CN110831273A

CN110831273A - Adjustable stabilizer and driving method thereof

Info

Publication number: CN110831273A
Application number: CN201810901180.9A
Authority: CN
Inventors: 王涵远; 吴建铭; 黄嘉宏; 陈重山
Original assignee: Bluesea Co ltd; Eutop Technology Co Ltd
Current assignee: Bluesea Co ltd; Eutop Technology Co Ltd
Priority date: 2018-08-09
Filing date: 2018-08-09
Publication date: 2020-02-21

Abstract

The invention provides an adjustable stabilizer and a driving method thereof. The adjustable ballast can drive the hot cathode fluorescent lamp to generate light energy. The adjustable stabilizer comprises a driving circuit and a feedback control circuit. The driving circuit provides electric energy to drive the hot cathode fluorescent lamp. The feedback control circuit is coupled to the driving circuit. The feedback control circuit obtains feedback information related to the light energy from the hot cathode tube. The feedback control circuit controls the driving circuit according to the feedback information so as to adjust the frequency and the current of the electric energy.

Description

Adjustable stabilizer and driving method thereof

Technical Field

The present invention relates to a hot cathode fluorescent lamp, and more particularly, to an adjustable ballast and a driving method thereof.

Background

The hot cathode tube device can generate light, such as visible light or ultraviolet light. In some applications, the cathode ray tube device can generate light with sufficient energy to purify air. For example, the ultraviolet energy of the cathode ray tube device can ionize moisture and oxygen in the air to generate ozone (O)₃) Negative oxygen ion (O)₂-) OH, OH free radical

And hydrogen peroxide (H)₂O₂) And active agents (active agents) having an oxidizing activity. The generated purification factors can react with pollutants in the air (such as formaldehyde, toluene and ammonia …) or surface pollutants (such as bacteria, mould and second-hand smoke …) to remove the pollutants, thereby achieving the purification effect.

The hot cathode tube device has a ballast and a hot cathode tube (e.g., an ultraviolet tube). In order to overcome the negative resistance characteristic of the hot cathode fluorescent lamp, the ballast generates a proper starting voltage to light the lamp, and then returns to a lower working voltage to maintain the hot cathode fluorescent lamp in a normal lighting state. There is no dimming ballast or adjustable ballast available in the market to drive uv lamps, especially short wavelength (wavelength less than 200nm) uv lamps that can produce photolysis (photolysis) or ozone. Since the output power of the ultraviolet lamp cannot be adjusted, the photolysis reaction rate or the ozone yield cannot be controlled naturally.

The general ballast for driving the ultraviolet lamp cannot dynamically adjust the output power of the ultraviolet lamp. Generally, the conventional ballast drives the ultraviolet lamp with a constant power, i.e., the ultraviolet lamp emits ultraviolet light with a constant power. The ballast is usually used to drive the UV lamp with a constant power to emit UV light, which means that the ozone yield is constant. If the space is too large, the indoor ozone concentration may be too low. If the space is too small, the ozone concentration in the room may be too high.

Disclosure of Invention

The invention provides an adjustable stabilizer and a driving method thereof, which can feed back and adjust the output power of a hot cathode lamp tube.

The embodiment of the invention provides an adjustable stabilizer for driving a hot cathode lamp tube to generate light energy. The adjustable stabilizer comprises a driving circuit and a feedback control circuit. The driving circuit is used for providing electric energy to drive the hot cathode lamp tube. The feedback control circuit is coupled to the driving circuit. The feedback control circuit is used for obtaining feedback information related to the light energy from the hot cathode tube. The feedback control circuit controls the driving circuit according to the feedback information so as to adjust the frequency and the current of the electric energy.

In an embodiment of the invention, the driving circuit includes a resonant circuit and an inverter circuit. The inverter circuit is coupled to the resonant circuit. The inverter circuit is used for driving the hot cathode lamp tube. The feedback control circuit adjusts one or more of at least one inductance value and at least one capacitance value of the resonant circuit according to the feedback information so as to adjust the frequency and the current of the electric energy.

