KR20010056859A - Power protect circuit - Google Patents

Power protect circuit Download PDF

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Publication number
KR20010056859A
KR20010056859A KR1019990058509A KR19990058509A KR20010056859A KR 20010056859 A KR20010056859 A KR 20010056859A KR 1019990058509 A KR1019990058509 A KR 1019990058509A KR 19990058509 A KR19990058509 A KR 19990058509A KR 20010056859 A KR20010056859 A KR 20010056859A
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KR
South Korea
Prior art keywords
power
control signal
switching transistor
protection circuit
base
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KR1019990058509A
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Korean (ko)
Inventor
이용석
Original Assignee
이형도
삼성전기주식회사
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Priority to KR1019990058509A priority Critical patent/KR20010056859A/en
Publication of KR20010056859A publication Critical patent/KR20010056859A/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/20—Emergency 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 voltage
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/20—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for electronic equipment

Abstract

PURPOSE: A protection circuit for an electric power source is provided to prevent the overvoltage from applying to the other circuits by using the switching unit operated by the clock signal having a predefined duty ratio. CONSTITUTION: The protection circuit comprises an input port to receive an electric power(VCC), an output port to apply the power to the target circuit, a control signal input port to receive the control signal used to control the power supply, and a switching unit to supply or to stop of the power supplying according to the control signal. The protection circuit includes the first switching transistor where the emitter and the collector are connected and the base is connected to the collector via the first capacitor and connected to the collector of the second switching transistor via a resistor and the first and second capacitors are grounded, and the emitter of the second switching transistor is grounded and the collector and the base are connected each other via a resistor and the base of the second switching transistor is connected to the control signal input port via a resistor. The protection circuit bypasses the applied input voltage to the output port when the voltage level of the base of the second switching transistor is high level, and isolates the applied input voltage when the voltage level of the base is low level.

Description

전원보호회로{POWER PROTECT CIRCUIT}Power protection circuit {POWER PROTECT CIRCUIT}

본 발명은 과전압 인가시 이를 후단에 인가되지 않도록 하여 회로를 보호하는 전원보호회로에 관한 것으로, 보다 상세하게는 소정의 듀티비를 갖는 클럭신호에 의해 동작하는 스위칭수단을 통해 전원을 인가시켜 과전압이 다른 회로에 인가되는 것을 방지하는 전원보호회로에 관한 것이다.The present invention relates to a power supply protection circuit for protecting a circuit by preventing it from being applied to the rear end when an overvoltage is applied, and more particularly, by applying a power supply through a switching means operated by a clock signal having a predetermined duty ratio. The present invention relates to a power supply protection circuit that prevents it from being applied to another circuit.

일반적으로, 전원보호회로는 도 1의 (A),(B)에 도시한 바와 같이, 전원(VCC)이 통과하는 라인에 소정 값의 인덕터(L1) 또는 저항(R1)을 연결하고, 상기 인덕터(L1) 또는 저항(R1)의 양단을 각각 캐패시터(C1,C2)를 통해 접지시켜 구현된다.In general, as shown in (A) and (B) of FIG. 1, a power supply protection circuit connects an inductor L1 or a resistor R1 having a predetermined value to a line through which the power supply VCC passes. Both ends of L1 or resistor R1 are grounded through capacitors C1 and C2, respectively.

이러한 종래의 전원보호회로는 단순하게 전원을 해당 회로에 인가하는데 있어, 교류잡음신호를 접지된 캐패시터(C1,C2)를 통해 바이패스시키고, 해당 전원이 인덕터(L1) 또는 저항(R1)에 의해 감쇄되도록 하여 소정 레벨이상의 과전압이 다른 회로에 인가되는 것을 방지하도록 하고 있는 것이다.The conventional power protection circuit simply applies power to the circuit, bypasses the AC noise signal through the grounded capacitors C1 and C2, and the power is supplied by the inductor L1 or the resistor R1. The attenuation is prevented from applying an overvoltage above a predetermined level to other circuits.

