GB1146976A - Surge protection circuit - Google Patents

Surge protection circuit

Info

Publication number
GB1146976A
GB1146976A GB2096865A GB2096865A GB1146976A GB 1146976 A GB1146976 A GB 1146976A GB 2096865 A GB2096865 A GB 2096865A GB 2096865 A GB2096865 A GB 2096865A GB 1146976 A GB1146976 A GB 1146976A
Authority
GB
United Kingdom
Prior art keywords
resistor
motor
thermistor
capacitor
protection
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
Application number
GB2096865A
Inventor
John MERRETT
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.)
Philips Components Ltd
Original Assignee
Mullard Ltd
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
Application filed by Mullard Ltd filed Critical Mullard Ltd
Priority to GB2096865A priority Critical patent/GB1146976A/en
Publication of GB1146976A publication Critical patent/GB1146976A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/005Emergency protective circuit arrangements for limiting excess current or voltage without disconnection avoiding undesired transient conditions

Abstract

1,146,976. Switching surge protection arrangements. MULLARD Ltd. 28 March, 1966 [18 May, 1965], No. 20968/65. Heading H2H. A protection arrangement suitable for use with an electric motor whose speed is controlled by varying the firing point of semi-conductor controlled rectifiers, for example as in the control circuit described in Specification 1,146,977, comprises a capacitor 1 whose charging time is determined by the setting of a switch 4 and which in turn determines the firing instant of a semi-conductor controlled rectifier (not shown) by means of an oscillator circuit comprising a transistor 8, a transformer T and a diode 10, the charging time being increased for a period immediately succeeding the energization of the motor to fire the rectifier late in each half-wave cycle and so reduce the current surges produced by such energization. In the described embodiment the protection is provided for the high speed setting of the motor by using a thermistor 7 having an initially high resistance which rapidly falls to a value corresponding (with that of resistor 2) to the normal speed of the motor on this setting. For the low and medium speed settings conventional resistors 5, 6 are used, since the rectifier fires late for these settings and hence protection is not required. For three high speed settings resistors 5, 6, 7 may be conventional and the resistor 2 may be a thermistor. Other modifications include omitting the resistor 2, shunting the thermistor with a resistor or connecting it in series with a bleed resistor connected to the negative side of the supply. In order to synchronize the timing of the charging of capacitor 1, a Zener diode (not shown) can be connected in parallel with the voltage divider 9 and shunting the capacitor 1, the Zener diode being arranged to conduct on certain portions of a rectified half wave supplied to the circuit.
GB2096865A 1965-05-18 1965-05-18 Surge protection circuit Expired GB1146976A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2096865A GB1146976A (en) 1965-05-18 1965-05-18 Surge protection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2096865A GB1146976A (en) 1965-05-18 1965-05-18 Surge protection circuit

Publications (1)

Publication Number Publication Date
GB1146976A true GB1146976A (en) 1969-03-26

Family

ID=10154898

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2096865A Expired GB1146976A (en) 1965-05-18 1965-05-18 Surge protection circuit

Country Status (1)

Country Link
GB (1) GB1146976A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2162387A (en) * 1984-05-22 1986-01-29 Mabuchi Motor Co Speed control
WO2009120785A3 (en) * 2008-03-25 2009-12-30 Ebr Systems, Inc. Implantable wireless acoustic stimulators with high energy conversion efficiencies
US8364276B2 (en) 2008-03-25 2013-01-29 Ebr Systems, Inc. Operation and estimation of output voltage of wireless stimulators
US9180285B2 (en) 2008-03-25 2015-11-10 Ebr Systems, Inc. Implantable wireless accoustic stimulators with high energy conversion efficiencies
US11654287B2 (en) 2019-08-30 2023-05-23 Ebr Systems, Inc. Pulse delivery device including slew rate detector, and associated systems and methods

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2162387A (en) * 1984-05-22 1986-01-29 Mabuchi Motor Co Speed control
WO2009120785A3 (en) * 2008-03-25 2009-12-30 Ebr Systems, Inc. Implantable wireless acoustic stimulators with high energy conversion efficiencies
US8364276B2 (en) 2008-03-25 2013-01-29 Ebr Systems, Inc. Operation and estimation of output voltage of wireless stimulators
US9180285B2 (en) 2008-03-25 2015-11-10 Ebr Systems, Inc. Implantable wireless accoustic stimulators with high energy conversion efficiencies
US9343654B2 (en) 2008-03-25 2016-05-17 Ebr Systems, Inc. Method of manufacturing implantable wireless acoustic stimulators with high energy conversion efficiencies
US9981138B2 (en) 2008-03-25 2018-05-29 Ebr Systems, Inc. Operation and estimation of output voltage of wireless stimulators
US10052493B2 (en) 2008-03-25 2018-08-21 Ebr Systems, Inc. Implantable wireless accoustic stimulators with high energy conversion efficiencies
US10512785B2 (en) 2008-03-25 2019-12-24 Ebr Systems, Inc. Implantable wireless accoustic stimulators with high energy conversion efficiencies
US10806938B2 (en) 2008-03-25 2020-10-20 Ebr Systems, Inc. Implantable wireless accoustic stimulators with high energy conversion efficiencies
US11712572B2 (en) 2008-03-25 2023-08-01 Ebr Systems, Inc. Implantable wireless acoustic stimulators with high energy conversion efficiencies
US11654287B2 (en) 2019-08-30 2023-05-23 Ebr Systems, Inc. Pulse delivery device including slew rate detector, and associated systems and methods

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