KR100672028B1 - Fluorescent lamp ballast for controlling dimming - Google Patents

Abstract

A fluorescent lamp ballast for controlling dimming is provided to maintain uniform intensity of illumination in a room by selecting a desired intensity of illumination level. In a fluorescent lamp ballast for controlling dimming, a bridge rectification part(2) generates a pulsating voltage by converting a commercial AC voltage inputted through an AC input part(1). A constant power supply part(3) controls harmonic currents, and maintains a constant output voltage regardless of the variation of an input voltage. An inverter part(5) performs high frequency switching by receiving an operation voltage from the constant power supply part. A frequency generation part(4) controls a lamp current by controlling a switching frequency of the inverter part. A frequency control part(6) controls an oscillation frequency of the frequency generation part. A current detection part(7) maintains a constant lamp current by sensing the inverter part and the lamp current. A resonant part(8) turns on a lamp by resonating a high speed switching voltage by the inverter part. An inverter current comparison part(9) generates a control signal of the frequency control part by comparing currents of the inverter part and the current detection part. A dimming control part(11) controls the inverter current comparison part by generating an operation current according to a control voltage from the outside.

Description

Fluorescent ballast for dimming control {FLUORESCENT LAMP BALLAST FOR CONTROLLING DIMMING}

1 is a block diagram showing a fluorescent lamp ballast for dimming control according to the present invention.

Figure 2 is an overall circuit diagram showing a fluorescent ballast for dimming control according to the present invention.

Figure 3 (a) to (e) is a characteristic diagram applied to the fluorescent lamp ballast for dimming control according to the present invention.

* Explanation of symbols for main parts of drawings *

1: AC input 2: bridge rectifier

3: constant power supply unit 4: frequency generator

5: inverter section 6: frequency control section

7 current detecting unit 8 resonating unit

9: inverter current comparison unit 10: initial dimming control unit

11: dimming control unit

The present invention relates to a fluorescent ballast for dimming control, and more particularly, it is possible to select a desired illuminance with an external voltage (DC 10V to 0V) to maintain uniform indoor illuminance and to control dimming of a plurality of ballasts simultaneously. The present invention relates to a fluorescent ballast for dimming control.

In general, the ballast serves to maintain the lighting of the lamp by continuously supplying a constant voltage to the lamp to interrupt the discharge of the lamp.

In addition, since the voltage-current of the lamp has a negative characteristic, when the initial lamp is turned on, the voltage continuously decreases and the current rises and eventually the lamp is destroyed. A ballast is required to prevent such a phenomenon. The ballast acts to limit the current by supplying a constant voltage to the lamp.

On the other hand, in the lighting design, the development of a ballast to improve the quality of lighting, such as creating a comfortable lighting environment, removing glare, controlling the illumination for the atmosphere, energy saving, etc. is required.

However, a conventional electronic ballast for dimming control has a problem in that the illuminance is different even when the ballast is installed at various places even in the same product during dimming control.

In addition, each time the lamp is produced, it is difficult to manufacture a product with a constant illuminance according to the difference between the lamp's own temperature and the ambient temperature, there is a problem to manage the lamp temperature and to supplement the set power according to the ambient temperature. , When the power is turned on / off at too low illuminance setting during the setting of illuminance, there is a problem that the ballast does not operate, and even when the ballast does not operate, the ballast is not maintained and the ballast is turned off or defective occurs in the middle.

In addition, when dimming control of a plurality of ballasts at the same time, there is a problem that the phase of the power supply line is interchanged with each other, resulting in a failure of the ballast.

The present invention has been made to solve the above problems, the purpose is to select the desired illuminance with an external voltage (DC 10V ~ 0V) can not only maintain the indoor illuminance uniformly, but also the power line of the dimming control unit and ballast By dividing and operating a dimming control unit separately to provide a dimming control fluorescent ballast that can control a plurality of ballasts at the same time.

