KR100499331B1 - Low level light igniting controller of ballast for fluorescent lamp and igniting method for the same - Google Patents

Abstract

The present invention forms a lighting condition through the preheating period when the fluorescent lamp is turned on, and then performs the lighting by satisfying the discharge start condition quickly, and when the discharge is started, a size for maintaining the set dimming level state before the lighting after a very short time. The low light lighting control device and lighting control method of the electronic ballast for fluorescent lamps supplying current to the lamp,

Preheat current control unit for providing a first control input for supplying a preheating current to the lamp during the preheating period when the lamp is turned on, and a second control input for supplying a maximum current to the lamp for a short time for starting discharge after preheating Discharge start control unit for providing a ballast control unit; And a ballast control unit that receives a plurality of control signal inputs including a low light lighting control unit including a timing control unit controlling a timing of a control current input supplied to the ballast control unit by varying the frequency outputted to the inverter and undergoing a preheating period. And discharges a large amount of tube current through the lamp for a short period of time, and then controls the current flowing through the lamp to the brightness before turning off.

Therefore, in the present invention, it is possible to immediately turn on the lighting with low illuminance.

Description

LOW LEVEL LIGHT IGNITING CONTROLLER OF BALLAST FOR FLUORESCENT LAMP AND IGNITING METHOD FOR THE SAME}

The present invention relates to an electronic ballast for fluorescent light control capable of illuminance control, in particular to form a lighting condition through a preheating period during lighting, to perform lighting in a very short time, to control to the previous brightness state in this lighted state The present invention relates to a low-light dimming control device for an electronic ballast for fluorescent lamps that can be lit in the original low-light state even when turned off in a low-light state.

Referring to Figure 1 will be described an electronic ballast according to the prior art.

As shown in FIG. 1, the electronic ballast of the prior art includes a filter unit 100, a rectifying unit 110, a power factor improving unit 120, an inverter unit 130, a resonance unit 140, a lamp unit 150, and an abnormal state detection unit. 160, the ballast control unit 170, and the lamp current feedback unit 180.

The function of each component part by a prior art is demonstrated.

First, the filter unit 100 is a component that removes the abnormal voltage or noise included in the commercial AC power supply and blocks the noise generated in the ballast.

The rectifier 110 is a component that converts alternating current into direct current.

The power factor improving unit 120 is a component that improves the power factor and outputs a DC voltage necessary for lighting the lamp.

The ballast controller 170 controls the brightness (illuminance) according to the lighting of the lamp and the dimming signal applied from the outside, senses the lamp current detected by the lamp current feedback unit 180, and the level of the dimming signal applied from the outside. The oscillation frequency is controlled so as to flow the lamp current to the inverter unit 130, the inverter unit 130 switches the supplied DC voltage at a high frequency in accordance with the frequency supplied from the ballast controller 170 resonator unit It is a component part supplied to 140.

The resonator 140 converts the high frequency pulse voltage switched by the inverter unit 130 into a sine wave and supplies the lamp unit 150 to drive the lamp.

The lamp current feedback unit 180 is a component that senses a lamp current and applies it to the ballast controller 170.

The abnormal state detection unit 160 detects overvoltage, overcurrent, and miswiring supplied to the lamp and notifies the ballast control unit 170 to ensure safety and prevent damage to the ballast.

In the conventional ballast, control of dimming or the like is possible only after the discharge of the fluorescent lamp is started and the current flows for a predetermined time even after the discharge is started, and the discharge is sufficiently stabilized. Therefore, the length of time that the initial lamp is turned on at the maximum brightness is long.

In such a conventional lighting method, it is generally controlled to turn on at the highest brightness and gradually to the low illuminance before re-lighting. However, when the film is slowly turned off after the movie screening, such as a movie theater, the lights are turned off completely and the screen is turned on again after the movie screening is suddenly turned to 100% brightness, which gives glare and cannot be used in this case.

