KR100640180B1 - Apparatus for dimming control of a fluorescent lamp using a normal adjuster of lamp - Google Patents

Abstract

A dimming controller of a fluorescent lamp using a standard light adjuster is provided to stabilize operation of the fluorescent lamp by removing flickers due to low energy supplied to the fluorescent lamp. A dimming controller of a fluorescent lamp includes a lamp driving voltage generator(70), a feedback amplifier(80), an initial pre-heating controller(90), and a shut-down controller(100). The lamp driving voltage generator detects an average DC voltage from an output voltage of a rectifier and generates a lamp driving voltage based on the average DC voltage. The feedback amplifier compares the lamp driving voltage with a feedback voltage and applies the compared result to a voltage controller. The initial pre-heating controller detects a peripheral temperature and adjusts a frequency for pre-heating. The shut-down controller detects abnormal waveforms from output switching elements and shuts down a driving circuit of the electronic ballast, when a magnitude of the abnormal waveform is greater than a predetermined value. When a lamp is inserted, the shut-down mode is cancelled.

Description

Apparatus for dimming control of a fluorescent lamp using a normal adjuster of lamp}

1 is a block diagram of a dimming control circuit of a fluorescent lamp using a general dimmer according to the present invention.

Figure 2 is a characteristic diagram for explaining the temperature compensation initial preheating mode of the present invention.

<Description of the symbols for the main parts of the drawings>

10 dimmer 20 rectifier

30: peak detector 40: reference power supply voltage

50: ballast circuit 51: voltage controller (VCO)

52: square wave generator 53: dead time circuit

54: drive circuit 55: LC_resonance circuit

60: lamp 70: lamp driving voltage generator

71: average detector 72: DC amplifier

73: gain adjusting means 74: temperature compensation

80: feedback amplifier 90: initial preheating controller

91: temperature detector 92: frequency control circuit

93: timer 94: initial preheat switch

100: shutdown control unit 101: waveform detection unit

102 delay unit 103 shutdown unit

104: restart control unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brightness control circuit of a fluorescent lamp, and in particular, to adjust the brightness of a fluorescent lamp by using a general dimmer without using a fluorescent lamp dimming controller.

Conventional fluorescent ballasts are choke coils wound around iron cores and are connected in series with fluorescent lamps to prevent the increase of current. Therefore, high power is consumed during initial lighting. Is developed.

In the electronic ballast, AC / DC or DC / HF conversion, noise such as surge and impulse voltage flowing from the input power has been solved so that there is no practical problem by using a filter, but overcurrent due to voltage rise during initial lighting Not only destroys the semiconductors by rapidly increasing the temperature, but also causes blackening of the lamp's filament, resulting in the inconvenience of frequent lamp replacement due to shortening of the lamp's lifespan, and power consumption due to difficulty in controlling the brightness of the fluorescent lamp. There were many problems.

In addition, in order to adjust the brightness of the fluorescent lamp, a line connected between the control device and the ballast of the fluorescent lamp requires at least four wires (two power lines and two control signal lines) such as a power supply line and a brightness control line. There was a disadvantage that it was complicated and required a control microcomputer on the ballast side.

The present invention is to provide a dimming control device of a fluorescent lamp using a light dimmer for controlling the brightness of the fluorescent lamp by using a general dimmer without using a dimming controller dedicated to the fluorescent lamp in view of such a conventional problem.

In addition, the present invention is to have a high temperature at a low temperature and a low temperature at a high temperature by the ambient temperature characteristics when generating a lamp driving voltage by dimming control.

In addition, the present invention is to allow the gain in the dimming control by the dimmer to be externally adjustable to protect the ballast and to prevent the vibration caused by the low energy level.

In addition, the present invention is to allow the lamp to be preheated at the maximum power during the low-temperature operation in accordance with the ambient temperature in the initial preheating mode to better the light, and to preheat the low power at high temperature to follow the dimming control signal immediately after the sweep. .

The present invention provides a rectifier for rectifying an input voltage phase controlled by a light bulb dimmer, a peak detector for removing peak noise from the rectified signal of the rectifier, and a voltage stabilized through the peak detector. After converting the voltage of the reference power supply voltage generated by the reference voltage (Vref) and the voltage controller (VCO) receiving the lamp driving voltage into a square wave having a 50% duty through the TFF, and maintains the dead time through the dead time circuit In the fluorescent lamp control circuit comprising a ballast circuit for driving the output element through the drive while driving the lamp through the LC_resonance circuit,

A lamp driving voltage generation unit for detecting a DC voltage that is averaged using an output circuit of the rectifying unit and converting the voltage to match the power of the lamp based on the DC voltage to generate a lamp driving voltage;

A feedback amplifier which compares the output voltage of the lamp driving voltage generator with the feedback voltage of the lamp and inputs it to the voltage controller;

An initial preheating control unit which detects an ambient temperature of fluorescent lamps, controls a frequency for initial preheating according to the temperature, and automatically controls a preheating time to give a control input to the voltage controller;

Detects the abnormal waveform of the output element and controls to shut down the drive circuit of the ballast circuit when a waveform having a predetermined width or more is detected, maintains the shutdown mode when the lamp is opened, and releases the shutdown mode when the lamp is inserted and starts the first time. And a shutdown control unit for controlling the mode.

