JPH09115678A - Fluorescent lamp electronic lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp electronic lighting device for protecting the deterioration or breakage of a thyrister in the terminal stage of the life of a fluorescent lamp by arranging a voltage dividing circuit and a charge/ discharge circuit in a non-power source side circuit of the fluorescent lamp. SOLUTION: In the terminal stage of the life of a fluorescent lamp, the peak value of lamp voltage for causing discharge is increased, and movement to the discharge state becomes difficult. A thyrister repeats retriggers, preheating current intermittently flows, and the power loss of the thyrister is increased to lead to breakage. While the thyrister Thy repeats triggers, charge to a first capacitor C2 proceeds, and finally, charge current is stopped to flow and the trigger of the thyrister Thy stops. By the stop of lighting operation, the power loss of the thyrister Thy caused by preheating current is prevented, and the thyrister Thy can be protected from deterioration or breakage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device for a fluorescent lamp, and more particularly to an electronic lighting device for starting a discharge lamp using a semiconductor switch.

[0002]

2. Description of the Related Art A glow starter is known as a device for starting a discharge lamp having a preheating electrode such as a fluorescent lamp. Since this glow starter has problems such as a long start-up time and a short life, an electronic lighting device using a semiconductor switch element has been developed as a lighting device for solving this problem.

FIG. 2 is a block diagram of a conventional electronic lighting device. In FIG. 2, the conventional electronic lighting device includes an AC power source E, a ballast, and a series circuit of a fluorescent lamp FL with a preheating electrode, and a thyristor Thy connected to the non-power supply side of the preheating electrode terminals h1 and h2 of the fluorescent lamp FL. , A trigger circuit connected to the control terminal of the thyristor Thy, and the trigger circuit is composed of a voltage dividing circuit (resistors R1 and R2) and a trigger element such as a Zener diode ZD.

[0004] The lighting of the fluorescent lamp is performed by preheating the preheating electrodes h1 and h2 to a predetermined temperature or higher and then setting the lamp voltage to a discharge voltage or higher to cause discharge. In the trigger circuit of the conventional electronic lighting device, the thyristor Thy that operates by the conduction of the Zener diode ZD due to the increase in the divided voltage of the voltage divider circuit accompanying the increase in the voltage of the AC power supply EL is turned on, and the thyristor Thy due to the reverse voltage is applied. The preheating electrodes h1 and h2 are preheated by the repeated operation with the turn-off, and after the preheating electrodes h1 and h2 are sufficiently heated, discharge is generated by the high-voltage pulse generated by the turn-off of the thyristor Thy to perform lighting.

[0005]

However, the conventional fluorescent lamp electronic lighting device has a problem that the operation of the thyristor becomes unstable at the end of the life of the fluorescent lamp. In general, at the end of the life of the fluorescent lamp, the peak value of the lamp voltage that causes the discharge increases, so that the thyristor repeats retriggering and is unlikely to shift to the discharge state. Therefore, the preheating current flows intermittently to increase the power loss of the thyristor, which may cause deterioration of the thyristor withstand voltage, damage, or even permanent destruction. Therefore, it is an object of the present invention to solve the above-mentioned conventional problems and provide a fluorescent lamp electronic lighting device that protects a thyristor from deterioration or damage at the end of the life of the fluorescent lamp.

[0006]

According to the first aspect of the present invention, there is provided a fluorescent lamp electronic lighting device comprising: (a) a series circuit of an AC power source, a ballast, and a fluorescent lamp with a preheating electrode; and (b) a fluorescent lamp with a preheating electrode. A thyristor with a unidirectional control pole that connects the anode terminal to the ballast side between the non-power supply side preheating electrode terminals, and (c) a voltage dividing circuit in which a first resistance and a second resistance are connected in series. , (D) a charge / discharge circuit in which a diode is connected in series to a parallel circuit of a first capacitor and a third resistor, a voltage dividing circuit and a thyristor with a unidirectional control pole are connected in parallel, and a first resistor and A charging circuit is connected between the connection point of the second resistor and the control pole of the thyristor with a one-way control pole.

