KR100493920B1 - Illumination Control Electric Neon Ballast - Google Patents

Abstract

The present invention controls the dimming of the neon tube by controlling the amount of current in the neon tube by controlling the amount of current in the neon tube by driving a half bridge inverter using pulse width modulation, while applying a mixed DC and AC bias to the neon tube. To provide a dimming control electronic neon tube ballast for that purpose. To this end, the present invention provides a dimming control electronic neon tube ballast, the bridge rectifier for rectifying the input AC voltage; A DC voltage charger for charging the bridge voltage to DC; A frequency generator for generating two frequencies having a predetermined phase difference according to the control signal; A power supply for supplying the AC voltage to the frequency generator; A dimming control unit for generating a control signal using a DC amplifier and controlling the dimming of the lamp by controlling the current of the neon tube by controlling the pulse width of the frequency generator through the control signal; A half bridge inverter unit for switching according to the pulse width of the frequency generator; A high voltage high frequency booster for boosting a switching voltage generated by the switching of the inverter to a high voltage; And a lamp lit by the applied power.

Description

Dimming control electronic neon tube ballast {Illumination Control Electric Neon Ballast}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic neon tube ballast, and more particularly, to an electronic neon tube ballast for controlling dimming using a half bridge inverter.

Dimming control for a conventional neon tube (lamp) (hereinafter simply referred to as "neon lamp") has been realized using a pulse width modulated flyback inverter method. However, the flyback inverter method has been applied at low (120Vac) A.C input voltage, has a problem of low efficiency and narrow dimming control range (50% ~ 100%) of the neon lamp.

In addition, a conventional electronic neon tube ballast has various problems by selectively using a lighting voltage of a DC bias or an AC bias.

In other words, since the DC bias method has a simple circuit configuration and can remove the influence of frequency, most of the DC bias methods adopt the DC bias method. However, neon signs are composed of neon tubes and argon tubes, and applying a DC bias removes the jelly beam phenomenon of the neon tubes, but as the mercury moves in the argon tubes, the lamp becomes darker and blackens as time passes. There is a problem of lowering the service life. In addition, the DC bias has a problem that the efficiency is reduced by using only half (1/2) of the high frequency generated in the inverter.

Next, AC bias has a good advantage because it does not generate mercury concentration in the argon tube generated in the DC bias. However, the AC bias does not occur in the mercury concentration of the argon tube, but may still cause the jelly beam phenomenon, depending on the lamp conditions, there is a problem that the frequency is severely affected. Therefore, there is still a problem that needs to be improved.

On the other hand, the conventional electronic neon tube ballast has a problem that there is a lack of a device that enables the normal operation of the ballast by detecting an abnormal state such as no-load / overload and ground current generated during the operation of the ballast and taking measures accordingly.

The present invention is to solve the above problems, by driving a half-bridge inverter using a pulse width modulation (Pulse Width Modulation) method, by adjusting the current amount of the neon tube (lamp) to adjust the neon tube It is an object to provide a dimming control electronic neon tube ballast for controlling dimming of (lamp) while applying a bias mixed with direct current (DC) and alternating current (AC) to a neon tube.

In addition, the present invention shuts down the operation of the frequency generator of the electronic neon tube ballast when ground current or no load / overload is detected, thereby enabling the electronic neon tube ballast to be stably operated even when ground current or no load / overload is detected. The purpose is to provide.

The present invention for achieving the above object, the dimming control electronic neon tube ballast, AC voltage input unit 10 for receiving a commercial AC voltage; A bridge rectifier 20 for converting a commercial AC voltage input through the AC voltage input unit into a pulse current voltage; A DC voltage charger 30 for charging the bridge voltage of the bridge rectifier to DC; A frequency generator 40 for generating two frequencies having a predetermined phase difference according to the control signal; A power supply unit 70 for supplying an AC voltage applied from the AC voltage input unit to the frequency generator formed of an integrated circuit; Dimming control unit 100 for generating a control signal using a DC amplifier, and controlling the dimming of the lamp by controlling the current of the neon tube (lamp) by controlling the pulse width of the frequency generator through the control signal ; A half bridge inverter unit (50) for switching operation according to the pulse width of the frequency generator by receiving the inverter operating voltage from the DC voltage charging unit; A high voltage high frequency boosting unit 60 for boosting a switching voltage generated by switching of the inverter unit to a high voltage; And a lamp 120 that is turned on by the power applied from the high voltage high frequency booster.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an embodiment of a dimming control electronic neon tube ballast according to the present invention.

