US3005069A - Reed relay for small voltages - Google Patents

Reed relay for small voltages Download PDF

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Publication number
US3005069A
US3005069A US85313A US8531361A US3005069A US 3005069 A US3005069 A US 3005069A US 85313 A US85313 A US 85313A US 8531361 A US8531361 A US 8531361A US 3005069 A US3005069 A US 3005069A
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US
United States
Prior art keywords
relay
coil
reed
relays
reed relay
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US85313A
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English (en)
Inventor
Frederick W Sippach
Jr Robert H Luppold
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hagan Chemicals and Controls Inc
Original Assignee
Hagan Chemicals and Controls Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to NL270281D priority Critical patent/NL270281A/xx
Application filed by Hagan Chemicals and Controls Inc filed Critical Hagan Chemicals and Controls Inc
Priority to US85313A priority patent/US3005069A/en
Priority to FR876056A priority patent/FR1303833A/fr
Application granted granted Critical
Publication of US3005069A publication Critical patent/US3005069A/en
Priority to GB1426/62A priority patent/GB995432A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H51/00—Electromagnetic relays
    • H01H51/28—Relays having both armature and contacts within a sealed casing outside which the operating coil is located, e.g. contact carried by a magnetic leaf spring or reed
    • H01H51/281—Mounting of the relay; Encapsulating; Details of connections

Definitions

  • This invention relates to, electrical-relays. ⁇ In'particular, it relates to means for maintainingk equal temperatures atlthe terminals of magnetically activated reed relays.
  • the so-called reed relay has recently become eXtensively used in electrical devices requiring many switching operations because ofits low cost, long life, and minimumk contact contamination.
  • the life expectancy of -a reed relay is ⁇ in the many millions of operations.
  • 'Ilhe cost is smallcompared to stand- ⁇ -ard mercury or. other types of relays.
  • the reed contact strips which are generally made of a ferrous alloy having a high nickel content, arey joined to the leads, which are generally of copper, at points several inches apart on the same relay.
  • the junctions form thermocouples which produce yan in the neighborhood of 30 microvolts per degree centigrade of temperature difference. The generated by the thermocouplejunctions at each end of the relay is canceled out to the extent that there is no difference in the two temperatures. However, where there is a difference in temperature between the two lead-reed junctions of a single relay, the is quite significant.
  • the relay is to be used to close -a circuit from a transducer having an output measured in microvolts, such as a thermocouple, for example, the error is likely to be as large as the analog signal. It is therefore imperative, if the reed relay is to be used for handling small voltages, that a means for compensating or correcting this error be provided.
  • FIGURES la and lb are two views of a single presently commercially available reed relay capsule.
  • FIG. 2 is a cross section of a single complete'reed relay equipped with our invention.
  • FIG. 3 is a perspective View of a presently preferred form of our thermal shunt capable of accommodating ytwo reed relays.
  • FIGS. 4a and 4b are an overhead sectional view and a cross section of a package of four relays, two of which are enclosed in the thermal shunt of our invention and two of which are outside the thermal shunt but within the insulated package.
  • the illustrated relay capsule comprises two metal strips 1 and 2 sealed in glass enclosure 3. i
  • the strips are of ferromagnetic,
  • electrically "conductive metal preferably a nickel-iron alloy having a coefficient of expansion approximately equal to that of theglass enclosure.
  • Contact surfaces 4 are. gold-coated for improved conductance at the contact point.
  • the interior 5 of the glass enclosure 3 is preferably filled with an inertv gas to minimize contact contamination and deterioration through corrosion, etc.
  • space between contacts 4 is preferably about 2 or 3 mi1limeters.
  • Each reed is securely anchored in the glass enclosureat 6. kApplication of a magnetic eld from the coil causes the reeds to assume a position parallel with the magnetic lines of force, thereby contacting each other.
  • the coil providedfor the unit described should have at least about 110 ampere turns per capsule to operate depend- Thermal shunt 44 next surrounds the relay. On this is placed vanother layer of insulating material 45.
  • the energizing coil 46 is positioned concentrically on the insulating layer.
  • the coil may, of course, be covered by a plastic insulating or protective layer 47.
  • FIG. 3 is va presently preferred form of our thermal shunt.
  • This shunt is capable of accommodating two reed relays side by side.
  • the material is one of high thermal conductivity but preferably also of relativelyk high specific heat; that is, it should be a good conductor f of heat and at the same time a given mass of material should absorb a relatively large number of calories for each degree of temperature change.
  • a relatively large mass of such material in the form of our thermal shunt will result in a correspondingly high thermal inertia.
  • the relay will not operate if the thermal shunt has ferromagnetic properties.
  • excellent material with respect to thermal conductivity, specific heat, and cost, is copper. Copper is our presently preferred composition for the thermal shunt.
  • silver and copper alloys having the above described characteristics.
  • FIG. 4a shows the use of our invention in a package of four relays.
  • This is an overhead view illustrating relays lltl, 11, 12, and 13 of the type illustrated in FIG. l.
  • Surrounding relays 11 and 12 is the thermal shunt 14 of FIG. 3.
  • the other relays 10 and 13 are preferably positioned as shown, adjacent to the thermal shunt.
  • Coil 17 surrounds the several relays such that energizing the coil 17 actuates all four relays at once.
  • the entire package as shown is surrounded by a plastic protector.
  • Insulating material 18 performs the important function of insulating the thermal shunt and the relay capsule within it from the relatively large temperature changes which occur in the coil.
  • the insulating material should extend Ibeyond the ends of the reeds and seal off the ends of the package, as shown. By retarding the conduction of heat from the coil to the thermal shunt, the insulating material minimizes the effect of temperature change, resulting in minimal thermal gradients in the contact strips.
  • the coil is preferably of ythe same shape as the shunt and equidistant from it on opposite sides.
  • the copper leads 19 are preferably as thin as possible in order yto minimize the conductance of heat through them to the ther-mocouple-like junctions 20, 21, 22, rand 23. It is these junctions, of course, which should be equalized so far yas is possible in temperature. Our invention provides a remarkably effective means for accomplishing this object.
  • the shunt should overhang the lead junctions to equalize the temperature so far as possible on all sides.
  • the thermal shunt is placed lconcentrically between the coil and therelay or relays to be protected.
  • Most of the heat changes which cause the thermal gradients at the ends of an ordinary relay originate with the energizing of the coil.
  • the balance of the trouble comes lfrom the influence of air currents and the like originating outside the relay.
  • the heat changes caused by the -coil and conducted to the ends of the relay are thus virtually equal. Indeed, the temperature changes throughout the length of the relay at the same rate. Compensation is therefore also made for any differences in alloy composition of the reeds resulting in a thermocouple effect at the contact surface.
  • a reed relay unit comprising an elongated energizing coil, a layer of insulating material concentrically Within said coil, a copper enclosure within said insulating layer, and two elongated gas filled reed relay capsules substantially enclosed by said copper enclosure.
  • a reed relay capable of handling very small voltages without errors caused by temperature gradients comprising an elongated gas filled glass capsule having two ferromagnetic contact strips passing through it, a copper tube enclosing said capsule, an insulating layer surrounding 4 said copper tube, and an energizing coil around said insulating layer.
  • the relay unit of claim 1 including at least one additional elongated reed relay capsule within said insulating layer but routside said copper enclosure.
  • An electrical reed relay unit capable of simultaneously Iachieving a plurality of electrical contacts without Vsigniicant temperature gradients within said unit lcomprising:
  • said shunt enclosing and extending at least to the extremities of said reeds

