KR200407568Y1 - Electronic ballast with dimming control by individual dimming - Google Patents

Abstract

The present invention is rectified by the power input unit 1, a bridge rectifier 2 for rectifying the power of the power input unit, and the bridge rectifier so as to easily operate the dimming control unit that can be dimmed in multiple stages with a simple configuration. An inverter unit 5 for driving a lamp 14 by inverting a voltage into a high frequency signal, a frequency oscillator 4 for generating an oscillation frequency for adjusting the brightness of the lamp and applying it to the inverter unit 5, and An electronic ballast having a dimming control function, comprising a resonator unit (8) for forming a resonant circuit with the lamp, which is coupled to the frequency oscillator (4) and controls the oscillation frequency of the frequency oscillator (4). (6); And a dimming control unit generating a control signal of the frequency control unit 6. In addition, the dimming control unit, by changing the input voltage (V2) of one input terminal, compared to the reference voltage (V1) of the other terminal, the control signal (V3) to the frequency control unit 6 through the output terminal And a second comparator IC4 for outputting a multi-level dimming voltage for each ballast as the resistance value of the resistor VR1 (CDS; Q5) having a variable resistance value is changed. The brightness of the lamp is controlled by changing the input voltage V2 of the one terminal of the comparator IC4.

Ballast, Dimming Control, Individual Dimming, Variable Resistor, CDS, Phototransistor

Description

ELECTRONIC BALLAST HAVING A DIMMING-CONTROLLING PART WHICH IS CONTROLLED INDEPENDENTLY}

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

2 is a detailed circuit diagram of a first embodiment of the dimming control electronic ballast according to the present invention.

3A is an operation characteristic diagram of the initial dimming control unit of the embodiment shown in FIG. 2;

Figure 3b is a detailed circuit diagram of the initial dimming control unit of the ballast of the second embodiment of the present invention.

3C is an operation characteristic diagram of the initial dimming controller of the embodiment shown in FIG. 3B.

Figure 4a is a detailed circuit diagram of the current sensing unit of the ballast of the third embodiment of the present invention.

Figure 4b is an operating characteristic diagram of the current sensing unit according to the present invention.

5 is a detailed circuit diagram of a dimming control unit of the ballast of the fourth embodiment of the present invention.

6 is a detailed circuit diagram of a dimming control unit of the ballast of the fifth embodiment of the present invention.

7 is a detailed circuit diagram of a dimming control unit of the ballast of the sixth embodiment of the present invention.

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

1. Power input 2. Bridge rectifier

3. Constant Power Supply (PFC) 4. Frequency Oscillator

5. Inverter section 6. Frequency control section

7. Current sensing unit 8. Resonant circuit unit

9. Current comparator 10. Initial dimming controller

11. Dimming voltage generator 12. External controller

13. DC voltage generator 14. Lamp

The present invention relates to an electronic ballast having a dimming control function, and more particularly to an electronic ballast having a dimming control unit by individual dimming.

In particular, an electronic ballast having a dimming control function according to the present invention relates to an electronic ballast in which the dimming control of each ballast is individually performed in a simple configuration, and dimming individually according to the light receiving degree of a variable resistor or a CDS or phototransistor. This would be possible.

In addition, the present invention relates to an electronic multi-stage dimming control electronic fluorescent ballast having a good advantage of selecting and using the illuminance of the ballast for each location of a room.

Electronic ballasts contain a starting semiconductor element in the ballast, which preheats the electrode with its switching action or electrode heating winding and starts the lamp by the semiconductor switching action, while the lamp is heated by the lamp current and the electrode heating winding during lighting. Ballast used in the circuit method

Conventional dimming control electronic ballast requires a very complicated configuration for multi-stage dimming control, and even if the same product is installed in several places, there is a difference in illuminance. It is difficult to produce a constant product according to the difference, and for this purpose, there is a problem of managing the lamp temperature and supplementing the set power according to the ambient temperature. In this case, the ballast does not operate, and even when the ballast does not maintain the lamp current, the ballast is often turned off or bad.

In addition, the group dimming control has a problem that the phase of the power supply line is changed with each other causing a failure of the ballast.

Therefore, the present invention can easily operate the dimming control unit that can be dimmed in multiple stages with a simple configuration so as to solve the problems with the conventional dimming control electronic ballast as described above.

