JPH06335241A - Transformer-coupled secondary dc power-supply forming device - Google Patents

Transformer-coupled secondary dc power-supply forming device

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Publication number
JPH06335241A
JPH06335241A JP18153293A JP18153293A JPH06335241A JP H06335241 A JPH06335241 A JP H06335241A JP 18153293 A JP18153293 A JP 18153293A JP 18153293 A JP18153293 A JP 18153293A JP H06335241 A JPH06335241 A JP H06335241A
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Japan
Prior art keywords
circuit
charging
overcurrent
dc power
resistor
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Pending
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JP18153293A
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Japanese (ja)
Inventor
Shinichi Akimoto
Yoshiaki Matsumoto
芳昭 松本
信一 秋元
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Tokyo Electric Co Ltd
東京電気株式会社
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Priority to JP5-67812 priority Critical
Priority to JP6781293 priority
Application filed by Tokyo Electric Co Ltd, 東京電気株式会社 filed Critical Tokyo Electric Co Ltd
Priority to JP18153293A priority patent/JPH06335241A/en
Publication of JPH06335241A publication Critical patent/JPH06335241A/en
Application status is Pending legal-status Critical

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Abstract

PURPOSE: To stabilize a protective function against overcurrent and at the same time miniaturize a device and reduce its weight and cost by forming an overcurrent detection circuit by connecting a time-constant circuit consisting of a charging resistor and a capacitor for charging in parallel with the auxiliary winding of a transformer.
CONSTITUTION: An overcurrent detection circuit 50 is formed of a charging resistor R51 and a charging capacitor C51 connected in series between the positive pole side of an auxiliary winding L12 of a transformer 20 and the negative pole side of a rectification circuit 14 and a discharging resistor R52 connected in parallel with the charging capacitor C51 and in series with the charging resistor R51. Then, the point between the charging resistor R51 and the charging capacitor C51 is connected to an element 16 for protection against overcurrent, thus indirectly detecting overcurrent from a control voltage VC and an oscillation frequency, thus miniaturizing the overcurrent detection circuit 50, achieving stabilization against the voltage fluctuation of an AC power supply 11 by adding a constant current circuit, and further easily coping with the change-over of the voltage of the AC power supply 11.
COPYRIGHT: (C)1994,JPO

Description

【発明の詳細な説明】 DETAILED DESCRIPTION OF THE INVENTION

【0001】 [0001]

【産業上の利用分野】本発明は、1次直流電源回路と2 BACKGROUND OF THE INVENTION The present invention is a primary DC power supply circuit and 2
次直流電源回路とをトランスを介して接続結合し、かつ過電流保護機能を備えたトランス結合型2次直流電源生成装置に関する。 Connect coupling to the next DC power supply circuit via a transformer, and relates to trans-coupled secondary DC power generating device including an overcurrent protection function.

【0002】 [0002]

【従来の技術】図7において、1次直流電源回路10と2次直流電源回路30とは、トランス20を介して接続されている。 BACKGROUND OF THE INVENTION FIG. 7, the primary DC power supply circuit 10 and the secondary direct current power source circuit 30 are connected via a transformer 20. 1次直流電源回路10は、交流電源11, The primary DC power supply circuit 10 includes an AC power source 11,
スイッチ12,ノイズフィルター13,整流回路14, Switch 12, the noise filter 13, rectifier circuit 14,
平滑コンデンサC10,スイッチング素子(トランジスタ)15,制御回路(40)を含み形成され、スイッチング素子15はトランス20の1次巻線L11と整流回路14の負極側との間に接続されている。 A smoothing capacitor C10, switching element (transistor) 15 is formed includes a control circuit (40), the switching element 15 is connected between the negative electrode side of the primary winding L11 and the rectifying circuit 14 of the transformer 20. また、制御電圧Vcは補助巻線L12から誘起されダイオードD10 The control voltage Vc is induced from the auxiliary winding L12 diode D10
を介して発振生成されかつ抵抗R10を通して供給される。 It supplied through oscillated generated and resistor R10 through.

【0003】また、2次直流電源回路30は、トランス20の2次巻線L21に接続されたダイオードD21、 [0003] The secondary DC power supply circuit 30 includes a diode D21 connected to the secondary winding L21 of the transformer 20,
平滑コンデンサC21,C22を含み形成され、負荷3 Formed includes a smoothing capacitor C21, C22, load 3
5に接続される。 5 is a connection. 45は安定化回路で、ホトカプラを含むフィードバック信号発生回路46に電圧検出信号を入力する。 45 is a stabilization circuit, inputs the voltage detection signal to the feedback signal generating circuit 46 comprising a photocoupler.