In an embodiment of the invention, the resonant circuit includes an inductor and a first capacitor. The feedback control circuit adjusts the inductance value of the inductor according to the feedback information. The first end of the first capacitor is coupled to the first end of the inductor. The second terminal of the first capacitor is coupled to a first filament of the hot cathode tube. The feedback control circuit adjusts the capacitance value of the first capacitor according to the feedback information.

In an embodiment of the invention, the resonant circuit further includes a second capacitor. The first terminal of the second capacitor is coupled to the first filament of the hot cathode tube. The second terminal of the second capacitor is coupled to the second filament of the hot cathode fluorescent lamp.

In an embodiment of the invention, the inverter circuit includes a transformer, a first switch, a first diode, a first capacitor, a second switch, and a second diode. The transformer has a first coil, a second coil, a third coil and a fourth coil. The first end of the first coil is coupled to the first direct current voltage path. The second end of the first coil is coupled to the first end of the second coil. The first end of the third coil is coupled to the first direct current voltage path. The second end of the third coil is coupled to the first end of the first filament of the hot cathode tube. The first terminal of the first switch is coupled to the first DC voltage path. The second terminal of the first switch is coupled to the second dc voltage path. The control end of the first switch is coupled to the second end of the first coil and the first end of the fourth coil. The cathode of the first diode is coupled to the first DC voltage path. The anode of the first diode is coupled to the second dc voltage path. The first end of the first capacitor is coupled to the first direct current voltage path. The second end of the first capacitor is coupled to the second end of the second coil and the first end of the second filament of the hot cathode tube. The first end of the second switch is coupled to the second end of the first capacitor. The second terminal of the second switch is coupled to the second dc voltage path. The control end of the second switch is coupled to the second end of the fourth coil. The cathode of the second diode is coupled to the second end of the first capacitor. An anode of the second diode is coupled to the second dc voltage path.

In an embodiment of the invention, the resonant circuit includes an inductor, a first coil, a second coil, a third coil, and a second capacitor. The first end of the inductor is coupled to the first direct current voltage path. The second end of the inductor is coupled to the second end of the first coil. The feedback control circuit adjusts the inductance of one or more of the inductor, the first coil, the second coil and the third coil according to the feedback information. The first end of the second capacitor is coupled to the second end of the third coil. The second end of the second capacitor is coupled to the first end of the first filament of the hot cathode tube. The feedback control circuit adjusts the capacitance of the second capacitor according to the feedback information.

In an embodiment of the invention, the adjustable ballast further includes a second capacitor. The first terminal of the second capacitor is coupled to the second terminal of the first filament of the hot cathode tube. The second terminal of the second capacitor is coupled to the second terminal of the second filament of the hot cathode tube.

In an embodiment of the invention, the inverter circuit includes a transformer, a first Solid State Relay (SSR), a first diode, a first capacitor, a second SSR, a second diode, and a resistor. The transformer has a first coil, a second coil, a third coil and a fourth coil. The first end of the first coil is coupled to the first direct current voltage path. The second end of the first coil is coupled to the first end of the second coil. The first end of the third coil is coupled to the first direct current voltage path. The second end of the third coil is coupled to the first end of the first filament of the hot cathode tube. A first terminal of the first solid state relay is coupled to the first dc voltage path. The control end of the first solid-state relay is coupled to the second end of the first coil and the first end of the fourth coil. The cathode of the first diode is coupled to the first DC voltage path. An anode of the first diode is coupled to a second terminal of the first solid-state relay. The first end of the first capacitor is coupled to the first direct current voltage path. The second end of the first capacitor is coupled to the second end of the second coil and the first end of the second filament of the hot cathode tube. The first terminal of the second solid-state relay is coupled to the second terminal of the first capacitor. A second terminal of the second solid state relay is coupled to the second dc voltage path. The control terminal of the second solid-state relay is coupled to the second terminal of the fourth coil. The cathode of the second diode is coupled to the second end of the first capacitor. The anode of the second diode is coupled to the anode of the first diode. The first end of the resistor is coupled to the anode of the first diode. The second end of the resistor is coupled to the second direct current voltage path.