In addition, the inverter and the lamp current is detected to form a comparison voltage, the inverter current comparison unit calculates the reference voltage and the comparison voltage to keep the inverter and the lamp current constant, and through the initial dimming control unit of the input voltage at the minimum dimming level In case of ON / OFF, the lamp is discharged and the illuminance is stopped even when the ballast stops operating due to the minimum dimming level or the unlit state according to the ambient temperature and the lack of lamp current in winter, or the difference between the lamp temperature and the ambient temperature occurs. It is to provide a fluorescent ballast for dimming control that can be maintained.

The dimming control fluorescent ballast of the present invention for achieving the above object is a dimming control fluorescent ballast for maintaining a constant illuminance of a lamp, by converting a commercial AC voltage input through the AC input unit 1 to the pulse Controls the current harmonics according to the phase difference between the current and the voltage of the input (AC) generated in the process of converting the voltage of the bridge rectifier 2 for generating a voltage, the pulse current input from the bridge rectifier 2 into a direct current (DC) voltage The constant power supply unit 3 maintains the output voltage constant even when the input voltage changes, the inverter unit 5 which receives the operating voltage from the constant power supply unit 3 and performs high frequency switching, and the inverter unit 5. Frequency generator 4 for controlling the lamp current by adjusting the switching frequency of the frequency, frequency controller 6 for controlling the oscillation frequency of the frequency generator 4, the inverter unit ( 5) and a current detector 7 which senses a lamp current to maintain a constant lamp current, and a resonator 8 which turns on a lamp by resonating a high speed switching voltage by the inverter unit 5. ), An inverter current comparison unit 9 which generates a control signal of the frequency controller 6 by comparing the currents of the inverter unit 5 and the current detection unit 7, and a control voltage (10V to 0V) from the outside. And a dimming control unit 11 for generating an operating current to control the inverter current comparison unit 9.

In addition, it is preferable to further include an initial dimming control unit 10 for controlling the dimming from the dimming control unit 11 when the control voltage (10V ~ 0V) from the outside.

When the control voltage (10V to 0V) from the outside is turned on (10V), the positive input of the inverter current comparator 9 is made high and the oscillation frequency of the frequency generator 4 is lowered. It is desirable to maximize the power of the lamp.

Preferably, the control voltage 10V to 0V from the outside is applied to the dimming controller 11 through the diode D24 and the resistor R41 to control the voltage of the transistor Q5 to control the dimming controller ( The voltage of 11 is induced by the resonator 8 to be used as a voltage source, and the operating current of the transistor Q5 is induced to the port coupler OC1 to control the inverter current comparator 9.

Hereinafter, a fluorescent lamp ballast for dimming control according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a dimming control fluorescent ballast according to the present invention, Figure 2 is an overall circuit diagram showing a dimming control fluorescent ballast according to the present invention.

As shown in Fig. 1 and Fig. 2, the fluorescent lamp ballast for dimming control according to the present invention is an AC input unit 1, a bridge rectifier 2, a constant power supply unit 3, a frequency generator 4, an inverter unit 5 And a frequency controller 6, a current detector 7, a resonator 8 and a lamp L, an inverter current comparator 9, an initial dimming controller 10 and a dimming controller 11.

Specifically, the AC input unit 1 is a means for supplying a commercial AC voltage from the outside, a fuse for blocking the application of AC overvoltage, and a line filter L1 for removing high frequency noise components included in the AC voltage. It includes.

The bridge rectifier 2 converts a commercial AC voltage input through the AC input unit 1 to generate a pulse current voltage, and includes bridge diodes D1 to D4 and capacitors C2 and C3.

The constant power supply unit 3 (PFC) is configured to provide a phase difference between the current and the voltage of the input AC generated in the process of converting the pulse current voltage input from the bridge rectifier 2 into a direct current voltage. Control the current harmonic according to the change, and keep the output voltage constant even with ± 20% change of input voltage, resistor (R1 ~ R14), capacitor (C4 ~ C8), diode (D5, D6 and D7), integrated circuit ( IC1), field effect transistor Q1, and boost transformer T1.

The inverter unit 5 receives the operating voltage from the constant power supply unit 3 and performs high frequency switching, and the capacitor C12, the diodes D8 to D13, the resistors R24 and R25 and the field effect transistors Q2 and Q3. ).

The frequency generator 4 stably controls the lamp L current by adjusting the switching frequency of the inverter unit 5, and includes an integrated circuit IC2, resistors R15 and R16, and capacitors C10 and C11. do.