That is, the dimming control electronic neon tube ballast according to the present invention as shown in the drawings, the AC voltage input unit 10 for receiving a commercial AC voltage, the commercial AC voltage input through the AC voltage input unit pulse voltage By controlling the pulse width of the frequency generator of the integrated circuit by using the bridge rectifier 20 for converting the power supply, the power supply 70 for supplying the initial power to the frequency generator of the integrated circuit, the DC amplifier, Dimming controller 100 for controlling the dimming of the lamp by controlling the current of the neon tube (lamp) (hereinafter, simply referred to as "neon lamp"), the operation of the frequency generator when the ground current (earth current) is detected The ground current detection unit 110 for controlling the voltage to stop the operation of the inverter unit, the DC voltage charging unit 30 for charging the bridge voltage of the bridge rectifying unit to DC, the power supply unit A frequency generator 40 for generating two frequencies having a 180 ° phase difference according to a control signal of a dimming controller by receiving a circle, and receiving an inverter operating voltage from a DC voltage charger according to the pulse width of the frequency generator. Half-bridge type inverter unit 50 for the switching action, a high voltage high frequency booster 60 for boosting the switching voltage generated by the switching of the inverter unit to a high voltage, the power applied from the high voltage high frequency booster Lamp 120 which is turned on by the no-load / overload detection unit 90, the ground current detection unit and the no-load / overload detection unit to stop the operation of the inverter unit by detecting an abnormal overvoltage at no load or overload and controlling the frequency generating control unit. Accordingly, the frequency generation control unit 80 for controlling the frequency generation unit is included.

That is, the dimming control electronic neon tube ballast according to the present invention having the configuration as described above, can control the dimming of the neon lamp (120), eliminates the jelly beam phenomenon generated in the lighting of the neon lamp and In order to remove the mercury concentration, a high voltage high frequency voltage mixed with an AC bias and a DC bias may be applied to the neon lamp 120.

Detailed functions of the above components will be described with reference to FIG. 2.

Figure 2 is a circuit diagram of an embodiment of the dimming control electronic neon tube ballast according to the present invention.

First, the commercial AC voltage applied from the outside is passed through a bridge rectifier circuit composed of a fuse of the AC voltage input unit 10, a line filter LF of the bridge rectifying unit 20, and diodes D1 to D4. Converted to a pulse voltage.

The pulsating voltage of the bridge rectifying unit 20 is charged to a DC voltage which is a driving voltage of the inverter unit 50 in the DC voltage charging unit 30 including the capacitor C3 and the resistor R4.

In addition, the power supply unit 70 including the diodes D5 and D6, the resistors R1 and R2, the transistor TR1, the zener diode D7, and the capacitor C4 supplies the commercial AC voltage to the frequency generator 40. Leads to the integrated circuit operating voltage (DC 12V). In this case, the voltage of the power supply unit 70 is determined by the ratio of the resistors R1 and R2 and the current amplification factor hfe of the transistor TR1 through the resistor R1, and the initial operating current of the integrated circuit Standby supply. current) must be satisfied. That is, the output voltage is AC input voltage × (R2 / R1 + R2) Vdc, and the resistance (R1) value is (AC input voltage ÷ R1) × hfe = Standby supply current.

The voltage induced by the power supply unit 70 operates the frequency generator 40 including the integrated circuit IC2, the capacitors C5, C6, and C7, and the resistors R6, R9, R10, and R11. Generate two frequencies with phase difference. In this case, the frequency generator 40 generates a frequency according to the charge and discharge voltage of the CT terminal C5 and the RT terminal R11.

On the other hand, in order to obtain a pulse width modulation (PWM) signal from the frequency generator 40, a DC amplifier (amplification factor = 1) is formed in the dimming control unit 10 so that the positive comparison input of the integrated circuit IC2 is DC. Should be controlled by voltage.

In this case, a DC amplifier (amplification factor = 1) using the operational amplifier (OP Amp.) May connect a (-) comparison input to an output of two inputs and apply a (+) DC voltage to a (+) comparison input. Configure the circuit so that it

That is, the DC amplifier connects the (-) comparison input of the operational amplifier (OP Amp.) To the output terminal, and the (+) comparison voltage connects the reference voltage (+ 5V) of the integrated circuit IC2 to the resistors R5 and R7. ) Is distributed to the variable resistor VR1 and applied as a positive DC voltage. At this time, the resistance value of the variable resistor VR1 and the positive DC voltage induced in the resistor R7 output a positive comparison input voltage according to the amplification factor of the DC amplifier.

As a result, when the output voltage of the DC amplifier is high, the frequency of the frequency generator 40 is smaller in width (Duty-cycle = 10%). On the contrary, when the output voltage is low, the frequency is widened in (Duty-cycle = 49%).

