GB1187402A - Overload Protection Circuits - Google Patents

Overload Protection Circuits

Info

Publication number
GB1187402A
GB1187402A GB1735267A GB1735267A GB1187402A GB 1187402 A GB1187402 A GB 1187402A GB 1735267 A GB1735267 A GB 1735267A GB 1735267 A GB1735267 A GB 1735267A GB 1187402 A GB1187402 A GB 1187402A
Authority
GB
United Kingdom
Prior art keywords
transistor
circuit
capacitor
conducting
input signal
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
GB1735267A
Inventor
David Jenkins
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.)
Fujitsu Services Ltd
Original Assignee
Fujitsu Services 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 Fujitsu Services Ltd filed Critical Fujitsu Services Ltd
Priority to GB1735267A priority Critical patent/GB1187402A/en
Publication of GB1187402A publication Critical patent/GB1187402A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/08Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
    • H02H3/093Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current with timing means
    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03KPULSE TECHNIQUE
    • H03K17/00Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/08Modifications for protecting switching circuit against overcurrent or overvoltage
    • H03K17/082Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit
    • H03K17/0826Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit in bipolar transistor switches

Landscapes

  • Electronic Switches (AREA)

Abstract

1,187,402. Protecting transistor circuits. INTERNATIONAL COMPUTERS Ltd. 24 May, 1968 [14 April, 1967], No. 17352/67. Heading H3T. [Also in Division H2] A circuit has a load 26 in series with a switching device, e.g. a transistor 2, a bi-stable circuit 12 means to apply an input signal to the switching device to render it conducting and to the circuit 12, to initiate a change to a state in which it renders the switching device 2 non- conducting and means to prevent the circuit 12 changing its state providing the device 2 conducts normally within a predetermined time. In the arrangement shown, a signal at a terminal 4 causes a transistor 1 to conduct to apply an input signal to the transistor 2 to render it conductive and to the circuit 12 where current flows through a resistor 18 and a Zener diode 16 to charge a capacitor 17. Providing no overload condition exists, the collector potential of the transistor 2 becomes such as to unblock a diode 22 to prevent the input signal charging the capacitor. However, should there be an overload condition, then the collector potential of the transistor 2 remains or becomes sufficiently positive to block the diode 22, the capacitor 17 charges so that after the predetermined time the potential across the capacitor causes the transistors 13, 14 to conduct and connect the base of the transistor 2 to a negative potential sufficient to stop it conducting. The transistors 13, 14 remain conducting until the fault condition is removed and a test/reset switch 24 is operated. A fault-indicating lamp 25 is provided.
GB1735267A 1967-04-14 1967-04-14 Overload Protection Circuits Expired GB1187402A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1735267A GB1187402A (en) 1967-04-14 1967-04-14 Overload Protection Circuits

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1735267A GB1187402A (en) 1967-04-14 1967-04-14 Overload Protection Circuits

Publications (1)

Publication Number Publication Date
GB1187402A true GB1187402A (en) 1970-04-08

Family

ID=10093678

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1735267A Expired GB1187402A (en) 1967-04-14 1967-04-14 Overload Protection Circuits

Country Status (1)

Country Link
GB (1) GB1187402A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2310039A1 (en) * 1975-02-03 1976-11-26 Ibm LOGIC CONTROL CIRCUIT INCLUDING AN OUTPUT PROTECTION DEVICE

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2310039A1 (en) * 1975-02-03 1976-11-26 Ibm LOGIC CONTROL CIRCUIT INCLUDING AN OUTPUT PROTECTION DEVICE

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees