JP4655347B2 - Voltage frequency conversion circuit and lighting device - Google Patents

Voltage frequency conversion circuit and lighting device Download PDF

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Publication number
JP4655347B2
JP4655347B2 JP2000291531A JP2000291531A JP4655347B2 JP 4655347 B2 JP4655347 B2 JP 4655347B2 JP 2000291531 A JP2000291531 A JP 2000291531A JP 2000291531 A JP2000291531 A JP 2000291531A JP 4655347 B2 JP4655347 B2 JP 4655347B2
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voltage
capacitor
circuit
charging
limit value
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JP2002100968A (en
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紀之 北村
博志 寺坂
勉 垣谷
文則 仲矢
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Toshiba Lighting and Technology Corp
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Toshiba Lighting and Technology Corp
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Description

【０００１】
【発明の属する技術分野】
本発明は、放電灯に供給する高周波電源電圧のオン時間および周波数を制御する電圧周波数変換回路および点灯装置に関する。
【０００２】
【従来の技術】
一般に、放電灯点灯装置は、一対のスイッチング素子を交互にオンオフさせて放電灯に高周波電圧を印加するインバータ回路を有し、交流の電源電圧を直流に変換し、その直流電圧を高周波電圧に変換して放電灯に印加して点灯維持させるものである。インバータ回路のスイッチング素子は発振器を用いた制御回路でオンオフ制御される。
【０００３】
図３は、そのような放電灯点灯装置の構成例を示した回路図である。商用電源１から供給される交流電圧は電源回路２により整流された後、所定の電圧の直流に変換され、スイッチング素子３ａ、３ｂに印加される。これらスイッチング素子３ａ、３ｂは駆動回路４により交互にオンオフされ、所定の電圧の直流を高周波でスイッチングする。これにより、スイッチング素子３ａ、３ｂから高周波電流がコイルＬを介してコンデンサＣ１が並列接続された放電灯５に出力されて、放電灯５が点灯する。
【０００４】
この放電灯５に印加される負荷電圧は、抵抗Ｒ１、Ｒ２により分圧され、さらにコンデンサＣ２、Ｃ３およびダイオードＤ１、Ｄ２からなる電圧整流回路により電圧整流されて、電圧周波数変換回路６にフィードバックされる。電圧周波数変換回路６はフィードバック電圧に応じて、その発振周波数を変え、発振信号を駆動回路４に出力する。駆動回路４は入力される発振信号の周波数に同期した駆動信号をスイッチング素子３ａ、３ｂのゲートに出力して、スイッチング素子３ａ、３ｂを高周波でスイッチングさせる。これにより、電圧周波数変換回路６はスイッチング素子３ａ、３ｂから出力される高周波電圧の周波数を調整するようにしている。
【０００５】
この電圧周波数変換回路６で高周波電圧の周波数を調整するにあたっては、図示省略のコンデンサの充放電電流を可変させて周波数を可変したり、コンデンサの容量を切り替えて周波数を可変したりしている。
【０００６】
【発明が解決しようとする課題】
ところが、コンデンサの充放電電流を変化させるためには回路構成が複雑になり、コンデンサの容量を切り替えて周波数を可変する場合には、切り替え用のコンデンサが必要となる。
【０００７】
本発明の目的は、簡単な回路構成でコンデンサの充放電電流を一定にしたままで高周波電圧の周波数を可変できる電圧周波数変換回路および点灯装置を提供することである。
【０００８】
【課題を解決するための手段】
請求項１の発明に係わる電圧周波数変換回路は、スイッチング素子をオンオフ制御して高周波電圧の周波数を可変するための電圧調整器で可変された電圧を分圧し上限値および下限値を定める抵抗分圧回路と；コンデンサに充放電電流を流し前記コンデンサの充電電圧が前記抵抗分圧回路で定まる上限値になったとき前記スイッチング素子をオフし下限値になったとき前記スイッチング素子をオンし前記電圧調整器の可変電圧に応じた高周波電圧を出力する出力回路と；を備え、前記出力回路は、前記コンデンサの電圧が前記抵抗分圧回路で定まる上限値になったときリセット信号を出力する第１のコンパレータと；前記コンデンサの電圧が前記抵抗分圧回路で定まる下限値になったときセット信号を出力する第２のコンパレータと；前記セット信号が出力されたとき前記コンデンサの充電を開始し前記リセット信号が出力されたとき前記コンデンサの充電を停止させる第１の充放電制御回路と；前記コンデンサに流す充電電流を調整して前記第１の充放電制御回路に調整された充電電流を供給し前記コンデンサの充電特性を可変にして前記スイッチング素子のオンオフ時間のデューティ比を調整可能とする第１の直流電流電源と；前記リセット信号が出力されたとき前記コンデンサの放電を開始し前記セット信号が出力されたとき前記コンデンサの放電を停止させる第２の充放電制御回路と；前記コンデンサに流す充電電流を調整して前記第２の充放電制御回路に調整された充電電流を供給し前記コンデンサの放電特性を可変にして前記スイッチング素子のオンオフ時間のデューティ比を調整可能とする第２の直流電流電源と；を備えたことを特徴とする。
