KR20010008551A - Circuit for limiting over current - Google Patents

Circuit for limiting over current Download PDF

Info

Publication number
KR20010008551A
KR20010008551A KR1019990026454A KR19990026454A KR20010008551A KR 20010008551 A KR20010008551 A KR 20010008551A KR 1019990026454 A KR1019990026454 A KR 1019990026454A KR 19990026454 A KR19990026454 A KR 19990026454A KR 20010008551 A KR20010008551 A KR 20010008551A
Authority
KR
South Korea
Prior art keywords
current
output
operational amplifier
resistor
overcurrent
Prior art date
Application number
KR1019990026454A
Other languages
Korean (ko)
Inventor
임성호
Original Assignee
이형도
삼성전기 주식회사
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 이형도, 삼성전기 주식회사 filed Critical 이형도
Priority to KR1019990026454A priority Critical patent/KR20010008551A/en
Publication of KR20010008551A publication Critical patent/KR20010008551A/en

Links

Classifications

    • 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
    • H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
    • 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
    • H02H7/10—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 converters; for rectifiers
    • H02H7/12—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 converters; for rectifiers for static converters or rectifiers
    • 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
    • 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
    • H02H9/005—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection avoiding undesired transient conditions

Abstract

PURPOSE: An over current limit circuit is provided to reduce the capacity in a power source supplying device of a computer which has a CD-ROM drive which needs much current initially. CONSTITUTION: A circuit is provided to a switching mode power source supplying device controlled by a PWM IC. A power source voltage outputted to a power source outputting end of a power source supplying device is applied to a current level detecting means. The power source voltage is passed through a load, and detects the level of the output current. An overcurrent limit circuit section compares the output current detected by the current level detecting means with a standard level. If the output current is over the standard level, the state is determined to be the overcurrent state.

Description

과전류 제한 회로{CIRCUIT FOR LIMITING OVER CURRENT}Overcurrent Limiting Circuit {CIRCUIT FOR LIMITING OVER CURRENT}

본 발명은 휴대용 컴퓨터(일명, 노트북)에서 사용되는 어댑터에 구비되는 과전류 제한 회로에 관한 것으로, 보다 상세하게는 어댑터의 정격용량을 줄이면서 부품의 수명을 높힐 수 있는 구조로 설계된 과전류 제한 회로에 관한 것이다.The present invention relates to an overcurrent limiting circuit provided in an adapter used in a portable computer (aka, laptop), and more particularly, to an overcurrent limiting circuit designed to increase the life of components while reducing the rated capacity of the adapter. will be.

일반적으로, 휴대용 컴퓨터는 초기기동시, CD-ROM드라이브의 기동등에 의해 많은 전류를 소모하지만, 일단 동작이 시작되면 휠씬 작은 전류로 동작상태를 유지한다. 그렇기 때문에, 보통 기재되어 있는 정격전력은 실제 동작시의 소모전력보다 휠씬 높다.In general, a portable computer consumes a large amount of current due to a CD-ROM drive, etc., during initial startup, but maintains an operation state with a much smaller current once the operation is started. Therefore, the rated power usually described is much higher than the power consumption in actual operation.

그리고, 휴대용 컴퓨터를 동작시키는 전원이 인가될 때, 불필요한 과전류가 발생하게 되면, 시스템의 과부하에 의해 고장이 발생할 수 있기 때문에, 도 1에 도시한 바와 같이 전원출력단(Vout+, Vout-)에 과전류제한회로(OVER CURRENT LIMIT CIRCUIT)를 설치하여, 제한치 이상의 과전류가 흐르지 못하도록 제어한다.When an unnecessary overcurrent occurs when a power source for operating a portable computer is applied, a failure may occur due to an overload of the system. Thus, as shown in FIG. 1, an overcurrent limit is applied to the power output terminals Vout + and Vout-. OVER CURRENT LIMIT CIRCUIT is installed to control over current beyond the limit.

