the elemental metal with another element, producing, for example, a metal oxide, a metal salt or equivalent compound.
  • the device of the present invention requires an element with an incomplete dor fshell.
  • Germanium one of the most widely used semiconductor materials, does not satisfy this requirement. 1
  • Vanadium sesquioxide V 0 has a sharp transition at about 150 Kelvin and a poorly defined transition at about 500 Kelvin.
  • doping of this material with 1 percent of chromium sesquioxide Cr O shifts the low temperature transition to about 170 degrees Kelvin and sharpens the high temperature transition and lowers it to about 270 Kelvin.
  • This second transition is in the opposite direction to the first transition. This illustrates the possibility of using dopants to produce materials with useful transitions.
  • the actual transition temperature can be adjusted by varying the amount of doping.
  • the device illustrated can be used as a relay, the state of which is changed by the heating and the cooling of the film of vanadium oxide.
  • the vanadium oxide used in the film 4 has been doped so that its critical or switching temperature is 55 centigrade. When its temperature is below that critical temperature, the resistance between the pins 15 and 17 typically would be 200 X ohms.
  • a voltage between the pins 19 and 21 a current is caused to flow through the resistive film 7, and the heat so generated passes into the sapphire chip 1 and heats up the vanadium oxide film 4.
  • the resistance between pins and 17 falls abruptly to a much smaller value, typically to 200 ohms.
  • the film 4 switches after about l5 milliseconds.
  • the time taken for the film 4 to relapse to its original low-temperature, high-resistance state (if it is carrying no current) is about the same, say 15 milliseconds. It is possible to effect more rapid switching between the high-resistance state and the low resistance state by using a higher power dissipation in film 7, but the increased heat storage in the chip causes the relapse time to be longer. It has been found possible to supply the heating power as a pulse of relatively high power, which give the desired quicker switching in the high-to-low resistance direction, while keeping down the total heat input and so enabling relatively quick relapsing to the high-resistance state.
  • the applied potential is a direct-current producing potential, then a considerable reduction in either temperature or current (by external circuit action) may be needed to bring all the material down to its more highly resistive state. If the applied potential is an alternating current producing potential, then twice during each cycle the heating current and thus the heating effect will fall to zero. This permits the material to relapse into its high resistance state at a temperature usually close to the temperature at which transition in the opposite sense took place.
  • FIG. 6 illustrates a circuit which detects an overcurrent in the load R603 and turns off npn transistor O to limit the current in the load to a safe value.
  • Resistor R605 is chosen so as to give enough base current to allow Q, to provide load current under normal operation.
  • the film 4 is connected between the emitter and the base of transistor Q and a resistor R605 of 1000 ohms is connected between the base and collector.
  • the heating resistor film 7 is connected in series with the load R603.
  • transistor Q Under normal operating conditions, transistor Q is conducting since film 4 is below its critical temperature. When excess current flows through load R605 and heater film 7, the film 4 is switched to its low resistance condition and this limits the current through the load to that value which is required to maintain film 4 in the conducting state.
  • the circuit shown in FIG. 7 is similar to the previous one except that it is self-latching after film 4 is heated to its low resistance condition.
  • An npn transistor Q is connected with the heater film 7 and a resistive load R803 across a dc. supply 805.
  • the film is connected in series with a resistor R807 across the supply 805, and the base of the transistor is connected through Zener diode D801 to the junction of the film 4 and the resistor R807.
  • Zener diode D801 is used to bring the base of the transistor up to a correct level to offset residual voltage in film 4 when device is in the ON state.
  • Resistor R809 is connected between the base and emitter of the transistor to shunt the leakage current of D801 away from the base of Q
  • the circuit shown in FIG. 8 is a development of the previous circuit where an independent bias voltage supply 907 is used to offset the voltage across film 4 instead of a Zener diode.
  • the heater film 7 is shunted with a low value resistor R905 so that the circuit can be used with higher load currents.
  • the base of the transistor is connected to the junction of film 4 and resistor R909. This circuit is also self-latching after the film 4 is heated to its low resistance condition.
  • the circuit shown in FIG. 9 makes use of the device shown in FlGS. 1 to 3 in conjunction with a twodirection silicon controlled rectifier device 950 commonly known as a Triac.
  • the device 950 is an a.c. switch and is connected in series with an a.c. power supply 951 and a load 953.
  • the film 4 is connected in series with a resistor R955 of 1,000 ohms across the device 950, and the trigger electrode of the device is connected to the junction between the film 4 and the resistor R955.
  • the heater resistor 7 is connected to a regulable control current supply 957, typically operating at voltages in the range to 50 volts.
  • the voltage between the load circuit and the control circuit can well be 1,500 volts rms.
  • the small control voltage is used to control the resistance of the film 4, and the consequent voltage applied to the trigger electrode of the device 950 controls the current through the load 953. Current will flow in the load as long as the film 4 is maintained at above its critical temperature by the voltage applied to the heater resistor 7.
  • FIG. 9 is a good illustration of the advantages of the relay device of the. present invention.
  • the control voltage circuit is electrically isolated from the controlled. circuit, and thus it is possible to use asimple cheap and safe control circuit-to control high voltages and currents.
  • the circuit of FIG. 9 makes use of a relay device which is comparable in size to a standard transistor, and in fact makes use of the same T05 header as illustrated in FIG. 5, but unlike such a transistor it provides electrical isolation between control and controlled circuits which is limited only by the thickness and material of the chip 1.
  • circuits shown are basic circuits, andit will be clear to those skilled in the art that temperature compensation for changes in ambient temperature can be inserted in known manner in those circuits.
  • An electrical relay capable of providing a substantially complete high voltage isolation between its control element and its temperature sensitive switching element comprising:
  • a plate-like heat conductive supporting substrate made of electrically insulating material having a high dielectric strength and good thermal conductivity, the thickness of said substrate being approximately 0.006 inch;
  • ii. contains a substance effective to remove sand pelectrons from the conduction bands of said atoms

