KR20030071095A - A Dimmer for a Fluorescent Lamp and a Dimming Control Method for a Fluorescent Lamp - Google Patents

Abstract

PURPOSE: An apparatus and a method for controlling intensity of illumination in a fluorescent lamp are provided to control the intensity of illumination by utilizing a switch for controlling the fluorescent lamp. CONSTITUTION: An apparatus for controlling intensity of illumination in a fluorescent lamp includes a switching element(108), a phase detector(102), a phase controller(104), and a driver(106). The switching element(108) is used for switching an electric path of a power supply portion to an electronic stabilizer in order to control the intensity of electric power. The phase detector(102) is used for detecting a phase of the supplied power. The phase controller(104) is used for controlling a phase of a supplied voltage according to the desired intensity of illumination by using the phase of the supplied power of the phase detector(102). The driver(106) is used for driving the switching element(108) according to a controlled phase value of the phase controller(104).

Description

A Dimmer for a Fluorescent Lamp and a Dimming Control Method for a Fluorescent Lamp

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an illuminance controller and method of fluorescent lamps for adjusting illuminance (brightness) of fluorescent lamps, and more particularly, to an illuminance controller and method of fluorescent lamps for controlling illuminance of fluorescent lamps employing an electronic ballast.

In a fluorescent lamp (hereinafter, simply referred to as an "electronic fluorescent lamp") that is lit using an electronic ballast and maintains a discharge, the input commercial AC power is rectified and converted into a DC power source, and the DC power source is switched to switch the fluorescent lamp. The fluorescent lamp is supplied to the lighting circuit. As a method of controlling the illuminance of an electronic fluorescent lamp as described above, a technical idea of using a slide is disclosed. According to the illuminance control method of the electronic fluorescent lamp using the slide, the illuminance of the fluorescent lamp is controlled by varying the power supply voltage using the slide and applying the variable power supply voltage to the lighting circuit.

However, according to the illumination control method of the electronic fluorescent lamp using the above-mentioned slide, there are disadvantages that the volume of the slide itself is very large, and the power consumption is large due to the characteristics of the slide. In addition, as the power supply voltage is limited by the slide, ripple and flicker may occur during discharge, and thus, a fluorescent lamp having a controlled illuminance flickers. Such a flashing phenomenon not only makes the human eye easily tired, but also has a problem in that the control of illumination is unstable and thus the practicality is poor.

The present invention has been made to solve the above problems, an object of the present invention is to provide an illuminance controller and method of an electronic fluorescent lamp which is easy to control illuminance but does not cause a flicker phenomenon of discharge and consumes little power.

1 is a conceptual block diagram of an illumination controller of an electronic fluorescent lamp according to an embodiment of the present invention.

2 schematically illustrates an example of a specific circuit diagram of the illuminance controller of FIG.

3A is a voltage and current waveform diagram of a main portion of a conventional electronic fluorescent lamp.

Figure 3b is a voltage and current waveform diagram of the main part of the fluorescent lamp to which the illumination controller of the electronic fluorescent lamp according to an embodiment of the present invention.

Figure 4 is a flow chart showing one embodiment of the operation of the illumination controller of the electronic ballast according to the present invention.

5 is a conceptual block diagram of an illumination controller of an electronic fluorescent lamp according to another embodiment of the present invention.

* Explanation of the symbols of the main parts of the drawings

10 power supply 20 electronic ballast 100 illuminance controller

102 phase detector 104 phase adjuster 106 driver

In order to achieve the above object, the present invention, in the illuminance controller of the fluorescent lamp having an electronic ballast supplied with power from a commercial AC power supply, switching the power supply path from the power source to the electronic ballast to supply to the electronic ballast Switching element for adjusting the amount of power to be; A phase detector for detecting a phase of the power supply; A phase adjuster for calculating an adjusted phase value for adjusting the phase of the voltage supplied to the electronic ballast according to the illuminance desired by the user using the phase of the commercial power source detected from the phase detector; And a driver for controlling the phase of power supplied to the electronic ballast by driving the switching element according to the adjusted phase value calculated by the phase adjuster.

According to another aspect of the present invention, there is provided an illuminance control method for a fluorescent lamp having an electronic ballast supplied with electric power from a commercial AC power supply, the method comprising: reading an illuminance setting value set by a user; Calculating a turn-on time t to start supplying power from the power supply to the electronic ballast in response to a desired illuminance setting value of the user; Detecting a phase of the waveform of the power supply voltage and determining whether the waveform of the power supply voltage has reached the turn-on time t; If it is determined that the waveform of the power supply voltage has reached the turn-on time t, initiating power supply from the power supply to the electronic ballast; And repeating the above steps every half cycle of the power supply.

