JP2000294391A - Dc lighting device for fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily separate a high tension DC power source and a constant current DC power source by connecting a starter for starting to one end of a filament of a fluorescent lamp in series, and connecting a constant current DC power source through a first diode for reverse blocking and a high tension DC power source through a resistor for keeping high voltage, to the other end in series. SOLUTION: When a fluorescent lamp starter for starting is switched ON, the electric current from a constant current DC power source heats a filament of a fluorescent lamp through a first diode 2 for reverse blocking. On the other hand, as the high tension DC power source has a resistor 4 for keeping high voltage, high voltage can be kept. When the fluorescent lamp starter 1 for starting is switched OFF, the electric current form the high tension DC power source 5 flows in the fluorescent lamp as it is blocked by a second diode 2 for reverse blocking, and high voltage is added to both ends of the fluorescent lamp approximately as it is. As the voltage at both ends of the fluorescent lamp is lowered immediately after the lighting, the electric current from the constant DC power source 3 lights the fluorescent lamp through the first diode 2 for reverse blocking.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC lighting device for a fluorescent lamp.

[0002]

2. Description of the Related Art There are two types of fluorescent lamps that emit light by commercial alternating current and those that emit light by high-frequency alternating current. Some light sources emit DC light.

[0003]

If the current flowing through the fluorescent lamp is an alternating current, there is a problem that light emission, flickering and darkening occur. High frequency systems have environmental problems of electromagnetic noise. In the conventional DC system, since the internal circuit configuration is a high-frequency switching system, electromagnetic noise still occurs, and the DC system is complicated and expensive. Although there is a DC lighting device that employs a capacitor step-down circuit, the addition of the dimming function causes problems such as poor efficiency and a dark end effect.

[0004]

There are a number of measures taken by the present invention to solve the above problems.

More specifically, a first aspect of the present invention is a constant current DC power supply in which a starter for starting is connected in series to one end of a filament of a fluorescent lamp, and a first diode for reverse blocking is connected to the other end of the filament. Are connected in series with a high-voltage DC power supply via a high-voltage maintaining resistor.

According to a second aspect of the present invention, a starting starter is connected in series to one end of a filament of a fluorescent lamp, and a high voltage DC power supply and a constant current DC power supply are connected in series to the other end of the filament. Configuration.

[0007] The third aspect of the present invention is the first or second aspect.
In the configuration of the invention, the constant current DC power supply comprises a capacitor and a voltage zero switching element connected in series between an AC power supply and a rectifier circuit, and a detection circuit is connected in parallel to the capacitor, Each time the charge or discharge charge reaches a predetermined amount, the voltage zero switching element is controlled to be turned off.

According to a fourth aspect of the present invention, in the configuration of the first aspect of the present invention, a control switch is turned on in the high-voltage DC power supply, and the control means is turned on and then turned off.

According to a fifth aspect of the present invention, in the configuration of the first aspect of the present invention, when the output of the high-voltage DC power supply is an iron core transformer, the high-voltage maintaining resistor is a second diode for reverse blocking,
In the case of a ceramic transformer, the high-voltage maintaining resistance value is replaced with a zero resistance, and the high-voltage generation time is provided with means for synchronizing with the moment when the starter is turned off.

According to a sixth aspect of the present invention, in the configuration of the second aspect of the present invention, a control switch is connected to both ends of the high-voltage DC power supply, and the control switch is controlled to be always on, and to be turned off when a high voltage is applied. This is the configuration that has been performed.

According to a seventh aspect of the present invention, in the configuration of the first and second aspects, a three-contact two-circuit switch is provided at an output terminal of the constant current DC power supply or the high voltage DC power supply for changing the polarity and for turning off the power. Connects and powers contacts out of 3 contacts
This is a configuration used for OFF.

According to an eighth aspect of the present invention, in the configuration of the seventh aspect of the present invention, the three-contact two-circuit switch for changing the polarity and for turning off the power is configured to short-circuit the power-off contact in the two circuits. Is what you do.

According to a ninth aspect of the present invention, in the configuration of the first to eighth aspects of the present invention, a polarity changing switch is provided, and it is determined whether or not to change the polarity at the moment when the AC power switch is turned on. Is determined by whether the value is plus or minus.