The frequency controller 6 processes the signal of the dimming controller 11 to adjust the oscillation frequency of the frequency generator 4, and includes resistors R17 and R18, a diode D17, and a transistor Q7.

The current detector 7 detects the inverter unit 5 and the lamp current to maintain a constant current of the lamp, and the transformer T3, the resistors R27, R28 and R29, and the capacitor C17. And a diode D16.

The resonator 8 performs a function of turning on a lamp by resonating the high speed switching voltage by the inverter unit 5, and resonant transformer T4, capacitors C13, C14, C15 and C16, and a resistor ( R26) and diodes D14 and D15.

The inverter current comparison unit 9 compares the currents of the inverter unit 5 and the current detection unit 7 to generate a control signal of the frequency controller 6, and includes the integrated circuit IC3 and the resistors R30, R31, and R32. And a capacitor C18.

The initial dimming control unit 10 smoothly maintains dimming when the external power is initially turned on and off, and includes resistors R33, R34 and R35, a capacitor C20, a diode D19, and a transistor Q4.

The dimming control unit 11 controls the operating current according to the external control voltage (10V ~ 0V), resistors (R39, R40, R41 and R42), capacitors (C21, C22), diodes (D20, D21, D22, D23 and D24), transistor Q5 and photocoupler OC1. That is, the dimming control unit 11 controls the operating current of the transistor Q5 in accordance with the external control voltage (10V ~ 0V).

Hereinafter, the operation of the dimming control fluorescent ballast according to the present invention will be described in detail with reference to FIG.

First, the bridge rectifier 2 outputs an AC voltage input through the fuse of the AC input unit 1 and the line filter L1 through the diodes D1 to D4 and the capacitors C2 and C3. do.

Thereafter, the pulse current voltage output from the bridge rectifier 2 is applied to the constant power supply unit 3.

At this time, the constant power supply unit 3 is applied from the bridge rectifier 2 through the resistor (R1 ~ R3) and the capacitor (C4) by the breeder (breeder) detects the input pulse voltage (breeder) to match the height of the pulse voltage The width is adjusted to operate the field effect transistor Q1.

The operation of the field effect transistor Q1 generates a high induced voltage in the boost transformer T1.

At this time, the induced voltage VL of the boost transformer T1 is -L di / dt (v).

On the other hand, the induced voltage VL of the boost transformer T1 charges the capacitors C7 and C8 via the diode D7.

That is, the charging voltages of the capacitors C7 and C8 are breathed by the resistors R10, R11, and R12, and are calculated with the comparison voltage 2.5V in the integrated circuit IC1, so that the gate of the field effect transistor Q1. It is charged by adjusting the pulse width.

At this time, when the charge voltage of the capacitors C7 and C8 is higher than the set voltage, the pulse width of the gate of the field effect transistor Q1 is reduced, and when the charge voltage is lower than the set voltage, the pulse width is widened to maintain the charge voltage constant. .

On the other hand, the pulsation voltages from the bridge rectifier 2 and the constant power supply 3 are passed through the resistors R20 and R21, the lamp filament and the resistors R22 and R23. It is applied as the initial operating voltage to IC2).

When an initial voltage is applied to the integrated circuit IC2, the frequency generator 4 generates a frequency by the resistors R15, R16 and R17 and the capacitors C10 and C11.

At this time, the oscillation frequency of the frequency generator 4 receives a frequency from the transformer T2 and applies an operating frequency to the inverter unit 5.

That is, the inverter unit 5 performs a high speed switching operation according to the operating frequency induced from the transformer T2.

Subsequently, the high frequency high voltage generated through the high speed switching operation of the inverter unit 5 forms a waveform with a square wave in the resonator unit 8 via the capacitor C12 to discharge the lamp.

In addition, the high frequency high voltage generated by the operation of the inverter unit 5 generates the power supply voltage of the frequency generator 4 through the resistor R26, the capacitor C16, and the diodes D14 and D15. Keep the operation of (4) smoothly.