Furthermore, according to another aspect of the present invention, there is provided a method of controlling illuminance of a fluorescent lamp having an electronic ballast supplied with power from a commercial AC power supply, the method comprising: detecting a phase of the power supply; Calculating an adjustment phase value for adjusting the phase of the voltage supplied to the electronic ballast according to the illuminance desired by the user using the detected phase of the commercial power supply; And controlling the amount of power supplied to the electronic ballast by switching a power supply path from the power source to the electronic ballast according to the calculated adjustment phase value. It provides a method of controlling the illumination of the illuminance.

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

First, referring to FIG. 1, FIG. 1 is a conceptual block diagram of an illumination controller of an electronic fluorescent lamp according to an embodiment of the present invention. As shown, the illumination controller 100 of the electronic fluorescent lamp according to the present invention, the switching element 108 for controlling the amount of power supplied to the electronic ballast 20 by switching the power supply path from the commercial AC power supply 10 to the conventional electronic ballast 20 Include. Specifically, the switching element 108 controls the amount of power supplied to the electronic ballast by controlling the phase of the charging voltage charged in the smoothing capacitor (not shown) included in the electronic ballast 20, thereby adjusting the illuminance of the fluorescent lamp. To control.

In order to control the switching operation of the switching element 108 as described above, the illuminance controller 100 according to the present invention includes a phase detector 102 for detecting the phase of the commercial power supply 10 from both ends of the commercial power supply 10, that is, the terminal a and the terminal b. A phase adjuster 104 for calculating an adjusted phase value used to adjust a phase of a charging voltage charged to the smoothing capacitor according to a desired illuminance by using a phase of the commercial power supply 10 detected from the phase detector 102. And a driver 106 for driving the switching element 108 to adjust the phase of the charging voltage charged in the smoothing capacitor according to the adjustment phase value calculated by the phase adjuster 104.

The phase detector 102 is used to detect the phase of the commercial power supply 10 as power is applied, and this operation is easily performed by detecting a zero crossing point of the voltage supplied from the commercial power supply 10. Can be.

The phase adjuster 104 receives the user's illuminance setting value for setting the illuminance desired by the user, and converts the phase of the voltage supplied to the electronic ballast (specifically, the smoothing capacitor) 20 to the illuminance setting value of the user. Compute the adjustment phase value to adjust to the corresponding value.

The driver 106 generates a driving signal for controlling the switching operation of the switching element 108 according to the adjustment phase value calculated by the phase adjuster 104 and supplies it to the switching element 108.

As shown in the drawing, the switching device 108 is preferably a power switching device such as Triac. In this case, the drive signal from the driver 106 is supplied to the gate of the triac. Hereinafter, an example in which the switching element 108 is configured of the triac will be described. In general, the triac is turned on from the time when the turn-on signal is input to the gate thereof and remains in the turn-on state until the polarity of the voltage applied to both ends thereof is reversed, and the polarity of the applied voltage is reversed. In this case, it is turned off and is turned on by inputting a turn-on signal to the gate again.

Referring to FIG. 2, an example of a detailed circuit diagram of the illuminance controller 100 of FIG. 1 is schematically illustrated. As shown, the phase detector 102 includes a voltage divider 1022 connected to both ends of the commercial power supply 10, and a comparator 1024 whose one input is connected to the output of the voltage divider 1022 and the other input is grounded. When the power source 10 is applied and a voltage is applied to both ends of the voltage divider 1022, the comparator 1024 can detect a time point at which the polarity of the voltage of the power source 10 is reversed, that is, a zero crossing point. The zero pass position thus detected is used as a reference value of the adjustment phase value.

The phase adjuster 104 receives an illuminance adjuster 1044 for allowing a user to set a desired illuminance, a phase of the commercial power supply 10 detected by the phase detector 102, and a desired illuminance setting value provided by the illuminance adjuster 1044. The microprocessor 1042 may perform a calculation to adjust a phase of the voltage supplied to the electronic ballast (ie, the smoothing capacitor) 20 to a value corresponding to the illumination setting value of the user.

The illuminance controller 1044 may be easily implemented by a user as a rotary variable resistor or an electronic variable resistor.

The microprocessor 1042 performs an operation for adjusting the phase of the voltage supplied to the electronic ballast 20 to a value corresponding to the illumination setting value of the user. That is, the microprocessor 1042 supplies the electric ballast 20 to the electronic ballast 20 by an amount corresponding to the illuminance setting value set by the user from the zero pass point of the voltage of the commercial power supply 10 as shown in FIG. 3A. The value of the adjusted phase φ is obtained by the following calculation. In other words,

Here, L is the illuminance set by the user when the maximum illuminance of the fluorescent lamp is viewed as one. That is, to obtain roughness corresponding to 90% of the maximum roughness, L = 0.9 may be substituted.