In addition, the inverter and the lamp current is detected to form a comparison voltage, and the comparison circuit calculates the reference voltage and the comparison voltage to keep the inverter and the lamp current constant, and the lamp discharge when the input voltage is ON / OFF at the minimum dimming level. By developing an initial dimming control circuit to assist the system, it is possible to reduce illuminance even when the ballast stops operating due to lack of minimum dimming level, unlit state due to cold winter temperature, and insufficient lamp current, or the difference between lamp temperature and ambient temperature. The present invention provides a dimming control electronic ballast circuit that is kept constant.

Further objects or effects of the present invention will become more apparent from the following detailed description of the invention described with reference to the accompanying drawings.

In order to achieve the above object, the electronic ballast having the dimming control unit by the individual dimming according to the present invention, by the power source input unit 1, the bridge rectifier (2) for rectifying the power source of the power input unit, the bridge rectifier An inverter unit 5 driving the lamp 14 by inverting the rectified voltage into a high frequency signal, and a frequency oscillation unit 4 generating an oscillation frequency for adjusting the brightness of the lamp and applying it to the inverter unit 5. And a resonator (8) for forming a resonant circuit with the lamp, which is coupled to the frequency oscillator (4) and controls the oscillation frequency of the frequency oscillator (4). Frequency control section 6; And a dimming control unit generating a control signal of the frequency control unit 6. In addition, the dimming control unit, by changing the input voltage (V2) of one input terminal, compared to the reference voltage (V1) of the other terminal, the control signal (V3) to the frequency control unit 6 through the output terminal And a second comparator IC4 for outputting a multi-level dimming voltage for each ballast as the resistance value of the resistor VR1 (CDS; Q5) having a variable resistance value is changed. The brightness of the lamp is controlled by changing the input voltage V2 of the one terminal of the comparator IC4.

The resistor whose resistance value is variable may be a variable resistor VR1, a CDS element CDS, or a phototransistor Q5.

As a result, an electronic ballast having a dimming control function according to the present invention includes a bridge rectifier circuit for generating an AC input and a pulse current, and a current of an input (AC) generated during the conversion of the pulse current to a DC (direct current) voltage. PFC (Power Factor Correction) circuit and PFC (Power Factor Correction) circuit that controls current harmonics according to the phase difference of voltage and keeps the output power constant even if the input voltage changes by ± 20%. Inverter for high frequency switching by receiving operating voltage, frequency oscillator for stably controlling lamp current by adjusting switching frequency of inverter, frequency controller for controlling oscillation frequency of frequency oscillator by processing signal of dimming controller And an inverter and lamp current sensing unit for detecting a lamp current to maintain a constant lamp current, and an inverter and a lamp current sensing unit. An inverter current comparator for comparing the current to generate a control signal for the frequency controller, a dimming voltage generator for four-stage setting, an initial dimming controller for smoothly maintaining dimming when the initial power is turned on and off, and an external controller. It features.

Best Mode for Carrying Out the Invention An optimal embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a dimming control electronic ballast according to the present invention, and FIG. 2 is a detailed circuit diagram of a first embodiment of the dimming control electronic ballast according to the present invention.

First, the A.C input voltage outputs a pulsation voltage from the bridge rectifier circuit 2 including the diodes D1 to D4 and the capacitors C2 and C3 through the fuse FUSE and the line filter L1. The pulsed voltage, which is the output of the bridge rectifier, is connected to the resistors R1 to R14, the capacitors C4 to C8, the diodes D5, D6 and D7, the first IC IC1, the FET Q1, and the boost transformer T1. It is applied to the PFC (Power Factor Correction) circuit which is comprised.

The PFC circuit operates the FET Q1 by adjusting a reference pulse width corresponding to the height of the pulse voltage by breathing the pulse voltage of the input voltage from the resistors R1 to R3 and the capacitor C4.

The operation of the FET Q1 generates a high induced voltage in the boost transformer T1. The induced voltage of the boost transformer T1 is VL = -L · (di / dt) (V). The induced voltage VL of the boost transformer is charged to the capacitors C7 and C8 via the diode D7.

