US3917978A - Apparatus for eliminating effects of electrostatic discharge - Google Patents

Apparatus for eliminating effects of electrostatic discharge Download PDF

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Publication number
US3917978A
US3917978A US450740A US45074074A US3917978A US 3917978 A US3917978 A US 3917978A US 450740 A US450740 A US 450740A US 45074074 A US45074074 A US 45074074A US 3917978 A US3917978 A US 3917978A
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US
United States
Prior art keywords
equipment
discharge
structural members
static electricity
discharge path
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
US450740A
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English (en)
Inventor
Willi Menzel
Peter Bauer
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Siemens AG
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Siemens AG
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Filing date
Publication date
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Publication of US3917978A publication Critical patent/US3917978A/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0067—Devices for protecting against damage from electrostatic discharge

Definitions

  • an object of the invention to provide a means for eliminating the effect of electrostatic discharge of persons on themselves, as well as on the highly sensitive electronic components.
  • the invention has application, inter alia, with electrical equipment equipped with highly sensitive electronic parts or modules, such as communication facilities, computers, etc. containing digital sequential circuits, electric storages, integrated circuits, etc., having parts connected to a ground network, over which the mainte- 2 nance personnel charged with static electricity are discharged.
  • electrical equipment equipped with highly sensitive electronic parts or modules, such as communication facilities, computers, etc. containing digital sequential circuits, electric storages, integrated circuits, etc., having parts connected to a ground network, over which the mainte- 2 nance personnel charged with static electricity are discharged.
  • the invention solves the problem described herein above by inserting a resistance between the parts of the equipment and the ground network.
  • the resistance is of a value which permits discharge currents of the static electricity which at the very most are as large as the changes in the operating current occurring in the equipment.
  • a value for the discharge currents is obtained, by properly determining the resistance, which, at the very most, is as large as the changes in the operating current occurring in the equipment. This value is no longer adequate to destroy the built-in electronic components or to initiate any switching operations.
  • the pieces of equipment in question e.g. the handles thereof, of a material whose resistance value corresponds to the re sistance described hereinabove.
  • This resistance is inserted between the parts and the ground network.
  • a handle could, for example, be made of plastic with a low conductance.
  • FIG. 1 is a partial side elevation of a handle and cabinet arrangement on a plug-in unit and FIG. 2 is a partial side elevation of an alternate preferred embodiment employing direct connection.
  • a metal handle I is attached in a known manner, by screws 6, to a plug-in unit 4 of metal together with a metal shield 2.
  • An insulating intermediate member 3 is inserted for electrically separating the handle 1 and the shield 2 from the plug-in unit 4, insulating discs being mounted underneath screws 6.
  • the outer metal parts 1 and 2 are connected to a printed conductor path 8 via a resistor 5 to point 7 which, in turn, is grounded within the equipment.
  • the electrostatic voltage applied to the handle 1 or to the shield 2 can be discharged to earth via the resistor S and the printed conductor 8.
  • handle 11 and the shield 12 are connected directly and electrically to the plug-in unit 14, as shown in FIG. 2.
  • handle 11 and shield 12 consist of a ma terial having a specified conductivity, and thus, reduce the discharge current upon contact with the handle 11 or shield 12 to a value such as, likewise, is effected by the resistor 5 shown in FIG. 1.
  • the plug-in unit 14, as shown in FIG. 2, may also have above and/or underneath an additional frame made of the same material as the shield 12 and which is connected thereto or directly to the plug-in unit 14. In this way, the highly sensitive electronic components, of which only a few are shown in transistor cans 9, are better protected against random contact when the plug-in unit is pulled out. Also the plug-in unit 4 shown in FIG. 1 can be supplemented in the say way.
  • resistance means having a value which will permit the flow of discharge currents having a value up to the changes in the operating current occurring in said equipment, said resistance means being connected between the said structural members which might be contacted by an operator and said discharge path.
  • Electrical equipment having components which will respond to static electricity from an external source, comprising:
  • structural members for receiving said static electricity from said external source and a discharge path which is conductive at all times from said structural members to ground network
  • said structural members being composed of a material having a resistance value which will permit the flow of currents to said discharge path which, at a maximum, as large as the change in the operating current in said equipment.
US450740A 1973-03-13 1974-03-13 Apparatus for eliminating effects of electrostatic discharge Expired - Lifetime US3917978A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2312469A DE2312469C2 (de) 1973-03-13 1973-03-13 Elektrisches Gerät mit hochempfindlichen elektronischen Bauteilen, das Mittel zur Entladung der statischen Elektrizität des Wartungspersonals aufweist

Publications (1)

Publication Number Publication Date
US3917978A true US3917978A (en) 1975-11-04

Family

ID=5874640

Family Applications (1)

Application Number Title Priority Date Filing Date
US450740A Expired - Lifetime US3917978A (en) 1973-03-13 1974-03-13 Apparatus for eliminating effects of electrostatic discharge

Country Status (10)