On the other hand, Out B of the pulse width modulation voltage of the frequency generator 40 is the field effect transistor TR3 of the inverter unit 50 through the resistor R13 and the diode D9, and Out A is Waveform shaping is performed on capacitor C7 and resistor R6 to magnetize secondary coil with decentralized transformer T2 to apply gate voltage to field effect transistor TR2 through resistor R12 and diode D8. Supply to achieve a switching operation.

That is, the pulse width modulated square wave is generated in the X part by the switching of the inverter unit 50 as described above, and the pulse width modulated square wave is the capacitor C7, C8, C10, the resistor R14, and the boost transformer T2. The high voltage high frequency booster 60 is configured to induce a high voltage high frequency to light the neon lamp 120.

In summary, the dimming control electronic neon tube ballast according to the present invention generates a pulse width modulated signal by controlling the frequency generator 40 by using the DC amplifier of the dimming controller 100, -Bridge The inverter is controlling the dimming of the neon lamp.

That is, in the DC amplifier of the dimming control unit 100, the (-) comparison input is connected to the output, and the reference voltage (Reference Voltage 5Vdc) is distributed (divide) by the resistors R5, R7, and VR1. By configuring the comparison input, a positive comparison input of the frequency generator 40 is controlled to generate a pulse width modulated signal.

In addition, the dimming control electronic neon tube ballast according to the present invention, by detecting the voltage from the feedback (FB) coil of the step-up transformer (T2) at no load / overload, the diode (D13, D14, D15, D16), resistor (R24), capacitor A high DC voltage is generated at (C13) to conduct the zener diode (D10) so that the integrated circuit configuration SCR (the negative comparison input of the integrated circuit IC2 B is referred to as the resistor R5 and the resistor R12, and the positive comparison input is A diode D11 connected to the output) to control the shutdown function of the frequency generator 40 to stop the switching operation of the inverter unit 50, and to conduct the transistor TR4 to conduct the power supply unit 70 of the power supply unit 70. The LED was turned on while the voltage was lowered to indicate the abnormality of the lamp 120.

On the other hand, in order to prevent abnormal conditions generated during the operation of the normal dimming control electronic neon tube ballast as described above, the no-load / overload detection unit 90, the ground current detection unit 110 and the frequency generation control unit 80 has been added to the circuit.

First, when an overcurrent flows in the lamp 120 or becomes an open load state during the operation of the normal dimming control electronic neon tube ballast as described above, an overvoltage is induced in the secondary coil FB of the step-up transformer T2. Zener detects an abnormal overvoltage in the no-load / overload detection unit 90 composed of diodes D13, D14, D15, and D16, resistors R15, R16, and R17, capacitors C11 and C12, and feedback FB coils. The frequency generation control unit 80 is controlled by operating the diode D10.

That is, the abnormal overvoltage of the no-load / overload detection unit 90 controls the frequency generation control unit 80 through the SCR function composed of the integrated circuit IC1A, the resistors R18, R19, R20, R21, and the diodes D11, D12. By lowering the integrated circuit operating voltage induced by the power supply unit 70 below the minimum voltage lockout threshold, the operation of the frequency generator 40 is stopped, resulting in a switching action of the inverter unit 50. It stops to block the overload is applied to the lamp 120.

Next, when ground (ground) current flows due to external reasons during the operation of the normal electronic neon ballast as described above, the capacitors C14, C15, C16, diodes D17, D18, D19, D20, and resistor R22. Ground (ground) at ground current detection unit (110) consisting of R23, R24, R25, R26, transistor (TR5), photocoupler (IC3), shunt regulator (SR), and ground current sensing aluminum plate (AL.Plate) By detecting the current, the frequency generating control unit 80 is operated to stop the operation of the frequency generating unit 40 to stop the switching operation of the inverter unit 50.

That is, when the ground voltage due to the ground current is detected in the ground (earth) current sensing aluminum plate of the ground current detector 110, the ground voltage is the DC voltage at the diodes D16, D17, D18, and D19 and the capacitor C15. (Vc15) is generated, and the voltage divided by the resistors R24 and R25 is (R25 / R24 + R25) x VC16 (V), and the shunt regulator SR is operated by this voltage.

The operation of the shunt regulator S.R turns on the photocoupler IC3 by operating the transistor TR5, which turns on S.C.R configured as an integrated circuit of the frequency generation controller 80. On the other hand, when the SCR is turned on, the transistor TR4 is conducted through the resistor R13 to lower the base voltage of the transistor TR1 through the resistor R1 through the resistor R3 and the light emitting diode LED. The operation of the frequency generator 40 is stopped.