도 1에 보인 과전류제한회로는 전원출력단(Vout+,Vout-)를 통해 부하로 흐르는 출력전류(I0)를 부하에 직렬로 연결된 전류검출용 센싱저항(RS)으로 검출하고, 연산증폭기(U1)를 통해 이를 기준값(Vref)과 비교한다. 상기 연산증폭기(U1)에 의해 (+)의 기준값(Vref)과 (-)의 검출전류(I0)가 비교될 때, 출력전류(I0)의 증가로 센싱저항(Rs)의 양단에서의 전압강화가 기준값보다 커지면, 연산증폭기(U1)로부터 로우레벨전압이 출력되고, 이에 포토커플러(P/C)가 동작한다. 즉, 상기 포토커플러(P/C)의 발광다이오드가 점등됨에 의해 그에 대응하는 포토트랜지스터가 온되고, 이 포토트랜지스터의 온신호는 도시되지 않았으나, 출력전압크기를 제어하는 PWM제어기(도시생략)로 입력되어, PWM제어기가 출력전압을 다운되도록 제어한다.The overcurrent limiting circuit shown in FIG. 1 detects the output current I 0 flowing to the load through the power output terminals Vout + and Vout- with a current detection sensing resistor R S connected in series with the load, and the operational amplifier U1. ) And compare it with the reference value (Vref). When the reference value (Vref) of (+) and the (+) detection current (I 0 ) are compared by the operational amplifier (U1), the output current (I 0 ) is increased at both ends of the sensing resistor (Rs). When the voltage increase is greater than the reference value, the low level voltage is output from the operational amplifier U1, and the photocoupler P / C operates. That is, when the light emitting diode of the photocoupler P / C is turned on, the phototransistor corresponding thereto is turned on. Although the on-signal of the phototransistor is not shown, a PWM controller (not shown) controls the output voltage size. Input, the PWM controller controls the output voltage to be down.

여기에서, 상기와 같은 종래의 과전류제한회로에서는 CD-ROM 드라이브의 구동용량을 감안하여, 정격용량보다 훨씬 큰 값으로 과전류한계치를 설정하여, 해당 한계치 이상으로 과전류가 발생할 때, 과전류리미트동작을 실시하도록 하고 있다.Here, in the conventional overcurrent limiting circuit as described above, in consideration of the driving capacity of the CD-ROM drive, the overcurrent limit value is set to a value much larger than the rated capacity, and an overcurrent limit operation is performed when an overcurrent occurs above the limit value. I'm trying to.

그렇기 때문에, 부품의 크기도 커지고, 이에 따라 단가가 상승하게 되는 문제점이 있다.Therefore, there is a problem in that the size of the component is also increased, thereby increasing the unit price.

본 발명은 상술한 종래의 문제점을 해결하기 위하여 안출된 것으로서, 그 목적은 전원공급장치에 있어서 그 정격용량은 줄이면서, 초기 기동시에 필요한 적정 전류를 확보할 수 있는 과전류 제한 회로를 제공하는 것이다.SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide an overcurrent limiting circuit which can secure an appropriate current required at initial startup while reducing its rated capacity in a power supply.

도 1은 어댑터의 출력측에 구비되는 종래의 과전류 제한 회로(over current limit circuit)를 도시한 회로도이다.1 is a circuit diagram showing a conventional over current limit circuit provided on the output side of an adapter.

도 2는 본 발명에 따른 과전류 제한 회로를 도시한 회로도이다.2 is a circuit diagram illustrating an overcurrent limiting circuit according to the present invention.