The charging current in the charging / discharging circuit acts as a gate current to the control pole of the thyristor with a one-way control pole, and the discharging current flows through the third resistor. The fluorescent lamp electronic lighting device of the present invention, by the voltage dividing circuit and the charging and discharging circuit,
(A) Turning on the fluorescent lamp, (B) Stopping the lighting operation at the end of the life of the fluorescent lamp, and (C) Relighting when the lamp goes out.

(A) A lamp voltage is applied to the voltage dividing circuit by parallel connection with a thyristor to form a voltage divided voltage according to the resistance ratio of the first resistance and the second resistance. When the lamp voltage is the forward voltage of the thyristor, the charging current is passed through the first capacitor of the charging / discharging circuit. The charging current to the first capacitor is input as a gate current to the control electrode of the thyristor and triggers the thyristor. On the other hand, when the lamp voltage is the reverse voltage of the thyristor, the diode is turned off to prevent discharging of the first capacitor. When the thyristor is turned on by the trigger, a current flows through the preheating electrode of the fluorescent lamp to heat the preheating electrode. After the preheating electrode is heated, the high pressure pulse generated by turning off the thyristor causes the fluorescent lamp to start discharging, which causes
The fluorescent lamp is turned on.

(B) At the end of the life of the fluorescent lamp,
When the transition to the discharge state is less likely to occur, the trigger is repeated. While the trigger is repeated, the charging of the first capacitor proceeds, and finally the charging current stops flowing. As a result, the thyristor trigger is stopped and the lighting operation is stopped.

(C) Furthermore, while the fluorescent lamp is lit,
When the lamp voltage of the fluorescent lamp decreases, the voltage of the voltage dividing circuit also decreases, the first capacitor discharges until it equilibrates with the divided voltage, and the charged state is maintained at the divided voltage. It stops flowing. Further, the third resistor is adjusted so that the value of the current flowing at the time of completion of the charging is a value that does not trigger the thyristor. This stops the thyristor trigger. At this time, if the discharge lamp that is being turned on is extinguished due to extinguishing due to a decrease in the power supply voltage or the like, the first capacitor is discharged, and the state becomes rechargeable. After that, when the power is restored, the charging current flows again, and the thyristor is retriggered. by this,
The light is turned on again when it goes out.

The fluorescent lamp electronic lighting device of the second invention of the present application is (a) a series circuit of an AC power source, a ballast, and a fluorescent lamp with a preheating electrode, and (b) a non-power source of the fluorescent lamp with a preheating electrode. Between the side preheating electrode terminals, a thyristor with a unidirectional control pole for connecting the anode terminal to the ballast side, (c) a voltage dividing circuit in which a first resistance and a second resistance are connected in series, (d) A first charge / discharge circuit in which a diode is connected in series to a parallel circuit of a first capacitor and a third resistor; and (e) a second charge / discharge circuit in which a second capacitor and a fourth resistor are connected in parallel. Equipped with a voltage divider circuit and a thyristor with a unidirectional control pole connected in parallel,
Connect the first charge / discharge circuit between the connection point of the first resistor and the second resistor and the control pole of the thyristor with unidirectional control pole, and The configuration is such that one end of the second charge / discharge circuit is connected.

The charge current in the second charge / discharge circuit acts as a gate current to the control pole of the thyristor with a one-way control pole, and the discharge current flows through the third resistor. In the second charging / discharging circuit, the second capacitor is a capacitor for absorbing pulse noise and preventing malfunction of the trigger due to the noise, and the fourth resistor is the discharging resistance of the second charging / discharging circuit. It also becomes the gate protection resistance of the thyristor.