When there is a need to turn on low light in theaters, there is a way to give enough preheating time of filament and to control low tube current so that it turns on even in low light even though it is turned on. In consideration of changes in the lighting conditions due to changes in the environment, especially temperature, there is a problem such that the lighting may not be turned on by setting the control point of the tube current.

The present invention has been made to solve the above problems, and the object of the present invention is to form a lighting condition through a preheating period at the time of lighting, supply a sufficient current at the start of discharge for a very short time, and then immediately lower the tube current The present invention provides a low-light lighting control device and a lighting control method of an electronic ballast for a fluorescent lamp that can realize lighting stably even at low light while being limited.

As a technical means for achieving the above object of the present invention, the low illuminance lighting control device of the present invention outputs a controlled oscillation frequency so that a lamp current suitable for the lighting of a lamp and a level of a dimming signal applied from the outside can flow. A low light lighting control device of an electronic ballast having a ballast control unit and an inverter for switching a supplied DC voltage at a high frequency in accordance with a frequency supplied from a ballast control unit, the low light illuminating control device comprising: for supplying a preheating current to the lamp during a preheating period when the lamp is turned on. A preheat current control unit providing a first control input to the ballast control unit; A discharge start control unit for providing a second control input to the ballast control unit for supplying a current necessary for the discharge start to the lamp for a short time for the discharge start after preheating; And a low illuminance lighting control unit including a timing control unit controlling a timing of a control current input supplied to the ballast control unit, and varying a frequency output from the ballast controller to the inverter by the plurality of control inputs to initiate discharge of the lamp. And controlling the discharge current of the lamp at a predetermined brightness after discharge.

The ballast control unit may further include a third control input for supplying a current that is capable of stabilizing lighting after the lamp is discharged before controlling the discharge current of the lamp at the brightness before turning off the lamp. It is characterized by further comprising a post-discharge current control unit provided in the to control the current of the lamp to a predetermined brightness after maintaining the discharge current of the lamp for a certain period after the lamp is discharged.

In addition, the low light lighting control unit of the present invention determines the discharge start of the lamp based on the current flowing through the lamp, the discharge start detection unit for outputting a discharge start signal to the timing control unit, and the discharge start detection unit detects the discharge start And further comprising a re-sensing prevention unit for preventing re-sensing of the discharge start afterwards to control the timing of the discharge start control unit.

In addition, the present invention is the ballast control unit for controlling the frequency so that the lamp current is controlled in accordance with the lighting of the lamp and the dimming signal applied from the outside, and switching the supplied DC voltage at a high frequency in accordance with the frequency supplied from the ballast control unit to the lamp In the low illuminance lighting control method of an electronic ballast having a supplying inverter, when power is applied, a low current lower than a current required for lighting is supplied to the lamp for a predetermined preheating period to form a lighting condition of the lamp. A preheating step of applying a first control input to the ballast control unit; Ballast control unit cuts off the first control input when the preheating period elapses, and supplies a current corresponding to the maximum brightness that can be discharged to the lamp instantaneously during the discharge initiation period which is a time unrecognizable to the eye. A discharge start step of applying a second control input to the discharge; And after the discharge start period has elapsed, the second control input is cut off, and the ballast controller comprises a lighting step of controlling a frequency such that a current corresponding to a previous illuminance state or a predetermined illuminance is supplied to the lamp. It is characterized by being turned on in low light.

In addition, the low illuminance lighting control method of the electronic ballast of the present invention is a lamp with a current lower than the current of the discharge start period for a certain period of time for the stabilization of the lighting state after the discharge start period has elapsed, before the lighting step is performed. And a lighting maintaining step of applying a third control input to the ballast control unit to supply.

In addition, the low light lighting control method of the electronic ballast of the present invention includes a discharge start detection step of performing the second control input after sensing the current of the lamp to start the discharge; And after detecting the discharge start once, characterized in that it further comprises a re-detection prevention step of preventing the detection of the discharge start again.