The charging voltages of the capacitors C7 and C8 are breathed by the resistors R10, R11, and R12, and calculated with a comparison voltage (for example, 2.5V) inside the first IC to pulse the gate of the FET Q1. After adjustment, the capacitors C7 and C8 are charged again.

At this time, when the charging voltage of the capacitors C7 and C8 is higher than the predetermined set voltage, the gate pulse width of the FET Q1 is reduced, and when the charging voltage is low, the pulse voltage is widened to maintain the charging voltage constant.

In addition, the pulse voltage is applied to the initial operation voltage to the second IC (IC2) that is the IC of the frequency generator (4).

When an initial voltage is applied to the second IC IC2, a frequency is generated by the resistors R15, R16, and R17 and the capacitors C10 and C11. The oscillation frequency of the frequency generator is derived from the transformer T2 and applies an operating frequency to the inverter unit 5.

That is, according to the induction frequency of the transformer T2, the inverter unit including the diodes D8 to D13, the resistors R18 and R19, and the FETs Q2 and Q3 performs a high speed switching operation.

In addition, the high frequency high voltage generated by the high speed switching operation of the inverter unit 5 is waveform-shaped by a square wave in the resonator unit consisting of the resonant transformer T4 and the capacitors C13, C14, and C15 via the capacitor C12. Discharge.

In addition, the high frequency high voltage generated by the operation of the inverter unit generates a power supply voltage of the frequency oscillator in the resistor R39, the capacitor C21, and the diodes D22 and D23 to smoothly maintain the operation of the frequency oscillator.

On the other hand, the secondary winding of the resonant transformer T4 generates a DC voltage Vcc by the DC voltage generator 13 including the resistors R24 and R28, the diode D14, and the capacitor C16 by receiving the resonance current. In this way, operating power is applied to the dimming voltage generator 11, the inverter current comparator 9, and the initial dimming controller 10.

Therefore, the operation power source Vcc of the dimming voltage generator 11, the inverter current comparator 9 and the initial dimming controller 10 is connected to the main circuits 1, 2, 3, 4, 5, 6, 14 of the ballast. Since it is separated from the power supply circuit of the power supply circuit and the inverter unit 5 and the resonator unit 8, it is possible to solve the problem of the prior art that the phase of the power supply line is changed with each other during group dimming control, resulting in a failure of the ballast. By separating the dimming control unit and the power supply circuit of the ballast, it is possible to control several ballasts in groups. Furthermore, as will be described later, the dimming control circuits 9, 10, 11, 12, 13 are also connected to the frequency control section 6 through the photocoupler (O.C1), so that the ballast main circuit section according to the application of the control signal In addition, the influence of the can be minimized.

On the other hand, in order to detect and feedback the resonant current, current detection is required. The inverter and the lamp current are detected by the third transformer T3, which is another transformer, so that the resistors R25, R26, R27, capacitor C17, Inverter current comparison section 8 composed of a fourth IC (IC4), resistor R31, and capacitor C18 as a second comparator by forming a control voltage in current sensing section 7 composed of diode D15. Is applied via a resistor R29. More specifically, the output terminal of the current sensing unit is connected to the negative input terminal of the second comparator IC4 through the resistor R41.

Thus, when the resonant current of the resonator 8 is high, the inverter current comparator 9 increases the negative input voltage V1 of the second comparator IC2, thereby lowering the output of the second comparator IC2. Low to stop the operation of the photocoupler (O. C1) through the diode (D16) and the resistor (R30), thereby making the base voltage of the transistor (Q4) high (high), and thus the transistor (Q4). ) Will work. When the transistor Q4 operates, the resistors R15 and R39 become parallel resistors, so that the total resistance value is lowered and the frequency is increased. In addition, the increased oscillation frequency of the frequency oscillator 4 reduces the resonance current of the resonance circuit, so that the resonance current is kept constant. The above is briefly shown as follows.

Operation path 1

Resonant current high → IC4 output low → O.C1 off → Q4 turn on → Total resistance decrease → Frequency increase → Resonance current decrease

On the other hand, the other input (+) of the second comparator IC4 of the inverter current comparator 9 has resistors R36 and R34, a capacitor C20, a DIP switch SW DIP-3, and a diode D19. It is connected to the dimming voltage generator 11 consisting of, D20, D21.