In the fluorescent lamp electronic lighting device according to the second aspect of the present invention, (A) the fluorescent lamp is lit by a voltage dividing circuit and a charging / discharging circuit,
(B) Stopping the lighting operation at the end of the life of the fluorescent lamp,
(C) The operation of relighting at the time of turning off is performed in the same manner as in the first invention. In the second charging / discharging circuit in the fluorescent lamp electronic lighting device of the second invention, the second capacitor is a high-voltage pulse generated when the thyristor is turned off or a whisker-shaped voltage generated in the lamp voltage, The thyristor is prevented from malfunctioning by absorbing the pulse or whisker-like voltage, and the fourth resistor protects the gate of the thyristor while discharging the electric charge charged in the second capacitor.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a circuit diagram for explaining a fluorescent lamp electronic lighting device according to the present invention. (Configuration example of fluorescent lamp electronic lighting device) In FIG. 1, the configuration of the fluorescent lamp electronic lighting device includes a series circuit of an AC power supply E, a ballast, and a fluorescent lamp FL with a preheating electrode, and a fluorescent lamp FL with a preheating electrode.
Thyristor Th with a unidirectional control electrode for connecting the anode terminal to the ballast side between the non-power supply side preheating electrode terminals h1 and h2
y, a voltage dividing circuit in which a first resistor R1 and a second resistor R2 are connected in series, and a charging / discharging circuit in which a diode D3 is connected in series with a parallel circuit of a first capacitor C2 and a third resistor R6. A voltage dividing circuit is connected in parallel with the thyristor Thy with a unidirectional control pole, and the voltage dividing circuit is connected to a connection point A between the first resistor R1 and the second resistor R2 and a thyristor T with a unidirectional control pole.
It is connected to the control pole of hy. Further, a second charge / discharge circuit is formed by a parallel circuit of the second capacitor C3 and the fourth resistor R7, and one end thereof is connected to the control pole of the thyristor Thy with a unidirectional control pole.

The ballast comprises a choke coil L, and a capacitor C1 and a resistor R3 form a series circuit. The capacitor C1 and the resistor R3 are a noise prevention circuit that absorbs noise generated by distortion of the current waveform of the fluorescent lamp. Also, a series circuit of the diode D1 and the resistor R4 is connected with the terminal direction of the AC power supply E on the choke coil L side being the forward direction from the control pole of the thyristor Thy with the unidirectional control pole.

The series circuit of the first resistor R1 and the second resistor R2 constitutes a voltage dividing circuit, and the lamp voltage is applied to the first resistor R1.
And the second resistor R2, and the divided voltage is applied from the connection point A to the first charge / discharge circuit.

The first charge / discharge circuit includes a first capacitor C.
A diode D3 is connected in series to a parallel circuit of the second and third resistors R6, and the diode D3 is connected from the connection point A to the control pole in a forward direction. The first capacitor C2 of the first charge / discharge circuit is charged by the forward current of the diode D3, and its time constant is determined by the resistance value and capacitance of the voltage dividing circuit and the first charge / discharge circuit. The voltage across the resistor R6 is equal to the charging voltage of the first capacitor C2.

The trigger for turning on the thyristor Thy with a unidirectional control pole is performed by the charging current of the first charging / discharging circuit flowing into the control pole as a gate current. The thyristor Thy with one-way control electrode is turned off by applying a reverse voltage of the AC power supply and causing a current to flow from the control electrode side in the forward direction of the diode D1.

First capacitor C2 of the first charge / discharge circuit
Although the charging current does not flow in the state where the charging is completed, the current flows as the gate current to the control electrode side via the third resistor R6. The resistance value of the resistor R6 is adjusted so that the current flowing through the resistor R6 does not turn on the thyristor and has a current value that does not turn on the thyristor. This stops the trigger. The discharge of the first capacitor C2 of the first charge / discharge circuit is performed via the third resistor R6.

Further, the second capacitor C3 constituting the second charge / discharge circuit absorbs a high voltage pulse generated by turning off the thyristor and a whisker-like voltage generated in the lamp voltage, thereby preventing the thyristor from malfunctioning. To do. Further, the fourth resistor R7 discharges the electric charge charged in the second capacitor C3 and protects the gate of the thyristor.

The diode in the first charge / discharge circuit,
The connection order of the resistor and the capacitor can be changed within a range that does not change the electrical characteristics. Also, thyristor T
The variations in the hy trigger characteristic and the like can be adjusted by adjusting the divided voltage at the point P or inserting a resistor between the point P and the control pole of the thyristor Thy.

(Operation of the First Configuration Example of the Fluorescent Lamp Electronic Lighting Device) The operation examples of the first configuration example are as follows: (A) Fluorescent lamp lighting, (B) Fluorescent lamp end-of-life lighting operation Stop,
(C) Each operation of relighting at the time of turning off will be described as an example.