【０００９】
本発明及び以下の発明において、特に指定しない限り用語の意味は以下による。電圧周波数変換回路は、放電灯に印加する高周波電圧の周波数およびオン時間を定めるものであり、抵抗分圧回路により上限値および下限値の２つの閾値を設け、比較する電圧は出力回路のコンデンサに定電流回路で充放電電流を流すことで周波数およびオン時間を決定するものである。
【００１０】
電圧調整器は、入力電圧を可変して出力するものであり、例えば、放電灯の負荷電圧に比例した入力電圧を可変して、可変された入力電圧を分圧抵抗で分圧する抵抗分圧回路に印加する。抵抗分圧回路は可変された入力電圧を分圧して、上限値および下限値を出力する。つまり、抵抗分圧回路は、可変された入力電圧に応じて上限値および下限値を定めることになる。
【００１１】
出力回路は、充放電を繰り返し行うコンデンサを有し、コンデンサの充電電圧が抵抗分圧回路で定まる上限値になったときオンし、下限値になったときオフする高周波電圧を出力する。
【００１２】
これにより、コンデンサの充放電電流を一定に保ったままで、入力電圧を電圧調整器で可変とするだけで、放電灯に印加する高周波電圧の周波数およびオン時間を可変にする。
【００１４】
出力回路は、抵抗分圧回路からの上限値とコンデンサの充電電圧とを比較する第１のコンパレータと、抵抗分圧回路からの下限値とコンデンサの充電電圧とを比較する第２のコンパレータとの２つのコンパレータを有する。
【００１５】
第１のコンパレータは、コンデンサの電圧が抵抗分圧回路で定まる上限値になったときリセット信号を出力し、第２のコンパレータは、コンデンサの電圧が抵抗分圧回路で定まる下限値になったときセット信号を出力する。
【００１６】
第１の充放電制御回路および第２の充放電制御回路は、コンデンサの充放電電流を調整制御するものであり、第１の充放電制御回路は、第１の直流電流電源で調整された充電電流をコンデンサに流し、第２の充放電制御回路は、第２の直流電流電源で調整された放電電流をコンデンサに流す。
【００１７】
そして、第１の充放電制御回路は、第１のコンパレータからセット信号が出力されたときはコンデンサの充電を開始し、第２のコンパレータからリセット信号が出力されたときはコンデンサの充電を停止させる。一方、第２の充放電制御回路は、第１のコンパレータからリセット信号が出力されたときはコンデンサの放電を開始し、第２のコンパレータからセット信号が出力されたときはコンデンサの放電を停止させる。これにより、コンデンサは充放電を繰り返し行う。
【００１８】
請求項２の発明に係わる点灯装置は、請求項１の電圧周波数変換回路と；直流電源電圧が印加され前記電圧周波数変換回路からの高周波電圧に基づいてオンオフする１個または複数個のスイッチング素子と；を備えたことを特徴とする。
【００１９】
スイッチング素子は、請求項１の電圧周波数変換回路からの可変された周波数およびオン時間のオンオフ信号でオンオフ制御される。
【００２０】
【発明の実施の形態】
以下、本発明の実施の形態を説明する。図１は本発明の実施の形態に係わる電圧周波数変換回路の回路構成図である。
【００２１】
放電灯の負荷電圧に比例した電圧Ｖは電圧調整器７に入力され、電圧調整器７にてその入力電圧Ｖは調整され可変される。電圧調整器７で調整された電圧はオペアンプ８を介して抵抗分圧回路に入力される。抵抗分圧回路は抵抗Ｒ３〜Ｒ５で構成され、上限値Ｈおよび下限値Ｌが得られる。上限値Ｈは出力回路の第１のコンパレータ９に入力され、下限値Ｌは出力回路の第２のコンパレータ１０に入力される。
【００２２】
出力回路は、第１のコンパレータ９および第２のコンパレータ１０に加え、充放電を繰り返し行うコンデンサＣｔ、第１のコンパレータ９からのリセット信号および第２のコンパレータ１０からのセット信号により動作するフリップフロップ１１、第１の直流電流電源１２で調整された充電電流をコンデンサＣｔに流す第１の充放電制御回路１３、第２の直流電流電源１４で調整された充電電流をコンデンサＣｔに流す第２の充放電制御回路１５、コンデンサＣｔに制御電源から充電電流を供給する充電電流供給回路１６から構成される。
【００２３】
この出力回路は、コンデンサＣｔに充放電電流を流してコンデンサＣｔの充放電により高周波電圧を出力するものであり、コンデンサＣｔの充電電圧が抵抗分圧回路で定まる上限値Ｈになったときにオフし下限値になったときにオンする高周波電圧Ｖ０を出力する。
【００２４】
図２は、電圧周波数変換回路の動作を示す特性図である。図２（ａ）は充電電流と放電電流とが同じである場合のコンデンサ電圧Ｃｔと出力電圧Ｖ０との特性図である。
【００２５】
コンデンサＣｔは入力電圧が下限値Ｌになったときに充電を開始し出力電圧Ｖ０をオンにする（ｔ１）。すなわち、第２のコンパレータ１０がセット信号を出力したときに、第１の充放電制御回路１３は充電電流供給回路１６をオンしコンデンサＣｔを充電する。コンデンサＣｔの充電中は、出力電圧Ｖ０はオン状態である。
【００２６】