【0004】かくして、かかるRCC方式の自励発振型(周波数変動型)のトランス結合型2次直流電源生成装置では、制御回路(トランジスタ40)をフィードバック信号でON−OFFさせることにより制御電圧Vcを用いてスイッチング素子15をON−OFF制御して1 [0004] Thus, in trans conjugated secondary DC power generating device of a self-pulsation of such RCC method (frequency variation form), the control voltage Vc by ON-OFF control circuit (transistor 40) by a feedback signal 1 and ON-OFF control of the switching element 15 using
次巻線L11から2次巻線L21に電力エネルギーを供給する。 Supplying electrical energy from the primary winding L11 to the secondary winding L21. 2次直流電源回路30では、ダイオードD21 In the secondary DC power supply circuit 30, the diode D21
で整流し、かつ平滑コンデンサC21,C22で平滑して2次直流電源を生成し負荷35に供給する。 In rectified and smoothed and supplies the generated load 35 secondary DC power supply smoothing capacitor C21, C22. 負荷35 Load 35
の変動は、2次直流電源電圧の変動として安定化回路4 The variations, stabilizing circuit 4 as a change in secondary DC power supply voltage
5で検出されフィードバック信号生成回路46に出力される。 Detected in 5 is output to the feedback signal generation circuit 46. これにより、2次直流電源電圧が安定化される。 Thus, the secondary DC power supply voltage is stabilized.

【0005】したがって、負荷35が軽い場合には、スイッチング素子15に流れる電流が減少して発振周波数が高くなる。 Accordingly, when the load 35 is light, the oscillation frequency increases the current flowing through the switching element 15 is decreased. 一方、負荷35が重くなると、スイッチング素子15に流れる電流が増大し発振周波数は低くなる。 On the other hand, when the load 35 is heavy, the oscillation frequency current flowing through the switching element 15 is increased is reduced. 制御回路(40)によるスイッチング素子15のO O of the switching element 15 by the control circuit (40)
Nデューティーが一定のためによる。 N duty is due for certain.

【0006】また、図8に示す他励フライバック方式の周波数固定型では、制御回路40はPWM・ICから形成され、負荷35が軽い場合にはスイッチング素子15 [0006] In the fixed frequency of the separately-excited flyback type shown in Figure 8, the control circuit 40 is formed from a PWM · IC, when the load 35 is light switching element 15
に流れる電流が減少しその通電時間が短くなる。 Current flowing to the its energization time decreased shorter. 一方、 on the other hand,
負荷35が重くなると、スイッチング素子15に流れる電流が増大しそれに伴って通電時間が長くなる。 When the load 35 becomes heavier, the current flowing through the switching element 15 increases the energization time becomes long accordingly. 発振周波数が一定のためである。 This is because the oscillation frequency is constant. なお、制御回路40の駆動電源(電圧Vd)は、2次巻線L12で発振誘起されダイオードD10をと通して供給される。 The driving power source (voltage Vd) of the control circuit 40 is supplied through the oscillation induced diode D10 in the secondary winding L12. すなわち、この駆動電圧Vdは、図7の場合の制御電圧Vcと同様に生成されるわけである。 That is, the driving voltage Vd is not generated similarly to the control voltage Vc in the case of FIG.

【0007】ところで、いずれの方式の場合でも、特にスイッチング素子15を過電流から保護するために、1 By the way, in any case of method, in particular for protecting the switching element 15 from overcurrent, 1
次直流電源回路10側に過電流検出回路(R50)と過電流保護用素子16とを設けている。 It is provided with overcurrent detection circuit (R50) and over-current protection element 16 to the next DC power supply circuit 10 side. 過電流検出回路はスイッチング素子15と整流回路14の負極側との間に接続された抵抗R50から形成され、かつ過電流保護用素子16はスイッチング素子15のベースと整流回路1 Overcurrent detection circuit is formed from a resistor connected R50 between the switching element 15 and the negative electrode side of the rectifier circuit 14, and the overcurrent protection element 16 is based rectifier circuit 1 of the switching element 15
4の負荷側とに接続されている。 4 are connected to the load side. そして、スイッチング素子15と抵抗R50との間と過電流保護用素子(MO Then, during the overcurrent protection element of the switching element 15 and the resistor R50 (MO
S・FET)16の駆動端子(ゲート)とを接続している。 And connects the driving pin S · FET) 16 (gate).

【0008】したがって、スイッチング素子15に流れる電流が増大すると過電流検出回路(R50)によって検出電圧Vaが高くなる。 Accordingly, the detection voltage Va increases the current flowing through the switching element 15 is increased by an overcurrent detection circuit (R50). すると、過電流保護用素子1 Then, over-current protection element 1
6がONとなるから、スイッチング素子15に流れ込んでいた電流が過電流保護用素子16に引き込まれる。 Because 6 is ON, the current that has flowed to the switching element 15 is pulled into the over-current protection element 16. よって、スイッチング素子15をOFFして過電流から保護することができる。 Therefore, it is possible to protect the switching element 15 from OFF to overcurrent.

