JP2000012267A - Fluorescent lamp lighting device - Google Patents

Fluorescent lamp lighting device

Info

Publication number
JP2000012267A
JP2000012267A JP21170298A JP21170298A JP2000012267A JP 2000012267 A JP2000012267 A JP 2000012267A JP 21170298 A JP21170298 A JP 21170298A JP 21170298 A JP21170298 A JP 21170298A JP 2000012267 A JP2000012267 A JP 2000012267A
Authority
JP
Japan
Prior art keywords
fluorescent lamp
circuit
voltage
load
lamp lighting
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.)
Pending
Application number
JP21170298A
Other languages
Japanese (ja)
Inventor
Akihito Yasuhara
朗仁 安原
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.)
Hitachi Lighting Ltd
Original Assignee
Hitachi Lighting Ltd
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 Hitachi Lighting Ltd filed Critical Hitachi Lighting Ltd
Priority to JP21170298A priority Critical patent/JP2000012267A/en
Publication of JP2000012267A publication Critical patent/JP2000012267A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To protect even the particularly slight disconnection without overlooking it by providing a detecting circuit regarding it as no-load time when the electrode filaments are disconnected even if a fluorescent lamp is connected needless to say that the fluorescent lamp is not connected. SOLUTION: Half bridge-shaped inverter circuits 2, 3, 9, 10 are provided to convert voltage of a DC power source 40 into high frequency voltage. Fluorescent lamp lighting circuits 4, 5, 6 are provided. A control circuit 1 is provided to control the inverter circuits. An abnormal voltage detecting circuit is provided to monitor tube voltage of a fluorescent 4 belonging to the fluorescent lamp lighting circuits. A no-load detecting circuit is provided to detect the existence of the connection of the fluorescent lamp 4. Output of the inverter circuits is at least restricted at abnormal voltage detecting time and no-load time. The no-load detecting circuit is a detecting circuit regarding it as no-load time when the electrode filaments 4a, 4b are disconnected even if the fluorescent lamp 4 is connected needless to say that the fluorescent lamp 4 is not connected.

Description

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

【0001】[0001]

【発明の属する技術分野】本発明は蛍光灯点灯装置に関
するものである。特にその無負荷検出回路に関するもの
である。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp lighting device. In particular, it relates to the no-load detection circuit.

【0002】[0002]

【従来の技術】蛍光灯が接続されていない無負荷時のイ
ンバータ動作は、発熱・損失・破壊の原因となる。そこ
で、そのような状態を検出する無負荷検出回路を付加
し、無負時にインバータ回路の出力を制限(停止を含
む)する。
2. Description of the Related Art Inverter operation at no load when a fluorescent lamp is not connected causes heat generation, loss and destruction. Therefore, a no-load detection circuit for detecting such a state is added, and the output of the inverter circuit is limited (including stop) when there is no load.

【0003】[0003]

【発明が解決しようとする課題】蛍光灯を除去した状態
を蛍光灯点灯回路の側から眺めれば、蛍光灯の電極フィ
ラメントは断線していることとなる。この意味では電極
フィラメントの断線検知回路を兼ねる。しかし、少し異
なる。電極フィラメントの一部が僅かに断線した状態の
場合はその断線箇所が微放電により電気的に繋がるの
で、出力制限の保護がかからない。本発明の目的は蛍光
灯が接続されていない場合はもとより、該蛍光灯が接続
されていてもその電極フィラメントが断線している場合
は無負荷時とみなす検出回路とすることである。特にそ
の僅かな断線であっても、見逃さずに保護を掛けること
である。
When the state where the fluorescent lamp is removed is viewed from the fluorescent lamp lighting circuit side, the electrode filament of the fluorescent lamp is broken. In this sense, it also serves as a disconnection detection circuit for the electrode filament. But a little different. In the case where a part of the electrode filament is slightly broken, the broken portion is electrically connected by the slight discharge, so that the output limitation is not protected. An object of the present invention is to provide a detection circuit that considers no load when an electrode filament is broken even when a fluorescent lamp is connected, as well as when the fluorescent lamp is connected. In particular, it is to protect even a slight disconnection without overlooking it.