At this time, the secondary winding of the resonant transformer T4 of the resonator unit 8 receives a resonant current, and the DC voltages of the resistors R43 and R44, the diode D25 and the capacitor C23 of the current detector 7 are induced. After the generation, it is applied to the inverter current comparison unit 9, the initial dimming control unit 10, and the dimming control unit 11 as operating power.

Meanwhile, the inverter unit 5 and the lamp current are detected through the transformer T3 of the current detector 7 and controlled through the resistors R27, R28 and R29, the capacitor C17, and the diode D16. After the voltage is formed, it is applied via the resistor R30 of the inverter current comparison section 9.

In this case, the inverter current comparison unit 9 sets the output low when the resonance current is high, and lowers the base voltage of the transistor Q7 through the resistor R31 and the diode D17 of the frequency controller 6. The transistor Q7 is operated.

When the transistor Q7 operates, the resistors R15 and R17 are connected in parallel, so that the resistance is lowered and the frequency is increased.

The increased oscillation frequency of the frequency generator 4 reduces the resonance current of the resonator 8 to keep the resonance current constant.

Meanwhile, the other input (+) of the inverter current comparison unit 9 is connected to the resistors R36, R37 and R38, the photocoupler OC1, and the initial dimming control unit 10 to form a dimming voltage comparison unit.

At this time, the dimming voltage is an operating characteristic of the photocoupler OC1, and the current flowing through the resistor R36 and the current of the photocoupler OC1 are added together to increase the voltage drop of the resistors R37 and R38, thereby increasing the dimming comparison voltage. To increase the lamp current.

When the dimming voltage is high, the inverter unit 5 and the lamp current are increased to increase the illuminance. On the contrary, when the dimming voltage is low, the illuminance is lowered.

The initial dimming control unit 10 is composed of resistors (R33, R34 and R35), capacitor (C20) and transistor (Q4), when the power source is turned on (ON), the base potential of the transistor (Q4) is 0.7V than the emitter Will be lower.

At this time, when the base voltage of the transistor Q4 is lower than the emitter by 0.7V or more, the transistor Q4 is operated.

When the transistor Q4 is operated, the positive input of the inverter current comparator 9 becomes high to lower the oscillation frequency of the frequency generator 4 to maintain the lamp at 100% power. Let's do it.

On the other hand, the base voltage of the transistor Q4 is gradually increased by the integrating circuit composed of the resistors R33 and R34 and the capacitor C20.

At this time, when the base voltage gradually increases to become the same potential as the emitter voltage, the transistor Q4 is turned off and is independent of the inverter current comparator 9.

The dimming control unit 11 includes resistors R39, R40, R41 and R42, capacitors C21 and C22, diodes D20, D21, D22, D23 and D24, a transistor Q5, and a photocoupler OC1. ) Controls the operating current of the transistor Q5 in accordance with the external control voltage (10V ~ 0V).

That is, the external control voltage 10V to 0V is applied to the dimming control unit 11 through the diode D24 and the resistor R41 to control the voltage of the transistor Q5, thereby controlling the voltage of the dimming control unit 11. It is induced by the resonator 8 and used as a voltage source.

The operating current of the transistor Q5 is induced to the port coupler OC1 to control the inverter current comparison unit 9.

At this time, when the external voltage is 10V, since the base of the transistor Q5 becomes high, the transistor Q5 is operated and the photocoupler OC1 is operated to increase the dimming reference voltage. Current is 100% output.

On the other hand, when the external voltage is 0 V, since the base of the transistor Q5 is low, the transistor Q5 is not operated and the operation of the port coupler OC1 is stopped, and the dimming reference voltage is the lowest. Therefore, the lamp current is 10% output.

That is, even if the power supply line is isolated by the external voltage (10V to 0V) and the port coupler (OC1) to perform dimming control of a plurality of ballasts, the phases of the power supply lines do not cross each other, so that the ballast can operate stably. Will be.

On the other hand, the characteristics of the dimming control fluorescent ballast according to the present invention configured as described above will be described through (a) to (e) of FIG.