EMBODIMENT OF THE INVENTION Hereinafter, the structure and effect | action of the electronic ballast low illuminance lighting control device and lighting control method which concern on this invention with reference to an accompanying drawing are demonstrated in detail. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

2 is a block diagram of a functional block of the electronic ballast low light lighting control device according to the present invention. Referring to FIG. 2, the electronic ballast low light lighting control device according to the present invention includes a filter unit 100 for removing noise, Rectifier 110, power factor improvement unit 120, inverter unit 130, resonator unit 140, lamp unit 150, abnormal state detection unit 160, ballast controller 170, lamp current feedback unit 180 And low light control unit 200 is included. Here, the filter unit 100, the rectifier unit 110, the power factor improvement unit 120, the inverter unit 130, the resonator unit 140, the lamp unit 150, the abnormal state detection unit 160, the ballast control unit 170 In addition, the lamp current feedback unit 180 has the same configuration and operation as that of the components of the conventional dimmer disclosed in FIG. 1, and a characteristic configuration of the present invention is to further include a low light illuminating controller 200.

FIG. 3 is a block diagram showing in detail the configuration of the low illuminance lighting control unit 200 of the present invention. Referring to FIG. 3, the low illuminance lighting control unit 200 of the present invention includes a timing control unit 210 and a preheating current control unit ( 220, a discharge start control unit 230, a post discharge current control unit 240, a discharge start monitoring unit 250, and a redetection prevention unit 260.

The preheat current controller 220 is configured to provide a first control input to the ballast controller 170 to supply a preheat current to the lamp during the preheating period when the lamp is turned on.

The discharge start control unit 230 is configured to provide a second control input to the ballast control unit 170 to supply a current necessary for discharge start to the lamp for a short time for the discharge start after preheating.

The post-discharge current control unit 240 is configured to provide a third control input to the ballast controller 170 for supplying a minimum current for maintaining the discharge to the lamp after the lamp is discharged.

In addition, the timing controller 210 controls the preheat current controller 220, the discharge start controller 230, and the discharge current controller 240 after the power is turned on to control the first control input, the second control input, and the third control input. The ballast controller 170 is sequentially supplied to the ballast controller 170, and the ballast controller 170 controls the frequency supplied to the inverter unit 130 according to each control signal input, and the inverter unit 130 controls the ballast controller 170. The DC voltage supplied from the power factor improving unit 120 is switched at a high frequency in accordance with the frequency from () to control the magnitude of the current supplied to the resonator unit 150.

In addition, the discharge start detection unit 250 detects the discharge start of the lamp by the current of the lamp unit 150 to control the timing of the discharge start control unit 230 in synchronization with the discharge of the lamp. The re-sensing prevention unit 260 is configured to prevent the discharge start detection unit 250 from monitoring the discharge start again. However, the discharge start detection unit and the re-detection prevention unit may not be included in the configuration when the discharge start point is correct.

4 is a configuration diagram of a low light illumination control device according to a first embodiment of the present invention, and FIG. 5 is a signal timing chart of a current control unit of the low light illumination control device according to the first embodiment. The configuration and operation of the first embodiment of the present invention will be described with reference to.

When power is turned on, the timing controller 210 supplies a voltage to the output terminal DO1 connected to the gate of the switching element FET1 of the preheat current controller 220 for a time required for preheating, as shown in FIG. When the switching element FET1 is turned on, the resistor R10 connected to the Cc terminal, which is the feedback current correcting terminal of the ballast controller 170 (in this embodiment, Fairchild's KA7543 is used) is grounded during that time. . The tube current flowing through the lamp can be controlled by the value of the resistor R10, and the value is set to a current value sufficient for preheating without being lit.

