JPH0511175A - Power source control circuit - Google Patents

Power source control circuit

Info

Publication number
JPH0511175A
JPH0511175A JP16560791A JP16560791A JPH0511175A JP H0511175 A JPH0511175 A JP H0511175A JP 16560791 A JP16560791 A JP 16560791A JP 16560791 A JP16560791 A JP 16560791A JP H0511175 A JPH0511175 A JP H0511175A
Authority
JP
Japan
Prior art keywords
circuit
voltage
light receiving
control circuit
light
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.)
Granted
Application number
JP16560791A
Other languages
Japanese (ja)
Other versions
JP2997957B2 (en
Inventor
Yoichi Seki
陽一 関
Michio Kawai
道雄 川合
Hiroyuki Saito
浩幸 斉藤
Shinichi Endo
慎一 遠藤
Akira Ito
顕 伊藤
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.)
Seikosha KK
Original Assignee
Seikosha KK
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 Seikosha KK filed Critical Seikosha KK
Priority to JP16560791A priority Critical patent/JP2997957B2/en
Publication of JPH0511175A publication Critical patent/JPH0511175A/en
Application granted granted Critical
Publication of JP2997957B2 publication Critical patent/JP2997957B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Landscapes

  • Automatic Focus Adjustment (AREA)
  • Exposure Control For Cameras (AREA)
  • Details Of Cameras Including Film Mechanisms (AREA)
  • Stroboscope Apparatuses (AREA)

Abstract

PURPOSE:To provide a power source control circuit capable of utilizing voltage generated in a boosting circuit to a control circuit, as well in addition to a light receiving circuit and supplying always the stable voltage to the light receiving circuit and the control circuit. CONSTITUTION:Usually, the voltage Vsn of the output part P1 of a boosting circuit 1 is 5.5 volt by a boosting voltage switching circuit 5, from a constant voltage circuit 11, 5 volt the power source voltage is supplied to the light receiving circuit 12 and the control circuit 13. Before prescribed time the light receiving circuit 12 operates, the voltage Vsn of the output part P1 of the boosting circuit 1 is 10 volt. When the light receiving circuit 12 is in the operating state, the operation of the boosting circuit 1 is stopped in the prescribed time interval by a boost stopping circuit 20 and simultaneously the light emitting circuit 14 is operated and the prescribed operation is performed in the light receiving circuit 12.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明はカメラ等に用いる電源制
御回路に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply control circuit used for a camera or the like.

【0002】[0002]

【従来の技術】従来のオートフォーカスカメラ用の電源
制御回路として、例えば特公平3−18165号公報に
記載されたものがある。
2. Description of the Related Art As a conventional power supply control circuit for an autofocus camera, there is one disclosed in Japanese Patent Publication No. 3-18165.

【0003】これは、発光素子を発光させる直前に昇圧
回路(DC/DCコンバータ)を動作させて電池電圧を
昇圧し、発光および受光動作をしている間は昇圧回路の
動作を停止するものである。したがって、受光動作時に
は昇圧動作にともなうノイズ等の影響がないので、受光
回路が正確に動作するというものである。
This is to boost the battery voltage by operating the booster circuit (DC / DC converter) immediately before the light emitting element emits light, and stop the operation of the booster circuit during the light emitting and light receiving operations. is there. Therefore, during the light receiving operation, there is no influence of noise or the like due to the boosting operation, so that the light receiving circuit operates accurately.

【0004】[0004]

【発明が解決しようとする課題】しかしながら、上記従
来例では、発光素子を発光させる直前にのみ昇圧動作を
行うため、昇圧回路で生じる電圧は発光回路および受光
回路で用いられるだけであり、発光回路や昇圧回路の動
作等を制御する制御回路では昇圧電圧を利用することが
できなかった。また、発光動作にともなう昇圧回路出力
部の電圧低下によって受光回路に供給される電圧が低下
し、受光回路の動作が不正確になるという問題点もあっ
た。
However, in the above-mentioned conventional example, since the boosting operation is performed only immediately before the light emitting element emits light, the voltage generated in the boosting circuit is used only in the light emitting circuit and the light receiving circuit, and the light emitting circuit is used. The boosted voltage cannot be used in the control circuit that controls the operation of the booster circuit or the like. Further, there is also a problem that the voltage supplied to the light receiving circuit is lowered due to the voltage drop of the booster circuit output portion accompanying the light emitting operation, and the operation of the light receiving circuit becomes inaccurate.