Rather than directly controlling the switching operation of the triac 108 by using the phase value obtained by Equation 1, it is easier to generate the driving signal using the turn-on time point on the time axis corresponding to the phase value. In some embodiments, the following operation may be performed. That is, if φ = ω t, and substitute this into Equation 1 to solve for the time t,

Becomes Here, 60 is the frequency f of the commercial power supply.

Accordingly, the driving unit 106 is a zero pass position at which the polarity of the voltage of the commercial power supply 10 is inverted from the turn-on time t calculated by Equation 2 in every half cycle of the waveform of the commercial power supply 10 (ie, the turn). By driving the triac 108 to be turned on until the zero passing time after the on time t, the amount of power supplied to the electronic ballast 20 can be adjusted.

Referring to Figure 3, the operation of the illumination controller 100 of the electronic fluorescent lamp according to the present invention as described above will be described in more detail. 3A is a voltage and current waveform diagram of a main part of a conventional electronic fluorescent lamp, and FIG. 3B is a voltage and current waveform diagram of a main part of a fluorescent lamp to which an illumination controller 100 of the electronic fluorescent lamp according to an embodiment of the present invention is applied.

As shown in FIG. 3A, since the electric power from the commercial power supply 10 is directly supplied to the conventional electronic ballast 20, a smoothing capacitor (not shown) inside the electronic ballast 20 from a zero-pass position of the voltage of the commercial power supply 10. ), The phase difference of the voltage charged in the C) always has a value of " [pi] / 2 (= 90 [deg.]) ”.

However, as the illuminance controller 100 according to the present invention is added, as shown in FIG. 3B, only power is turned from the turn-on time t calculated by Equation 2 to the next zero pass position of the voltage of the commercial power supply 10. By driving the switching element 108 to be supplied, it is possible to adjust the amount of power supplied to the electronic ballast 20.

In this embodiment, an example in which the switching element 108 is formed of a triac has been described. In view of the switching characteristic of the triac and the charging characteristic of the smoothing capacitor by the electronic ballast 20, the phase φ is 0 or more π / 2. In the case of having the following values (ie, when the frequency of the commercial power supply is 60 Hz, the turn-on time t is 0 or more and 1/240 seconds or less), the amount of power equal to the maximum illuminance is equal to the electronic ballast. Supplied with 20.

If the user sets the illuminance setting value L to 0 by using the illuminance controller 100 having the above configuration, that is, if the fluorescent lamp does not emit light at all, substitutes L = 0 in Equation 2 and t = 1. / 120 seconds (0 seconds is the maximum value, meaning nothing). That is, in this case, since the turn-on time point of the triac 108 becomes the zero pass time point, the power supplied to the electronic ballast 20 becomes zero. However, if the illuminance of about half of the maximum illuminance, that is, L = 1/2 is set, the turn-on time point t becomes (= 1/120) * (5/6) seconds from Equation 2, It can be seen that the triac 108 is turned on near the rear end of every half cycle of the commercial power supply.

Of course, when the switching device 108 is configured using a power switching device other than a triac, it is possible to control the amount of power supplied to the electronic ballast 20 through the entire half cycle of the commercial power supply 10. It may be. However, the selection of the switching element 108 and the selection of the power supply position accordingly are merely design options according to the embodiments of the present invention, and will be apparent to those skilled in the art. Omit.

Next, an embodiment of the operation of the illumination controller 100 of the electronic ballast according to the present invention will be described in detail with reference to FIG. 4. 4 is a flowchart illustrating an embodiment of an operation of the illumination controller 100 of the electronic ballast according to the present invention.

When the commercial power source 10 is supplied and operation starts (step 400), the illuminance setting value set by the user is read (step 402).

Next, the time t at which the switching element 108 should be turned on is calculated in response to the desired illuminance setting value of the user (step 404). In step 406, Equation 2 may be used.

Next, it is determined whether the waveform of the voltage of the commercial power supply 10 is at the zero pass position (step 406). As a result of the determination in step 406, if it is determined that the voltage waveform of the power source 10 is not at the zero pass position, the step 406 is repeatedly performed until the waveform of the power voltage reaches the zero pass position.

Thus, once the voltage waveform of the commercial power supply 10 has reached the zero pass position, the control variable k is initially initialized to zero (step 408).

Next, wait (step 410) for a predetermined unit time (e.g., 0.1 msec), and increase the control variable k by the unit time (step 412).

Thus, it is determined whether the control variable k is equal to or greater than the turn-on time t (step 416). As a result, if it is determined that the control variable k is still smaller than the turn-on time t, the process returns to step 412. Repeat steps 412 to 416 above.