전원을 항시 인가되는 대부분의 경우에는 상기와 같은 단순한 종래의 전원보호회로를 통해 과전압을 방지하는데 효과를 볼 수 있으나, 절전효과등을 위하여 일정 주기로 동작하는 회로등에는 동작전원(VCC)이 상기 동작주기에 맞춰 인가되어야 하는데, 이 경우, 상기와 같은 종래의 전원보호회로를 사용하면 전원(VCC) 온시점의 피크치등과 같은 과전압이 그대로 후단에 인가되어, 라인인터페이스(line interface)회로에서 발생할 수 있는 과전압을 방지할 수 없어, 다른 회로까지 고장나게 하는 문제점이 있다.In most cases where the power is always applied, it is effective to prevent overvoltage through the simple conventional power protection circuit as described above, but the operation power supply (VCC) operates the circuit to operate at regular intervals for power saving effect. In this case, if the conventional power protection circuit as described above is used, an overvoltage, such as a peak value at the time of power supply (VCC), is applied to the rear stage as it is, and may occur in a line interface circuit. There is a problem that overvoltage cannot be prevented, which causes other circuits to fail.

또한, 음전원이 먼저 인가되어야 하는 특수한 회로에 있어서, 상기와 같은 전원보호회로는 양전원이 먼저 입력되는 것을 방지할 수 없는 문제점이 있다.In addition, in a special circuit to which the negative power must be applied first, the power protection circuit as described above has a problem that the positive power cannot be prevented from being input first.

또한, 과전압에 의한 고장 발생시, 과전압이 거의 그대로 인가됨으로서, 어느 부분에 고장이 발생하였는지를 쉽게 찾을 수 없다는 문제점이 있다.In addition, when a failure occurs due to overvoltage, the overvoltage is almost applied as it is, so there is a problem that it is not easy to find in which part the failure occurs.

본 발명은 상기와 같은 종래의 문제점을 해결하기 위하여 발명된 것으로서, 그 목적은 소정의 듀티비를 갖는 클럭신호에 의해 동작하는 스위칭수단을 통해 동작전원을 인가시켜 과전압이 다른 회로에 인가되는 것을 방지하는 전원보호회로를 제공하는 것이다.The present invention has been invented to solve the conventional problems as described above, and its object is to prevent the overvoltage from being applied to other circuits by applying the operating power through a switching means operated by a clock signal having a predetermined duty ratio. It is to provide a power supply protection circuit.

도 1은 종래의 전원보호회로를 도시한 회로도이다.1 is a circuit diagram showing a conventional power protection circuit.

도 2는 본 발명에 의한 전원보호회로를 보이는 회로도이다.2 is a circuit diagram showing a power protection circuit according to the present invention.

*도면의 주요 부분에 대한 부호의 설명** Description of the symbols for the main parts of the drawings *

Q10 : PNP 트랜지스터Q10: PNP transistor

Q20 : NPN 트랜지스터Q20: NPN transistor

R21, R22, L21, L22 : 저항R21, R22, L21, L22: resistor

C21, C22 : 캐패시터C21, C22: Capacitor

21 : 전원입력단21: power input terminal

22 : 전원출력단22: power output terminal

23 : 제어신호입력단23: control signal input terminal

상술한 본 발명의 목적을 달성하기 위한 구성수단으로서, 본 발명에 의한 전원 보호회로는As a constitutional means for achieving the above object of the present invention, the power protection circuit according to the present invention

전원(VCC)을 인가받는 입력단과,An input terminal to which a power supply VCC is applied,

전원이가 대상회로에 연결되어 전원을 가하는 출력단과,An output terminal to which power is connected to the target circuit to apply power;

전원인가여부를 제어하는 제어신호가 인가되는 제어신호입력단과,A control signal input terminal to which a control signal for controlling power supply is applied;

상기 입출력단 사이에 구비되어 상기 제어신호입력단으로부터 인가되는 제어신호에 따라서 도통/차단상태가 되어 출력단으로 전원을 인가 또는 차단시키는 스위칭수단으로 이루어짐을 특징으로 한다.The switching device is provided between the input and output terminals to be in a conduction / blocking state according to a control signal applied from the control signal input terminal, and is configured to switch power to or from the output terminal.

이하, 첨부한 도면을 참조하여 본 발명에 의한 전원보호회로의 구성 및 작용을 설명한다.Hereinafter, with reference to the accompanying drawings will be described the configuration and operation of the power protection circuit according to the present invention.