コンデンサＣｔの充電によりコンデンサＣｔの電圧が上昇し上限値Ｈとなると（ｔ２）、第１のコンパレータ９が動作しリセット信号を出力する。これにより、第１の充放電制御回路１３は充電電流供給回路１６をオフしコンデンサＣｔの充電を停止すると共に、第２の充放電制御回路１５はコンデンサＣｔの放電を開始する。このコンデンサＣｔの放電中は出力電圧Ｖ０はオフである。
【００２７】
そして、コンデンサＣｔの電圧が下限値Ｌになると、第２のコンパレータが動作しセット信号を出力する。これにより、コンデンサＣｔは充電を開始し出力電圧Ｖ０をオンにする（ｔ３）。以下、このコンデンサＣｔの充放電により出力電圧Ｖ０はオンオフを繰り返し行い高周波電圧を発生する。
【００２８】
図２（ｂ）は、電圧調整回路７により抵抗分圧回路に印加される入力電圧を下げることにより、図２（ａ）の上限値Ｈおよび下限値Ｌより下げた上限値Ｈ’および下限値Ｌ’とした場合のコンデンサ電圧Ｃｔと出力電圧Ｖ０との特性図である。
【００２９】
図２（ｂ）に示すように、抵抗分圧回路に印加される入力電圧を下げた場合には、コンデンサＣｔの充放電特性が同じであっても出力電圧Ｖ０の周波数が高くなる。すなわち、上限値Ｈ’と下限値Ｌ’との幅が図２（ａ）の上限値Ｈと下限値Ｌとの幅より小さくなるので、コンデンサＣｔの充電時にはコンデンサＣｔの電圧が速く上限値Ｈ’に到達し、放電時にはコンデンサＣｔの電圧が速く下限値Ｌ’に達する。従って、コンデンサＣｔの充放電の繰り返しサイクルが短くなり、出力電圧Ｖ０はコンデンサＣｔの充放電特性が同じであっても、より周波数が高い高周波電圧となる。
【００３０】
図２（ｃ）は、抵抗分圧回路に印加される入力電圧は一定のままで、放電電流特性を緩慢にした場合のコンデンサ電圧Ｃｔと出力電圧Ｖ０との特性図である。
【００３１】
図２（ｃ）に示すように、抵抗分圧回路に印加される入力電圧およびコンデンサＣｔの充電電流特性を図１（ａ）の場合と同じとし、コンデンサＣｔの放電電流特性を緩慢にさせると、出力電圧Ｖ０のオフ時間が長くなる。逆に、コンデンサＣｔの充電電流特性を緩慢にさせると、出力電圧Ｖ０のオン時間が長くなる。
これにより、オンオフ時間のデューティ比の調整が可能となる。
【００３２】
充電電流特性は第１の直流電流源１３を調整することにより可変し、放電特性は第２の直流電流電源１４を調整することにより可変とする。
【００３３】
このように、電圧周波数変換回路は、放電灯に印加する高周波電圧の周波数を抵抗分圧回路への入力電圧の調整により行い、また、放電灯に印加する高周波電圧のオンオフ時間のデューティ比を第１の直流電流電源１２および第２の直流電電流源１４の調整により行う。これにより、所望の周波数およびオン時間の高周波電圧が得られる。
【００３４】
この電圧周波数変換回路は、一例として図３に示した放電灯点灯装置に適用される。すなわち、放電灯点灯回路に適用された本発明の電圧周波数変換回路は、スイッチング素子３ａ、３ｂを可変された周波数およびオン時間のオンオフ信号でオンオフ制御する。これにより、放電灯に高周波電圧を印加し、所望の周波数およびオン時間で放電灯を点灯制御できることになる。
【００３５】
【発明の効果】
以上述べたように、本発明によれば、電圧周波数変換回路によれば、コンデンサの充放電電流を一定に保ったままで、入力電圧を電圧調整器で可変とするだけで、放電灯に印加する高周波電圧の周波数およびオン時間を可変できる。また、コンデンサの充放電特性を変化させることで高周波電圧のオンオフ時間のデューティ比を可変にできる。従って、ダイナミックレンジが広く取れる。
【００３６】
また、この電圧周波数変換回路を有した放電灯点灯装置により放電灯を適正に点灯制御できる。
【図面の簡単な説明】
【図１】本発明の実施の形態に係わる電圧周波数変換回路の回路構成図。
【図２】本発明の実施の形態に係わる電圧周波数変換回路６動作を示す特性図。
【図３】放電灯点灯装置の回路構成図。
【符号の説明】
１…商用電源、２…電源回路、３…スイッチング素子、４…駆動回路、５…放電灯、６…電圧周波数変換回路、７…電圧調整回路、８…オペアンプ、９…第１のコンパレータ、１０…第２のコンパレータ、１１…フリップフロップ、１２…第１の直流電流電源、１３…第１の充放電制御回路、１４…第２の直流電流電源、１５…第２の充放電制御回路、１６…充電電流供給回路[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a voltage frequency conversion circuit and a lighting device that control the on-time and frequency of a high-frequency power supply voltage supplied to a discharge lamp.
[0002]
[Prior art]
Generally, a discharge lamp lighting device has an inverter circuit that applies a high frequency voltage to a discharge lamp by alternately turning on and off a pair of switching elements, converts an AC power supply voltage to DC, and converts the DC voltage to a high frequency voltage. Then, it is applied to the discharge lamp to maintain the lighting. The switching element of the inverter circuit is on / off controlled by a control circuit using an oscillator.