In an embodiment of the invention, the feedback control circuit includes a feedback circuit and a power control circuit. The feedback circuit is coupled to the hot cathode tube to obtain feedback information related to the light energy. The power control circuit is coupled to the feedback circuit to receive the feedback information. The power control circuit controls the driving circuit according to the feedback information so as to adjust the frequency and the current of the electric energy.

In an embodiment of the invention, the feedback control circuit further controls the driving circuit according to a rotation speed of the fan module to adjust a frequency and a current of the electric energy.

In an embodiment of the invention, when the rotation speed of the fan module increases, the feedback control circuit adjusts the frequency and the current of the electrical energy, so as to increase the output power of the hot cathode fluorescent lamp. When the rotating speed of the fan module is reduced, the feedback control circuit adjusts the frequency and the current of the electric energy so as to reduce the output power of the hot cathode fluorescent lamp.

In an embodiment of the invention, the feedback control circuit further controls a rotation speed of the fan module according to a wind speed command of the user interface circuit.

The embodiment of the invention provides a driving method of an adjustable stabilizer. The adjustable ballast is used to drive the hot cathode fluorescent lamp to generate light energy. The driving method includes: providing electric energy by a driving circuit to drive the hot cathode lamp tube; obtaining feedback information related to the light energy from a hot cathode tube by a feedback control circuit; and controlling the driving circuit by the feedback control circuit according to the feedback information so as to adjust the frequency and the current of the electric energy.

In an embodiment of the invention, the step of controlling the driving circuit includes: and adjusting one or more of at least one inductance value and at least one capacitance value of a resonant circuit of the driving circuit by the feedback control circuit according to the feedback information so as to adjust the frequency and the current of the electric energy.

In an embodiment of the invention, the driving method further includes: the feedback control circuit controls the driving circuit according to the rotating speed of the fan module so as to adjust the frequency and the current of the electric energy.

In an embodiment of the invention, the step of controlling the driving circuit according to the rotation speed of the fan module includes: when the rotating speed of the fan module is increased, the frequency and the current of the electric energy are adjusted by the feedback control circuit, so that the output power of the hot cathode lamp tube is increased; and when the rotating speed of the fan module is reduced, the frequency and the current of the electric energy are adjusted by the feedback control circuit, so that the output power of the hot cathode lamp tube is reduced.

In an embodiment of the invention, the driving method further includes: the feedback control circuit controls the rotating speed of the fan module according to the wind speed instruction of the user interface circuit.

Based on the above, the adjustable ballast and the driving method thereof according to the embodiments of the invention can obtain feedback information related to light energy from the hot cathode fluorescent lamp. According to the feedback information, the feedback control circuit can dynamically control the driving circuit to adjust the frequency and the current of the driving electric energy of the hot cathode lamp tube. Therefore, the adjustable stabilizer can feed back and adjust the output power of the hot cathode lamp tube.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic diagram of a circuit block (circuit schematic block) of an adjustable ballast according to an embodiment of the invention.

Fig. 2 is a flowchart illustrating a driving method of an adjustable ballast according to an embodiment of the invention.

Fig. 3 is a schematic circuit block diagram of an adjustable ballast according to another embodiment of the invention.

Fig. 4 is a circuit diagram illustrating the resonant circuit of fig. 3 according to an embodiment of the invention.

Fig. 5 is a circuit diagram illustrating the resonant circuit, the inverter circuit and the feedback circuit shown in fig. 3 according to another embodiment of the invention.