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

1 is a block diagram of a lamp brightness control circuit according to the present invention.

As shown therein, the rectifier 20 rectifies the input voltage whose phase is controlled by the general light dimmer 10 through the bridge diode, and the peak detector removes peak noise from the rectified signal of the rectifier 20. 30, a reference power supply voltage unit 40 for generating a voltage stabilized through the peak detector 30 as the operating voltage Vcc and the reference voltage Vref, and a voltage controller for receiving a lamp driving voltage ( VCO) 51 is converted into a square wave having a 50% duty through a square wave generator (TFF) 52, and then output switching device through the drive 54 while maintaining dead time through the dead time circuit 53. In the fluorescent lamp control circuit comprising a ballast circuit 50 for driving (Q1, Q2) to drive the lamp 60 through the LC_resonance circuit 55,

A lamp driving voltage generator for detecting an output DC voltage of the rectifier 20 using an integrating circuit and converting the voltage to match the power of the lamp based on the DC voltage to generate a lamp driving voltage ( 70);

A feedback amplifier 80 which compares the output voltage of the lamp driving voltage generator 70 with the feedback voltage of the lamp and inputs it to the voltage controller 51;

An initial preheating control unit (90) which detects an ambient temperature of fluorescent lamps, controls a frequency for initial preheating according to the temperature, and automatically adjusts the preheating time to provide a control input to the voltage controller (51);

When abnormal waveforms of the output switching elements Q1 and Q2 are detected and a waveform having a predetermined width or more is detected, the drive 54 of the ballast circuit 50 is controlled to shut down, and when the lamp 60 is opened. It is configured to include a shutdown control unit 100 to maintain the shutdown mode, release the shutdown mode when the lamp is inserted and to control the first startup mode.

The lamp driving voltage generation unit 70 is an integrated circuit that detects the DC voltage after dividing the voltage so that the IC can receive the AC voltage controlled by the dimmer 10 and rectified by the rectifier 20. The control unit (V_AVG) 71, a DC amplifier 72 for converting the voltage to match the power of the lamp by comparing the voltage of the average detection unit 71 and the reference voltage thereof, and controlled by the dimmer 10 Gain control means 73 for externally controlling the gain of the DC amplifier 72 to shut off the ballast in a state where the waveform whose phase is cut too much is more than a predetermined range, and the DC according to the ambient temperature of the fluorescent lamp. The output of the amplifier 72 consists of a temperature compensator 74 that adjusts the output resistance ratio of the DC amplifier 72 to supply more power to the lamp at the lowest illuminance and low temperature.

The initial preheating control unit 90 controls the temperature detector 91 for detecting the ambient temperature of the fluorescent lamp and frequency for initial preheating based on the temperature detection value of the temperature detector 91, but for the entire preheating time. A frequency control circuit 92 which releases the preheating mode after the preheating time has elapsed after controlling to the minimum frequency starting gradually from the maximum frequency and initially setting the initial value of the timer 93 and the timer 93 for controlling the initial preheating time. The voltage controller 51 is controlled based on the output signal of the frequency control circuit 92 during the preheating time, and when the initial preheating time has elapsed, the voltage controller 51 is output by the feedback amplifier 80. It consists of an initial preheat switch 94 which switches to be controlled.

The shutdown controller 100 includes a waveform detector 101 for detecting abnormal waveforms of the output switching elements Q1 and Q2 of the driving circuit unit 50 through the current sensing resistor Rs, and the waveform detector 101. The delay unit 102 delays to detect whether the waveform signal inputted through the signal is a width for shutting down through the capacitor (CDP), and if the waveform having a width greater than or equal to shutdown is detected by the delay unit 102, the drive ( A shutdown section 103 for shutting down 54 and an open state of the lamp 60 are detected to cause the shutdown section 103 to shut down the drive 54 when the lamp is opened, and shutdown when the lamp 60 is mounted. The restart control unit 104 controls to release the mode.

The present invention configured as described above operates as a circuit for adjusting the brightness of the lamp using a general dimmer without using an independent dimming controller.