[0003]
FIG. 3 is a circuit diagram showing a configuration example of such a discharge lamp lighting device. The AC voltage supplied from the commercial power supply 1 is rectified by the power supply circuit 2 and then converted to a predetermined voltage DC and applied to the switching elements 3a and 3b. These switching elements 3a and 3b are alternately turned on and off by the drive circuit 4 to switch a predetermined voltage direct current at a high frequency. As a result, a high-frequency current is output from the switching elements 3a and 3b via the coil L to the discharge lamp 5 to which the capacitor C1 is connected in parallel, and the discharge lamp 5 is lit.
[0004]
The load voltage applied to the discharge lamp 5 is divided by resistors R1 and R2, further voltage rectified by a voltage rectifier circuit including capacitors C2 and C3 and diodes D1 and D2, and fed back to the voltage frequency conversion circuit 6. The The voltage frequency conversion circuit 6 changes its oscillation frequency according to the feedback voltage and outputs an oscillation signal to the drive circuit 4. The drive circuit 4 outputs a drive signal synchronized with the frequency of the input oscillation signal to the gates of the switching elements 3a and 3b to switch the switching elements 3a and 3b at a high frequency. Thereby, the voltage frequency conversion circuit 6 adjusts the frequency of the high frequency voltage output from the switching elements 3a and 3b.
[0005]
When the frequency of the high frequency voltage is adjusted by the voltage frequency conversion circuit 6, the frequency is varied by changing the charge / discharge current of a capacitor (not shown), or the frequency is changed by switching the capacitance of the capacitor.
[0006]
[Problems to be solved by the invention]
However, in order to change the charge / discharge current of the capacitor, the circuit configuration becomes complicated. When the frequency is varied by switching the capacitance of the capacitor, a switching capacitor is required.
[0007]
An object of the present invention is to provide a voltage frequency conversion circuit and a lighting apparatus capable of varying the frequency of the high-frequency voltage while the charging and discharging current of the capacitor to be constant with a simple circuit configuration.