On the other hand, in performing the two functions (ground current detection, no load / overload detection), the operation of the SCR composed of the integrated circuit of the frequency generation control unit 80 turns on the light emitting diode (LED), the lamp failure, no load Indicates that the operation of the inverter unit 50 has stopped due to overload and ground current.

3A to 3D illustrate an embodiment of a pulse width modulated signal according to control of a DC amplifier in the dimming controller 100 according to the present invention.

That is, as shown in FIG. 3A, the output voltage of the DC amplifier, FIG. 3B is the output from the output terminal OUT A of the integrated circuit IC2 of the frequency generator 40, and FIG. An output at another output terminal OUT B of IC2) is shown, and FIG. 3D shows a switching pulse width modulation waveform at the inverter section 50.

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

The present invention as described above has an excellent effect of improving the discharge of the lamp to increase the luminous efficiency and expand the dimming range (20% to 100%).

That is, the present invention can control the dimming of the neon lamp, and by applying a high-frequency high-frequency voltage mixed with AC bias and DC bias to the neon lamp, which is generated when the neon lamp is turned on. By eliminating the jelly beam phenomenon and the concentration of mercury in the lamp, there is an excellent effect of improving the lamp efficiency, extending the lamp life and improving the defect rate of the ballast.

1 is a block diagram of an embodiment of a dimming control electronic neon tube ballast according to the present invention;

Figure 2 is a circuit diagram of an embodiment of the dimming control electronic neon tube ballast according to the present invention.

3A to 3D illustrate an embodiment of a pulse width modulated signal under control of a DC amplifier in the dimming controller 100 according to the present invention.

Claims (4)

delete In the dimming control electronic neon tube ballast, A bridge rectifier 20 for rectifying the input AC voltage; A DC voltage charger 30 for charging the bridge voltage of the bridge rectifier to DC; A frequency generator 40 for generating two frequencies having a predetermined phase difference according to the control signal; A power supply unit 70 for supplying an AC voltage applied from the AC voltage input unit to the frequency generator formed of an integrated circuit; Dimming control unit 100 for generating a control signal using a DC amplifier, and controlling the dimming of the lamp by controlling the current of the neon tube (lamp) by controlling the pulse width of the frequency generator through the control signal ; A half bridge inverter unit (50) for switching operation according to the pulse width of the frequency generator by receiving the inverter operating voltage from the DC voltage charging unit; A high voltage high frequency boosting unit 60 for boosting a switching voltage generated by switching of the inverter unit to a high voltage; And It includes a lamp 120 that is turned on by the power applied from the high-voltage high-frequency boosting unit, The DC amplifier of the dimming control unit 100, Connect the negative comparison input to the output terminal, divide the reference voltage with resistors R5, R7, VR1, and configure it as a positive comparison input.If the output voltage of the DC amplifier is high, A dimming control electronic neon tube ballast characterized in that the frequency width of 40) is reduced (Duty-cycle = 10%), and conversely, when the output voltage is low, the frequency width is widened (Duty-cycle = 49%). The method of claim 2, A no load / overload detection unit 90 for stopping the operation of the inverter unit by detecting an abnormal overvoltage at no load or overload and controlling the frequency generation control unit; And And a frequency generation controller 80 for controlling the frequency generator according to the detection voltage of the no-load / overload detector. The no load / overload detection unit 90 senses a voltage in the feedback coil of the boost transformer T2 at no load / overload and detects a voltage in the diodes D13, D14, D15, and D16, the resistor R24, and the capacitor C13. When the frequency generating control unit 80 is operated by generating a high DC voltage to conduct the zener diode D10, the frequency generating control unit 80 controls the shutdown function of the frequency generating unit 40 so that the inverter unit operates. A dimming control electronic neon tube ballast characterized by stopping the switching operation of 50. The method of claim 3, wherein When the ground current (earth current) is detected further comprises a ground current detection unit 110 for controlling the operating voltage of the frequency generator 40 to stop the operation of the inverter unit 50, The ground current detector 110, When the ground voltage caused by the ground current is detected by the aluminum plate for ground (earth) current sensing, the ground voltage generates a DC voltage (Vc15) at the diodes (D16, D17, D18, and D19) and the capacitor (C15). The shunt regulator SR is operated by the voltages distributed by R24 and R25, and the operation of the shunt regulator SR operates the transistor TR5 to turn on the photocoupler IC3 to turn on the frequency generation controller 80. ), The frequency generating control unit (80) stops the switching operation of the inverter unit (50) by controlling the shutdown function of the frequency generating unit (40).