The AC signal controlled in phase through the general dimmer 10 is rectified through the rectifier 20 as a bridge diode and input to the lamp driving voltage generator 70. The lamp driving voltage generator 70 divides the voltage so that the IC can receive the AC signal rectified by the average detector V_AVG 71 and generates an average value as a kind of integrated circuit that makes DC. This average value is proportional to the power controlled in the dimmer 10.

The average value is input to the DC amplifier 72 and compared and amplified with the reference value. The average value generated by the average value detector 71 converts the voltage to match the power of the lamp to be used now, and the lamp driving signal LV_CON signal. As a comparison input terminal, a feedback input terminal of the feedback amplifier 80 is applied.

At this time, the output signal LV_CON of the DC amplifier 72 is determined by the resistance ratio, but the minimum voltage is high at low temperature and low at high temperature by using the temperature characteristic of the diode so as to supply more power at low temperature. The output resistance ratio is controlled by the temperature compensator 74. That is, the temperature compensator outputs a DC amplifier by using a diode whose resistance ratio is controlled by ambient temperature.

In other words, after integrating the dimming waveform, the voltage is converted to match the characteristics of the lamp through the DC amplifier, and at the same time, the lowest illuminance acts as a line voltage conversion circuit with temperature compensation using the temperature characteristics of the diode.

Since the phase controlled A / C waveform is used as the dimming signal and the energy source, the ballast is turned off when the phase is cut too much, that is, when the waveform is cut more than 70%. By adjusting the gain adjusting means 73, which is the gain GAIN adjustment resistor of the DC amplifier, to protect the ballast and preventing the vibration caused by the low energy level. This is controlled externally to adjust the sensitivity.

Therefore, in the section where the waveform is cut to about 30 to 70%, set the gain control resistor of the DC amplifier to maintain the lowest illuminance, and the dimming should be made in the 40 to 100% section, that is, in the section with relatively high energy level. This allows the lamp to operate stably.

On the other hand, the initial preheating control unit 90 performs frequency control for the frequency control circuit 92 to perform initial preheating at the first startup. That is, during the determined time, the frequency changes from Fmax (about 2.5 times Fmin) to Fmin. When the total preheating time is T, the initial preheating time is about 0.2T while maintaining the Fmax. After SWEEP, when T (total preheating time) passes, the preheating mode is released and the frequency of the voltage controller 51 is controlled by the dimming voltage which is the output voltage of the feedback amplifier 80.

The characteristic of this circuit is that the SWEEP period is differentiated according to the ambient temperature detected by the temperature detector 91.

2 is a characteristic diagram illustrating an initial preheating control state according to a temperature according to the present invention. That is, while maintaining Fmax for an initial predetermined time, the frequency is swept from Fmax to Fmin. For example, in the case of -25 ° C, 25 ° C, and 100 ° C.

For example, at -25 ° C, Fmax will be 0.2T, but during 0.2T ~ 0.6T period, the frequency will be swept from Fmax-> Fmin and keep Fmin until 0.6T ~ T. The lamp was warmed up by the power preheating, and at high temperature (100 ℃), it was allowed to sweep for 0.2T ~ T period to follow the dimming control signal immediately after the sweep.

In this way, the frequency for driving the lamp is controlled by the voltage controller (VCO) 51 under the control of the initial preheating controller 90, and the square wave having the 50% duty through the square wave generator (TFF) 52. The dead time is maintained at the dead time generating circuit (DEAD TIME) 53, and is finally output through the drive circuit 54 to drive the LC_resonance circuit (LC_TANK) 55. The lamp 60 is turned on.

If there is an error in the load when the lamp is turned on, an abnormal waveform is detected by Rs (current sensing resistor) to shut down the entire circuit. In this case, the delay unit 102 is used to prevent shutdown due to noise. When the signal is generated to a certain width or more (about 800 nS) by using the CPD, the shutdown unit 103 operates to shut down the drive 54 circuit.

When the lamp 60 is opened, that is, when the lamp 60 is not present, the lamp 60 is detected and the shutdown controller 103 is controlled by the restart control unit 104 to control the shutdown mode. If the lamp is inserted, it will exit the shutdown mode and enter the initial start mode.

The voltage driving the output has a peak detector (PEAK_DET) 30 next to the rectifier 20 of the bridge diode. The phase controlled waveform of the dimmer 10 is generally not stable, and since the waveforms are different, the circuit for detecting only the peak value and making the waveform somewhat stable is supplied. After it is rectified again by the peak detector 30, it is applied to drive the LC resonant circuit circuit 55.

After initial start-up, IC power is supplied from AUX_VCC (auxiliary power generation circuit). Even if the dimmer output is small, if AUX_VCC provides stable auxiliary power, it has more stable dimming characteristics.