[0008]
[Means for Solving the Problems]
A voltage frequency conversion circuit according to a first aspect of the present invention is a resistance voltage dividing circuit that divides a voltage varied by a voltage regulator for varying a frequency of a high frequency voltage by controlling on / off of a switching element to determine an upper limit value and a lower limit value. circuit and; the switching element oN and the voltage adjusted when it becomes the lower limit value to turn off the switching element when the charging voltage of the capacitor flowing discharge current reaches the upper limit value determined by the resistor divider to the capacitor An output circuit for outputting a high-frequency voltage corresponding to a variable voltage of the capacitor, wherein the output circuit outputs a reset signal when the voltage of the capacitor reaches an upper limit value determined by the resistance voltage dividing circuit. A second comparator that outputs a set signal when the voltage of the capacitor reaches a lower limit value determined by the resistance voltage dividing circuit; A first charging / discharging control circuit that starts charging the capacitor when a signal is output and stops charging the capacitor when the reset signal is output; and adjusting the charging current flowing through the capacitor to adjust the charging current. A first direct current power supply that supplies a regulated charging current to a charge / discharge control circuit of 1 to vary a charging characteristic of the capacitor and adjust a duty ratio of an on / off time of the switching element ; A second charge / discharge control circuit that starts discharging the capacitor when output and stops discharging the capacitor when the set signal is output; and adjusts a charging current flowing through the capacitor to adjust the second charge / discharge supplying the adjusted charging current to the discharge control circuit to the discharge characteristics of the capacitor in the variable on-off time of the switching element Dew Characterized by comprising a; and second direct current power source that enables adjusting the I ratio.
[0009]
In the present invention and the following inventions, the meanings of terms are as follows unless otherwise specified. The voltage frequency conversion circuit determines the frequency and on-time of the high-frequency voltage applied to the discharge lamp. The resistance voltage dividing circuit provides two threshold values, an upper limit value and a lower limit value, and the voltage to be compared is applied to the capacitor of the output circuit. The frequency and the on-time are determined by flowing a charge / discharge current in a constant current circuit.
[0010]
The voltage regulator variably outputs an input voltage, for example, a resistance voltage dividing circuit that varies an input voltage proportional to a load voltage of a discharge lamp and divides the variable input voltage with a voltage dividing resistor. Apply to. The resistance voltage dividing circuit divides the variable input voltage and outputs an upper limit value and a lower limit value. That is, the resistance voltage dividing circuit determines the upper limit value and the lower limit value according to the variable input voltage.
[0011]
The output circuit includes a capacitor that repeatedly charges and discharges, and outputs a high-frequency voltage that turns on when the charging voltage of the capacitor reaches an upper limit value determined by the resistance voltage dividing circuit and turns off when the capacitor voltage reaches the lower limit value.
[0012]
As a result, the frequency and on-time of the high-frequency voltage applied to the discharge lamp are made variable by merely changing the input voltage with the voltage regulator while keeping the charge / discharge current of the capacitor constant.
[0014]
The output circuit includes a first comparator that compares the upper limit value from the resistance voltage dividing circuit and the charging voltage of the capacitor, and a second comparator that compares the lower limit value from the resistance voltage dividing circuit and the charging voltage of the capacitor. It has two comparators.
[0015]
The first comparator outputs a reset signal when the capacitor voltage reaches an upper limit value determined by the resistance voltage dividing circuit, and the second comparator outputs a reset signal when the capacitor voltage reaches a lower limit value determined by the resistance voltage dividing circuit. A set signal is output.
[0016]
The first charge / discharge control circuit and the second charge / discharge control circuit adjust and control the charge / discharge current of the capacitor, and the first charge / discharge control circuit is a charge adjusted by the first DC current power supply. The current is caused to flow through the capacitor, and the second charge / discharge control circuit causes the discharge current adjusted by the second direct current power source to flow through the capacitor.
[0017]
The first charge / discharge control circuit starts charging the capacitor when the set signal is output from the first comparator, and stops charging the capacitor when the reset signal is output from the second comparator. . On the other hand, the second charge / discharge control circuit starts discharging the capacitor when the reset signal is output from the first comparator, and stops discharging the capacitor when the set signal is output from the second comparator. . As a result, the capacitor is repeatedly charged and discharged.
[0018]
According to a second aspect of the present invention, there is provided a lighting device according to the first aspect, the voltage frequency conversion circuit according to the first aspect; one or a plurality of switching elements that are turned on and off based on a high frequency voltage from the voltage frequency conversion circuit when a DC power supply voltage is applied; It is characterized by comprising;
[0019]
Switching elements, Ru is on-off controlled by the on-off signal of the variable frequency and on-time from the voltage frequency conversion circuit of claim 1.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. FIG. 1 is a circuit configuration diagram of a voltage frequency conversion circuit according to an embodiment of the present invention.