【0004】[0004]

【課題を解決するための手段】本発明装置は、直流電源
電圧を高周波電圧に変換するハーフブリッジ形のインバ
ータ回路を備える。前記インバータ回路から給電される
蛍光灯点灯回路を備える。前記インバータ回路を制御す
る制御回路を備える。前記蛍光灯点灯回路に属する蛍光
灯の管電圧を監視する異常電圧検出回路を備える。前記
蛍光灯の接続有無を検出する無負荷検出回路を備える。
異常電圧検出時およお無負荷時に前記インバータ回路の
出力を少なくとも制限する。本発明の前記無負荷検出回
路を前記蛍光灯が接続されていない場合はもとより、前
記蛍光灯が接続されていてもその電極フィラメントが断
線している場合は無負荷時とみなす検出回路である。
The device of the present invention comprises a half-bridge type inverter circuit for converting a DC power supply voltage to a high-frequency voltage. A fluorescent lamp lighting circuit supplied with power from the inverter circuit. A control circuit for controlling the inverter circuit. An abnormal voltage detection circuit for monitoring a tube voltage of the fluorescent lamp belonging to the fluorescent lamp lighting circuit is provided. And a no-load detection circuit for detecting whether or not the fluorescent lamp is connected.
The output of the inverter circuit is limited at least when an abnormal voltage is detected and when there is no load. The no-load detection circuit of the present invention is a detection circuit that considers no load when not only the fluorescent lamp is not connected but also when the electrode filament is disconnected even when the fluorescent lamp is connected.

【0005】[0005]

【発明の実施の形態】図1を用いて本発明の実施形態に
ついて説明する。本発明装置は直流電源40電圧を高周
波電圧に変換するハーフブリッジ形のインバータ回路を
備える。直流電源40の例は図外の交流電源電圧を整流
平滑する整流形電源である。インバータ回路の構成要素
は順直列一対のスイッチング素子(図のそれはトランジ
スタ)2・3と直列一対のブリッジアーム用コンデンサ
9・10と前記各スイッチング素子2・3を交互にオン
オフするように制御する制御回路1である。制御回路1
は各スイッチング素子2・3を介してインバータ回路全
体を制御する。インバータ回路の出力を適宜に制限する
ことが可能である。前記インバータ回路から給電される
蛍光灯点灯回路を備える。その構成要素は蛍光灯(蛍光
ランプ)4と蛍光灯4に直列のバラスト用インダクタ5
と蛍光灯4に並列の予熱用コンデンサ6である。蛍光灯
4の管電圧を監視する異常電圧検出回路を備える。異常
電圧検出回路の構成要素は異常電圧検出主回路7とそれ
に付属する分圧抵杭11・12である。実際には蛍光灯
4の管電圧にブリッジアーム用コンデンサ10電圧等の
直流成分電圧を加えた値を検出するでの、異常電圧検出
主回路7内の図外のカップリングコンデンサを用いてそ
の直流成分電圧を除外して判定する。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. The device of the present invention includes a half-bridge type inverter circuit that converts a DC power supply 40 voltage to a high-frequency voltage. An example of the DC power supply 40 is a rectified power supply that rectifies and smoothes an AC power supply voltage (not shown). The components of the inverter circuit are a pair of switching elements (transistors in the figure) 2, 3 in series, a pair of capacitors 9 and 10 for a bridge arm in series, and control for controlling the switching elements 2, 3 to be turned on and off alternately. Circuit 1. Control circuit 1
Controls the entire inverter circuit via the switching elements 2 and 3. It is possible to appropriately limit the output of the inverter circuit. A fluorescent lamp lighting circuit supplied with power from the inverter circuit. Its components are a fluorescent lamp (fluorescent lamp) 4 and a ballast inductor 5 in series with the fluorescent lamp 4.
And a preheating capacitor 6 parallel to the fluorescent lamp 4. An abnormal voltage detection circuit for monitoring the tube voltage of the fluorescent lamp 4 is provided. The components of the abnormal voltage detecting circuit are the abnormal voltage detecting main circuit 7 and the voltage dividing resistors 11 and 12 attached thereto. In practice, a value obtained by adding a DC component voltage such as the voltage of the bridge arm capacitor 10 to the tube voltage of the fluorescent lamp 4 is detected, and the DC voltage is detected using a coupling capacitor (not shown) in the abnormal voltage detection main circuit 7. The determination is made excluding the component voltage.