(A) Lighting of fluorescent lamp: When the voltage of the power source E rises in the forward direction of the thyristor Thy with a unidirectional control pole,
The lamp voltage of the fluorescent lamp FL increases, and the resistance R1 of the voltage dividing circuit is increased.
And the voltage divided by the resistance ratio of the resistor R2 is
R2 is formed. The first capacitor C2 is charged by the divided voltage, and a charging current flows.

The charging current to the first capacitor C2 is input to the control electrode of the thyristor as a gate current to trigger the thyristor to turn it on. As a result, a preheating current flows through the power source E, the choke coil L, the fluorescent lamp electrode h1, the anode of the thyristor Thy, the cathode of the thyristor Thy, the diode D3, the fluorescent lamp electrode h2, and the power source E in this order. Heat. This preheating current becomes a delay current due to the inductance component of the choke coil L, and continues to flow for a while even if the power supply voltage is reversed.

When the power supply voltage is reversed, the diode D
1, a current opposite to the preheating current flows from the control pole of the thyristor Thy to the power supply side of the choke coil L through the resistor R4. Due to this reverse current, the preheating current decreases rapidly and the thyristor Thy turns off. This thyristor Th
A high voltage pulse is generated from the choke coil L by the turn-off of y, and the high voltage pulse is applied to both ends of the fluorescent lamp FL. When a reverse voltage is applied, the diode D3 is turned off to prevent discharge from the first capacitor C2, so that the electric charge charged in the first capacitor C2 is retained by the diode D3.

The fluorescent lamp FL starts discharge by this high voltage pulse and is turned on. If the discharge does not start even by the application of the high-voltage pulse, the same operation as described above is repeated in the next cycle of the AC power supply E. Normally, the fluorescent lamp FL starts discharging after repeating about 15 times (in the case of 50 cycles) for about 0.3 seconds.

By starting the discharge of the fluorescent lamp FL, the fluorescent lamp FL is
Lamp voltage decreases. As the lamp voltage decreases, the voltage applied to the first capacitor C2 in the charge / discharge circuit also decreases. In the case of the forward voltage, the first capacitor C2 is continuously charged according to the divided voltage, and normally, the values of the capacitor and the resistance are set so that the charging is completed in about 0.5 seconds after the start of discharging.

When the charging of the first capacitor C2 is completed, the charging current to the control pole of the thyristor Thy stops.
Even when the charging current is stopped due to the completion of the charging, the current flows to the control pole through the third resistor R6 in the first charging / discharging circuit. If this current is large, the thyristor T
hy is turned on, causing a malfunction. Therefore, the resistance value of the third resistor R6 is adjusted so that the current flowing through the resistor R6 does not turn on the thyristor Thy. The adjustment of the resistance value can be set in advance by an experiment or the like. As a result, after the first charging / discharging circuit is completely charged, the trigger is stopped and the fluorescent lamp FL is normally lit.

(B) Stopping the lighting operation at the end of the life of the fluorescent lamp; When the end of the life of the fluorescent lamp is reached, the peak value of the lamp voltage that causes discharge generally increases, and the transition to the discharge state does not occur easily. Therefore, the thyristor repeats retrigger.

In the configuration example, while the thyristor Thy repeats the trigger, the charging of the first capacitor C2 proceeds, and finally the charging current stops flowing. Therefore, the trigger of the thyristor is stopped and the lighting operation is stopped.

By stopping the lighting operation of the thyristor Thy, the power loss of the thyristor due to the preheating current can be prevented and the thyristor can be protected from deterioration and damage.

(C) Re-lighting when the fluorescent lamp is turned off: While the fluorescent lamp is lit, if the power supply voltage drops abnormally and the lamp voltage of the fluorescent lamp drops, the first capacitor C2 causes the point A The voltage is discharged through the resistor R6 until the voltage is balanced with the divided voltage, and the charged state is maintained with the divided voltage. As a result, the charging current stops flowing, and
Since the current flowing through the third resistor R6 is also sufficiently small, the trigger of the thyristor Thy stops.