[0021]
A voltage V proportional to the load voltage of the discharge lamp is input to the voltage regulator 7, and the input voltage V is adjusted and varied by the voltage regulator 7. The voltage adjusted by the voltage regulator 7 is input to the resistance voltage dividing circuit via the operational amplifier 8. The resistance voltage dividing circuit includes resistors R3 to R5, and an upper limit value H and a lower limit value L are obtained. The upper limit value H is input to the first comparator 9 of the output circuit, and the lower limit value L is input to the second comparator 10 of the output circuit.
[0022]
In addition to the first comparator 9 and the second comparator 10, the output circuit is a flip-flop that operates by a capacitor Ct that repeatedly charges and discharges, a reset signal from the first comparator 9, and a set signal from the second comparator 10. 11. A first charging / discharging control circuit 13 for flowing the charging current adjusted by the first DC current power supply 12 to the capacitor Ct, and a second charging current adjusted by the second DC current power supply 14 for flowing the capacitor Ct. The charging / discharging control circuit 15 includes a charging current supply circuit 16 that supplies a charging current from a control power source to the capacitor Ct.
[0023]
This output circuit outputs a high frequency voltage by charging / discharging the capacitor Ct by supplying a charging / discharging current to the capacitor Ct, and is turned off when the charging voltage of the capacitor Ct reaches the upper limit value H determined by the resistance voltage dividing circuit. The high-frequency voltage V0 that is turned on when the lower limit is reached is output.
[0024]
FIG. 2 is a characteristic diagram showing the operation of the voltage frequency conversion circuit. FIG. 2A is a characteristic diagram of the capacitor voltage Ct and the output voltage V0 when the charging current and the discharging current are the same.
[0025]
The capacitor Ct starts charging when the input voltage reaches the lower limit L and turns on the output voltage V0 (t1). That is, when the second comparator 10 outputs a set signal, the first charge / discharge control circuit 13 turns on the charging current supply circuit 16 and charges the capacitor Ct. While the capacitor Ct is being charged, the output voltage V0 is on.
[0026]
When the voltage of the capacitor Ct rises to the upper limit value H by charging the capacitor Ct (t2), the first comparator 9 operates and outputs a reset signal. As a result, the first charge / discharge control circuit 13 turns off the charge current supply circuit 16 to stop charging the capacitor Ct, and the second charge / discharge control circuit 15 starts discharging the capacitor Ct. During the discharge of the capacitor Ct, the output voltage V0 is off.
[0027]
Then, when the voltage of the capacitor Ct reaches the lower limit value L, the second comparator operates and outputs a set signal. As a result, the capacitor Ct starts charging and turns on the output voltage V0 (t3). Thereafter, the output voltage V0 is repeatedly turned on and off by the charging and discharging of the capacitor Ct to generate a high frequency voltage.
[0028]
FIG. 2B shows an upper limit value H ′ and a lower limit value lower than the upper limit value H and the lower limit value L of FIG. 2A by lowering the input voltage applied to the resistance voltage dividing circuit by the voltage adjustment circuit 7. FIG. 6 is a characteristic diagram of a capacitor voltage Ct and an output voltage V0 when L ′.
[0029]
As shown in FIG. 2B, when the input voltage applied to the resistance voltage dividing circuit is lowered, the frequency of the output voltage V0 increases even if the charge / discharge characteristics of the capacitor Ct are the same. That is, since the width between the upper limit value H ′ and the lower limit value L ′ is smaller than the width between the upper limit value H and the lower limit value L in FIG. 2A, the voltage of the capacitor Ct becomes faster when the capacitor Ct is charged. The voltage of the capacitor Ct quickly reaches the lower limit L ′ at the time of discharge. Therefore, the charge / discharge cycle of the capacitor Ct is shortened, and the output voltage V0 becomes a high-frequency voltage having a higher frequency even if the charge / discharge characteristics of the capacitor Ct are the same.
[0030]
FIG. 2C is a characteristic diagram of the capacitor voltage Ct and the output voltage V0 when the input voltage applied to the resistance voltage dividing circuit remains constant and the discharge current characteristic is slow.
[0031]
As shown in FIG. 2C, when the input voltage applied to the resistance voltage dividing circuit and the charging current characteristic of the capacitor Ct are the same as those in FIG. 1A, and the discharge current characteristic of the capacitor Ct is made slow. The off time of the output voltage V0 becomes longer. Conversely, if the charging current characteristic of the capacitor Ct is made slow, the ON time of the output voltage V0 becomes longer.