【0009】 [0009]

【発明が解決しようとする課題】ところで、2次直流電源回路30側の負荷35が大型化すると、1次直流電源回路10側のスイッチング素子15に流れる電流もより大電流となる。 [SUMMARY OF THE INVENTION Incidentally, the load 35 of the secondary DC power supply circuit 30 side is enlarged, the current flowing through the switching element 15 of the primary DC power supply circuit 10 side becomes higher current. すると、当然に過電流検出回路を形成する抵抗R50には大きな電流ストレスが加わるから、抵抗R50自体を大容量としなければならず、形状も大きくなる。 Then, since the resistor R50 to naturally form an overcurrent detecting circuit applied a large current stress, the resistance R50 itself must be as large, the shape becomes large. しかるに、一層の軽量・小型化とコスト低減とが強く望まれるに至り、過電流検出回路(抵抗R50) However, lead to and the further weight and miniaturization and cost reduction are strongly demanded, the overcurrent detection circuit (resistor R50)
がその達成を阻害する要因の一つとなって来た。 There came one of the factors that inhibit achieve that.

【0010】また、交流電源11の電圧(例えば、AC [0010] In addition, the voltage of the AC power supply 11 (for example, AC
100V)が変動(例えば、85〜138V)すると、 100V) is a variation (for example, 85~138V) Then,
過電流保護ポイントが変化してしまうので定数設定が難しい。 Constant setting is so difficult overcurrent protection point is changed. さらに、適用性拡大のために交流電源11を例えばAC100VとAC200Vとのいずれかに選択使用可能に構築した場合、その抵抗R50の抵抗値を交換しなければならず煩わしいという問題もある。 Furthermore, there is a case constructed to be selectable using either an AC power source 11 for the application of expansion and e.g. AC100V and AC200V, also the resistance R50 of the resistance value troublesome must be replaced.

【0011】本発明の目的は、過電流保護機能を安定して発現させつつ軽量・小型化とコスト低減とを達成することのできるトランス結合型2次直流電源生成装置を提供することにある。 An object of the present invention is to provide a transformer-coupled secondary DC power generating device capable of achieving light weight and downsizing and cost reduction while stably expressing the overcurrent protection function.

【0012】 [0012]

【課題を解決するための手段】請求項1の発明に係るトランス結合型2次直流電源生成装置は、整流回路,平滑コンデンサ,スイッチング素子,制御回路を含む1次直流電源回路と、安定化回路を含む2次直流電源回路とをトランスを介して接続結合し、安定化回路から制御回路へフィードバック信号を加えつつスイッチング素子をO Means for Solving the Problems] trans conjugated secondary DC power generating apparatus according to the invention of claim 1 includes a rectifier circuit, a smoothing capacitor, a switching element, a primary DC power supply circuit including a control circuit, a stabilizing circuit a secondary DC power supply circuit connected coupled via a transformer, a switching element while applying a feedback signal from the stabilizing circuit to the control circuit O containing
N−OFF制御して2次直流電源を生成するように形成され、かつ過電流検出回路で過電流が検出されたときに過電流保護用素子を介して該スイッチング素子をOFF N-OFF control and is formed so as to generate a secondary DC power supply, and OFF the switching element via an overcurrent protection device when an overcurrent is detected by overcurrent detection circuit
させて過電流保護するように形成されたトランス結合型2次直流電源生成装置において、前記過電流検出回路を、前記トランスの補助巻線の正極側と前記整流回路の負極側との間に直列接続された充電抵抗および充電用コンデンサと、この充電用コンデンサと並列でかつ充電抵抗と直列に接続された放電抵抗とから形成し、かつ充電抵抗と充電用コンデンサとの間と前記過電流保護用素子の駆動端子とを接続したことを特徴とする。 In trans-linked secondary DC power generating device formed such that an overcurrent protection is, the overcurrent detection circuit, series between the negative electrode side of the positive electrode side and the rectifier circuit of the transformer auxiliary winding and connected charging resistor and a charging capacitor, formed from this and the charging capacitor and connected discharge resistor in parallel a and the charging resistor in series with, and for the over-current protection between the charging capacitor and the charging resistor characterized in that connecting the drive terminal of the element.

【0013】また、請求項2の発明は、前記トランスの補助巻線から生成された電圧を入力としかつ前記充電抵抗と充電用コンデンサとに流す電流を一定とする定電流回路を設けたことを特徴とする。 Further, that the invention of claim 2, in which a constant current circuit for the current flowing voltage generated from the transformer auxiliary winding and the charging capacitor and the input Toshikatsu the charging resistor is constant and features.

【0014】 [0014]

【作用】上記構成による請求項1の発明の場合、例えば周波数変動型の場合は2次直流電源回路の負荷が重くなって来ると、スイッチング素子に流れる電流が増大し発振周波数は低くなる。 [Action] For the invention of claim 1 of the above construction, for example, the case of the frequency variable-load of the secondary DC power supply circuit comes heavier, the oscillation frequency current flowing through the switching element is increased is low. つまり、制御電圧の発振周波数が低下する。 That is, the oscillation frequency of the control voltage decreases. この発振周波数に相当する周期が、充電抵抗と充電用コンデンサとの充電時定数の周期よりも長くなると、充電用コンデンサの電圧が設定電圧に高まるので、過電流保護用素子がONする。 Period corresponding to the oscillation frequency, becomes longer than the period of the charging time constant of the charging capacitor and the charging resistor, the voltage of the charging capacitor is so increased the set voltage, the overcurrent protection device is turned ON. したがって、スイッチング素子をOFFさせ過電流から保護できる。 Therefore, can be protected from overcurrent is OFF the switching element. その後、充電用コンデンサに蓄積された電荷は、適時に放電抵抗を通して放電される。 Thereafter, the charge accumulated in the charging capacitor is discharged through the timely discharge resistor. なお、負荷が軽く発振周波数が高い場合は、充電用コンデンサの電圧が設定電圧に到達しないので、過電流保護用素子はOFFのままであるから、通常制御運転を続行できる。 Incidentally, when the load is lightly oscillation frequency is high, the voltage of the charging capacitor does not reach the set voltage, the overcurrent protection devices because remains OFF, the can continue normal control operation.