도 2는 본 발명에 의한 전원 보호 회로의 구성을 보이는 회로도로서, 전원(VCC)인가 라인상에 제1스위칭트랜지스터(Q10)를 콜렉터-이미터(C-E) 접속되도록 연결하고, 상기 제1스위칭트랜지스터(Q10)의 베이스는 캐패시터(C21)을 통해 콜렉터에 연결함과 동시에, 상기 캐패시터(C21) 및 캐패시터(C22)를 통해 접지시키면서, 또한 저항(R22)을 통해 제2스위칭트랜지스터(Q20)의 콜렉터에 연결하고, 전원(VCCin)이 입력되는 상기 제1스위칭트랜지스터(Q10)의 이미터는 저항(R21)을 통해 상기 제2스위칭트랜지스터(Q20)의 콜렉터에 연결하고, 상기 제2스위칭트랜지스터(Q20)의 이미터는 접지시키면서, 그 콜렉터 및 베이스를 저항(L22)을 통해 연결하고, 상기 제2스위칭트랜지스터(Q20)의 베이스는 저항(R21)을 통해 제어전압(Vin)이 입력되는 제어신호입력단자(23)에 연결하여 구성한다.FIG. 2 is a circuit diagram illustrating a power protection circuit according to an embodiment of the present invention. The first switching transistor Q10 is connected to a collector-emitter CE on a power supply VCC line, and the first switching transistor is connected to the first switching transistor Q10. The base of Q10 is connected to the collector through the capacitor C21, and grounded through the capacitor C21 and the capacitor C22, and also through the resistor R22, the collector of the second switching transistor Q20. The emitter of the first switching transistor Q10 to which the power supply VCCin is input is connected to the collector of the second switching transistor Q20 through a resistor R21, and the second switching transistor Q20. While the emitter of the ground is connected to the collector and the base through the resistor (L22), the base of the second switching transistor (Q20) the control signal input terminal (Cin) through which the control voltage (Vin) is input. 23) to connect and configure .

상기에서, 제1스위칭트랜지스터(Q10)는 NPN트랜지스터이고, 제2스위칭트랜지스터(Q20)는 PNP트랜지스터로서, 상기 전원 보호 회로는 제1스위칭트랜지스터(Q10)가 도통될 때 교류잡음이 캐패시터(C21, C22)를 통해 접지로 바이패스되면서, 전원(VCC)이 출력단(22)으로 출력되고, 상기 제1스위칭트랜지스터(Q10)는 제2스위칭트랜지스터(Q20)가 도통될 때, 입력단(21)으로 인가된 전원(VCCin)이 도통된 제2스위칭트랜지스터(Q20)을 통해 접지되면서, 그 베이스의 전압이 소정 레벨, 예를 들어, 거의 OV로 낮아져 도통상태가 된다.In the above description, the first switching transistor Q10 is an NPN transistor, the second switching transistor Q20 is a PNP transistor, and the power protection circuit has an AC noise when the first switching transistor Q10 is conducted. Bypassing to ground through C22, the power supply VCC is output to the output terminal 22, and the first switching transistor Q10 is applied to the input terminal 21 when the second switching transistor Q20 is conducted. As the grounded power supply VCCin is grounded through the conductive second switching transistor Q20, the voltage of the base is lowered to a predetermined level, for example, almost OV, thereby becoming a conductive state.

그리고, 상기 제2스위칭트랜지스터(Q20)은 제어신호입력단자(23)를 통해 소정 기준레벨이상의 전압이 인가될 때, 그 베이스전압이 높아져 도통상태가 되고, 기준레벨이하의 낮은 전압이 인가될 때, 그 베이스전압이 OV이하로 낮아져 차단상태가 된다.When the second switching transistor Q20 is applied with a voltage higher than or equal to a predetermined reference level through the control signal input terminal 23, the base voltage is increased to become a conductive state, and when a lower voltage lower than or equal to the reference level is applied. As a result, the base voltage is lowered below OV, and the state is cut off.