Country Link
US (1) US3917978A (xx)
AT (1) AT325700B (xx)
BE (1) BE812253A (xx)
CH (1) CH565498A5 (xx)
DE (1) DE2312469C2 (xx)
FR (1) FR2221896B1 (xx)
GB (1) GB1457615A (xx)
IT (1) IT1008403B (xx)
LU (1) LU69606A1 (xx)
NL (1) NL164724B (xx)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4166206A (en) * 1975-09-29 1979-08-28 P. R. Mallory & Co. Inc. Metal strap electrically grounding a motor to a timer
US4531176A (en) * 1983-06-27 1985-07-23 At&T Bell Laboratories Cartridge having improved electrostatic discharge protection
US4605988A (en) * 1983-02-25 1986-08-12 Herman Miller, Inc. Anti-static grounding arrangement for work environment system
US4654746A (en) * 1984-11-23 1987-03-31 Lewis Jr Robert O Static dissipator for electronic devices
EP0317469A2 (en) * 1987-11-18 1989-05-24 International Business Machines Corporation Electrostatic discharge protection for electronics packages
US5386346A (en) * 1991-08-29 1995-01-31 Hubbell Incorporated Circuit card assembly with shielding assembly for reducing EMI emissions
US5463532A (en) * 1994-04-15 1995-10-31 Hubbell Incorporated Electrical circuit card with EMI shielding strip adapted to make contact with non-outwardly facing surface of card-receiving housing
US6172880B1 (en) 1998-07-31 2001-01-09 Hubbell Incorporated Faceplate for an electronic circuit card for reducing EMI emissions between circuit cards inserted in a circuit card housing
US6424505B1 (en) 1999-05-06 2002-07-23 Read-Rite Corporation Method and system for providing electrostatic discharge protection for flex-on suspension, trace-suspension assembly, or cable-on suspension
WO2009015025A2 (en) * 2007-07-23 2009-01-29 Staticoff Llc Improved electrostatic discharge device
US10582630B1 (en) 2015-12-28 2020-03-03 Roger Graham Method and apparatus for managing static electricity

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19731805A1 (de) * 1997-07-24 1999-01-28 Bayerische Motoren Werke Ag Vorrichtung zur Vermeidung von Überschlägen bei Förderfahrzeugen
DE102006008892B4 (de) * 2006-02-19 2008-04-30 Gerhard Dipl.-Ing. Richter (FH) Speicherkartenlesegerät

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3099774A (en) * 1960-01-08 1963-07-30 John J Crane Static discharge device
US3594490A (en) * 1970-07-17 1971-07-20 Ibm Electronic grounding system
US3711742A (en) * 1971-02-22 1973-01-16 Cons Foods Corp System for preventing electrostatic spark discharge from a person operating an electrical appliance
US3780345A (en) * 1972-09-14 1973-12-18 E Earman Static electricity deshocker

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3099774A (en) * 1960-01-08 1963-07-30 John J Crane Static discharge device
US3594490A (en) * 1970-07-17 1971-07-20 Ibm Electronic grounding system
US3711742A (en) * 1971-02-22 1973-01-16 Cons Foods Corp System for preventing electrostatic spark discharge from a person operating an electrical appliance
US3780345A (en) * 1972-09-14 1973-12-18 E Earman Static electricity deshocker

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4166206A (en) * 1975-09-29 1979-08-28 P. R. Mallory & Co. Inc. Metal strap electrically grounding a motor to a timer
US4605988A (en) * 1983-02-25 1986-08-12 Herman Miller, Inc. Anti-static grounding arrangement for work environment system
US4531176A (en) * 1983-06-27 1985-07-23 At&T Bell Laboratories Cartridge having improved electrostatic discharge protection
US4654746A (en) * 1984-11-23 1987-03-31 Lewis Jr Robert O Static dissipator for electronic devices
EP0317469A2 (en) * 1987-11-18 1989-05-24 International Business Machines Corporation Electrostatic discharge protection for electronics packages
EP0317469A3 (en) * 1987-11-18 1990-01-17 International Business Machines Corporation Electrostatic discharge protection for electronics packages
US5386346A (en) * 1991-08-29 1995-01-31 Hubbell Incorporated Circuit card assembly with shielding assembly for reducing EMI emissions
US5463532A (en) * 1994-04-15 1995-10-31 Hubbell Incorporated Electrical circuit card with EMI shielding strip adapted to make contact with non-outwardly facing surface of card-receiving housing
US6172880B1 (en) 1998-07-31 2001-01-09 Hubbell Incorporated Faceplate for an electronic circuit card for reducing EMI emissions between circuit cards inserted in a circuit card housing
US6424505B1 (en) 1999-05-06 2002-07-23 Read-Rite Corporation Method and system for providing electrostatic discharge protection for flex-on suspension, trace-suspension assembly, or cable-on suspension
WO2009015025A2 (en) * 2007-07-23 2009-01-29 Staticoff Llc Improved electrostatic discharge device
WO2009015025A3 (en) * 2007-07-23 2009-04-30 Staticoff Llc Improved electrostatic discharge device
US10582630B1 (en) 2015-12-28 2020-03-03 Roger Graham Method and apparatus for managing static electricity

Also Published As

Publication number Publication date
BE812253A (fr) 1974-09-13
FR2221896B1 (xx) 1979-07-06
IT1008403B (it) 1976-11-10
DE2312469C2 (de) 1975-04-10
LU69606A1 (xx) 1974-07-10
NL7402537A (xx) 1974-09-17
ATA94374A (de) 1975-01-15
DE2312469B1 (de) 1974-08-22
AT325700B (de) 1975-11-10
GB1457615A (en) 1976-12-08
CH565498A5 (xx) 1975-08-15
FR2221896A1 (xx) 1974-10-11
NL164724B (nl) 1980-08-15

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