【0015】また、周波数固定型の場合には、2次直流電源回路の負荷が重くなって来ると、スイッチング素子に流れる電流が増大し通電時間が長くなる。 [0015] In the case of fixed frequency, when the load of the secondary DC power supply circuit comes heavier, current flowing through the switching element becomes longer energized time increases. つまり、制御回路の駆動電圧の発振時間が長くなる。 That is, the oscillation time of the drive voltage of the control circuit is prolonged. したがって、 Therefore,
通電時間が充電抵抗と充電用コンデンサとの充電時定数の時間よりも長くなると、充電用コンデンサの電圧が設定電圧に高まるので、過電流保護用素子をONさせることができる。 The energization time becomes longer than the time of the charging time constant of the charging capacitor and the charging resistor, the voltage of the charging capacitor increases the set voltage, it is possible to turn ON the overcurrent protection device. したがって、スイッチング素子をOFFし過電流から保護できる。 Accordingly, to protect the switching element from OFF to overcurrent. なお、軽負荷時には過電流保護用素子はOFFのままである。 Incidentally, at the time of light load overcurrent protection element remains OFF.

【0016】また、請求項2の発明では、請求項1の作用に加え、制御電圧または駆動電圧を定電流回路に入力させ、この定電流回路から充電抵抗と充電用コンデンサとに定電流を流す。 [0016] In the invention of claim 2, in addition to the operation of claim 1, the control voltage or the driving voltage is input to the constant current circuit, a constant current is supplied to the charging capacitor and the charging resistor from the constant current circuit . したがって、交流電源の電圧変動や交流電源の高低切替えが行われる状態で使用した場合でも、過電流保護ポイントを一定に保持できる。 Therefore, even when the level of the voltage or the AC power supply of the AC power supply switch is used in a state that takes place can hold overcurrent protection point constant.

【0017】 [0017]

【実施例】以下、本発明の実施例を図面を参照して説明する。 EXAMPLES Hereinafter, an embodiment of the present invention with reference to the drawings. (第1実施例)本トランス結合型2次直流電源生成装置は、図1に示す如く、基本的構成が従来例(図7)と同じRCC方式の自励発振型(周波数変動型)とされ、かつ過電流検出回路50を制御電圧Vcの発振周波数を利用して間接的に過電流検出するように形成されている。 (First Embodiment) This trans-coupled secondary DC power generating device, as shown in FIG. 1, the basic configuration is an example conventional self-pulsation type (frequency variation type) of the same RCC type (FIG. 7) , and it is formed an overcurrent detection circuit 50 so as to indirectly overcurrent detection using the oscillation frequency of the control voltage Vc.

【0018】なお、従来例(図7)と共通する部分については同一の符号を付しその説明は簡略又は省略する。 [0018] Incidentally, the description the same reference numerals are given to parts in common with the conventional example (FIG. 7) is simplified or omitted.

【0019】図1において、補助巻線L12の正極側の制御電圧Vcを発振生成するダイオードD10と抵抗R [0019] In FIG 1, a diode D10 for oscillating generates a control voltage Vc on the positive electrode side of the auxiliary winding L12 resistor R
10との間と、整流回路14の負極側との間には、周波数検出方式の過電流検出回路50が設けられている。 And between 10 and between the negative electrode side of the rectifier circuit 14, overcurrent detection circuit 50 of the frequency detection scheme is provided. この過電流検出回路50は、充電抵抗R51と充電用コンデンサC51とを直列接続し、かつこの充電用コンデンサC51に放電抵抗R52を並列接続して形成されている。 The overcurrent detection circuit 50 is formed of a charging resistor R51 and charging capacitor C51 are connected in series, and connected in parallel with the discharge resistor R52 to the charging capacitor C51. そして、充電抵抗R51と充電用コンデンサC51 Then, the charging capacitor and charging resistor R51 C51
との間と、MOS・FETからなる過電流保護用素子1 And between the overcurrent protection element consisting of MOS · FET 1
6の駆動端子(ゲート)とを電路で接続してある。 6 the drive pin and a (gate) is connected by path.