At this time, when the fluorescent lamp FL is extinguished and turned off, the first capacitor C2 is further discharged and becomes ready to be charged again. After that, when the power is restored, the charging current flows again and the thyristor Thy is retriggered. As a result, the light is turned on again when it goes out.

As described above, in the configuration example of the fluorescent lamp electronic lighting device, it is possible to perform lighting of the fluorescent lamp, stop of the lighting operation at the end of the life of the fluorescent lamp, and re-lighting at the time of extinction.

In the second charging / discharging circuit, the second capacitor C3 is a capacitor for absorbing pulse noise and preventing malfunction of the trigger due to the noise. Prevents inflow to the control pole and prevents false triggers. The second capacitor C3 is charged by noise, but the fourth resistor R7 connected in parallel discharges the charged electric charge to prepare for the next noise removal.

The diode D1 is a thyristor Th.
When the forward voltage is y, no current flows through the control electrode of the thyristor Thy through the resistor R4, and the fluorescent lamp FL
The voltage difference between lighting and non-lighting is increased to prevent malfunction of the lighting operation and reduce the power loss in the resistor R4 by half. The diode D2 has a resistance R when the thyristor Thy is not conducting.
4. Prevent reverse voltage from being applied between the cathode terminal and the control electrode via the diode D1. The diode D
2 is when a reverse voltage is applied to the thyristor Thy,
It prevents current from flowing through the voltage dividing circuit and the charging / discharging circuit to cause power loss.

In this configuration example, the thyristor Thy is used.
Since a control element such as a Zener diode is not used for the trigger control of, the trigger can be performed at a low voltage, the electrodes of the fluorescent lamp FL can be quickly heated, and the time required for lighting can be shortened. Therefore, there is an effect that the consumption of the electrodes can be reduced and the life of the fluorescent lamp can be extended.

[0038]

As described above, according to the present invention,
It is possible to provide a fluorescent lamp electronic lighting device that protects a thyristor from deterioration or damage at the end of the life of the fluorescent lamp.

[Brief description of the drawings]

FIG. 1 is a circuit diagram for explaining a fluorescent lamp electronic lighting device of the present invention.

FIG. 2 is a circuit diagram for explaining a conventional fluorescent lamp electronic lighting device.

[Explanation of symbols]

 E AC power supply FL Fluorescent lamp with preheating electrode h1, h2 Preheating electrode terminal Thy Thyristor with unidirectional control pole R1, R2, R3, R4, R5, R6, R7 Resistor D1, D2, D3 Diode C1, C2, C3 Capacitor L Choke coil E AC power supply ZD Zener diode

Claims (2)

[Claims] 1. A unidirectional control in which an anode terminal is connected to a ballast side between a series circuit of an AC power supply, a ballast, and a fluorescent lamp with a preheating electrode, and a non-power source side preheating electrode terminal of the fluorescent lamp with a preheating electrode. A thyristor with poles, a voltage divider circuit in which a first resistor and a second resistor are connected in series, and a charge / discharge circuit in which a diode is connected in series to a parallel circuit of a first capacitor and a third resistor, A voltage divider circuit and a thyristor with a unidirectional control pole were connected in parallel, and a charge / discharge circuit was connected between the connection point of the first resistor and the second resistor and the control pole of the thyristor with a unidirectional control pole. An electronic lighting device for fluorescent lamps, characterized in that 2. A unidirectional control for connecting an anode terminal to a ballast side between a series circuit of an AC power source, a ballast, and a fluorescent lamp with a preheating electrode, and a non-power source side preheating electrode terminal of the fluorescent lamp with a preheating electrode. A thyristor with a pole, a voltage dividing circuit in which a first resistor and a second resistor are connected in series, a first charge / discharge circuit in which a diode is connected in series to a parallel circuit of a first capacitor and a third resistor, A second charge and discharge circuit in which a second capacitor and a fourth resistor are connected in parallel, the voltage dividing circuit and a thyristor with a unidirectional control pole are connected in parallel, the first resistor and the second resistor. Connect the first charging / discharging circuit between the connection point and the control pole of the thyristor with unidirectional control pole, and connect one end of the second charging / discharging circuit to the control pole of the thyristor with unidirectional control pole. An electronic lighting device for a fluorescent lamp, characterized in that