According to a tenth aspect of the present invention, in the configuration of the second aspect of the invention, the high-voltage power supply is replaced with a center tap type resonance type inverter lighting circuit, the starting starter is replaced with a starting capacitor, and after turning on, the function of the inverter is stopped. Upper switching element is ON, lower switching element is O
The configuration is such that the FF is controlled.

According to an eleventh aspect of the present invention, in the configuration of the second aspect of the present invention, the high-voltage power supply is replaced by a bridge-type resonant inverter lighting circuit, the starting starter is replaced by a starting capacitor, and after turning on, the function of the inverter is stopped. Are turned into polarity change switches.

According to a twelfth aspect of the present invention, in the configuration of the first aspect, there are a number of fluorescent lamps and a plurality of starters connected to one end thereof, and the other ends of the fluorescent lamps are respectively connected in series to sequentially connect the respective starters. Is turned off.

According to a thirteenth aspect of the present invention, in any of the above aspects, a power-mistor is connected in series to an output terminal of the constant current DC power supply.

[0018]

According to the configuration of the first aspect of the present invention, at the time of starting, the starting starter is turned on, and the current from the constant current DC power supply heats the filament of the fluorescent lamp through the first diode for reverse blocking. On the other hand, since the high-voltage DC power supply has a high-voltage maintaining resistor, the high voltage is maintained even when the starter for starting is turned on. Next, when the starter for starting is turned off, the current of the high-voltage DC power supply is blocked by the first diode for reverse blocking, so it must only flow through the fluorescent lamp tube. Since it is much larger than the high voltage maintaining resistance, the high voltage is applied almost directly to both ends of the fluorescent lamp. Since the voltage at both ends of the fluorescent lamp immediately drops after lighting, the current from the constant current DC power supply passes through the first diode for reverse blocking to light the fluorescent lamp.

According to the configuration of the second aspect of the present invention, the constant current DC power supply supplies a heating current and a lighting current through the high voltage DC power supply, while the high voltage DC power supply applies a high lighting voltage to the fluorescent lamp through the constant current DC power supply. Therefore, if the "internal resistance" of the high-voltage DC power supply is small, the high-voltage DC power supply and the constant-current DC power supply work without interference even without the reverse blocking first diode and the high-voltage maintaining resistance.

In addition, since the high-voltage DC power supply and the constant-current DC power supply are connected in series, the output voltage of the constant-current DC power supply is applied to the high-voltage DC power supply. However,
When the lamp is turned on, the output voltage of the constant current DC power supply is considerably lower than the output voltage of the high voltage DC power supply. Therefore, even if the output polarity of the constant current DC power supply changes, the output voltage of the high voltage DC power supply has little effect. Therefore, the switch for changing the polarity can be connected to the constant current DC power supply having a relatively low voltage.

According to the configuration of the third aspect of the present invention, for example, when the capacitor is fully charged, the voltage at both ends is detected and stored, and then the voltage at both ends is gradually lowered by discharging. Switching element off
Then, substantially the same voltage is charged in the next cycle.
By repeating this, even if the input voltage and load change, the amount of charge is determined by the product of the charge and discharge voltage and the capacitance of the capacitor.
The flowing current also becomes constant.

According to the configuration of the fourth aspect of the present invention, since the high voltage DC power supply originally only needs to be turned on at a moment, a control switch is turned on on the input power supply side or the output side of the high voltage DC power supply, turned on and then turned off.

According to the configuration of the fifth aspect of the present invention, at the same time as the starter is turned off, a high voltage is instantaneously generated from the high-voltage DC power supply to turn on the fluorescent lamp, and then the constant current DC power supply supplies a lighting current. Therefore, a high-voltage maintaining resistor is not required. If the output of the high-voltage DC power supply is an ordinary iron core transformer, a second diode for reverse blocking is inserted so as not to short-circuit the constant current DC power supply. In the case of a ceramic transformer, since the "internal resistance" is originally large, the second diode for reverse blocking does not need to be provided.

According to the configuration of the sixth aspect of the present invention, in the configuration of the second aspect of the present invention, when the output resistance of the high-voltage DC power supply is large, a control switch is connected to both ends thereof, and when the heating current flows, it is turned on and turned on. It is controlled to turn off when a high voltage for use is generated, and to turn on again when a lighting current flows.