Fig. 6 is a circuit diagram illustrating the resonant circuit, the inverter circuit and the feedback circuit shown in fig. 3 according to another embodiment of the invention.

[ notation ] to show

10: direct current power supply

20: hot cathode lamp tube

21: first filament

22: second filament

30: user interface circuit

40: fan module

100: adjustable stabilizer

110: driving circuit

120: feedback control circuit

300: adjustable stabilizer

310: driving circuit

311: resonant circuit

312: inverter circuit

320: feedback control circuit

321: feedback circuit

322: power control circuit

330: protective circuit

C1, C2, C3, C4, C5, C6, C7, C8, C9: capacitor with a capacitor element

CL, CC: control signal

D1, D2, D3, D4: diode with a high-voltage source

DC 1: first direct current road roller

DC 2: second DC voltage path

EE: electric energy

EL: light energy

FB: feedback information

L1: inductance

L2: first coil

L3: second coil

L4: third coil

L5: fourth coil

Q1, Q2: switch with a switch body

R1, R2, R3, R4, R5, R6, R7: resistance (RC)

S1, S2, S3: signal

S210 to S230: step (ii) of

SSR1, SSR 2: solid state relay

T1: transformer device

Detailed Description

The term "coupled" as used throughout this specification, including the claims, may refer to any direct or indirect connection. For example, if a first device couples (or connects) to a second device, it should be construed that the first device may be directly connected to the second device or the first device may be indirectly connected to the second device through some other device or some connection means. Further, wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts. Elements/components/steps in different embodiments using the same reference numerals or using the same terms may be referred to one another in relation to the description.

The following embodiments will describe a ballast capable of adjusting the output power of a hot cathode fluorescent lamp. The output power of the hot cathode lamp tube can be changed by the adjustable ballast through adjusting the output current and the working resonant frequency of the ballast. The change in output power directly affects the radiation intensity of light (e.g., ultraviolet light). If the uv light of the hot cathode fluorescent lamp is applied to the photolysis reaction, the adjustable stabilizer can control the yield of the product of the photolysis reaction (such as ozone) because the intensity of the uv light radiation is closely related to the rate of the photolysis reaction.

The following embodiments will use photolysis as an example of the application of the hot cathode fluorescent lamp, and assume that the light generated by the hot cathode fluorescent lamp is ultraviolet light. In any case, the adjustable ballast and the hot cathode fluorescent lamp of the present invention can also be used in other applications. For example, the light generated by the hot cathode tube may be visible light, and the adjustable ballast and the hot cathode tube of the present invention may also be used in lighting applications.

In recent years, some products generate negative ions or ozone by means of high-voltage discharge. Good surface bacteriostasis is expected to be achieved by releasing high-concentration negative ions or ozone into the environment, but the high-concentration negative ions can generate a black wall effect, and the pollution on the surface of the environment around the equipment is increased. In addition, nitrogen oxides are generated while ozone is generated in a high-voltage discharge mode, so that the problem of surface pollution cannot be solved, and more air pollution problems are caused. The indoor environmental pollution problem includes the pollution problem of the surfaces of various objects besides the air pollution which is often mentioned. The pollution on the surface of the object comprises the pollution problems of bacteria, viruses, molds, three-hand smoke and the like attached to the surfaces of various objects such as walls, floors, table tops, ceilings, furniture, clothes and the like. Although the conventional air cleaner can effectively solve the problem of air pollution under normal operation, the conventional air cleaner is still unsure about the surface pollutants. If the photo-catalytic coating is used, the photo-catalytic coating is limited by the light and the performance of the photo-catalytic coating is greatly reduced due to the influence of the environmental moisture.

Fig. 1 is a schematic diagram of a circuit block of an adjustable ballast 100 according to an embodiment of the invention. The dc power supply 10 shown in fig. 1 can supply power to the adjustable ballast 100. The dc power supply 10 may be any power supply circuit/component. For example, the dc power supply 10 may be an existing power supply circuit or other power supply circuit/component.