이에 의하여, 상기 도 2와 같은 본 발명에 의한 전원 보호 회로는 제어신호입력단자(23)로 입력되는 제어신호에 따라서, 그 전압레벨이 하이(HIGH)일때, 도통상태가 되어, 입력단(21)으로 들어오는 전원(VCC)를 출력단(22)을 통해 출력하고, 그 전압레벨이 로우(LOW)일때, 차단동작하여 입력단(21)으로 인가되는 전원(VCC)이 출력단(22)으로 출력되지 못하게 한다.Thus, according to the control signal input to the control signal input terminal 23, the power protection circuit according to the present invention as shown in FIG. 2 becomes a conduction state when the voltage level is HIGH, and the input terminal 21 The output power supply (VCC) is output through the output terminal 22, and when the voltage level is LOW, it cuts off so that the power supply (VCC) applied to the input terminal 21 is not output to the output terminal 22. .

본 실시예에서는 상기 제어신호입력단(23)으로 인가하는 제어신호로서 듀티비가 8:2 인 클럭신호를 예로 드는데, 이렇게 듀티비가 8:2인 클럭신호를 상기 제어신호입력단(23)에 인가하여 클럭신호가 하이상태일때만 전원(VCC)가 출력되도록 함으로서, 라인인터페이스(LIF) 회로에서 발생할 수 있는 과전압이 다른 회로에 인가되는 것을 방지할 수 있다.In this embodiment, a clock signal having a duty ratio of 8: 2 is given as an example of a control signal applied to the control signal input terminal 23. Thus, a clock signal having a duty ratio of 8: 2 is applied to the control signal input terminal 23 to clock. By supplying the power supply VCC only when the signal is high, it is possible to prevent the overvoltage that may occur in the line interface LIF circuit from being applied to the other circuit.

상기 제어신호입력단(23)으로 인가되는 제어신호는 전원을 가해야 할 대상 회로의 동작특성에 맞춰 설정할 수 있다. 예를 들어, 전원인가 대상 회로가 소정의 주기로 동작하는 회로라면, 그 주기와 일치하는 클럭신호를 상기 제어신호입력단(23)에 인가하여, 해당 회로의 동작시에만 전원이 인가되도록 하여 절전효과를 볼 수 있다.The control signal applied to the control signal input terminal 23 may be set according to an operation characteristic of a target circuit to which power is applied. For example, if the circuit to be powered is operated at a predetermined cycle, a clock signal corresponding to the cycle is applied to the control signal input terminal 23 so that power is applied only when the circuit is operated, thereby reducing power savings. can see.

또한, 입력단(23)으로 인가되는 전원(VCCin)이 과전압일 경우, 상기 제1스위칭트랜지스터(Q10)에 의해 출력단(22)에 연결되는 회로로는 해당 과전압이 인가되지 않고, 상기 제1스위칭트랜지스터(Q10)를 포함하는 전원보호회로만 과전압에 의해 소손되므로, 과전압에 의한 전체 회로의 소손을 방지하고, 회로교체시 상기와 같은 전원보호회로만 교체하면 된다.In addition, when the power VCCin applied to the input terminal 23 is an overvoltage, the overvoltage is not applied to the circuit connected to the output terminal 22 by the first switching transistor Q10, and the first switching transistor is not applied. Since only the power protection circuit including (Q10) is burned out by the overvoltage, the burnout of the entire circuit due to the overvoltage is prevented, and only the above power protection circuit needs to be replaced when the circuit is replaced.

이상 상술한 바와 같이, 본 발명에 의한 전원 보호 회로에 의하면, 순간적인 과전압 발생시, 이에 의하여 전원이 가해지는 대상회로의 소손을 방지할 수 있으며, 라인인터페이스회로에서 발생할 수 있는 과전압에 의한 소손을 방지할 수 있고어 본 전원 보호 회로가 사용되는 시스템의 전체적인 안정화를 도모할 수 있는 우수한 효과가 있다.As described above, according to the power supply protection circuit according to the present invention, when an instantaneous overvoltage occurs, it is possible to prevent the burnout of the target circuit to which the power is applied, and to prevent the burnout due to the overvoltage that may occur in the line interface circuit. In addition, there is an excellent effect that can achieve overall stabilization of the system in which the power protection circuit is used.

또한, 전원 인가 대상 회로의 동작특성에 맞춰 전원제어가 가능함으로서, 다양한 회로에 적용가능하다는 우수한 효과가 있다.In addition, the power supply can be controlled in accordance with the operation characteristics of the power supply target circuit, there is an excellent effect that can be applied to various circuits.