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

U1~U3 : 연산증폭기U1 ~ U3: Operational Amplifier

P/C : 포토커플러P / C: Photocoupler

R1~R11 : 저항R1 ~ R11: resistance

C1~C5 : 캐패시터C1 ~ C5: Capacitor

RS: 전류검출저항R S : Current detection resistor

상술한 본 발명의 목적을 달성하기 위한 구성수단으로서, 본 발명은 PWM IC에 의해 제어되는 스위칭모드 전원 공급장치에 구비되는 과전류 제한 회로에 있어서,As a constitutional means for achieving the above object of the present invention, the present invention provides an overcurrent limiting circuit provided in a switching mode power supply controlled by a PWM IC,

상기 전원 공급장치의 전원출력단으로 출력되는 전원전압이 인가되어 부하를 통과해 흐르는 출력전류의 레벨을 검출하는 전류레벨 검출수단과,Current level detection means for detecting a level of an output current flowing through a load by applying a power supply voltage output to a power output terminal of the power supply device;

상기 전류레벨 검출수단에 의해서 검출된 출력전류를 기준레벨과 비교하여 기준레벨이상일때 과전류상태로 판단하여 이를 전원공급장치를 제어하는 PWM IC에 알리는 과전류리미트회로부와,An overcurrent limit circuit unit for comparing the output current detected by the current level detecting means with a reference level to determine an overcurrent state when the current level is higher than the reference level and informing the PWM IC controlling the power supply device;

상기 전류레벨 검출수단에서 검출된 출력전류가 기준레벨보다 커질때, 상기 과전류 리미트회로부의 과전류신호 출력을 소정 시간 지연시키는 딜레이회로부로 이루어짐을 특징으로 한다.When the output current detected by the current level detecting means is greater than the reference level, it is characterized in that the delay circuit portion for delaying the output of the over-current signal portion of the over-current limit circuit portion for a predetermined time.

이하, 첨부한 도면을 참조하여 본 발명에 의한 과전류 제한 회로의 구성 및 작용을 상세하게 설명한다.Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the overcurrent limiting circuit according to the present invention.

본 발명에 의해 제안된 과전류 제한 회로는, CD-ROM 드라이브는 초기 구동될 때, 몇 초만 소비용량이 크고, 그 다음부터는 줄어드는 점을 감안하여 발명한 것으로, 과전류로 판단하는 기준이 되는 임계치(즉, 과전류 한계값)를 기동후 동작상태에서의 소모용량을 감안하여 된 레벨로 설정하고, 실제 출력전류가 상승할 때는, 소정 시간(즉, CD-ROM 드라이브가 초기 기동되는 시간)동안 상기 과전류제한회로의 동작을 지연시키는 것을 기술적 사상으로 한다.The overcurrent limiting circuit proposed by the present invention has been invented in view of the fact that when the CD-ROM drive is initially driven, the consumption capacity of the CD-ROM drive is large for a few seconds, and then decreases thereafter. , The overcurrent limit value is set to a level that takes into account the consumed capacity in the operating state after starting, and when the actual output current rises, the overcurrent limit for a predetermined time (that is, the time when the CD-ROM drive is initially started) The technical idea is to delay the operation of the circuit.