The adjustable ballast 100 can drive the hot cathode fluorescent lamp 20 to generate light energy. The CCFL 20 may include an ultraviolet lamp or other types of lamps, depending on design requirements. Besides sterilization, the short wavelength ultraviolet lamp tube can also be used for improving indoor environmental quality due to the effect of photolysis reaction. According to design requirements, in some application examples, the wavelength of the light emitted by the ultraviolet lamp tube is mainly concentrated in the UVC range (wavelength of 100-280 nm). When the output power can be changed according to the operation condition or the application scene, the use range can be enlarged, and the operation cost can be effectively reduced.

When the wavelength range of the light radiated by the ultraviolet lamp tube is less than 200nm, the ultraviolet lamp tube not only has sterilization effect, but also can drive photolysis reaction. The photolysis reaction can be divided into direct photolysis (direct photolysis) and indirect photolysis (indirect photolysis). The direct photolysis directly destroys the molecular bonds of the contaminants by the energy of the short wavelength (wavelength less than 200nm) uv light. The indirect photolysis reaction ionizes water vapor and oxygen in the air by the energy of short-wavelength ultraviolet light to generate active substances (or purification factors) having redox ability to pollutants, such as ozone, hydrogen peroxide, hydroxyl radicals, superoxide ions and the like, and then the active substances and the pollutants react to achieve the purpose of purifying the air and the surface pollutants.

The direct photolytic reaction is driven by ultraviolet light with a wavelength of less than 200 nm. The formula (3) can be obtained from the relationship between Planck-Einstein equation (1) and the wavelength and frequency of light (formula (2)). In the formulae (1), (2) and (3), E is the energy of the light (eV or kJ/mol), h is the Planckian constant, and v is the frequency(s) of the light^-1) C is the speed of light and λ is the wavelength of light (nm). Planck constant 4.1357 x 10^-15(eV · s) or 6.63 × 10^-34(J · s), wherein 1eV ═ 1.6 × 10^-19J. Light speed of 3x 10⁸m/s. The energy of ultraviolet light having a wavelength of 185nm (corresponding to 646kJ/mol) was calculated from the formula (3) to be 6.7 eV.

A

When the bond energy between molecules is smaller than the energy (646kJ/mol) emitted by ultraviolet light, the molecular bonds may be broken and disintegrated. On the contrary, when the molecular bond energy is larger than that of the ultraviolet light, the molecular bond is not easily broken. As a result, for example, the molecular bonds shown in Table 1 below may be broken by photolytic reactions. Table 1 contains the vast majority of indoor pollutants or odors.

Table 1: molecular bond and bond energy

Molecular bond	Bond energy (kJ/mol)	Molecular bond	Bond energy (kJ/mol)
				H-O	459	C-S	272
H-C	411	C＝S	573
				H-H	432	O-O	142
H-N	386	O＝O	494
				H-S	363	O-F	190
C-C	346	O＝S	522
				C＝C	602	S＝S	425
C-O	358	S-S	226
				C-F	485	N-O	201
C-Cl	327	N＝O	607

Nitrogen in air is up to 940kJ/mol due to the bonding energy of N ≡ N, and ultraviolet light with the wavelength of 185nm is not enough to decompose nitrogen to generate nitrogen oxides. Nitrogen oxides are generally only likely to be generated at high temperatures (combustion) or high electric fields (e.g., corona discharge from an ozone generator).

The indirect photolytic reaction is also driven by uv light with a wavelength of less than 200 nm. Referring to the reaction formulas shown in the following formulas (4) to (10), the strong energy of the ultraviolet light ionizes oxygen and water vapor in the air to generate ozone, hydronium ions, hydroxyl radicals, hydrogen peroxide, and superoxide ions (or negative oxygen ions, O)₂ ^-) And the like. Such purification factors have strong oxidation/reduction ability, particularly hydroxyl radicals, which rapidly react with pollutants in the air. Because the service life of the purification factors is less than 1ms, namely the purification factors are used up after being discharged from the reaction chamber or are reduced into water, the purification factors have no chance to cause harm to human bodies.