【0006】蛍光灯4の接続有無を検出する無負荷検出
回路を備える。無負荷検出回路の構成要素は無負荷検出
主回路8とそれに付属する各部品29・20・21・5
・22・13・14等である。以下、この点についても
う少し詳しく説明する。20は低圧の補助直流電源20
である。補助直流電源20は独立電源である必要はな
く、たとえばスイッチング素子3電圧を適宜に分圧し、
その分圧電圧で充電される図外の補助コンデンサを補助
直流電源20とすることも可能である。補助直流電源2
0→補助ダイオード21→バラスト用インダクタ5→電
極フィラメント4a→補助抵抗22→電極フィラメント
4b→限流抵抗13→限流抵抗14→限流抵抗29→補
助直流電源20の閉回路が成立する。その閉回路に補助
直流電源20電圧による微弱な直流電流が流れる。それ
による限流抵抗14電圧を無負荷検出主回路8で検出す
る。その電圧検出がなされない場合は無負荷時と判定す
る。その無負荷検出信号は制御回路1へ供給される。制
御回路1は無負荷検出主回路8からの無負荷検出信号あ
るいは異常電圧検出主回路7からの異常電圧検出信号に
応動してインバータ回路の出力を制限する機能をもつ。
制限態様の一つは出力停止(インバータ動作の停止)で
ある。
There is provided a no-load detecting circuit for detecting whether or not the fluorescent lamp 4 is connected. The components of the no-load detection circuit are the no-load detection main circuit 8 and the components 29, 20, 21 and 5 attached thereto.
・ 22 ・ 13 ・ 14 etc. Hereinafter, this point will be described in more detail. 20 is a low-voltage auxiliary DC power supply 20
It is. The auxiliary DC power supply 20 does not need to be an independent power supply, and for example, appropriately divides the voltage of the switching element 3 and
An auxiliary capacitor (not shown) charged by the divided voltage can be used as the auxiliary DC power supply 20. Auxiliary DC power supply 2
0 → auxiliary diode 21 → ballast inductor 5 → electrode filament 4a → auxiliary resistance 22 → electrode filament 4b → current limiting resistor 13 → current limiting resistor 14 → current limiting resistor 29 → auxiliary DC power supply 20 closed circuit is established. A weak DC current due to the voltage of the auxiliary DC power supply 20 flows through the closed circuit. The no-load detection main circuit 8 detects the resulting voltage of the current limiting resistor 14. If the voltage is not detected, it is determined that there is no load. The no-load detection signal is supplied to the control circuit 1. The control circuit 1 has a function of limiting the output of the inverter circuit in response to a no-load detection signal from the no-load detection main circuit 8 or an abnormal voltage detection signal from the abnormal voltage detection main circuit 7.
One of the limiting modes is output stop (stop of inverter operation).

【0007】蛍光灯4が取り外されたとき、あるいはそ
の各電極フィラメント4a・4bのどこかが切断した場
合は、共に無負荷時とみなされ、インバータ回路の出力
を制限する保護機能が働く。電極フィラメント4a・4
bの切断が僅かでああっても、その間にその切断箇所に
放電・微放電が生じないように補助直流電源20電圧を
小さく設定する。図1のダイオード21上端はバラスト
用インダクタ5の左端に接続されている。その点を改め
バラスト用インダクタ5の右端に接続することも可能で
ある。この場合はスイッチング素子3を経由する電流を
制限する役割を兼ねる限流抵抗29を省略しても構わな
い。
When the fluorescent lamp 4 is removed, or when any of the respective electrode filaments 4a and 4b is cut off, it is considered that no load is present, and a protection function for limiting the output of the inverter circuit is activated. Electrode filaments 4a and 4
Even if the disconnection of b is slight, the voltage of the auxiliary DC power supply 20 is set to be small so that no discharge / small discharge occurs at the disconnection point during that time. The upper end of the diode 21 in FIG. 1 is connected to the left end of the ballast inductor 5. This point can be connected to the right end of the ballast inductor 5 again. In this case, the current limiting resistor 29 also serving to limit the current passing through the switching element 3 may be omitted.