Thereby, the duty ratio of the on / off time can be adjusted.
[0032]
The charging current characteristic is made variable by adjusting the first DC current source 13, and the discharging characteristic is made variable by adjusting the second DC current power source 14.
[0033]
Thus, the voltage frequency conversion circuit adjusts the frequency of the high frequency voltage applied to the discharge lamp by adjusting the input voltage to the resistance voltage dividing circuit, and sets the duty ratio of the on / off time of the high frequency voltage applied to the discharge lamp to the first value. The adjustment is performed by adjusting the first DC current power source 12 and the second DC current source 14. As a result, a high-frequency voltage having a desired frequency and on-time can be obtained.
[0034]
This voltage frequency conversion circuit is applied to the discharge lamp lighting device shown in FIG. 3 as an example. That is, the voltage frequency conversion circuit of the present invention applied to the discharge lamp lighting circuit controls on / off of the switching elements 3a, 3b with an on / off signal having a variable frequency and an on time. As a result, a high frequency voltage is applied to the discharge lamp, and the discharge lamp can be controlled to light at a desired frequency and on time.
[0035]
【The invention's effect】
As described above, according to the present invention, the voltage frequency conversion circuit applies the input voltage to the discharge lamp only by changing the input voltage with the voltage regulator while keeping the charge / discharge current of the capacitor constant. The frequency and on-time of the high frequency voltage can be varied. Further, the duty ratio of the on / off time of the high-frequency voltage can be made variable by changing the charge / discharge characteristics of the capacitor. Therefore, a wide dynamic range can be taken.
[0036]
Further, the discharge lamp lighting device having this voltage frequency conversion circuit can appropriately control lighting of the discharge lamp.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram of a voltage frequency conversion circuit according to an embodiment of the present invention.
FIG. 2 is a characteristic diagram showing the operation of the voltage frequency conversion circuit 6 according to the embodiment of the present invention.
FIG. 3 is a circuit configuration diagram of a discharge lamp lighting device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Commercial power supply, 2 ... Power supply circuit, 3 ... Switching element, 4 ... Drive circuit, 5 ... Discharge lamp, 6 ... Voltage frequency conversion circuit, 7 ... Voltage adjustment circuit, 8 ... Operational amplifier, 9 ... 1st comparator, 10 DESCRIPTION OF SYMBOLS 2nd comparator, 11 ... Flip-flop, 12 ... 1st direct current power supply, 13 ... 1st charging / discharging control circuit, 14 ... 2nd direct current power supply, 15 ... 2nd charging / discharging control circuit, 16 ... Charging current supply circuit

Claims (2)

スイッチング素子をオンオフ制御して高周波電圧の周波数を可変するための電圧調整器で可変された電圧を分圧し上限値および下限値を定める抵抗分圧回路と；
コンデンサに充放電電流を流し前記コンデンサの充電電圧が前記抵抗分圧回路で定まる上限値になったとき前記スイッチング素子をオフし下限値になったとき前記スイッチング素子をオンし前記電圧調整器の可変電圧に応じた高周波電圧を出力する出力回路と；を備え、
前記出力回路は、前記コンデンサの電圧が前記抵抗分圧回路で定まる上限値になったときリセット信号を出力する第１のコンパレータと；
前記コンデンサの電圧が前記抵抗分圧回路で定まる下限値になったときセット信号を出力する第２のコンパレータと；
前記セット信号が出力されたとき前記コンデンサの充電を開始し前記リセット信号が出力されたとき前記コンデンサの充電を停止させる第１の充放電制御回路と；
前記コンデンサに流す充電電流を調整して前記第１の充放電制御回路に調整された充電電流を供給し前記コンデンサの充電特性を可変にして前記スイッチング素子のオンオフ時間のデューティ比を調整可能とする第１の直流電流電源と；
前記リセット信号が出力されたとき前記コンデンサの放電を開始し前記セット信号が出力されたとき前記コンデンサの放電を停止させる第２の充放電制御回路と；
前記コンデンサに流す充電電流を調整して前記第２の充放電制御回路に調整された充電電流を供給し前記コンデンサの放電特性を可変にして前記スイッチング素子のオンオフ時間のデューティ比を調整可能とする第２の直流電流電源と；
を備えたことを特徴とする電圧周波数変換回路。 A resistance voltage dividing circuit that divides the voltage varied by a voltage regulator for varying the frequency of the high-frequency voltage by controlling on / off of the switching element to determine an upper limit value and a lower limit value;
When a charging / discharging current flows through the capacitor and the charging voltage of the capacitor reaches an upper limit value determined by the resistance voltage dividing circuit, the switching element is turned off, and when the charging voltage reaches the lower limit value, the switching element is turned on and the voltage regulator is variable. An output circuit that outputs a high-frequency voltage corresponding to the voltage;