The dimming voltage of this embodiment is, for example, composed of three different constant voltage sources, and is applied to the reference voltage V2 of the inverter current comparison unit 9 through the resistor R34.

Therefore, when the set dimming voltage V2 generated by the dimming voltage generator 11 is high, the reference voltage V2 of the second comparator IC4 becomes higher than the comparison voltage V1, and thus the second comparator IC2. ) Is made high, so that the operation is reversed to the 'operation path 1', and the inverter current and the lamp current are increased, resulting in a high illumination (see 'operation path 2'), On the contrary, when the dimming voltage V2 set generated by the dimming voltage generator 11 is low, the dimming voltage V11 operates as in the operation path 1, and thus the illumination intensity is low.

Operation path 2

Resonant current low → IC4 output high → O.C1 operation → Q4 off → Total resistance increase → Frequency decrease → Resonance current increase

Now, when the initial dimming control unit 10 is described in detail, it comprises a resistor (R33, R35), a capacitor (C19), and a third IC (IC3), which is a first comparator, and dimming the dimming voltage generator when the initial power is turned on. Maximize the voltage so that the circuit operates at 100%.

In detail, when the power is turned on, the positive input of the first comparator IC3 is inputted with the dimming voltage V5 of the dimming voltage generator 11, and the negative input is connected with the resistor R33. The voltage divider R33 and R35 of the integrating circuit of the capacitor C19 and the voltage V4 of the connection point of the capacitor C19 are input.

Therefore, the integrating circuit of the resistor R33 and the capacitor C19 gradually charges the voltage by the integral constant. As such, the negative input V4 of the first comparator IC3 is lower than the positive input V5 for a considerable time (for example, 20 seconds) so that the output of the first comparator IC3 is high. The high signal is input to the inverter current comparison section 9 via the diode D17. Therefore, since the positive input V2 of the second comparator IC4 of the inverter current comparator 9 is higher than the negative input V1, the output V3 of the second comparator IC4 is changed. Since the output is high, the oscillation frequency of the frequency oscillator 4 is lowered, thereby maintaining 100% lamp power. In summary, it is as follows 'operation path 3'.

Operation path 3

Ballast turn-on → IC3 output high → IC4 output high → O.C1 operation → Q4 off → Total resistance increase → Frequency decrease → Resonance current increase

However, the negative input of the first comparator IC3 of the initial dimming controller 10 becomes higher than the positive input after a predetermined time (for example, 20 seconds), and the first comparator IC3 is low. ), So that the dimming circuit of the current comparator 9 is no longer affected.

Therefore, in the initial state when the power is initially turned on, the lamp current is maintained at 100% for a certain time, and after a certain time, the lamp output is maintained at a predetermined state according to the DIP switch.

However, the resistor R37, the second photocoupler (O.C2) and the diode D18 of the dimming voltage generator 11 are connected to the external controller 12 and operate according to a signal of the external controller. For example, when the signal of the external controller 12 is input to high, the positive input of the second comparator IC4 of the inverter current comparator 9 is made higher than the negative input of the second comparator ( Since IC4) is output high, the lamp current is maintained at 100% as shown in the following 'Operation Path 4'.

Operation path 4

External controller signal high → IC4 output high → O.C1 operation → Q4 off → Total resistance increase → Frequency decrease → Resonance current increase

When this function is installed in the office or other places (corridor, stairs), the lamp current is maintained at 100% if there is a person inside, and the lamp output is supplied to the DIP switch if it does not exist, such as when a person is out. Therefore, the illumination is maintained in a preselected state.

Like the circuit of the present application, the external controller 12, the dimming control unit 7, 9, 10, 11, 13 and the ballast circuits 1, 2, 3, 4, 5, 6, 8, 14 are insulated transformer ( T3, T4) or photocouplers (O.C1, O.C2) isolate the power lines between circuits, and even if a lot of ballasts are dimmed, the phases of the power lines do not cross each other. The ballast will operate stably.

The operation of the electronic ballast of the present invention is described below with reference to FIGS. 3A to 7.

3A is an operation characteristic diagram of the initial dimming control unit 10 of the embodiment shown in FIG. 2, FIG. 3B is a detailed circuit diagram of the initial dimming control unit 10 'of the ballast of the second embodiment of the present invention, and FIG. FIG. 3B is an operation characteristic diagram of the initial dimming control unit 10 'of the second embodiment shown in FIG.