Claims (3)

전원(VCC)을 인가받는 입력단과,An input terminal to which a power supply VCC is applied, 전원이가 대상회로에 연결되어 전원을 가하는 출력단과,An output terminal to which power is connected to the target circuit to apply power; 전원인가여부를 제어하는 제어신호가 인가되는 제어신호입력단과,A control signal input terminal to which a control signal for controlling power supply is applied; 상기 입출력단 사이에 구비되어 상기 제어신호입력단으로부터 인가되는 제어신호에 따라서 도통/차단상태가 되어 출력단으로 전원을 인가 또는 차단시키는 스위칭수단으로 이루어짐을 특징으로 하는 전원 보호 회로.And a switching means provided between the input and output terminals to be in a conducting / blocking state according to a control signal applied from the control signal input terminal to apply or cut power to the output terminal. 제 1 항에 있어서, 상기 스위칭수단은The method of claim 1, wherein the switching means 입력단과 출력단 사이에 직렬로 제1스위칭트랜지스터를 이미터-콜렉터결합시키고, 상기 제1스위칭트랜지스터의 베이스는 저항을 통하여, 그 베이스가 저항을 통해 상기 제어신호입력단에 연결된 제2스위칭트랜지스터의 콜렉터를 연결하고, 상기 제2스위칭트랜지스터의 콜렉터는 저항을 통해 입력단에 연결하며, 상기 제1스위칭트랜지스터의 베이스는 캐패시터를 통해 자신의 콜렉터에 연결함과 동시에 다른 캐패시터를 통해 접지시켜 구성하는 것을 특징으로 하는 전원 보호 회로.Emitter-collector coupling of the first switching transistor in series between the input terminal and the output terminal, the base of the first switching transistor through a resistor, the base of the second switching transistor connected to the control signal input terminal through a resistor And the collector of the second switching transistor is connected to an input terminal through a resistor, and the base of the first switching transistor is connected to its collector through a capacitor and simultaneously grounded through another capacitor. Power protection circuit. 제1항 또는 제2항에 있어서, 상기 제어신호입력단에는 듀티비가 8:2인 클럭신호를 인가하는 것을 특징으로 하는 전원 보호 회로.The power protection circuit according to claim 1 or 2, wherein a clock signal having a duty ratio of 8: 2 is applied to the control signal input terminal.
KR1019990058509A 1999-12-17 1999-12-17 Power protect circuit KR20010056859A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100684381B1 (en) * 2004-10-04 2007-02-20 양태식 A electricity roaster of the rotation
KR20160024591A (en) 2014-08-26 2016-03-07 (주)엔디비젼 monitor apparatus for controlling closed circuit television system and method thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0487516A (en) * 1990-07-23 1992-03-19 Hitachi Ltd Overcurrent protective method and ringing choke converter type switching power supply
JPH05244722A (en) * 1992-02-13 1993-09-21 Nec Corp Protective circuit for dc power supply
KR960025683A (en) * 1994-12-30 1996-07-20 최석한 Flexible cycle
KR960025818A (en) * 1994-12-01 1996-07-20 양승택 Data downloading method using high speed communication line
KR970068083A (en) * 1996-03-08 1997-10-13 김광호 Switching mode power supply with overcurrent and overvoltage protection

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0487516A (en) * 1990-07-23 1992-03-19 Hitachi Ltd Overcurrent protective method and ringing choke converter type switching power supply
JPH05244722A (en) * 1992-02-13 1993-09-21 Nec Corp Protective circuit for dc power supply
KR960025818A (en) * 1994-12-01 1996-07-20 양승택 Data downloading method using high speed communication line
KR960025683A (en) * 1994-12-30 1996-07-20 최석한 Flexible cycle
KR970068083A (en) * 1996-03-08 1997-10-13 김광호 Switching mode power supply with overcurrent and overvoltage protection

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100684381B1 (en) * 2004-10-04 2007-02-20 양태식 A electricity roaster of the rotation
KR20160024591A (en) 2014-08-26 2016-03-07 (주)엔디비젼 monitor apparatus for controlling closed circuit television system and method thereof

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