According to the configuration of the seventh aspect of the present invention, since the switch for changing the polarity and the switch for interrupting the power supply are provided together, the probability that the polarity differs from the previous state increases each time the power switch is turned on. .

According to the configuration of the eighth aspect of the present invention, since the two power-off contacts 2 of the three-contact two-circuit switch (12) are short-circuited, each time the power switch is turned off, the electric charge remaining in the electronic starter is reduced. Discharges quickly.

According to the ninth aspect of the present invention, the probability that the polarity of the commercial AC input becomes plus or minus is １ ／ at the moment when the AC power supply switch is turned on. If it is determined whether or not to change, the probability of the lighting polarity is also halved.

According to the tenth aspect of the present invention, at the time of starting, the fluorescent lamp is turned on by the center-tap resonant inverter lighting circuit. After the lamp is turned on, the function of the inverter is stopped, and a lighting current is supplied to the fluorescent lamp from the constant current DC power supply through the upper switching element.

According to the eleventh aspect of the present invention, at the time of starting, the fluorescent lamp is turned on by the bridge type resonance inverter lighting circuit. After turning on the light, the function of the inverter is stopped, and the four switching elements serving as bridges function as polarity change switches.

According to the structure of the twelfth aspect, when a large number of fluorescent lamps having starters are connected in series, each starter is first turned on at the time of starting, and each fluorescent lamp is heated. Then, when each start is sequentially turned off, a high voltage for starting is sequentially applied to each fluorescent lamp, and the fluorescent lamps are sequentially turned on.

According to the structure of the thirteenth aspect of the present invention, since the power thermistor is connected in series to the output terminal of the constant current DC power supply, the instability due to the negative resistance of the fluorescent lamp can be effectively reduced at the time of starting. , The resistance of the power thermistor gradually decreases, and the loss decreases.

[0032]

FIG. 1 shows an example in which the present invention is applied to a DC lighting device for a simple fluorescent lamp. The top and bottom are symmetric. The high-voltage DC power supply is a positive / negative voltage doubler rectifier circuit composed of Ca to Cd and Da to Dd. The constant current DC power supply is based on a capacitor step-down circuit composed of C1, BD1, C2 and RD1.

When the three-contact two-circuit switch is turned on (going to the contact 3 in the figure), the starter is first turned on, the current of the AC power source is limited by the capacitor C1, rectified by BD1, smoothed by C2, and RD1 To further heat the filament of the fluorescent lamp. At that time, since the resistance of RD1 is large, the voltage across C2 can be maintained high. Similarly, the output of the voltage doubler rectifier circuit
It is maintained by a high-voltage maintaining resistor.

Next, when the starter is turned off, the path of the constant current direct current is temporarily cut off, but the high voltage direct current is almost completely applied to both ends of the fluorescent lamp to emit light. Since the voltage at both ends of the fluorescent lamp that emits light is low, a constant current DC flows through the fluorescent lamp. Over time, the resistance of RD1 decreases and the heat loss decreases accordingly.

When the three-contact two-circuit switch is turned off (going to the contact 2 in the figure), the contact 2 is short-circuited and the electric charge remaining in the electronic starter is quickly discharged. Therefore, the fluorescent lamp can be frequently turned on and off. In addition, when the switch is turned on each time, it is optional to go to the contact 1 or the contact 3, so that the "dark end" problem due to the fixed polarity is improved.

FIG. 2 shows an example in which the present invention is applied to a fluorescent lamp DC lighting device having a dimming function. High voltage DC power supply is R
It consists of 1, C3, T1, and SW4. Constant current DC power supply is C1, BD1, S
Consists of W1, C2, IC2 and IC3.

When the power switch K1 is turned on, a polarity identification circuit
IC1 determines the polarity at the moment of AC input. Its output controls the four switching elements (Sa to Sd), and Sa and Sd are ON
Or whether Sb and Sc are turned ON.

Since the zero volt switch SW1 is ON at first, the constant current DC power flows in the same manner as in the first embodiment. However, to control the light, a constant current circuit IC2 is inserted in series instead of the power thermistor. A voltage detection circuit IC3 is provided at both ends of the constant current circuit to monitor a minimum necessary voltage for maintaining a constant current. If the voltage exceeds the minimum voltage, SW1 is turned off, and if it is low, SW1 is turned on.