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Thermally Actuated Switches (AREA)
US85313A 1961-01-27 1961-01-27 Reed relay for small voltages Expired - Lifetime US3005069A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
NL270281D NL270281A (fr) 1961-01-27
US85313A US3005069A (en) 1961-01-27 1961-01-27 Reed relay for small voltages
FR876056A FR1303833A (fr) 1961-01-27 1961-10-16 Perfectionnements apportés aux relais électriques
GB1426/62A GB995432A (en) 1961-01-27 1962-01-15 Electric relay

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US85313A US3005069A (en) 1961-01-27 1961-01-27 Reed relay for small voltages

Publications (1)

Publication Number Publication Date
US3005069A true US3005069A (en) 1961-10-17

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Family Applications (1)

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US85313A Expired - Lifetime US3005069A (en) 1961-01-27 1961-01-27 Reed relay for small voltages

Country Status (3)

Country Link
US (1) US3005069A (fr)
GB (1) GB995432A (fr)
NL (1) NL270281A (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3209107A (en) * 1962-07-26 1965-09-28 Thermal Engineering And Design Thermostats, motor protectors or the like having generally octagonal shaped and improved sealing end
US3254171A (en) * 1963-08-21 1966-05-31 Cts Corp Magnetically controlled switching device
US3284740A (en) * 1965-07-15 1966-11-08 Motorola Inc Electronic ignition system with encapsulated reed device and conducting sleeve thereabout forming a flux filter
US3320559A (en) * 1965-05-17 1967-05-16 Electro Scient Ind Inc Electrical chopper utilizing a shielded reed switch
US3408603A (en) * 1966-07-01 1968-10-29 Dynamics Instrumentation Compa Shielding arrangement for a reed relay
US3456216A (en) * 1967-02-08 1969-07-15 Hewlett Packard Co Reed relay having a low thermal emf
US3488760A (en) * 1968-04-10 1970-01-06 Julie Research Lab Inc Reed relay module
US3701960A (en) * 1971-07-12 1972-10-31 Coto Coil Co Inc Reed relay having low thermal emf
US4084142A (en) * 1976-09-27 1978-04-11 Coto-Coil Co., Inc. Reed relay having low differential thermal emf
US4286241A (en) * 1979-04-30 1981-08-25 Motorola Inc. Apparatus for mounting a reed switch
DE3412154C1 (de) * 1984-03-31 1985-07-25 Walter 6052 Mühlhein Steinecker Reedrelais mit Thermospannungs-Ausgleich
US5909163A (en) * 1996-09-11 1999-06-01 Hermetic Switch, Inc. High voltage reed switch
US5969244A (en) * 1998-04-13 1999-10-19 The United States Of America As Represented By The Secretary Of The Navy Switch assembly for withstanding shock and vibration