【0020】さて、スイッチング素子15に印加される電圧と流れる電流の波形は、図2に示すようになる。 [0020] Now, the waveform of the current flowing through the voltage applied to the switching element 15, as shown in FIG. すなわち、2次直流電源回路30の負荷35が軽い場合〔同(A)〕は、発振周波数f1(周期T1)が高い(短い)が、負荷35が重くなる〔同(B)〕と、発振周波数f2(周期T2)が低く(長く)なる。 That is, when the load 35 of the secondary DC power supply circuit 30 is light [the (A)], the oscillation frequency f1 (cycle T1) is high (short) is a load 35 becomes heavy and [the (B)], oscillation frequency f2 (period T2) is lower (longer). つまり、 That is,
制御電圧Vcの発振周波数f2(周期T2)が低く(長く)なる。 Oscillation frequency of the control voltage Vc f2 (cycle T2) is lower (longer).

【0021】かくして、スイッチング素子15を保護するために必要な過電流検出値が図2(A),(B)に点線で示す値であるとすれば、制御電圧Vcの発振周波数fが図2(B)に示す周期T2よりもさらに長い周期(T2+α)に相当する発振周波数(f2+α)になったことを検出することによって、過電流検出値を間接的に検出できる。 [0021] Thus, the overcurrent detection level required to protect the switching element 15 is FIG. 2 (A), the if the value indicated by the dotted line (B), the oscillation frequency f of the control voltage Vc 2 by detecting that the now corresponding to the oscillation frequency (f2 + alpha) further longer period (T2 + alpha) than the period T2 in which (B), the can indirectly detect the overcurrent detection value.

【0022】ここに、充電抵抗R51と充電用コンデンサC51の定時数(T)は、上記周期(T2+α)と等しく選択設定されている。 [0022] Here, scheduled number of the charging capacitor C51 and the charging resistor R51 (T) is chosen equal set to the period (T2 + α).

【0023】かかる構成の実施例において、2次直流電源回路30の負荷35が軽い場合は、スイッチング素子15の電圧波形と電流波形とは図2(A)に示すように発振周波数f1が高く周期T1が短い。 [0023] In an embodiment of such a configuration, when the load 35 of the secondary DC power supply circuit 30 is light, the voltage and current waveforms of the switching element 15 increases the oscillation frequency f1 as shown in FIG. 2 (A) cycle T1 is short. したがって、発振生成される制御電圧Vcの一部は充電抵抗R51と充電用コンデンサC51とを通して流れるが、その周期(T2)が設定周期(T2+α)よりも短いので、過電流保護用素子16をON駆動するための設定電圧Vaは確立されない。 Thus, a part of the control voltage Vc to be oscillated generated flows through the charging resistor R51 and charging capacitor C51, so that the period (T2) is set period (T2 + alpha) less than, ON the overcurrent protection element 16 set voltage Va for driving is not established. すなわち、過電流保護用素子16はOF That is, the overcurrent protection element 16 OF
Fのままであるから、スイッチング素子15をON−O Since remains F, ON-O switching element 15
FF制御して通常運転ができる。 It is usually operated with FF control.

【0024】ところが、負荷35が重くなって図2 [0024] However, the load 35 becomes heavier Figure 2
(B)に示すように発振周波数f2が低く周期T2が長くなり、さらに高い発振周波数(f2+α)で長い周期(T2+α)となると、充電用コンデンサC51にセットした設定電圧Vaが確立されるから、過電流保護用素子16がONとなる。 The oscillation frequency f2 is lower period T2 as shown in (B) becomes longer, becomes longer period (T2 + alpha) at higher oscillation frequency (f2 + alpha), because the set voltage Va which is set to the charging capacitor C51 is established, overcurrent protection element 16 is turned ON. したがって、スイッチング素子1 Therefore, the switching element 1
5をOFFできるから、スイッチング素子15を過電流から保護できる。 5 because the can OFF, to protect the switching element 15 from overcurrent.

【0025】なお、充電用コンデンサC51に蓄積された電荷は、制御電圧Vcが消失したときに、放電抵抗R [0025] Note that the charge stored in the charging capacitor C51, when the control voltage Vc is lost, the discharge resistor R
52を通して放電される。 52 is discharged through.

【0026】しかして、この実施例によれば、過電流検出回路50を、トランス20の補助巻線L12の正極側と整流回路14の負極側との間に直列接続された充電抵抗R51および充電用コンデンサC51と、この充電用コンデンサC51と並列でかつ充電抵抗R51と直列に接続された放電抵抗R52とから形成し、かつ充電抵抗R51と充電用コンデンサC51との間と過電流保護用素子16の駆動端子(ゲート)とを電路を介して接続した構成とし、制御電圧Vcの発振周波数から過電流を間接的に検出するように形成されているので、スイッチング素子15と直列接続した抵抗R50からなる従来例(図7)に比較して大容量で大型の抵抗(R50)を一掃できるから、その過電流保護機能を保障しながら装置の軽量小型化とコス [0026] Thus, according to this embodiment, the overcurrent detection circuit 50, charging resistor R51 and charging connected in series between the negative electrode side of the positive electrode side rectifying circuit 14 of the auxiliary winding L12 of the transformer 20 and use a capacitor C51, and formed from this and charging capacitor C51 in parallel a and the charging resistor R51 connected in series with the discharge resistor R52 Prefecture, and between the overcurrent protection element of the charging resistor R51 and charging capacitor C51 16 and the drive pin and (gate) configured connected through the path a, so the oscillation frequency of the control voltage Vc is formed so as to detect an overcurrent indirectly, from the switching element 15 connected in series with a resistor R50 conventional since it wipe a large resistor (R50) to a large capacity compared to (7), weight miniaturization and cost of the apparatus while ensuring the overcurrent protection function comprising 低減を達成することができる。 It is possible to achieve a reduction.