도 2는 상기와 같은 기술적 사상에 의해서 제안된 본 발명의 과전류제한회로(OVER CURRENT LIMIT CIRCUIT)를 도시한 것으로서, 전원공급장치의 전원전압이 출력되는 출력단(Vout-)에 직렬로 연결되는 전류검출저항(Rs)과, 기준값(Vref)과 상기 출력단(Vout-)의 출력전류를 각각 저항(R1,R2)을 통해 (+)입력단 및 (-)입력단으로 입력받아 비교연산하는 제1연산증폭기(U1)와, 상기 제1연산증폭기(U1)의 출력에 내부소자중 발광다이오드의 음극이 직렬연결된 다이오드(D1) 및 저항(R4)을 통해 연결되고 발광다이오드의 양극은 상기 어댑터의 출력단(Vout+)에 연결되는 포토커플러(P/C)와, 상기 전류검출저항(Rs)를 출력전류(Io)가 통과함에 의해 발생된 센싱전압(Vout-)과 두 저항(R6),(R7)의 저항비로 결정된 기준값(Vref)을 비교연산하는 제2연산증폭기(U2)와, 상기 제2연산증폭(U2)의 출력과 접지사이에 직렬연결되는 저항(R9) 및 캐패시터(C4)와, 상기 저항(R9)과 캐패시터(C4)의 접점이 그 (-)입력단에 연결되고 두 저항(R10,R11)의 저항비로 결정되는 기준값(Vref)이 (+)입력단에 연결되어 두 입력값을 비교연산하는 제3연산증폭기(U3)와, 상기 제3연산증폭기(U3)의 출력단에 음극이 연결되고 상기 포토커플러(P/C)의 발광다이오드 음극에 연결되는 다이오드(D2)로 이루어진다.FIG. 2 is a diagram illustrating an overcurrent limiting circuit of the present invention proposed by the technical concept as described above. The current detection is connected in series with an output terminal Vout- outputting a power supply voltage of a power supply device. The first operational amplifier receives and compares the resistance Rs, the reference value Vref, and the output current of the output terminal Vout- to the positive input terminal and the negative input terminal through the resistors R1 and R2, respectively. U1) and the cathode of the light emitting diode of the internal device are connected to the output of the first operational amplifier U1 through a diode D1 and a resistor R4 connected in series, and the anode of the light emitting diode is connected to the output terminal Vout + of the adapter. The photocoupler P / C connected to the sensor, the current detection resistance Rs, and the sensing ratio Vout- generated by the output current Io through the resistance ratios of the two resistors R6 and R7. A second operation amplifier U2 for comparatively comparing the determined reference value Vref, an output of the second operation amplifier U2, Resistor R9 and capacitor C4 connected in series between the ground and the contact point of resistor R9 and capacitor C4 are connected to their negative input terminals and are determined by the resistance ratio of the two resistors R10 and R11. (Vref) is connected to the (+) input terminal, the third operational amplifier (U3) for comparing the two input values and the negative terminal is connected to the output terminal of the third operational amplifier (U3) and the photocoupler (P / C) It consists of a diode (D2) connected to the light emitting diode cathode of.

상기 설명한 과전류제한회로는 다음과 같이 동작한다.The overcurrent limiting circuit described above operates as follows.

먼저, 상기 부하를 거쳐 흘러들어오는 출력전류(I0)가 센싱저항(Rs)를 통과하면서, 상기 센싱저항(Rs)의 양단에서 Rs[Ω]×Io[Α] 만큼의 전압강하가 생기며, 이렇게 센싱저항(Rs)에 걸리는 전압은 출력전류(I0)에 비례한다. 즉, 출력전류(I0)가 커질수록 상기 센싱저항(Rs)에서 일어나는 전압강하도 커진다.First, while the output current I 0 flowing through the load passes through the sensing resistor Rs, a voltage drop of Rs [Ω] × Io [Α] is generated at both ends of the sensing resistor Rs. The voltage across the sensing resistor Rs is proportional to the output current I 0 . That is, as the output current I 0 increases, the voltage drop occurring in the sensing resistor Rs also increases.

그리고, 상기 센싱저항(Rs)에 의해서 검출된 출력전류(I0)에 대응하는 센싱전압(Vout-)은 비교기로 동작하는 제1연산증폭기(U1)의 반전입력단(-)으로 입력된다. 또한, 상기 제1연산증폭기(U1)의 비반전입력단(+)으로는 기준전압(Vref)이 입력되므로, 출력전류(I0)가 증가하여 센싱저항(Rs)에서의 전압강하가 커지면, 상기 센싱전압(Vout-)과 기준전압(Vref)의 차가 상기 제1연산증폭기(U1)에 의해 증폭출력된다.The sensing voltage Vout− corresponding to the output current I 0 detected by the sensing resistor Rs is input to the inverting input terminal (−) of the first operational amplifier U1 operating as a comparator. In addition, since the reference voltage Vref is input to the non-inverting input terminal (+) of the first operational amplifier U1, when the output current I 0 increases and the voltage drop at the sensing resistor Rs increases, The difference between the sensing voltage Vout- and the reference voltage Vref is amplified and output by the first operational amplifier U1.