FIG. 3A is a characteristic diagram showing the case where the external voltage is low, (b) is a characteristic diagram showing the operation of the collector of the transistor Q5 when the external voltage is Low, (c) is a characteristic diagram showing the operation of the transistor Q4 of the initial dimming control unit 10 when the external voltage is low, and (d) shows the (+) input comparison voltage of the integrated circuit IC3. (E) is a frequency characteristic diagram of the frequency generating part 4. As shown in FIG.

That is, as shown in (a) of FIG. 3, when the power is turned on when the external control voltage is low, as shown in (c) of FIG. Since the transistor Q4 is high and the positive input comparison voltage of the integrated circuit IC3 is high, as shown in FIG. 3D, the frequency generator 4 Lowers the oscillation frequency to maximize the lamp current. In other words, the frequency characteristics of the frequency generator 4 are as shown in Fig. 3E.

Meanwhile, in FIG. 3C, when the transistor Q4 of the initial dimming control unit 10 is turned off due to the charging characteristic of the integrating circuit including the resistors R33 and R34 and the capacitor C20, the integrated circuit is integrated. Since the positive input comparison voltage of the circuit IC3 becomes low, the frequency generator 4 increases the oscillation frequency to minimize the lamp current.

Although the present invention has been described above according to an embodiment of the present invention, a person skilled in the art to which the present invention belongs has changed and modified within the scope without departing from the technical spirit of the present invention. Of course.

As described above, according to the dimming control fluorescent ballast according to the present invention, by selecting the desired illuminance by the external voltage (DC 10V ~ 0V) can not only maintain the room illuminance uniformly, but also separate the power line of the dimming control unit and the ballast And by operating the dimming control unit separately, a plurality of ballasts can be controlled dimming at the same time.

In addition, the inverter unit and the lamp current is detected to form a comparison voltage, and the inverter current comparison unit calculates the reference voltage and the comparison voltage to maintain the inverter and the lamp current constant, and at the minimum dimming level through the initial dimming controller. When the input voltage is ON / OFF, the lamp is discharged. Even if the ballast stops operating due to the minimum dimming level or the unlit state and the lamp current is insufficient due to the ambient temperature in winter, or the difference between the lamp temperature and ambient temperature occurs. The illuminance can be kept constant.

Claims (4)

As a fluorescent lamp ballast for dimming control that maintains a constant illuminance of a lamp, A bridge rectifier 2 for converting a commercial AC voltage input through the AC input unit 1 to generate a pulse current voltage; Current harmonics are controlled according to the phase difference between the current of the input AC and the voltage generated in the process of converting the pulse current voltage input from the bridge rectifier 2 into a direct current (DC) voltage. Constant power supply unit 3 to maintain a constant, An inverter unit 5 which receives an operating voltage from the constant power supply unit 3 and performs high frequency switching; A frequency generator 4 for controlling a lamp current by adjusting the switching frequency of the inverter 5; A frequency controller 6 for adjusting the oscillation frequency of the frequency generator 4, A current detector 7 which detects the inverter unit 5 and the lamp current and keeps the lamp current constant; A resonator unit 8 for resonating the high speed switching voltage by the inverter unit 5 so as to light a lamp; An inverter current comparison unit 9 which generates a control signal of the frequency controller 6 by comparing the currents of the inverter unit 5 and the current detector 7, and And a dimming control unit (11) for generating an operating current according to a control voltage (10V to 0V) from the outside to control the inverter current comparing unit (9). The method of claim 1, And an initial dimming control unit (10) for controlling dimming from the dimming control unit (11) when the external control voltages (10V to 0V) are turned on and off. The method according to claim 1 or 2, When the control voltage (10V to 0V) from the outside is turned on (10V), the positive input of the inverter current comparator 9 is made high, and the oscillation frequency of the frequency generator 4 is lowered so that the ramp ( Fluorescent ballast for dimming control, characterized in that to maximize the power of the lamp. The method according to claim 1 or 2, The control voltages 10V to 0V from the outside are applied to the dimming controller 11 through the diode D24 and the resistor R41 to control the voltage of the transistor Q5 in order to control the voltage of the dimming controller 11. The dimming control fluorescent lamp is characterized in that the voltage is induced by the resonator 8 and used as a voltage source, and the operating current of the transistor Q5 is induced by the port coupler OC1 to control the inverter current comparator 9. ballast.

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