The constant current heats the fluorescent lamp through the bridge circuit (13) and the starter. On the other hand, the current shunted by R1 charges C3. When the voltage exceeds a certain voltage, the pulse switch SW4 is turned on. Then, C3 discharges to the primary side of the iron core transformer instantaneously, and a high voltage is generated from the secondary side.
When the starter is turned off at the same time, the fluorescent lamp is turned on.

[0040]

According to the first aspect of the present invention, the separation between the high-voltage DC power supply and the constant-current DC power supply can be easily realized through the first diode for reverse blocking and the high-voltage maintaining resistor.

According to the configuration of the second aspect of the present invention, if the "internal resistance" of the high-voltage DC power supply is small, the constant-current DC power supply and the high-voltage DC power supply are simply connected in series. No need for a resistor. Moreover, the polarity changing device can be installed on the low voltage constant current DC power supply side.

According to the third aspect of the present invention, a constant current power supply capable of dimming without loss and noise by controlling the amount of charge and discharge of the capacitor is realized.

Claims 4, 5, 6, and 10
According to the present invention, the loss due to the high-voltage maintaining resistor is eliminated.

According to the seventh and eleventh aspects of the present invention, the two-contact two-circuit switch for changing the polarity can be connected to a constant-current DC power source having a relatively low voltage. In particular, the switch is constituted by an electronic circuit. In this case, the withstand voltage of the switching element is reduced, which is advantageous in terms of cost.

The inventions of claims 8 and 9 have solved the "dark end problem" peculiar to the DC lighting device of fluorescent lamps in a very simple and inexpensive manner.

According to the twelfth aspect, a large number of fluorescent lamps can be turned on by one circuit. Greater power saving effect at lower cost.

The invention of claim 13 has solved the problem of instability at the time of starting the fluorescent lamp by a very simple and inexpensive method. Moreover, the loss is smaller than that of a normal fixed resistor.

[Brief description of the drawings]

FIG. 1 is an explanatory view of the invention of claim 1;

FIG. 2 is an explanatory view of the invention of claim 2;

FIG. 3 is an explanatory view of the invention according to claim 3;

FIG. 4 is an explanatory view of the invention according to claim 4;

FIG.

FIG. 6 is an explanatory view of the invention of claim 5;

FIG. 7 is an explanatory view of the invention of claim 6;

FIG. 8 is an explanatory view of the invention according to claims 7 and 8;

FIG. 9 is an explanatory view of the invention according to claim 10;

FIG. 10 is an explanatory view of the invention of claim 11;

FIG. 11 is an explanatory view of the invention according to claim 12;

FIG. 12 is a simplified fluorescent lamp DC lighting device according to an embodiment of the present invention;

FIG. 13 is a DC lighting device with a dimming function according to an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fluorescent light starter 2 first diode for reverse blocking 3 constant current DC power supply 4 high voltage maintaining resistor 5 high voltage DC power supply 6 AC power supply 8 detection circuit 10 second diode for reverse blocking 11 ceramic transformer 12 3 contact 2 circuit switch 14 Center tap resonance inverter lighting circuit 15 Bridge resonance inverter lighting circuit K1 AC power switch SW1 Zero voltage switch SW1, SW2, SW3, SW4 Control switch Sa, Sb, Sc, Sd Switching element IC1 Polarity identification circuit IC2 Constant current circuit IC3 Voltage detection circuit K1 AC power switch BD1 Bridge C1 Current limiting capacitor C2 Smoothing capacitor C3 Charging / discharging capacitor C4 High frequency short circuit capacitor R1 Charging resistor T1 Core transformer Ca, Cb, Cc, Cd Double voltage rectifying capacitors Da, Db , Dc, Dd Double Rectifier Diode RDI Power Thermistor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 41/24 H05B 41/24 K 41/392 41/392 CF term (Reference) 3K072 AA02 AC20 BA03 BA05 BB01 DB03 GA01 GB18 GC04 HB03 3K082 AA39 AA54 AA61 BA02 BA05 BA24 BA25 BA58 BB05 BB07 BC02 BC26 CA37 3K098 DD22 DD35 EE14 5H006 AA01 BB00 CA01 CA08 CA12 CA13 CB04 CC01 CC02 DA02 DA04 5H730 AS04 AS11 BB02 BB02 BB01 BB00