【0005】本発明の目的は、昇圧回路で生じる電圧を
受光回路のほかに制御回路でも利用でき、しかも常に安
定した電圧を受光回路および制御回路に供給可能な電源
制御回路を提供することである。
An object of the present invention is to provide a power supply control circuit in which the voltage generated in the booster circuit can be used not only in the light receiving circuit but also in the control circuit, and which can always supply a stable voltage to the light receiving circuit and the control circuit. ..

【0006】[0006]

【課題を解決するための手段】本発明における電源制御
回路は、対象物を照射する照射光を生じる発光回路と、
上記照射光の対象物からの反射光を受光してその受光量
に応じた電気信号を生じる受光回路と、電池電圧を昇圧
して上記発光回路に供給する昇圧回路と、上記発光回路
および上記昇圧回路の動作を制御する制御回路と、上記
昇圧回路の出力を入力して常に定電圧を生じるととも
に、この定電圧を上記受光回路および上記制御回路の電
源電圧として供給する定電圧回路と、上記受光回路が動
作する所定時間前に上記昇圧回路の昇圧電圧を第1昇圧
電圧からこの第1昇圧電圧よりも電圧の高い第2昇圧電
圧に切換える昇圧電圧切換え回路と、上記受光回路が動
作しているときに上記昇圧回路の昇圧動作を停止する昇
圧停止回路とからなる。
A power supply control circuit according to the present invention comprises a light emitting circuit for generating irradiation light for irradiating an object,
A light receiving circuit that receives reflected light of the irradiation light from an object and generates an electric signal according to the amount of received light, a boosting circuit that boosts a battery voltage and supplies the light emitting circuit, the light emitting circuit and the boosting circuit. A control circuit for controlling the operation of the circuit, a constant voltage circuit that constantly receives the output of the booster circuit to generate a constant voltage, and supplies the constant voltage as a power supply voltage for the light receiving circuit and the control circuit, and the light receiving circuit. The booster voltage switching circuit that switches the boosted voltage of the booster circuit from the first boosted voltage to the second boosted voltage that is higher than the first boosted voltage and the light receiving circuit are operating a predetermined time before the circuit operates. And a boost stop circuit for stopping boost operation of the boost circuit.

【0007】[0007]

【実施例】図1は、オートフォーカスカメラ用の電源制
御回路の実施例を示した電気回路図である。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an electric circuit diagram showing an embodiment of a power supply control circuit for an autofocus camera.