【0027】(第2実施例)この第2実施例は、図3および図4に示される。 [0027] (Second Embodiment) The second embodiment is shown in FIGS. 図3において、このトランス結合型2次直流電源生成装置は、基本的構成が従来例(図8)と同じ制御回路40をPWM・ICから形成した周波数固定型とされ、かつ過電流検出回路50(R51, 3, the transformer-coupled secondary DC power generating device is basically configured is the conventional example (FIG. 8) the same control circuit 40 and is formed from a PWM · IC was fixed frequency, and the overcurrent detection circuit 50 (R51,
C51,R52)は第1実施例の場合と同じ構成とされている。 C51, R52) are the same configuration as in the first embodiment.

【0028】すなわち、この周波数固定型では、負荷3 [0028] That is, in this fixed frequency, the load 3
5が軽い場合はスイッチング素子15に流れる電流とその電圧の波形は図4(A)に示すようになり、その発振周波数fが一定で通電時間T1が短い。 If 5 is light waveform of the current and its voltage flowing through the switching element 15 becomes as shown in FIG. 4 (A), the oscillation frequency f is short energization time T1 is constant. 一方、負荷35 On the other hand, load 35
が重い場合の電圧・電流波形は同(B)に示すように発振周波数fが同一で通電時間T2が長くなる。 The voltage and current waveform when heavy oscillation frequency f as shown in (B) is energizing time T2 becomes longer identical. つまり、 That is,
補助巻線L12から発振生成される制御回路40の駆動電圧Vdの発振時間は、スイッチング素子15に流れる電流が小さければ短く(T1)、大きければ長く(T Oscillation time of the driving voltage Vd of the control circuit 40 which is oscillated generated from the auxiliary winding L12 is the smaller the current flowing through the switching element 15 shorter (T1), long greater (T
2)なる。 2) a.

【0029】したがって、充電抵抗R51と充電用コンデンサC51との時定数を、図4(B)に示す通電時間T2よりもさらに長い時間(T2+α)となるように選択設定しておけば、図4に点線で示した過電流検出値を通電時間として検出できる。 [0029] Thus, the time constant of the charging resistor R51 and charging capacitor C51, if selected set to be 4 (B) to the longer time than the energizing time T2 shown (T2 + alpha), Figure 4 the overcurrent detection value indicated by the dotted line can be detected as a current time.

【0030】なお、この第2実施例の場合の時定数(R [0030] Incidentally, the time constant in the case of the second embodiment (R
51×C51)は、第1実施例の場合の時定数(R51 51 × C51) is the time constant in the case of the first embodiment (R51
×C51)とは同一符号を用いたがその絶対値は異なる。 × C51) and was used with the same reference numerals are different absolute values.

【0031】しかして、この第2実施例の場合も、第1 [0031] Thus, also in this second embodiment, the first
実施例の場合と同様な作用効果を奏することができる。 It is possible to achieve the same effects as in Example.

【0032】(第3実施例)第3実施例は、基本的構成が第1実施例(図1)の場合と同じとされ、かつ過電流検出回路50に定電流を供給する定電流回路60を設け、制御電圧Vcの変動があっても過電流保護動作ポイントを一定に保持できるように構成してある。 [0032] (Third Embodiment) The third embodiment is basically configured is the same as that in the first embodiment (FIG. 1), and a constant current circuit for supplying a constant current to the overcurrent detection circuit 50 60 the provided, and are configured to be held overcurrent protection operating point constant even if the variation of the control voltage Vc.

【0033】すなわち、第1実施例(図1)において、 [0033] That is, in the first embodiment (FIG. 1),
交流電源11がAC100Vで所定の制御電圧Vcが生成された場合、コンデンサC51の充電電圧は図6 If the AC power source 11 is predetermined control voltage Vc is generated by AC100V, the charging voltage of the capacitor C51 is 6
(A)に実線で示すカーブで立上るから、設定電圧Va Since standing climb in the curve indicated by the solid line (A), the set voltage Va
となるまでの時間は図6(A)に示す「T」となる。 The time until the shown in FIG. 6 (A) is "T".

【0034】ここに、交流電源11がAC100Vから例えばAC85Vに電圧降下した場合、制御電圧はトランス20の特性からして所定の制御電圧Vcよりも低圧の「Vc2」となる。 [0034] Here, if the AC power source 11 has a voltage drop from AC100V for example AC85V, the control voltage is "Vc2" of pressure lower than the predetermined control voltage Vc to the characteristics of the transformer 20. この制御電圧Vc2では同(A) In the control voltage Vc2 same (A)
に点線で示すカーブで立上る。 Standing climb in the curve shown by the dotted line in. したがって、同一の設定電圧Vaに到達する迄の時間は「T2」となり、所定時間Tよりも長くなってしまう。 Therefore, the same set voltage time until reaching the Va becomes "T2", and longer than the predetermined time T. 一方、例えば、AC13 On the other hand, for example, AC13
8Vと電圧上昇すると、制御電圧Vc1が制御電圧Vc With increased 8V and the voltage, the control voltage Vc1 is control voltage Vc
よりも高くなるから1点鎖線で示すカーブで立上るために所定時間Tよりも短い時間T1で設定電圧Vaに到達する。 It reaches the set voltage Va with short time T1 than the predetermined time T in order to stand Take the curve shown by a chain line from higher than.