After the preheating period, the timing controller 210 drops the voltage output from the output terminal DO1 to '0' volt, as shown in FIG. 5 (a), so that the switching element FET1 of the preheat current control unit 220 is turned on. Turn off, and as shown in FIG. 5 (b), when the switching element FET2 of the discharge start controller 230 is turned on by outputting a voltage having a predetermined magnitude to the output terminal DO2, the resistor R11 It will be grounded. When the resistor R11 is grounded, the voltage of Vcc is divided by the resistor R13 and the resistor R11 to be applied to the dimming signal input terminal Vdm of the ballast controller 170 and the value is set to a value close to the maximum brightness. do. When the KA7543 is used as the ballast control unit, 0 volts is applied to the dimming signal input terminal (Vdm) when the maximum brightness is applied, and 2 volts is applied when the minimum brightness is applied.

This section is referred to as the discharge start control period in FIG. 5, and the period is so short that the brightness is hardly felt by the human eye.

After the discharge start control period ends, as shown in FIGS. 5B and 5C, a '0' volt is output to the output terminal DO2 of the timing controller 210 to turn off the switching device FET2. A predetermined voltage is output to the output terminal DO3 to turn on the switching device FET3 of the current control unit 240 after discharge. When the switching device FET3 is turned on, the resistor R12 is grounded. When the resistor R12 is grounded, the voltage of Vcc is divided by the resistor R13 and the resistor R12 to be applied to the dimming signal input terminal Vdm of the ballast controller 170, and the value is close to the medium brightness. Is set. This section is referred to as the post-discharge current control period in FIG. 5 (f), which serves to stabilize the discharge even more and may not be necessary depending on the type of lamp or the usage environment.

When the current control period after discharge ends, all the switching elements FET1 to FET3 are turned off by the timing controller 210, and as shown in FIG. 5 (f), the dimming signal set before lighting by the ballast controller 170 is turned on. According to the size of the dimming or a new variable dimming signal is adjusted according to the value.

In the first embodiment of the present invention, the low current illumination is enabled by using the feedback current correction terminal Cc and the dimming signal input terminal Vdm of the ballast control element, but the feedback current correction terminal Cc or feedback is given. By combining the current input terminal Vfb or the dimming signal input terminal Vdm, the same purpose can be achieved by limiting the tube current flowing through the lamp in any manner.

In addition, in the first embodiment of the present invention, it is disclosed that the low-light lighting control device is configured without the discharge start detecting unit and the re-sensing preventing unit.

FIG. 6 is a block diagram of a low light dimming control device according to a second embodiment of the present invention, and includes a discharge initiation detecting unit 310 and a re-sensing prevention unit 320 to configure a circuit using only analog elements.

The low illuminance lighting control unit 300 of the second embodiment includes a discharge start detection unit 310, a preheat current control unit 340, a discharge start control unit, a post-discharge current control unit 330, and a redetection prevention unit 320.

In the second embodiment, Pay Child's KA7543 is adopted as the ballast control unit 350. When power is supplied to the low light lighting controller 300, charging is started in the capacitor C6, and as shown in FIG. 7 (a), the switching element FET10 of the preheat current controller 340 for a predetermined time while charging is in progress. Is turned on. During this period, the resistor R20 connected to the feedback current compensating terminal Cc of the ballast control unit 350 is grounded through the switching element FET10, thereby reducing the voltage of the feedback current compensating terminal Cc. The current through the lamp is limited. Originally, the feedback current compensation terminal Cc is a terminal for compensating the feedback current flowing through the feedback current input terminal Vfb, but in this example, it is used for current limiting.

The preheating period of FIG. 7 corresponds to the operation of this part, and during this time, only a current for preheating the filament flows without the lamp being discharged.