그리고, 상기 센싱전압(Vout-)은 또한 제2연산증폭기(U2)의 비반전입력단(+)으로 인가되고, 상기 제2연산증폭기(U2)의 반전입력단(-)으로는 저항(R7,R9)의 저항비에 의해 결정되는 기준전압(Vref)이 인가된다.The sensing voltage Vout- is also applied to the non-inverting input terminal (+) of the second operational amplifier U2, and the resistors R7 and R9 to the inverting input terminal (-) of the second operational amplifier U2. A reference voltage Vref determined by the resistance ratio of Nf is applied.

따라서, 상기 출력전류(I0)가 증가하여 상기 센싱전압(Vout-)이 A포인트의 전압보다 커지면 상기 제2연산증폭기(U2)의 출력은 하이레벨이 된다.Therefore, when the output current I 0 increases and the sensing voltage Vout− becomes greater than the voltage at the A point, the output of the second operational amplifier U2 becomes high.

그리고, 상기 제2연산증폭기(U2)의 출력은 RC회로(R9,C4)를 통해 제3연산증폭기(U3)의 반전입력단에 인가되므로, 상기 센싱전압(Vout)이 기준전압보다 큰 경우 출력되는 제2연산증폭기(U2)의 하이레벨전압은 상기 RC회로(R9,C4)에 의한 시정수()만큼 딜레이된 후 제3연산증폭기(U3)에 입력된다. 그리고, 이때 하이레벨신호를 출력하던 제3연산증폭기(U3)는 반전입력단의 전압이 비반전입력단의 전압보다 커져, 로우레벨신호를 출력한다.Since the output of the second operational amplifier U2 is applied to the inverting input terminal of the third operational amplifier U3 through RC circuits R9 and C4, it is output when the sensing voltage Vout is greater than the reference voltage. The high level voltage of the second operational amplifier U2 is determined by the time constant of the RC circuits R9 and C4. After delayed by), it is input to the third operational amplifier U3. At this time, the third operational amplifier U3 outputting the high level signal outputs a low level signal because the voltage at the inverting input terminal is greater than the voltage at the non-inverting input terminal.

상기와 같이, 제1연산증폭기(U1)과 제2연산증폭기(U2)의 출력이 모두 로우레벨이 되어, 두 다이오드(D1, D2)의 내부 저항이 거의 제로가 되고, 이에 포토커플러(P/C)의 발광다이오드에 충분한 전류가 흘러 동작한다.As described above, the outputs of the first operational amplifier U1 and the second operational amplifier U2 are both at the low level, so that the internal resistances of the two diodes D1 and D2 become almost zero, and thus the photocoupler P / Sufficient current flows through the light emitting diode of C).

상술한 바와 같이, 본 발명에 의하면 출력전류가 증가하는 시점에서 일정시간동안은 과전류상태를 그대로 유지시킴에 의해 초기기동시 필요한 많은 전류를 충분히 제공할 수 있고, 소정 시간지연후 기동후 동작시 필요한 전류량으로 출력전류를 제한하여, 초기기동에 많은 전류가 필요한 CD-ROM드라이브가 구비된 컴퓨터등의 전원공급장치에서 정격용량을 낮추는 효과가 있으며, 그로인한 보다 작은 용량의 부품을 사용할 수 있는 우수한 효과가 있는 것이다.As described above, according to the present invention, by maintaining the overcurrent state for a predetermined time at the time when the output current increases, it is possible to provide a sufficient amount of current necessary for initial startup, and is necessary for operation after startup after a predetermined time delay. By limiting the output current by the amount of current, it has the effect of lowering the rated capacity in a power supply device such as a computer equipped with a CD-ROM drive that requires a large amount of current for initial start-up. There is.