H₂O+hv(＜200nm)→2H⁺+2e^-+1/2O₂..

O₂+hv(＜200nm)→O^·+O^·..

H₂O+H⁺→H₃O⁺The

H₂O+O^·→H₂O₂A.9

O₂+O^·→O₃A.9.a.9.a.

H⁺+e^-+O^·→OH^·a.

The purification factor can perform good sterilization and deodorization effects on pollutants such as peculiar smell in the environment, bacteria, viruses, mold, second-hand smoke and the like attached to the surface, so as to achieve the aim of purifying the environment. Theoretically, the higher the concentration of the purification factor, the better the sterilization and deodorization effects. However, in practical applications, the safety of people living in the environment must be considered, and an excessively high concentration of the purification factor may cause health risks. The amount of these purification factors generated is closely related to the output power of the hot cathode tube 20. The amount of the generated purification factor can be controlled by controlling the output power of the hot cathode fluorescent lamp 20.

The adjustable ballast 100 can adjust the output power of the hot cathode fluorescent lamp 20, so that the ozone concentration at the outlet can be controlled within a safe range. The ozone with the concentration within the safe range not only has the effects of sterilizing and deodorizing and purifying the environment, but also does not harm the human health. Since the hot cathode fluorescent lamp 20 is a negative resistance, its starting current (voltage) is much different from the operating current (voltage). When the operating power is adjusted, the operating current and frequency of the ccfl 20 need to be adjusted within the allowable range. The adjustable ballast 100 of the present embodiment uses a programmable controller (e.g., a microprocessor) and a built-in pulse width modulation function to detect the characteristics of the ccfl 20 and accordingly adjust the operating current and frequency of the ccfl 20. Therefore, the adjustable ballast 100 of the present embodiment can light the lamp and adjust the output power within a certain control range.

Referring to fig. 1, the adjustable ballast 100 includes a driving circuit 110 and a feedback control circuit 120. The dc power supply 10 may supply power to the driving circuit 110. The driving circuit 110 can provide power EE to drive the hot cathode fluorescent lamp 20 (e.g., an ultraviolet fluorescent lamp). When the ccfl 20 is activated, the driving circuit 110 first raises the tube voltage to turn on the two end electrodes of the ccfl 20, and further excites the gas discharge to generate light energy (e.g., ultraviolet light) EL. When the hot cathode tube 20 is turned on, the driving circuit 110 drops the voltage in real time to avoid burning the tube, and the driving circuit 110 drives the hot cathode tube 20 in the high frequency resonance mode to maintain the stable light energy EL.

The feedback control circuit 120 is coupled to the driving circuit 110. The feedback control circuit 120 can obtain feedback information related to the light energy EL from the ccfl 20. The feedback control circuit 120 controls the driving circuit 110 according to the feedback information to adjust the frequency and the current of the electric energy EE output by the driving circuit 110. That is, the feedback control circuit 120 can dynamically adjust the frequency and current of the driving power EE of the CCFL 20 in response to the light energy EL of the CCFL 20. Therefore, the adjustable ballast 100 can adjust the output power of the ccfl 20 in a feedback manner.

In some embodiments, the feedback control circuit 120 may also receive power adjustment commands from a user interface circuit (not shown), depending on design requirements. The feedback control circuit 120 can dynamically adjust the frequency and current of the driving power EE of the ccfl 20 in response to the power adjustment command, so as to adjust the output power of the ccfl 20.