【0008】昇圧回路1は、電池VB の電圧(1.5ボ
ルト〜3ボルト)を昇圧して、第1昇圧電圧(5.5ボ
ルト)および第2昇圧電圧(10ボルト)を生じるもの
であり、コイル2、ダイオ―ド3、トランジスタ4およ
びコンデンサC1 で構成されている。昇圧電圧切換え回
路5は、昇圧回路1の昇圧電圧を第1昇圧電圧または第
2昇圧電圧に切換えるものである。この昇圧電圧切換え
回路5は、図2に示すように、コンパレ−タ6、アンド
ゲ―ト7、切換え部8、抵抗R1 およびR2 、基準電圧
部VR1およびVR2で構成されている。基準電圧部VR2の
電圧は基準電圧部VR1の電圧よりも高くなるように設定
されている。定電圧回路11は、昇圧回路1の出力を受
けて安定化された定電圧VDD(5ボルト)を生じるもの
であり、この定電圧(5ボルト)は後述の受光回路12
および制御回路13の電源電圧として供給されるもので
ある。定電圧回路11の出力には昇圧回路1のコンデン
サC1 に比べてはるかに小容量のコンデンサC2 が接続
されている。受光回路12は、対象物(図示せず。)か
らの反射光を受光してその受光量に応じた電気信号(光
電変換信号)を生じるものであり、受光素子、アンプ、
演算回路等で構成されている。制御回路13は、昇圧回
路1、昇圧電圧切換え回路5および後述の発光回路14
の動作等を制御する。この制御回路13はCPU等で構
成されている。発光回路14は、対象物に照射する照射
光を生じるものであり、トランジスタ16、発光素子
(発光ダイオ−ド等)17および抵抗R3 で構成されて
いる。アンドゲ―ト(昇圧停止回路)20は、受光回路
12が動作しているときに昇圧回路1の昇圧動作を停止
するものである。
The booster circuit 1 boosts the voltage of the battery VB (1.5 to 3 volts) to generate a first boosted voltage (5.5 volts) and a second boosted voltage (10 volts). , A coil 2, a diode 3, a transistor 4 and a capacitor C1. The boost voltage switching circuit 5 switches the boost voltage of the boost circuit 1 to the first boost voltage or the second boost voltage. As shown in FIG. 2, the boosted voltage switching circuit 5 comprises a comparator 6, an AND gate 7, a switching unit 8, resistors R1 and R2, and reference voltage units VR1 and VR2. The voltage of the reference voltage section VR2 is set to be higher than the voltage of the reference voltage section VR1. The constant voltage circuit 11 receives the output of the booster circuit 1 and generates a stabilized constant voltage VDD (5 volts). This constant voltage (5 volts) is a light receiving circuit 12 described later.
And is supplied as the power supply voltage of the control circuit 13. The output of the constant voltage circuit 11 is connected to a capacitor C2 having a much smaller capacity than the capacitor C1 of the booster circuit 1. The light receiving circuit 12 receives the reflected light from the object (not shown) and generates an electric signal (photoelectric conversion signal) according to the amount of received light. The light receiving element, the amplifier,
It is composed of an arithmetic circuit and the like. The control circuit 13 includes a booster circuit 1, a boosted voltage switching circuit 5, and a light emitting circuit 14 described later.
Control the operation of. The control circuit 13 is composed of a CPU and the like. The light emitting circuit 14 generates irradiation light for irradiating an object, and is composed of a transistor 16, a light emitting element (light emitting diode or the like) 17 and a resistor R3. The AND gate (step-up stop circuit) 20 stops the step-up operation of the step-up circuit 1 when the light receiving circuit 12 is operating.

【0009】つぎに、図1および図2に示した回路の動
作を、図3に示したタイムチャ―トを参照して、説明す
る。
The operation of the circuit shown in FIGS. 1 and 2 will be described below with reference to the time chart shown in FIG.