Claims (2)

PWM IC에 의해 제어되는 스위칭모드 전원 공급장치에 구비되는 과전류 제한 회로에 있어서,In the overcurrent limiting circuit provided in the switching mode power supply controlled by the PWM IC, 상기 전원 공급장치의 전원출력단으로 출력되는 전원전압이 인가되어 부하를 통과해 흐르는 출력전류의 레벨을 검출하는 전류레벨 검출수단과,Current level detection means for detecting a level of an output current flowing through a load by applying a power supply voltage output to a power output terminal of the power supply device; 상기 전류레벨 검출수단에 의해서 검출된 출력전류를 기준레벨과 비교하여 기준레벨이상일때 과전류상태로 판단하여 이를 전원공급장치를 제어하는 PWM IC에 알리는 과전류리미트회로부와,An overcurrent limit circuit unit for comparing the output current detected by the current level detecting means with a reference level to determine an overcurrent state when the current level is higher than the reference level and informing the PWM IC controlling the power supply device; 상기 전류레벨 검출수단에서 검출된 출력전류가 기준레벨보다 커질때, 상기 과전류 리미트회로부의 과전류신호 출력을 소정 시간 지연시키는 딜레이회로부로 이루어짐을 특징으로 하는 과전류 제한 회로.And a delay circuit section for delaying the output of the overcurrent signal of the overcurrent limit circuit section for a predetermined time when the output current detected by the current level detecting means is greater than a reference level. 제1항에 있어서, 상기 과전류 제한 회로는The circuit of claim 1, wherein the overcurrent limiting circuit is 상기 전류레벨 검출수단은 전원공급장치의 출력단(Vout-)에 직렬로 연결되는 전류검출저항(Rs)으로 구성하고,The current level detecting means comprises a current detecting resistor (Rs) connected in series to the output terminal (Vout-) of the power supply, 상기 과전류리미트회로부는 상기 전류검출저항(Rs)이 구비된 출력단(Vout-)을 저항(R2)를 통해 제1연산증폭기(U1)의 반전입력단에 연결하고, 리퍼런스전압( Vref)을 저항을 통해 제1연산증폭기(U1)의 비반전입력단에 연결하고, 상기 제1연산증폭기(U1)의 출력단을 저항(R4)를 통해 다이오드(D1)의 음극에 연결하고, 상기 다이오드(D1)의 양극과 전원단(Vout+)사이에 포토트랜지스터가 PWM IC에 연결되는 포토커플러(P/C)의 발광다이오드를 직렬로 연결하여 구성하고,The overcurrent limit circuit unit connects the output terminal Vout- provided with the current detection resistor Rs to the inverting input terminal of the first operational amplifier U1 through the resistor R2 and the reference voltage Vref through the resistor. Connect to the non-inverting input terminal of the first operational amplifier (U1), connect the output terminal of the first operational amplifier (U1) to the cathode of the diode (D1) through the resistor (R4), and the anode of the diode (D1) Between the power supply terminals (Vout +), the phototransistor is configured by connecting the light emitting diode of the photocoupler (P / C) connected to the PWM IC in series, 상기 딜레이회로부는 상기 전류검출저항(Rs)가 구비된 출력단(Vou-)을 저항(R6)을 통해 제2연산증폭기(U2)의 비반전입력단에 연결하고, 상기 리퍼런스전압(Vref)을 반전입력단에 연결하고, 상기 제2연산증폭기(U2)의 출력단을 직렬연결된 저항(R9) 및 콘덴서(C4)를 통해 접지시키고, 상기 저항(R9)과 콘덴서(C4)의 접점을 제3연산증폭기(U3)의 비반전입력단에 연결하고, 상기 제3연산증폭기(U3)의 반전입력단은 상기 리퍼런스전압을 분압하는 저항(R11,R10)의 접점에 연결하고, 상기 제2연산증폭기(U3)의 출력은 다이오드(D2)의 음극에 연결하고, 상기 다이오드(D2)의 양극을 상기 포토커플러(P/C)와 다이오드(D1)의 접점에 연결하여 구성함을 특징으로 하는 과전류 제한 회로.The delay circuit unit connects an output terminal Vou- provided with the current detection resistor Rs to a non-inverting input terminal of the second operational amplifier U2 through a resistor R6, and connects the reference voltage Vref to an inverting input terminal. The output terminal of the second operational amplifier (U2) is connected to the ground through a resistor (R9) and a capacitor (C4) connected in series, and the contact of the resistor (R9) and the capacitor (C4) to the third operational amplifier (U3) The inverting input terminal of the third operational amplifier U3 is connected to the contact of the resistors R11 and R10 for dividing the reference voltage, and the output of the second operational amplifier U3 is And a cathode of the diode (D2) and an anode of the diode (D2) connected to a contact point of the photocoupler (P / C) and the diode (D1).
KR1019990026454A 1999-07-02 1999-07-02 Circuit for limiting over current KR20010008551A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1019990026454A KR20010008551A (en) 1999-07-02 1999-07-02 Circuit for limiting over current