When charging is performed to the capacitor C6 and the gate voltage of the switching device FET10 is lowered, the switching device FET10 is turned off at some point so that the resistor R20 connected to the terminal Cc of the ballast controller is open. Therefore, the current limit by the resistor R20 is released. When the current limit is released, the lamp is already preheated, and the discharge starts immediately, and when the discharge starts, a high voltage is applied to the resistance for detecting the discharge start (R30) and the die solution DA1 of the discharge start detection unit 310 through the diode D1. The voltage exceeds the break-over voltage of), and a voltage is applied to the gate of the thyristor SCR1 to turn on the thyristor SCR1. In this case, current flows in the circuit formed of the capacitor C5, the resistor R7, the thyristor SCR1, and the capacitor C2, and charging of the capacitors C5 and C2 starts.

When the capacitor C2 is charged and the potential at the VP3 point rises, the transistor TR1 and the thyristor SCR2 of the redetection prevention part 320 are turned on. The time until the charging of the capacitor C2 starts and the transistor TR1 is turned on is very short, during which the maximum current flows in the lamp, which is an advantageous time for the lamp to maintain stable discharge. It is a short time that is short and hardly noticeable by the human eye. This corresponds to the discharge start control period of FIG.

Thyristor (SCR1) is a circuit that operates only once when the power is turned on, but if it is controlled at low light and high light during normal lighting, it may be recognized as the start of discharge again through the diaak DA1 of the discharge start detection unit 310. In order for the start detection unit 310 to operate only once when the power of the lamp is turned on, the redetection prevention unit 320 is required.

When the thyristor SCR2 is turned on in advance, the redetection prevention unit 320 maintains the turn-on state as long as power is supplied since the thyristor SCR2 continues to flow through the resistor R1 and the diode D3. When the thyristor SCR2 is turned on, the potential of the terminal V1 is grounded through the diode D2 and the thyristor SCR2, so that the potential cannot be increased and therefore, as long as the power is maintained, the thyristor through the thyristor DA1. The triggering of (SCR1) again does not occur.

On the other hand, when the transistor TR1 is turned on, the feedback current compensation terminal Cc of the ballast control element IC1 is grounded through the resistor R21, and the potential of the feedback current compensation terminal Cc is set by the resistor R21. Can be controlled. The tube current of the lamp can be controlled by the potential of the feedback current compensation terminal Cc. At this time, if the value of the resistor R21 is determined so that a current of about the maximum brightness flows, it is very stable in most cases. Low light can be lit. In addition, it is possible to turn on the lamp even if it is controlled to be the lowest illuminance when it is used under certain good condition by limiting the type of lamp. This section corresponds to the post-discharge current control period in FIG.

On the other hand, after the charging of the capacitor C2 proceeds and the transistor TR1 is turned on, the charging proceeds to the capacitor C5 having a longer time constant than the capacitor C2, and the potential at the VP2 point of FIG. ) Is turned off.

When the thyristor SCR1 is turned off, the energy charged in the capacitor C2 is discharged through the diodes D5 and D8, and the potential of the VP3 is also lowered. As a result, the transistor TR1 is turned off and the feedback of the ballast control element IC1 is returned. The current compensation terminal Cc is in an open state, and then lights up in a dimmed state before extinguishing. This section corresponds to the normal lighting period of FIG.

According to the present invention, when the fluorescent lamp is turned off at the minimum illuminance, when the power is turned off and the fluorescent lamp is turned off and then turned on again, an extremely short period such as a discharge start current control period after a preheating period to reach the set brightness before extinguishing When a large amount of tube current flows for a while, the discharge is successful and then a period of time is stabilized, such as a current control period after discharge, or in the case of a lamp that can be stably lit, if the user immediately transitions to the brightness before turning off, It feels as if it is turned on immediately, and it is possible to perform low light lighting without any problem.

As described above, the present invention can realize the lighting at low light by using a method of controlling the current step by step when the light is turned off after low light and the lamp is turned off and then turned on again.

This invention has made it difficult to apply the conventional fluorescent lighting control technology, such as theaters, or it is possible to apply to many fields that were difficult to apply products that can be turned on low light.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can't.