Fig. 2 is a flowchart illustrating a driving method of an adjustable ballast according to an embodiment of the invention. Please refer to fig. 1 and fig. 2. The adjustable ballast 100 can drive the hot cathode fluorescent lamp 20 to generate light energy EL. In step S210, the driving circuit 110 provides the electric energy EE to drive the ccfl 20, so as to enable the ccfl 20 to generate the light energy EL. In step S220, the feedback control circuit 120 obtains feedback information related to the light energy EL from the hot cathode fluorescent lamp 20. In step S230, the feedback control circuit 120 controls the driving circuit 110 according to the feedback information to adjust the frequency and the current of the electric energy EE.

Fig. 3 is a circuit block diagram of an adjustable ballast 300 according to another embodiment of the invention. The adjustable ballast 300 shown in fig. 3 includes a driving circuit 310, a feedback control circuit 320 and a protection circuit 330. The protection circuit 330 may prevent the adjustable ballast 300 from over-current and/or over-voltage events. For example, the protection circuit 330 may prevent an unexpected excessive current (or voltage) from impacting the adjustable ballast 300. The embodiment does not limit the implementation of the protection circuit 330. For example, the protection circuit 330 may be a conventional ballast protection circuit or other protection circuit/device.

The dc power supply 10 shown in fig. 3 may supply power to the driving circuit 310 via the protection circuit 330. The present embodiment does not limit the embodiment of the dc power supply 10. For example, the dc power supply 10 may be a power adapter providing a small dc voltage (less than 50 volts), a mains rectifier, an onboard dc power supply, or other dc power circuit.

The driving circuit 310 shown in fig. 3 includes a resonant circuit 311 and an inverter circuit 312. The present embodiment does not limit the implementation of the resonance circuit 311. For example, the resonant circuit 311 may be an existing resonant circuit or other resonant circuit/component. In some embodiments, the resonant circuit 311 may be a series resonant series-parallel load (SRSPL) circuit. The inverter circuit 312 is coupled to the resonant circuit 311. The inverter circuit 312 may provide power EE to drive the hot cathode fluorescent lamp 20. For example, the inverter circuit 312 is responsible for boosting the voltage to provide the operating voltage to the hcfc 20.

The feedback control circuit 320 adjusts one or more of at least one inductance value and at least one capacitance value inside the resonant circuit 311 according to the feedback information FB to adjust the frequency and the current of the electric energy EE. The feedback control circuit 320 shown in fig. 3 includes a feedback circuit 321 and a power control circuit 322. The feedback circuit 321 is coupled to the hot cathode tube 20 to obtain feedback information FB related to the light energy EL. For example, the feedback circuit 321 is responsible for detecting and transmitting the power consumption of the load (the ccfl 20) back to the power control circuit 322.

The power control circuit 322 is coupled to the feedback circuit 321 to receive the feedback information FB. The power control circuit 322 controls the driving circuit 310 according to the feedback information FB to adjust the frequency and the current of the power EE. The power control circuit 322 may be a microcontroller, microprocessor, or other control circuit/element, depending on design requirements. For example, the feedback information FB may include the current power consumption of the load (the ccfl 20), and the power control circuit 322 may calculate the current value and the frequency value required by the target power, and control the resonant circuit 311 and/or the inverter circuit 312 according to the calculation result to adjust the frequency and the current of the power EE.

In other words, the power control circuit 322 can instantly know the current power consumption of the ccfl 20 in a dynamic sensing manner. The power control circuit 322 can dynamically adjust the frequency and current of the driving power EE of the ccfl 20 in response to the current power consumption (or the light energy EL) of the ccfl 20. Therefore, the adjustable ballast 300 can feedback and adjust the output power of the ccfl 20.

In some embodiments, power control circuitry 322 may also receive power adjustment instructions from user interface circuitry (not shown), depending on design requirements. The power control circuit 322 can dynamically adjust the frequency and current of the driving power EE of the ccfl 20 in response to the power adjustment command, so as to adjust the output power of the ccfl 20. For example, when receiving the power adjustment command, the power control circuit 322 may calculate the power to be adjusted, and then adjust the frequency of the resonant circuit 311 and the output current of the inverter circuit 312 to change the output power of the ccfl 20.