【0008】[0008]

【発明の効果】本発明は無負荷検出回路を蛍光灯が接続
されていない場合はもとより、該蛍光灯が接続されてい
てもその電極フィラメントが僅かに断線している場合も
無負荷時とみなす検出回路とすることを主たる特徴事項
とするものである。これによれば、断線が僅かであって
も、見逃さずに保護を掛けることが可能となり、安全性
等の点で有利となる。
According to the present invention, the no-load detecting circuit is regarded as a no-load condition not only when the fluorescent lamp is not connected but also when the electrode filament is slightly disconnected even when the fluorescent lamp is connected. The main feature is that it is a detection circuit. According to this, even if the disconnection is slight, it is possible to provide protection without overlooking it, which is advantageous in terms of safety and the like.

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

【図1】本発明装置の回路図である。FIG. 1 is a circuit diagram of the device of the present invention.

【符号の説明】[Explanation of symbols]

1:制御回路、2・3:スイッチング素子、4:蛍光
灯、4a・4b:電極フィラメント、5:バラスト用イ
ンダクタ、6:予熱用コンデンサ、7:異常電圧検出主
回路、8:無負荷検出主回路、9・10:ブリッジアー
ム用コンデンサ、11・12:分圧抵抗、13・14・
29:限流抵抗、20:補助直流電源、21:補助ダイ
オード、22:補助抵抗、40:直流電源
1: Control circuit, 2.3: switching element, 4: fluorescent lamp, 4a, 4b: electrode filament, 5: ballast inductor, 6: preheating capacitor, 7: abnormal voltage detection main circuit, 8: no-load detection main Circuit, 9 ・ 10: Capacitor for bridge arm, 11 ・ 12: Voltage dividing resistor, 13.14 ・
29: current limiting resistance, 20: auxiliary DC power supply, 21: auxiliary diode, 22: auxiliary resistance, 40: DC power supply

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】直流電源電圧を高周波電圧に変換するハー
フブリッジ形のインバータ回路を備え、前記インバータ
回路から給電される蛍光灯点灯回路を備え、前記インバ
ータ回路を制御する制御回路を備え、前記蛍光灯点灯回
路に属する蛍光灯の管電圧を監視する異常電圧検出回路
を備え、前記蛍光灯の接続有無を検出する無負荷検出回
路を備え、異常電圧検出時およお無負荷時に前記インバ
ータ回路の出力を少なくとも制限する蛍光灯点灯装置に
おいて、 前記無負荷検出回路を前記蛍光灯が接続されていない場
合はもとより、前記蛍光灯が接続されていてもその電極
フィラメントが断線している場合は無負荷時とみなす検
出回路としたことを特徴とする蛍光灯点灯装置。
An inverter circuit for converting a DC power supply voltage into a high-frequency voltage; a fluorescent lamp lighting circuit supplied from the inverter circuit; a control circuit for controlling the inverter circuit; An abnormal voltage detection circuit that monitors a tube voltage of a fluorescent lamp belonging to a lamp lighting circuit; and a no-load detection circuit that detects whether or not the fluorescent lamp is connected. In the fluorescent lamp lighting device for limiting the output at least, the no-load detection circuit is not loaded when the electrode filament is broken even when the fluorescent lamp is connected, even when the fluorescent lamp is not connected. A fluorescent lamp lighting device, characterized in that the detection circuit is regarded as time.
JP21170298A 1998-06-22 1998-06-22 Fluorescent lamp lighting device Pending JP2000012267A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP21170298A JP2000012267A (en) 1998-06-22 1998-06-22 Fluorescent lamp lighting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP21170298A JP2000012267A (en) 1998-06-22 1998-06-22 Fluorescent lamp lighting device

Publications (1)

Publication Number Publication Date
JP2000012267A true JP2000012267A (en) 2000-01-14

Family

ID=16610184

Family Applications (1)

Application Number Title Priority Date Filing Date
JP21170298A Pending JP2000012267A (en) 1998-06-22 1998-06-22 Fluorescent lamp lighting device

Country Status (1)

Country Link
JP (1) JP2000012267A (en)

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