【0010】通常(定常時)は、昇圧回路1は動作状態
であり、その出力部P1 の電圧Vsuは第1昇圧電圧
(5.5ボルト)となっている。このときの動作の詳細
は、以下の通りである。昇圧電圧切換え回路5の切換え
部8は、制御回路13からの信号(P3 に入力)により
基準電圧部VR1に接続されている。コンパレ―タ6の非
反転入力には基準電圧部VR1の電圧が入力されており、
反転入力には電圧Vsuを抵抗分割した電圧が入力されて
いる。アンドゲ―ト7の一方の入力にはコンパレ―タ6
の出力が入力され、他方の入力には制御回路13から昇
圧クロック信号(P4 に入力)が入力されている。した
がって、昇圧回路1の出力部P1 の電圧Vsuの電圧が低
いときにはアンドゲ―ト7からはクロック信号が出力さ
れ、昇圧回路1の出力部P1 の電圧Vsuの電圧が高いと
きにはアンドゲ―ト7の出力は論理値“0”となる。ア
ンドゲ―ト(昇圧停止回路)20の一方の入力には制御
回路13からの昇圧停止信号(P5 に入力)が入力され
ているが、通常この昇圧停止信号は論理値“1”(昇圧
状態)となっている。したがって、アンドゲ―ト20か
らはアンドゲ―ト7の出力がそのまま出力されることに
なる。すなわち、定常時は、コンパレ―タ6、アンドゲ
―ト7およびアンドゲ―ト20を通して昇圧回路1の出
力状態がフィ―ドバックされ、昇圧回路1の出力部P1
の電圧Vsuが第1昇圧電圧(5.5ボルト)に保持され
ていることになる。このようにして第1昇圧電圧(5.
5ボルト)に保持された電圧は定電圧回路11に入力さ
れ、定電圧回路11からは安定化した電圧VDD(5ボル
ト)が出力される。そして、定電圧回路11の出力電圧
VDDは、受光回路12および制御回路13に電源電圧と
して供給される。したがって、制御回路13は常に動作
状態に保持されているわけである。
Normally (in a steady state), the booster circuit 1 is in an operating state, and the voltage Vsu of its output portion P1 is the first boosted voltage (5.5 volts). Details of the operation at this time are as follows. The switching unit 8 of the boosted voltage switching circuit 5 is connected to the reference voltage unit VR1 by a signal from the control circuit 13 (input to P3). The voltage of the reference voltage section VR1 is input to the non-inverting input of the comparator 6,
A voltage obtained by resistance-dividing the voltage Vsu is input to the inverting input. One of the inputs of the AND gate 7 is a comparator 6
Of the booster clock signal (input to P4) from the control circuit 13 is input to the other input. Therefore, when the voltage Vsu of the output portion P1 of the booster circuit 1 is low, the clock signal is output from the AND gate 7, and when the voltage Vsu of the output portion P1 of the booster circuit 1 is high, the output of the AND gate 7 is output. Becomes a logical value "0". A boost stop signal (input to P5) from the control circuit 13 is input to one input of the AND gate (boost stop circuit) 20, but normally this boost stop signal is a logical value "1" (boost state). Has become. Therefore, the output of the AND gate 7 is output from the AND gate 20 as it is. That is, in a steady state, the output state of the booster circuit 1 is fed back through the comparator 6, the AND gate 7, and the AND gate 20, and the output portion P1 of the booster circuit 1 is fed back.
Therefore, the voltage Vsu of is held at the first boosted voltage (5.5 volts). In this way, the first boosted voltage (5.
The voltage held at 5 volts is input to the constant voltage circuit 11, and the constant voltage circuit 11 outputs a stabilized voltage VDD (5 volts). The output voltage VDD of the constant voltage circuit 11 is supplied to the light receiving circuit 12 and the control circuit 13 as a power supply voltage. Therefore, the control circuit 13 is always kept in the operating state.

【0011】受光回路12が動作する所定時間前になる
と(発光回路14の動作に対応して受光回路12が動作
することになるので、通常は発光回路14の動作期間と
受光回路12の動作期間とはほぼ一致している。したが
って、発光回路14が動作する所定時間前を基準にとる
ことも可能である。)、昇圧回路1の出力部P1 の電圧
Vsuは第2昇圧電圧(10ボルト)に上昇する。すなわ
ち、制御回路13からの信号(P3 に入力)により昇圧
電圧切換え回路5の切換え部8が基準電圧部VR2に接続
され、それに応じて昇圧回路1の出力部P1 の電圧Vsu
が上昇するわけである。なお、このときにも、定電圧回
路11の出力電圧VDDは5ボルトに保持されたままであ
る。
A predetermined time before the light receiving circuit 12 operates (the light receiving circuit 12 operates in accordance with the operation of the light emitting circuit 14, so normally, the operation period of the light emitting circuit 14 and the operation period of the light receiving circuit 12). Therefore, the voltage Vsu of the output portion P1 of the booster circuit 1 is the second boosted voltage (10 volts). Rise to. That is, the switching section 8 of the boosted voltage switching circuit 5 is connected to the reference voltage section VR2 by the signal from the control circuit 13 (input to P3), and accordingly the voltage Vsu of the output section P1 of the booster circuit 1 is supplied.
Will rise. Even at this time, the output voltage VDD of the constant voltage circuit 11 is still maintained at 5 volts.