As shown in the operating characteristic diagram of FIG. 3A, when the power supply of the ballast is turned ON, since the charging voltage V4 of the integrating circuit by the resistor R33 and the capacitor C19 is still a low voltage, Since the negative input of the first comparator IC3 of the dimming controller 10 is low, the outputs of both the first comparator IC3 and the second comparator IC4 of the inverter current comparator 9 are both high. It becomes (High), and since the oscillation frequency is low, the lamp current is maintained at 100%.

However, after a predetermined time to (for example, 20 seconds), since the charging voltage V4 of the integrating circuits R33 and C19 rises to a high voltage, the voltage of the first comparator IC3 ( Since the input becomes high, the output of the first comparator IC3 becomes low and does not affect the input terminal of the second comparator IC4 of the inverter current comparator 9, so that the dimming control part is dimmed. Affected by the voltage generator 11, it maintains the selected illuminance according to the setting of the DIP switch. Therefore, in general, since it is set to a lower illuminance, the oscillation frequency of the frequency oscillator 4 becomes higher after time to, and the final lamp current is lowered.

3b shows an initial dimming control unit 10 'of another embodiment of the present invention. In the second embodiment, a PNP transistor Q4 is used instead of the first comparator IC3. The base voltage of the transistor Q4 is connected to the connection point of the integrating circuit by the resistor R43 and the capacitor C19,

At initial startup of the ballast, the transistor is turned on because the base voltage of the transistor Q4 is a low voltage, and the positive input of the second comparator IC4 of the inverter current comparator 9 is set to High. The output of the IC4 also becomes high, and eventually the lamp current is maintained at 100%.

However, as can be seen from the characteristic diagram of Fig. 3C, the initial dimming control using the transistor of the second embodiment is similarly oscillated with the output voltage of the transistor Q4 gradually decreasing over time at the 100% output at the initial startup. The frequency also gradually increases, and eventually the illuminance gradually drops. In this respect, the first embodiment using the OP AMP as a comparator and the second embodiment using the transistor Q4 are different.

In addition, after a predetermined time (to), the output voltage of the transistor Q4 drops below the zener voltage, so that the transistor Q4 is turned off and does not affect the input terminal of the second comparator IC4 of the inverter current comparator 9. Since the dimming controller is affected by the dimming voltage generator 11, the dimming control unit maintains the selected illuminance according to the setting of the DIP switch.

Now, the operation of the current sensing unit 7 of the present invention will be described with reference to FIGS. 4A and 4B.

4A is a detailed circuit diagram of the current sensing unit of the ballast of the third embodiment of the present invention, and FIG. 4B is an operation characteristic diagram of the current sensing unit according to the present invention.

As shown in the operation characteristic diagram of FIG. 4B, when it is assumed that the voltage V2 of the positive input terminal of the second comparator IC4 of the inverter current comparator 9 is constant (see FIG. 4B (b)). When the voltage V1 at the negative input terminal of the second comparator IC4 due to the inverter and the lamp current is low (see (a) of FIG. 4B), the output V3 of the second comparator IC4 is Goes high; conversely, when V1 is high, V3 goes low.

On the other hand, as shown in FIG. 4A, instead of the transformer T of the first embodiment of FIG. 2, the resistor R44 can be used in the current sensing unit 7 'of the third embodiment of the present invention. have.

The circuit of using the resistor R44 of the third embodiment is simpler than the circuit of using the transformer T3 of the first embodiment, but the disadvantage thereof is that the value of the resistor R44 becomes large in order to detect current. At% power, there is a loss of resistance and a thermal problem. However, the circuit design is easy.

As shown in the characteristic diagram of Fig. 4B, when the inverter current rises (Fig. 4B (a)), the output of IC4 is relatively decreased (Fig. 4B (c)). When the output of the IC4 decreases, the frequency generator increases the frequency to drop the lamp current to maintain stable operation.