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US680704A (en) * 1900-11-24 1901-08-20 Electrical Safety Traction Company Electric-traction road.
US781993A (en) * 1903-10-09 1905-02-07 Leon F Moss Circuit-closer.
US1225507A (en) * 1916-10-09 1917-05-08 Nat Safety Appliance Co Magnetic circuit-closer for train-stops and signals.
US1348842A (en) * 1918-03-18 1920-08-10 William N Barlow Electric relay or circuit-closing device
US1868559A (en) * 1930-06-17 1932-07-26 American Telephone & Telegraph Relay
US2015156A (en) * 1932-11-17 1935-09-24 Autocall Company Electrical relay
US2203321A (en) * 1939-09-27 1940-06-04 Bell Telephone Labor Inc Switching device
US2520935A (en) * 1945-02-03 1950-09-05 Hubbell Harvey Magnetically operated switch
US2548581A (en) * 1949-03-04 1951-04-10 Gen Electric Magnetic switching device
US2660640A (en) * 1949-12-06 1953-11-24 Westinghouse Electric Corp Circuit interrupter
US2668884A (en) * 1951-11-21 1954-02-09 Gen Motors Corp Electrical switch apparatus
US2687500A (en) * 1949-12-06 1954-08-24 Westinghouse Electric Corp Circuit interrupter
US2715166A (en) * 1952-12-03 1955-08-09 Ibm Electromagnetic relay
US2770697A (en) * 1954-04-01 1956-11-13 Alfred L Kellett Magnetic electrical switch

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US680704A (en) * 1900-11-24 1901-08-20 Electrical Safety Traction Company Electric-traction road.
US781993A (en) * 1903-10-09 1905-02-07 Leon F Moss Circuit-closer.
US1225507A (en) * 1916-10-09 1917-05-08 Nat Safety Appliance Co Magnetic circuit-closer for train-stops and signals.
US1348842A (en) * 1918-03-18 1920-08-10 William N Barlow Electric relay or circuit-closing device
US1868559A (en) * 1930-06-17 1932-07-26 American Telephone & Telegraph Relay
US2015156A (en) * 1932-11-17 1935-09-24 Autocall Company Electrical relay
US2203321A (en) * 1939-09-27 1940-06-04 Bell Telephone Labor Inc Switching device
US2520935A (en) * 1945-02-03 1950-09-05 Hubbell Harvey Magnetically operated switch
US2548581A (en) * 1949-03-04 1951-04-10 Gen Electric Magnetic switching device
US2660640A (en) * 1949-12-06 1953-11-24 Westinghouse Electric Corp Circuit interrupter
US2687500A (en) * 1949-12-06 1954-08-24 Westinghouse Electric Corp Circuit interrupter
US2668884A (en) * 1951-11-21 1954-02-09 Gen Motors Corp Electrical switch apparatus
US2715166A (en) * 1952-12-03 1955-08-09 Ibm Electromagnetic relay
US2770697A (en) * 1954-04-01 1956-11-13 Alfred L Kellett Magnetic electrical switch

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3209107A (en) * 1962-07-26 1965-09-28 Thermal Engineering And Design Thermostats, motor protectors or the like having generally octagonal shaped and improved sealing end
US3254171A (en) * 1963-08-21 1966-05-31 Cts Corp Magnetically controlled switching device
US3320559A (en) * 1965-05-17 1967-05-16 Electro Scient Ind Inc Electrical chopper utilizing a shielded reed switch
US3284740A (en) * 1965-07-15 1966-11-08 Motorola Inc Electronic ignition system with encapsulated reed device and conducting sleeve thereabout forming a flux filter
US3408603A (en) * 1966-07-01 1968-10-29 Dynamics Instrumentation Compa Shielding arrangement for a reed relay
US3456216A (en) * 1967-02-08 1969-07-15 Hewlett Packard Co Reed relay having a low thermal emf
US3488760A (en) * 1968-04-10 1970-01-06 Julie Research Lab Inc Reed relay module
US3701960A (en) * 1971-07-12 1972-10-31 Coto Coil Co Inc Reed relay having low thermal emf
US4084142A (en) * 1976-09-27 1978-04-11 Coto-Coil Co., Inc. Reed relay having low differential thermal emf
US4286241A (en) * 1979-04-30 1981-08-25 Motorola Inc. Apparatus for mounting a reed switch
DE3412154C1 (de) * 1984-03-31 1985-07-25 Walter 6052 Mühlhein Steinecker Reedrelais mit Thermospannungs-Ausgleich
US5909163A (en) * 1996-09-11 1999-06-01 Hermetic Switch, Inc. High voltage reed switch
US5969244A (en) * 1998-04-13 1999-10-19 The United States Of America As Represented By The Secretary Of The Navy Switch assembly for withstanding shock and vibration

Also Published As

Publication number Publication date
NL270281A (fr)
GB995432A (en) 1965-06-16

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