However, when it is determined that the control variable k is larger than the turn-on time t as a result of the determination in step 416, a driving signal for turning on the switching element 108 is generated (step 418). ). Next, control returns to step 402.

Of course, according to the embodiment of the present invention, the adjustment phase value φ may be calculated using Equation 1 in step 406, and the following steps may be performed using this value.

Finally, referring to FIG. 5, FIG. 5 is a conceptual block diagram of an illumination controller of an electronic fluorescent lamp according to another embodiment of the present invention. As shown, the phase detector 102 detects the phase of the voltage applied across the switching element 108. According to the present embodiment, when the impedance of the phase detector 102 is sufficiently larger than the impedance of the electronic ballast 20, the phase of the voltage applied across the switching element 108 becomes substantially the same as the phase of the voltage of the power source 10.

As to how much the impedance of the phase detector 102 should specifically have, it is a value that can be obtained experimentally by those skilled in the art, and it is variable according to the desired precision. Omit.

According to this embodiment, although the phase of the power supply voltage itself is not detected and used, substantially the same result as that of directly detecting the phase of the power supply voltage can be achieved. Therefore, it is possible to perform the illumination control operation according to the technical idea of the present invention as described above.

As mentioned above, although the specific embodiment was described in detail regarding the technical idea of this invention, it should be noted that it does not impose any restriction on the technical idea of this invention by the above description.

According to the present invention, a stable illuminance control function can be realized even in a fluorescent lamp employing a low-cost electronic ballast.

Moreover, according to this invention, illumination intensity can be controlled by the switch which controls the said fluorescent lamp.

Furthermore, according to the present invention, since the illuminance can be controlled by controlling the power supplied to the smoothing capacitor of the electronic ballast, the overall energy consumption can be reduced.

Claims (11)

In an illuminance controller of a fluorescent lamp having an electronic ballast powered from a commercial AC power source, A switching element that controls the amount of power supplied to the electronic ballast by switching a power supply path from the power source to the electronic ballast; A phase detector for detecting a phase of the power supply substantially; A phase adjuster for calculating an adjustment phase value for adjusting the phase of the voltage supplied to the electronic ballast according to the illuminance desired by the user using the phase of the power source detected from the phase detector; And And a driver for controlling the phase of power supplied to the electronic ballast by driving the switching element according to the adjusted phase value calculated by the phase adjuster. The method of claim 1, The phase detector, An illumination controller of an electronic fluorescent lamp that substantially detects a zero crossing point of the power voltage as the power is applied. The method of claim 1, The switching element is an illumination controller of an electronic fluorescent lamp is a power switching element. The method of claim 1, The switching element is a triac (triac) of the illumination controller of the electronic fluorescent lamp. The method of claim 1, The phase detector, A voltage divider connected to both ends of the power supply; And And a comparator having one input connected to the output of the voltage divider and the other input grounded. The method of claim 1, The phase detector, A voltage divider connected to both ends of the switching element; And And a comparator having one input connected to the output of the voltage divider and the other input grounded. The method of claim 1, The phase adjuster, An illuminance adjuster for setting a desired illuminance to a user; And Receive the user's desired illuminance setting value provided by the phase detector and the illuminance adjuster detected by the phase detector, and set the phase of the voltage supplied to the electronic ballast to a value corresponding to the illuminance setting value of the user. An illumination controller of an electronic fluorescent lamp comprising a microprocessor for performing an operation for adjustment. In the illuminance control method of a fluorescent lamp having an electronic ballast supplied with power from a commercial AC power source, Reading the illumination setting value set by the user; Calculating a turn-on time t to start supplying power from the power supply to the electronic ballast in response to a desired illuminance setting value of the user; Detecting a phase of the waveform of the power supply voltage substantially to determine whether the waveform of the power supply voltage has reached the turn-on time t; If it is determined that the waveform of the power supply voltage has reached the turn-on time t, initiating power supply from the power supply to the electronic ballast; And And repeating the steps every half cycle of the power supply. The method of claim 8, And detecting a zero crossing point of the power supply voltage substantially as the power is applied. In the illuminance control method of a fluorescent lamp having an electronic ballast supplied with power from a commercial AC power source, Detecting a phase of the power supply substantially; Calculating an adjustment phase value for adjusting the phase of the voltage supplied to the electronic ballast according to the illuminance desired by the user using the detected phase; And controlling the amount of power supplied to the electronic ballast by switching a power supply path from the power source to the electronic ballast according to the calculated adjustment phase value. Method of illuminance control. The method of claim 10, And detecting a zero crossing point of the power supply voltage substantially as the power is applied.