Finally, Figures 4 to 7 shows a circuit for the dimming control unit of the individual dimming control method, which is a modification of the present invention. 5 is a detailed circuit diagram of the dimming control unit of the ballast of the fourth embodiment of the present invention, Figure 6 is a detailed circuit diagram of the dimming control unit of the ballast of the fifth embodiment of the present invention, Figure 7 is a view of the ballast of the sixth embodiment of the present invention Detailed circuit diagram of the dimming control unit.

An individual dimming ballast having a dimming voltage generator 11 'using the variable resistor of FIG. 5 generates a dimming voltage individually for each ballast as the resistance value of the variable resistor VR1 is changed, thereby comparing the inverter current. The dimming control is individually performed for each ballast by changing the input terminal V2 of the positive terminal of the second comparator IC4 of the section 9.

That is, as shown in FIG. 5, the individual dimming control method of the fourth embodiment receives the photocoupler O. C1 of the first embodiment (FIG. 2) connected to the driving voltage Vcc through the resistor R37. Instead of the element, variable resistor VR1 is used, the other end of the variable resistor is grounded through resistor R6, and the third variable terminal is connected to the positive input terminal of the second comparator IC4 through resistor R5. It is. At this time, a parallel circuit of the capacitor C21 and the zener diode D25 is connected in parallel with the variable resistor to the connection point of the resistor R37 and the variable resistor VR1.

Therefore, the constant voltage by the zener diode is divided into a resistor variable by the variable resistor and a resistor R45 + R32, and the divided voltage is input to the second comparator as a comparison voltage to perform dimming control. It is possible to individually perform dimming control of each ballast by the variable resistor. At this time, a parallel circuit of the capacitor C21 and the zener diode D25 is connected in parallel with the variable resistor to the connection point of the resistor R37 and the variable resistor VR1.

An individual dimming ballast having a dimming voltage generator 11 "using the CDS of FIG. 6 generates a dimming voltage separately for each ballast by using CDS instead of the variable resistor of the fourth embodiment (FIG. 5). It is a dimming control method of ballast to make dimming according to weather.

The individual dimming ballast having the dimming voltage generator 11 "'which uses the phototransistor Q5 of FIG. 7 is also according to the photosensitivity of the phototransistor Q5 instead of the variable resistor of 4th Example (FIG. 5). The dimming voltage is generated for each ballast individually, and is a dimming control method of the ballast which also controls dimming separately.

Although the present invention has been described with reference to the embodiments shown in the accompanying drawings, the present invention is not limited thereto, and various modifications may be made within a range easily understood by those skilled in the art. Therefore, the limitation of the present invention should be limited only by the following utility model registration claims.

As described above, according to the ballast according to the present invention, there is an advantage that the dimming control unit that can be dimmed in multiple stages with a simple configuration can be easily operated individually.

Claims (4)

The power input unit 1, the bridge rectifier 2 for rectifying the power of the power input unit, the inverter unit 5 for driving the lamp 14 by inverting the voltage rectified by the bridge rectifier into a high frequency signal, the lamp An electronics having a dimming control function, comprising a frequency oscillation unit 4 for generating an oscillation frequency for adjusting the brightness of the light source and applying it to the inverter unit 5, and a resonance unit 8 for forming a resonance circuit with the lamp. As a ballast, A frequency controller (6) coupled to the frequency oscillator (4), for controlling the oscillation frequency of the frequency oscillator (4); And Dimming control unit for generating a control signal of the frequency control unit 6; Including but not limited to: The dimming controller is configured to output the control signal V3 to the frequency controller 6 through an output terminal as compared with the reference voltage V1 of the other terminal by changing the input voltage V2 of one input terminal. 2 comparators (IC4), As the resistance value of the resistor VR1 (CDS; Q5) having a variable resistance value is changed, a dimming voltage of multiple stages is generated for each ballast separately, and an input voltage V2 of the one terminal of the second comparator IC4 is generated. Electronic ballast having a dimming control unit by individual dimming, characterized in that to adjust the brightness of the lamp by changing the). The method of claim 1, An electronic ballast having a dimming controller, characterized in that the resistor whose variable value is variable is a variable resistor (VR1). The method of claim 1, An electronic ballast having a light control section, characterized in that the resistor whose variable value is variable is a CDS element (CDS). The method of claim 1, An electronic ballast having a dimming controller, characterized in that the resistor whose variable value is variable is a phototransistor (Q5).

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