The output circuit includes a first comparator that outputs a reset signal when a voltage of the capacitor reaches an upper limit value determined by the resistance voltage dividing circuit;
A second comparator that outputs a set signal when the voltage of the capacitor reaches a lower limit value determined by the resistance voltage dividing circuit;
A first charge / discharge control circuit that starts charging the capacitor when the set signal is output and stops charging the capacitor when the reset signal is output;
The charging current flowing through the capacitor is adjusted, the adjusted charging current is supplied to the first charge / discharge control circuit, the charging characteristic of the capacitor is made variable, and the duty ratio of the on / off time of the switching element can be adjusted . A first direct current power supply;
A second charge / discharge control circuit that starts discharging the capacitor when the reset signal is output and stops discharging the capacitor when the set signal is output;
By adjusting the charging current flowing through the capacitor and supplying the adjusted charging current to the second charge / discharge control circuit, the discharge characteristics of the capacitor can be varied to adjust the duty ratio of the on / off time of the switching element. A second direct current power supply;
A voltage frequency conversion circuit comprising: 請求項１の電圧周波数変換回路と；直流電源電圧が印加され前記電圧周波数変換回路からの高周波電圧に基づいてオンオフする１個または複数個のスイッチング素子と；を備えたことを特徴とする点灯装置。 Lighting apparatus comprising the; voltage frequency conversion circuit according to claim 1; and one or a plurality of switching elements to be turned on and off based on the high-frequency voltage from the DC power supply voltage is applied the voltage frequency conversion circuit .
JP2000291531A 2000-09-26 2000-09-26 Voltage frequency conversion circuit and lighting device Expired - Fee Related JP4655347B2 (en)

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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59104629U (en) * 1982-12-28 1984-07-14 日本電気ホームエレクトロニクス株式会社 Voltage-to-frequency conversion circuit
JPS6123410A (en) * 1984-07-11 1986-01-31 Matsushita Electric Ind Co Ltd Triangular wave oscillation circuit
JPH02235427A (en) * 1989-03-08 1990-09-18 Nippon Precision Circuits Kk Oscillating circuit
JPH03135107A (en) * 1989-10-19 1991-06-10 Mitsubishi Electric Corp Triangle wave generator
JPH0454719A (en) * 1990-06-25 1992-02-21 Fujitsu Denso Ltd Frequency control circuit
JPH08154040A (en) * 1994-11-25 1996-06-11 Sony Corp Variable frequency oscillator
JPH10313235A (en) * 1997-05-09 1998-11-24 Rohm Co Ltd V/f conversion circuit
JPH1131593A (en) * 1997-07-10 1999-02-02 Toshiba Lighting & Technol Corp Lamp-lighting device, and lighting system
JP2000150180A (en) * 1998-11-10 2000-05-30 Toshiba Lighting & Technology Corp Discharge lamp lighting device and lighting system

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59104629A (en) * 1982-12-07 1984-06-16 Canon Inc Camera having automatic focusing control function

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59104629U (en) * 1982-12-28 1984-07-14 日本電気ホームエレクトロニクス株式会社 Voltage-to-frequency conversion circuit
JPS6123410A (en) * 1984-07-11 1986-01-31 Matsushita Electric Ind Co Ltd Triangular wave oscillation circuit
JPH02235427A (en) * 1989-03-08 1990-09-18 Nippon Precision Circuits Kk Oscillating circuit
JPH03135107A (en) * 1989-10-19 1991-06-10 Mitsubishi Electric Corp Triangle wave generator
JPH0454719A (en) * 1990-06-25 1992-02-21 Fujitsu Denso Ltd Frequency control circuit
JPH08154040A (en) * 1994-11-25 1996-06-11 Sony Corp Variable frequency oscillator
JPH10313235A (en) * 1997-05-09 1998-11-24 Rohm Co Ltd V/f conversion circuit
JPH1131593A (en) * 1997-07-10 1999-02-02 Toshiba Lighting & Technol Corp Lamp-lighting device, and lighting system
JP2000150180A (en) * 1998-11-10 2000-05-30 Toshiba Lighting & Technology Corp Discharge lamp lighting device and lighting system

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