【0035】つまり、入力電圧(交流電源→制御電圧) [0035] That is, the input voltage (AC power supply → control voltage)
が変動すると、過電流保護動作ポイントが変化してしまうので、適正な過電流保護ができなくなってしまう。 But when you change, because the overcurrent protection operating point is changed, it becomes impossible proper overcurrent protection. このことは、充電回路(R51,C51)へ流れる電流が、制御電圧Vc1,Vc,Vc2に相応して図6 This current flowing to the charging circuit (R51, C51) is, correspondingly to the control voltage Vc1, Vc, Vc2 6
(B)に示すIc1,Ic,Ic2と変化するからである。 Because Ic1, Ic, changes Ic2 shown in (B).

【0036】かくして、この第3実施例では、制御電圧Vcの時間管理により検出すればよいことから、定電流回路60によって制御電圧Vcの高低変動に拘わらず充電回路(R51,C51)へ一定電流(Ic)を流すことにしている。 [0036] Thus, in the third embodiment, a constant current since the may be detected by the time management of the control voltage Vc, the charging circuit regardless of the level variation of the control voltage Vc by the constant current circuit 60 (R51, C51) It is to shed (Ic).

【0037】しかして、この第3実施例によれば、第1 [0037] Thus, according to the third embodiment, the first
実施例の場合と同じ作用効果を奏することができる他、 Besides it has the same effect as in Example,
さらに交流電源11に電圧変動があっても、さらにまた例えば交流電源11をAC100VからAC200Vに切替えて使用しても、適正な通電流保護を確実かつ安定して行え、適用性を著しく拡大できる。 Further even if a voltage fluctuation in the AC power supply 11, the use further another example of the AC power supply 11 is switched from AC100V to AC200V, can proper energization current protection to reliably and stably, can be significantly expanded applicability.

【0038】なお、この第3実施例は、第1実施例(図1)に定電流回路60を設けた場合とされているが、第2実施例(図3)に定電流回路60を設けても同じ作用効果を得られる。 [0038] In this third embodiment, the first embodiment has been the case of providing the constant current circuit 60 (FIG. 1), the constant current circuit 60 provided in the second embodiment (FIG. 3) also it obtained the same action effect.

【0039】 [0039]

【発明の効果】請求項1の発明によれば、過電流検出回路を、トランスの補助巻線の正極側と整流回路の負極側との間に直列接続された充電抵抗および充電用コンデンサと、この充電用コンデンサと並列でかつ充電抵抗と直列に接続された放電抵抗とから形成し、かつ充電抵抗と充電用コンデンサとの間と過電流保護用素子の駆動端子とを接続した構成とし、周波数変動型の場合は発振周波数から,周波数固定型の場合は通電時間から過電流を間接的に検出する構成とされているので、スイッチング素子と直列接続した抵抗からなる従来例に比較して大容量で大型の抵抗を一掃できるから、その過電流保護機能を保障しながら装置の軽量小型化とコスト低減を達成することができる。 Effects of the Invention According to the present invention, the overcurrent detection circuit, a charging resistor and a charging capacitor connected in series between the negative side of the positive electrode side rectifying circuit of the auxiliary winding of the transformer, the form of the charging capacitor and connected discharge resistor in parallel a and the charging resistor in series and a connecting structure and a drive pin between the overcurrent protection element of the charging capacitor and the charging resistor, the frequency from the oscillation frequency in the case of variable-, since in the case of fixed frequency is configured to indirectly detect the overcurrent from the energization time, a large capacity as compared with the conventional example consists of resistors connected switching element in series in because it wipe a large resistance, it is possible to achieve weight reduction in size and cost reduction of the apparatus while ensuring the overcurrent protection function.

【0040】また、請求項2の発明によれば、請求項1 Further, according to the second aspect of the invention, claim 1
の効果に加え、充電抵抗と充電用コンデンサとに定電流回路から一定電流を流すものと形成しているので、交流電源が電圧変動しても、また交流電源電圧を高低に切替えて使用する場合でも確実な過電流保護を保障できるから、適用性を著しく拡大できる。 In addition to the effect, since the forms shall supplies a constant current from the constant current circuit to the charging capacitor and the charging resistor, also the AC power supply and voltage variations, also when using by switching the AC power source voltage to the high and low But because it guarantees a reliable overcurrent protection can significantly expand the applicability.

【図面の簡単な説明】 BRIEF DESCRIPTION OF THE DRAWINGS

【図1】本発明の第1実施例を示す回路図である。 1 is a circuit diagram showing a first embodiment of the present invention.