As described in detail above, the present invention has an effect of dimming control of fluorescent lamps using a general dimmer. In addition, the present invention has the effect of performing dimming control by temperature compensation in the dimming control temperature using the temperature characteristics of the diode. In addition, the present invention has the effect of protecting the ballast by adjusting the gain adjusting resistor of the DC amplifier, to prevent the vibration caused by the low energy level and to operate the lamp stably.

In addition, the present invention provides a temperature compensation for improving the lighting characteristics of the lamp even at low temperatures by the initial preheating frequency has a different sweep characteristics according to the ambient temperature, and enters the dimming control mode after a predetermined initial preheating time, stable lighting Has the effect of being possible.

In addition, when an abnormal waveform is detected due to an abnormal load on the lamp, a shutdown mode is executed, but the abnormal waveform is detected to shut down only a signal of a predetermined width so that the lamp can be protected while preventing the shutdown due to noise. There is.

Claims (4)

After rectifying the voltage controlled by the general light bulb dimmer 10 through the rectifier 20 and converting the voltage into a DC voltage after comparing with the feedback voltage of the lamp through the ballast circuit 50 including the voltage controller 51. In a fluorescent lamp control circuit configured to drive a lamp, A lamp driving voltage generator for detecting an output DC voltage of the rectifier 20 using an integrating circuit and converting the voltage to match the power of the lamp based on the DC voltage to generate a lamp driving voltage ( 70); A feedback amplifier 80 which compares the output voltage of the lamp driving voltage generator 70 with the feedback voltage of the lamp and inputs it to the voltage controller 51; An initial preheating control unit (90) which detects an ambient temperature of fluorescent lamps, controls a frequency for initial preheating according to the temperature, and automatically adjusts the preheating time to provide a control input to the voltage controller (51); The abnormal waveforms of the output switching elements Q1 and Q2 are detected to control to shut down the drive circuit of the ballast circuit 50 when a waveform having a predetermined width or more is detected, and the shutdown mode when the lamp 60 is opened. Dimming control circuit of a fluorescent lamp using a dimmer for a light bulb, characterized in that it comprises a shutdown control unit 100 to maintain the control unit to cancel the shutdown mode when the lamp is inserted into the initial startup mode The method of claim 1, wherein the lamp driving voltage generator 70, An average detection unit (V_AVG) 71 which is an integrated circuit which is controlled by the dimmer 10 and divides the voltage so that the IC can receive the AC voltage rectified by the rectifier 20 and detects it as a DC voltage, and the average thereof. The DC amplifier 72 converts the voltage of the detector 71 and the reference voltage to match the power of the lamp, and a waveform in which the phase controlled by the dimmer 10 is cut too much. Gain control means 73 for externally controlling the gain of the DC amplifier 72 to shut off the ballast in a predetermined range or more, and the output of the DC amplifier 72 is at least low temperature according to the ambient temperature of the fluorescent lamp. Dimming control circuit of a fluorescent lamp using a light dimmer for a light, characterized in that consisting of a temperature compensator for adjusting the output resistance ratio of the DC amplifier 72 to supply more power to the lamp at The method of claim 1, wherein the initial preheat control unit 90, The temperature detector 91 for detecting the ambient temperature of the fluorescent lamp and the frequency control for initial preheating are performed based on the temperature detection value of the temperature detector 91, but gradually decreases starting at the maximum frequency for the entire preheating time. A frequency control circuit 92 for canceling the preheating mode after the preheating time after the control to the minimum frequency, a timer 93 for controlling the initial preheating time, and the frequency control circuit 92 for the set initial preheating time of the timer 93. Initial preheating switch 94 to control the voltage controller 51 based on the output signal of the control unit, and to switch the voltage controller 51 to be controlled by the output of the feedback amplifier 80 when the initial preheating time has elapsed. Dimming control circuit of a fluorescent lamp using a dimmer for a light bulb, characterized in that consisting of The method of claim 1, wherein the shutdown control unit 100, The waveform detector 101 detects abnormal waveforms of the output switching elements Q1 and Q2 of the driving circuit unit 50 through the current sensing resistor Rs, and the waveform signal input through the waveform detector 101 shuts down. A delay unit 102 for delaying detection of a signal having a width to be made through a capacitor (CDP) and a shutdown unit for shutting down the drive 54 when a waveform having a width greater than or equal to the shutdown is detected by the delay unit 102 ( 103 and a restart control unit for detecting the open state of the lamp 60 to cause the shutdown unit 103 to shut down the drive 54 when the lamp is opened, and to release the shutdown mode when the lamp 60 is mounted. Dimming control circuit of a fluorescent lamp using a dimmer for a light bulb, characterized in that consisting of (104)

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