【0012】受光回路12あるいは発光回路14が動作
状態になると、昇圧回路1の動作が所定時間停止すると
ともに所定の動作が行なわれる。このときの動作の詳細
は、以下の通りである。アンドゲ―ト(昇圧停止回路)
20の一方の入力には制御回路13からの昇圧停止信号
(論理値“0”)が入力され、アンドゲ―ト20の出力
は論理値“0”に固定される。その結果、昇圧回路1の
昇圧動作は停止する。
When the light receiving circuit 12 or the light emitting circuit 14 is activated, the operation of the booster circuit 1 is stopped for a predetermined time and the predetermined operation is performed. Details of the operation at this time are as follows. And gate (boost stop circuit)
A boosting stop signal (logical value "0") from the control circuit 13 is input to one input of 20 and the output of the AND gate 20 is fixed to a logical value "0". As a result, the boosting operation of the booster circuit 1 is stopped.

【0013】一方、制御回路13からの信号により発光
回路14のトランジスタ16がオン状態となり、発光素
子17から対象物(図示せず。)に照射光が照射され
る。照射光の対象物からの反射光は受光回路12の受光
素子で受光され、受光素子からはその受光量に応じた電
気信号(光電変換信号)が生じる。受光回路12では、
この光電変換信号に対して所定の処理(増幅、演算等)
を行なう。この所定の処理が終了した後、昇圧停止信号
の論理値は“1”となり、再び昇圧回路1の昇圧動作が
開始される。図3に示すように連続的に発光させる場合
には、昇圧回路1の出力部P1 の電圧Vsuを急激に第2
昇圧電圧(10ボルト)まで回復させる必要があるの
で、昇圧クロックのデュ―ティを定常時よりも高くする
ことが好ましい。発光動作にともなって昇圧回路1の出
力部P1 の電圧Vsuは減少するが、その初期電圧(10
ボルト)が十分高いので、定電圧回路11の出力電圧V
DDが5ボルト以下になることはない。したがって、受光
回路12での処理は高精度で行なわれ、また制御回路1
3の動作も確実に行なわれる。
On the other hand, the transistor 16 of the light emitting circuit 14 is turned on by the signal from the control circuit 13, and the light emitting element 17 irradiates an object (not shown) with irradiation light. The reflected light of the irradiation light from the object is received by the light receiving element of the light receiving circuit 12, and the light receiving element generates an electric signal (photoelectric conversion signal) according to the received light amount. In the light receiving circuit 12,
Predetermined processing (amplification, calculation, etc.) for this photoelectric conversion signal
Do. After the completion of this predetermined process, the logical value of the boost stop signal becomes "1", and the boost operation of the boost circuit 1 is started again. When light is emitted continuously as shown in FIG. 3, the voltage Vsu of the output portion P1 of the booster circuit 1 is suddenly changed to the second value.
Since it is necessary to recover the boosted voltage (10 V), it is preferable to set the duty of the boosted clock higher than that in the steady state. The voltage Vsu of the output portion P1 of the booster circuit 1 decreases with the light emission operation, but the initial voltage (10
Volt) is sufficiently high, the output voltage V of the constant voltage circuit 11
DD never goes below 5 volts. Therefore, the processing in the light receiving circuit 12 is performed with high accuracy, and the control circuit 1
The operation of 3 is surely performed.

【0014】以上述べた実施例では、発光回路14用の
電源として昇圧回路1を用いていたが、この代りに電池
VB を直接電源として用いることも可能である。
Although the booster circuit 1 is used as the power source for the light emitting circuit 14 in the above-described embodiments, the battery VB can be directly used as the power source instead.

【0015】[0015]

【発明の効果】本発明における電源制御回路は、通常は
第1昇圧電圧を安定化した電圧で制御回路を動作させ、
受光回路が動作する所定時間前には第1昇圧電圧よりも
電圧の高い第2昇圧電圧に昇圧電圧を切換えるというも
のである。したがって、昇圧回路で生じる電圧を受光回
路のほかに制御回路でも利用できるとともに、昇圧動作
が停止している受光回路動作時にも安定した電圧を受光
回路および制御回路に供給可能となる。
The power supply control circuit of the present invention normally operates the control circuit with a voltage obtained by stabilizing the first boosted voltage,
The boosted voltage is switched to the second boosted voltage higher than the first boosted voltage a predetermined time before the light receiving circuit operates. Therefore, the voltage generated in the booster circuit can be used not only in the light receiving circuit but also in the control circuit, and a stable voltage can be supplied to the light receiving circuit and the control circuit even when the boosting operation is stopped.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明に係わる電源制御回路の実施例を示した
電気回路図である。
FIG. 1 is an electric circuit diagram showing an embodiment of a power supply control circuit according to the present invention.