1 is a block diagram of an electronic ballast according to the prior art

Figure 2 is a block diagram of an electronic ballast capable of lighting low light according to the present invention

3 is a block diagram showing the configuration of the low light lighting controller 200 of the present invention.

Figure 4 is a block diagram of a low light lighting control device according to a first embodiment of the present invention

5 is a signal timing chart of a current controller of the low light dimming control device according to the first embodiment of the present invention.

6 is a configuration diagram of a low light dimming control device according to a second embodiment of the present invention;

7 is a signal timing chart of a current control unit of a low light dimming control device according to a second embodiment of the present invention;

Claims (6)

Ballast control unit for outputting a controlled oscillation frequency so that lamp current corresponding to the lighting of the lamp and the level of the dimming signal applied from the outside, and an inverter for switching the supplied DC voltage at a high frequency in accordance with the frequency supplied from the ballast control unit In the low light lighting control device of the electronic ballast provided with; A preheat current control unit providing a first control input to the ballast controller to supply a preheat current to the lamp during a preheating period when the lamp is turned on; A discharge start control unit for providing a second control input to the ballast control unit so that a maximum current is instantaneously applied to the lamp to start discharge after the lamp is preheated; And Including a low-light lighting control unit having a timing control unit for controlling the input timing of the control input supplied to the ballast control unit by the preheat current control unit and the discharge start control unit according to the set timing, The discharge of the lamp is started by sequentially varying the frequency output from the ballast controller to the inverter according to the plurality of control inputs, The ballast control unit is low light lighting control device, characterized in that after the lamp discharge start to complete the lamp to the brightness according to the input dimming signal. According to claim 1, wherein the low light lighting control unit According to the control of the timing control unit, a third control input is provided to the ballast control unit for supplying a current such that the lighting can be stabilized before the lamp discharge is controlled at low light after the completion of the lamp discharge start. Further equipped with front and rear current control, And controlling the current of the lamp to a predetermined brightness after maintaining the discharge current of the lamp for a predetermined period after the lamp is discharged. The low light illuminating control unit of claim 1 or 2, A discharge start detection unit for determining a discharge start signal of the lamp based on a current flowing through the lamp and outputting a discharge start signal to a timing controller; and preventing the discharge start detection unit from redetecting the discharge start after detecting the discharge start. And a re-sensing prevention unit for controlling the timing of the discharge start control unit. Ballast control unit for controlling the frequency so that the lamp current is controlled according to the lighting of the lamp and an external dimming signal, and an inverter for switching the supplied DC voltage at a high frequency in accordance with the frequency supplied from the ballast control unit to supply to the lamp In the low illuminance lighting control method of an electronic ballast; A preheating step of applying a first control input to a ballast control unit so that a low current lower than a current required for lighting is supplied to the lamp for a predetermined preheating period when power is applied, to form a lighting condition of the lamp; Ballast control unit cuts off the first control input when the preheating period elapses, and supplies a current corresponding to the maximum brightness that can be discharged to the lamp instantaneously during the discharge initiation period which is a time unrecognizable to the eye. A discharge start step of applying a second control input to the discharge; And The second control input is cut off when the discharge start period has elapsed, and the ballast controller is configured to turn on a frequency so that a current corresponding to a previous illuminance state or a predetermined illuminance is supplied to the lamp. A low light lighting control method for an electronic ballast, characterized in that a fluorescent lamp is turned on even at low light. The method of claim 4, wherein After the discharge start period has elapsed and before the lighting step is performed, the lighting is applied to apply a third control input to the ballast controller to supply a current lower than the current of the discharge start section to the lamp for a certain period of time to stabilize the lighting state. Low light illumination control method characterized in that it further comprises a holding step. The method according to claim 4 or 5, A discharge start detection step of repeating the discharge start step if the discharge is not started by sensing the current of the lamp; And When the discharge is started, the low-light lighting control method of the electronic ballast characterized in that it further comprises a re-detection prevention step to prevent the detection of the discharge start again.