【図2】同じく、動作を説明するためのタイミングチャートである。 [Figure 2] Similarly, a timing chart for explaining the operation.

【図3】本第2実施例を示す回路図である。 3 is a circuit diagram showing this second embodiment.

【図4】同じく、動作を説明するためのタイミングチャートである。 [4] Also, a timing chart for explaining the operation.

【図5】本第3実施例を示す回路図である。 5 is a circuit diagram showing a third exemplary embodiment.

【図6】同じく、第1および第2実施例の改善余地例との比較において動作を説明するための図である。 [6] Similarly, a diagram for explaining the operation in comparison with room for improvement of the first and second embodiments.

【図7】周波数変動型の従来例を示す回路図である。 7 is a circuit diagram showing a conventional example of a frequency variation types.

【図8】周波数固定型の従来例を示す回路図である。 8 is a circuit diagram showing a conventional example of a fixed frequency.

【符号の説明】 DESCRIPTION OF SYMBOLS

10 1次直流電源回路 11 交流電源 12 スイッチ 13 ノイズフィルター 14 整流回路 15 スイッチング素子 16 過電流保護用素子 20 トランス 30 2次直流電源回路 35 負荷 40 制御回路 45 安定化回路 46 フィードバック信号発生回路 50 過電流検出回路 60 定電流回路 C10 平滑コンデンサ C51 充電用コンデンサ L12 補助巻線 R51 充電抵抗 R52 放電抵抗 Va 設定電圧 Vc 制御電圧 Vd 駆動電圧 10 primary DC power supply circuit 11 AC power source 12 switch 13 Noise filter 14 rectifier circuit 15 switching element 16 over-current protection element 20 transformer 30 secondary DC power supply circuit 35 load 40 control circuit 45 stabilizing circuit 46 feedback signal generation circuit 50 over current detecting circuit 60 a constant current circuit C10 smoothing capacitor C51 charging capacitor L12 auxiliary winding R51 charging resistor R52 discharge resistor Va setting voltage Vc control voltage Vd drive voltage

Claims (2)

    【特許請求の範囲】 [The claims]
  1. 【請求項1】 整流回路,平滑コンデンサ,スイッチング素子,制御回路を含む1次直流電源回路と、安定化回路を含む2次直流電源回路とをトランスを介して接続結合し、安定化回路から制御回路へフィードバック信号を加えつつスイッチング素子をON−OFF制御して2次直流電源を生成するように形成され、かつ過電流検出回路で過電流が検出されたときに過電流保護用素子を介して該スイッチング素子をOFFさせて過電流保護するように形成されたトランス結合型2次直流電源生成装置において、 前記過電流検出回路を、前記トランスの補助巻線の正極側と前記整流回路の負極側との間に直列接続された充電抵抗および充電用コンデンサと、この充電用コンデンサと並列でかつ充電抵抗と直列に接続された放電抵抗とから形成し 1. A rectifier circuit, a smoothing capacitor, a switching element, a primary DC power supply circuit including a control circuit, connected coupled via a transformer and a secondary DC power supply circuit comprising a stabilizing circuit, controlled from the stabilizing circuit while applying a feedback signal to the circuit is formed so as to generate a secondary DC power supply switching elements and oN-OFF control, and via an overcurrent protection device when an overcurrent is detected by overcurrent detection circuit in trans-linked secondary DC power generating device formed as overcurrent protection by OFF of the switching element, the overcurrent detection circuit, the negative electrode side of the rectifier circuit and the positive electrode side of the transformer auxiliary winding formed of a series connected charging resistor and a charging capacitor, this charging capacitor and connected discharge resistor in parallel a and the charging resistor in series between the かつ充電抵抗と充電用コンデンサとの間と前記過電流保護用素子の駆動端子とを接続したことを特徴とするトランス結合型2次直流電源生成装置。 And trans-coupled secondary DC power generating apparatus being characterized in that connecting the drive terminal of the overcurrent protection element and between the charging capacitor and the charging resistor.
  2. 【請求項2】 前記トランスの補助巻線から生成された電圧を入力としかつ前記充電抵抗と充電用コンデンサとに流す電流を一定とする定電流回路を設けたことを特徴とする請求項1のトランス結合型2次直流電源生成装置。 2. A according to claim 1, characterized in that a constant current circuit to the current flowing in said transformer input Toshikatsu said charge resistor the generated voltage from the auxiliary winding and a charging capacitor constant trans conjugated secondary DC power generator.
JP18153293A 1993-03-26 1993-07-22 Transformer-coupled secondary dc power-supply forming device Pending JPH06335241A (en)

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JP5-67812 1993-03-26
JP6781293 1993-03-26
JP18153293A JPH06335241A (en) 1993-03-26 1993-07-22 Transformer-coupled secondary dc power-supply forming device

Applications Claiming Priority (1)

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JP18153293A JPH06335241A (en) 1993-03-26 1993-07-22 Transformer-coupled secondary dc power-supply forming device

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JPH06335241A true JPH06335241A (en) 1994-12-02

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