Claims (13)

[Claims] A starter (1) for starting is connected in series to one end of a filament of a fluorescent lamp, and a constant current DC power supply (3) is connected to the other end of the filament via a first diode (2) for reverse blocking. Are connected in series, and a high-voltage DC power supply (5) is similarly connected in series to the other end of the filament via a high-voltage maintaining resistor (4). . 2. A starting starter (1) is connected in series to one end of a filament of a fluorescent lamp, and a high-voltage DC power supply (5) and a constant current DC power supply (3) are connected in series to the other end of the filament. A DC lighting device for fluorescent lamps, characterized in that: 3. A DC lighting device for a fluorescent lamp according to claim 1, wherein the constant current DC power supply (3) is connected between the AC power supply (6) and the rectifier circuit (BD1) with a current limiting capacitor (C1) and zero volts. It consists of a switching element (SW1) connected in series, and a detection circuit (8) is connected in parallel to the capacitor (C1). Zero-volt switching element (SW
A DC lighting device for a fluorescent lamp, wherein 1) is controlled to be turned off. 4. A direct-current lighting device for a fluorescent lamp according to claim 1, further comprising control means for turning on a high-voltage direct-current power supply (5), turning on a control switch (SW2), and then turning off the light. Lighting device for fluorescent lamps. 5. The DC lighting device for a fluorescent lamp according to claim 1, wherein the output means of the high-voltage DC power supply is an iron core transformer.
In the case of 1), the high-voltage maintaining resistor (4) is replaced with a second diode (10) for reverse blocking, and in the case of the ceramic transformer (11), the high-voltage maintaining resistor (4) is zero. A DC lighting device for a fluorescent lamp, wherein the high voltage generation time is synchronized with the moment when the starter (1) is turned off. 6. A fluorescent lamp direct-current lighting device according to claim 2, wherein a control switch (SW3) is provided at both ends of the high-voltage direct-current power supply (5).
Is connected and the control switch (SW3) is always
N. A DC lighting device for a fluorescent lamp, which is controlled to be turned off at the moment when a high voltage is applied. 7. A DC lighting device for a fluorescent lamp according to claim 1, wherein three terminals for changing the polarity and interrupting the power supply are provided at an output terminal of the constant current DC power supply or the high voltage DC power supply.
A DC lighting device for a fluorescent lamp, characterized in that a circuit switch (12) is connected and a middle contact 2 of the three contacts is used for intermittent power supply. 8. A direct-current lighting device for a fluorescent lamp according to claim 7, wherein the power switching contact 2 in the three-contact two-circuit switch (12) is short-circuited. 9. A fluorescent lamp direct-current lighting device according to claim 1, further comprising a polarity changing switch for determining whether or not to change the polarity at the moment when the AC power switch is turned on. A DC lighting device for fluorescent lamps, characterized by determining whether the polarity of the input is positive or negative by a polarity determination circuit (IC1). 10. A fluorescent lamp DC lighting device according to claim 2, wherein the high voltage DC power supply is replaced by a center tap type resonance type inverter lighting circuit (14), and the starting starter (1) is replaced by a starting capacitor (C5). A DC lighting device for a fluorescent lamp, characterized in that when a high frequency is turned on and then the function of the inverter is stopped, the upper switching element (Sa) is turned on and the lower switching element (Sb) is turned off. 11. The fluorescent lamp DC lighting device according to claim 2, wherein the high voltage DC power supply (5) is replaced by a bridge type resonance type inverter lighting circuit (15), and the starting starter (1) is replaced by a starting capacitor (C5). When the high-frequency lighting is performed, and then the function of the inverter is stopped, the four switching elements (Sa, Sb, Sc, Sd) constituting the bridge are changed to polarity changing switches and used. DC lighting device. 12. A direct-current lighting device for fluorescent lamps according to claim 1, wherein there are a large number of fluorescent lamps provided with starters (1), each of which is connected in series and each starter is turned off sequentially. DC lighting device for fluorescent lamps. 13. A DC lighting device for a fluorescent lamp according to claim 1, wherein a power thermistor (RD1) is connected in series to an output terminal of the constant current DC power supply (3). DC lighting device for fluorescent lamps.