【図2】図1の一部を示した電気回路図である。FIG. 2 is an electric circuit diagram showing a part of FIG.

【図3】図1および図2に示した回路の動作を示したタ
イムチャ―トである。
3 is a time chart showing the operation of the circuits shown in FIGS. 1 and 2. FIG.

【符号の説明】[Explanation of symbols]

1……昇圧回路 5……昇圧電圧切換え回路 11……定電圧回路 12……受光回路 13……制御回路 14……発光回路 20……昇圧停止回路 1 ... Booster circuit 5 ... Boost voltage switching circuit 11 ... Constant voltage circuit 12 ... Light receiving circuit 13 ... Control circuit 14 ... Light emitting circuit 20 ... Boost stop circuit

フロントページの続き (72)発明者 遠藤 慎一 千葉県四街道市鹿渡934−13番地 株式会 社精工舎千葉事業所内 (72)発明者 伊藤 顕 千葉県四街道市鹿渡934−13番地 株式会 社精工舎千葉事業所内Front page continuation (72) Inventor Shinichi Endo, 934-13 Shikato, Yotsukaido, Chiba Prefecture, Ltd., Seikosha Chiba Works, Inc. In the office

Claims (1)

【特許請求の範囲】 【請求項1】 対象物を照射する照射光を生じる発光回
路と、 上記照射光の対象物からの反射光を受光してその受光量
に応じた電気信号を生じる受光回路と、 電池電圧を昇圧して上記発光回路に供給する昇圧回路
と、 上記発光回路および上記昇圧回路の動作を制御する制御
回路と、 上記昇圧回路の出力を入力して常に定電圧を生じるとと
もに、この定電圧を上記受光回路および上記制御回路の
電源電圧として供給する定電圧回路と、 上記受光回路が動作する所定時間前に上記昇圧回路の昇
圧電圧を第1昇圧電圧からこの第1昇圧電圧よりも電圧
の高い第2昇圧電圧に切換える昇圧電圧切換え回路と、 上記受光回路が動作しているときに上記昇圧回路の昇圧
動作を停止する昇圧停止回路とからなる電源制御回路。
Claim: What is claimed is: 1. A light emitting circuit for generating irradiation light for irradiating an object, and a light receiving circuit for receiving reflected light of the irradiation light from the object and generating an electric signal according to the amount of received light. A booster circuit that boosts the battery voltage and supplies the booster circuit to the light emitting circuit; a control circuit that controls the operations of the light emitting circuit and the booster circuit; A constant voltage circuit that supplies this constant voltage as a power supply voltage to the light receiving circuit and the control circuit, and a boost voltage of the booster circuit from a first boosted voltage to a first boosted voltage before a predetermined time before the light receiving circuit operates. A power supply control circuit including a boost voltage switching circuit for switching to a second boost voltage having a high voltage, and a boost stop circuit for stopping the boost operation of the boost circuit when the light receiving circuit is operating.
JP16560791A 1991-07-05 1991-07-05 Power control circuit Expired - Fee Related JP2997957B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16560791A JP2997957B2 (en) 1991-07-05 1991-07-05 Power control circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16560791A JP2997957B2 (en) 1991-07-05 1991-07-05 Power control circuit

Publications (2)

Publication Number Publication Date
JPH0511175A true JPH0511175A (en) 1993-01-19
JP2997957B2 JP2997957B2 (en) 2000-01-11

Family

ID=15815577

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16560791A Expired - Fee Related JP2997957B2 (en) 1991-07-05 1991-07-05 Power control circuit

Country Status (1)

Country Link
JP (1) JP2997957B2 (en)

Also Published As

Publication number Publication date
JP2997957B2 (en) 2000-01-11

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