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1019990026454A KR20010008551A (en) 1999-07-02 1999-07-02 Circuit for limiting over current

Publications (1)

Publication Number Publication Date
KR20010008551A true KR20010008551A (en) 2001-02-05

Family

ID=19598761

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1019990026454A KR20010008551A (en) 1999-07-02 1999-07-02 Circuit for limiting over current

Country Status (1)

Country Link
KR (1) KR20010008551A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100608001B1 (en) * 2004-08-17 2006-08-02 삼성전자주식회사 Apparatus and method for limiting current of audio amplifier
KR100817053B1 (en) * 2006-05-10 2008-03-26 삼성전자주식회사 Over voltage protection circuit with logic for detecting over voltage and delay circuit in chip and method thereof
KR100839958B1 (en) * 2001-10-09 2008-06-19 삼성전자주식회사 Portable Computer
CN111697544A (en) * 2020-05-27 2020-09-22 国网天津市电力公司 Power supply overcurrent protector for distribution network automation equipment

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100839958B1 (en) * 2001-10-09 2008-06-19 삼성전자주식회사 Portable Computer
KR100608001B1 (en) * 2004-08-17 2006-08-02 삼성전자주식회사 Apparatus and method for limiting current of audio amplifier
KR100817053B1 (en) * 2006-05-10 2008-03-26 삼성전자주식회사 Over voltage protection circuit with logic for detecting over voltage and delay circuit in chip and method thereof
CN111697544A (en) * 2020-05-27 2020-09-22 国网天津市电力公司 Power supply overcurrent protector for distribution network automation equipment

Similar Documents

Publication Publication Date Title
US6127882A (en) Current monitors with independently adjustable dual level current thresholds
US7342761B2 (en) Apparatus and method for limiting application of electrical power to a load
KR101680792B1 (en) Electric device and control method of the same
KR20010008551A (en) Circuit for limiting over current
US8476877B2 (en) Fuel cell system and power management method thereof
JP3614693B2 (en) Power control device
JP3469172B2 (en) Chopper type regulator
KR20020016398A (en) Over voltage protection circuit for backlight inverter of LCD
JP3975828B2 (en) Semiconductor device
JP2000209777A (en) Power supply circuit and method for preventing rush current
JPH10336912A (en) Power supply switching device
KR20080109592A (en) Input apparatus for supplying power
JP2004185406A (en) Excess current protecting apparatus
KR20010047574A (en) Power device protection apparatus and method for inverter heat pump
JP3507164B2 (en) Power supply circuit for electronic equipment
JPH07184316A (en) Open phase detecting circuit
JP2001095236A (en) Switching power supply
KR200280913Y1 (en) CFIU Fan Operation Indicator
KR0140020Y1 (en) Output current limiting circuit
JP3629912B2 (en) DC / DC converter and communication apparatus using the same
JPH02262830A (en) Overcurrent protective circuit for inverter controller
WO2024062042A1 (en) Psu compatible load adaption
JP2000112540A (en) Dc stabilizing power source device
JPH1020948A (en) Redundant stabilized power source device
JPH10304662A (en) Switching power supply equipment

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E601 Decision to refuse application