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Thermistors And Varistors (AREA)
  • Conductive Materials (AREA)
  • Thermally Actuated Switches (AREA)
US00293323A 1971-10-01 1972-09-29 Electrical relay Expired - Lifetime US3843949A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA124190A CA938735A (en) 1971-10-01 1971-10-01 Electrical relay

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US3843949A true US3843949A (en) 1974-10-22

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US00293323A Expired - Lifetime US3843949A (en) 1971-10-01 1972-09-29 Electrical relay

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US (1) US3843949A (enExample)
JP (1) JPS5229828B2 (enExample)
AU (1) AU456375B2 (enExample)
CA (1) CA938735A (enExample)
DE (1) DE2247882C3 (enExample)
FR (1) FR2152332A5 (enExample)
GB (1) GB1361740A (enExample)
NL (1) NL7213197A (enExample)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0113463A1 (en) * 1982-12-15 1984-07-18 Tektronix, Inc. Electrical device for detecting power delivered to a resistive load
EP0096834A3 (de) * 1982-06-11 1985-10-30 Wickmann-Werke GmbH Schutzschaltung, insbesondere für elektrische Geräte
US8450711B2 (en) 2009-01-26 2013-05-28 Hewlett-Packard Development Company, L.P. Semiconductor memristor devices
US8455852B2 (en) 2009-01-26 2013-06-04 Hewlett-Packard Development Company, L.P. Controlled placement of dopants in memristor active regions
US8710483B2 (en) 2009-07-10 2014-04-29 Hewlett-Packard Development Company, L.P. Memristive junction with intrinsic rectifier
US20200024150A1 (en) * 2017-03-30 2020-01-23 Panasonic Intellectual Property Management Co., Ltd. Time-dependent element, physical property temporal change prediction device, and electric circuit breaker

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3149298A (en) * 1960-12-09 1964-09-15 Bell Telephone Labor Inc Neel effect switching device
US3543104A (en) * 1968-02-14 1970-11-24 Hitachi Ltd Solid-state switching device including metal-semiconductor phase transition element and method for controlling same
US3568125A (en) * 1967-10-20 1971-03-02 Int Standard Electric Corp Thermistor
US3614480A (en) * 1969-10-13 1971-10-19 Bell Telephone Labor Inc Temperature-stabilized electronic devices
US3621446A (en) * 1969-02-17 1971-11-16 Bell Telephone Labor Inc Thermal relay

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3149298A (en) * 1960-12-09 1964-09-15 Bell Telephone Labor Inc Neel effect switching device
US3568125A (en) * 1967-10-20 1971-03-02 Int Standard Electric Corp Thermistor
US3543104A (en) * 1968-02-14 1970-11-24 Hitachi Ltd Solid-state switching device including metal-semiconductor phase transition element and method for controlling same
US3621446A (en) * 1969-02-17 1971-11-16 Bell Telephone Labor Inc Thermal relay
US3614480A (en) * 1969-10-13 1971-10-19 Bell Telephone Labor Inc Temperature-stabilized electronic devices

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0096834A3 (de) * 1982-06-11 1985-10-30 Wickmann-Werke GmbH Schutzschaltung, insbesondere für elektrische Geräte
EP0113463A1 (en) * 1982-12-15 1984-07-18 Tektronix, Inc. Electrical device for detecting power delivered to a resistive load
US4510482A (en) * 1982-12-15 1985-04-09 Tektronix, Inc. Protective circuit for electronic test probes
US8450711B2 (en) 2009-01-26 2013-05-28 Hewlett-Packard Development Company, L.P. Semiconductor memristor devices
US8455852B2 (en) 2009-01-26 2013-06-04 Hewlett-Packard Development Company, L.P. Controlled placement of dopants in memristor active regions
US8710483B2 (en) 2009-07-10 2014-04-29 Hewlett-Packard Development Company, L.P. Memristive junction with intrinsic rectifier
US20200024150A1 (en) * 2017-03-30 2020-01-23 Panasonic Intellectual Property Management Co., Ltd. Time-dependent element, physical property temporal change prediction device, and electric circuit breaker

Also Published As

Publication number Publication date
JPS5229828B2 (enExample) 1977-08-04
DE2247882B2 (de) 1978-06-29
DE2247882C3 (de) 1979-03-08
GB1361740A (en) 1974-07-30
CA938735A (en) 1973-12-18
NL7213197A (enExample) 1973-04-03
JPS5012576A (enExample) 1975-02-08
AU456375B2 (en) 1974-12-19
DE2247882A1 (de) 1973-04-05
FR2152332A5 (enExample) 1973-04-20
AU4733472A (en) 1974-04-11

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