Fig. 4 is a circuit diagram illustrating the resonant circuit 311 shown in fig. 3 according to an embodiment of the invention. The resonant circuit 311 shown in fig. 4 includes an inductor L1 and a capacitor C1. A first terminal of the capacitor C1 is coupled to a first terminal of the inductor L1. The second terminal of the capacitor C1 is coupled to the first filament of the ccfl 20. The resonant circuit 311 may be selectively configured with a capacitor C2 according to design requirements. A first terminal of the capacitor C2 is coupled to a first filament of the ccfl 20. The second terminal of the capacitor C2 is coupled to the second filament of the ccfl 20.

The resonant frequency of the resonant circuit 311 shown in fig. 4 is affected by the inductance value of the inductor L1. The power control circuit 322 of the feedback control circuit 320 may adjust the inductance of the inductor L1 according to the feedback information FB. The present embodiment does not limit the implementation of the inductance L1. For example, the inductor L1 may be a conventional variable inductor or other inductor-type device/circuit. In some embodiments, the inductance L1 may comprise a coil with multiple taps (an adjustable inductor). The resonant frequency is changed by switching/selecting different taps to change the inductance of the inductor L1.

The resonant frequency of the resonant circuit 311 shown in fig. 4 is also affected by the capacitance value of the capacitor C1. The power control circuit 322 of the feedback control circuit 320 may adjust the capacitance of the capacitor C1 according to the feedback information FB. The present embodiment does not limit the implementation of the capacitor C1. For example, the capacitor C1 may be a conventional variable capacitor or other capacitive element/circuit. The pulse width modulation function of the microprocessor is used to slowly adjust the capacitance value to gently change the resonant frequency.

The square wave is expanded into Fourier series by using the basic wave approximation method, namely, the waveform can be regarded as a composite body consisting of a plurality of sine waves. The quality factor Q of the resonant circuit 311 can be determined according to design requirements, and the resonant circuit 311 can be an effect circuit of a high frequency filter. When the angular frequency is between the fundamental wave and the second harmonic, only the sine wave of the first harmonic exists, that is, only the sine wave voltage with the same frequency as the square wave voltage exists, so the input voltage can be considered as the sine wave. Based on this mode, the transfer function F (Vo/Vi) of the output to the input can be written as

Wherein the quality factor

w_sR is the resistance of the ccfl 20, L is the inductance of the inductor L1, and c is the switching frequency₁Is the capacitance value of the capacitor C1, C₂Is the capacitance value of the capacitor C2.

When the preheating starting stage is not conducted, the R value is relatively large, the quality factor Q value is also relatively large, and the voltage gain value is only close to 1. Trigger start phase, switch switching frequency w_sThe voltage gain is then increased with decreasing voltage. After the hot cathode fluorescent lamp 20 is turned on, the R value is rapidly decreased so that the Q value is decreased, the voltage is decreased, the resonance frequency is converged, and the heat is generatedThe cathode lamp 20 enters a stable light emitting state at the resonance frequency. If the L value and c are adjusted instantaneously₁Value and/or c₂The surge is easily generated, and the capacitor or the oscillating switch (transistor) is damaged due to the failure. Therefore, the PWM function of the power control circuit 322 (e.g., microprocessor) can gradually adjust the L value and c value₁Value and/or c₂The value is obtained.

Fig. 5 is a circuit diagram illustrating the resonant circuit 311, the inverter circuit 312 and the feedback circuit 321 shown in fig. 3 according to another embodiment of the invention. In the embodiment shown in fig. 5, the inverter circuit 312 includes a transformer T1, a switch Q1, a diode D1, a capacitor C3, a switch Q2, and a diode D2. The transformer T1 has a first coil L2, a second coil L3, a third coil L4 and a fourth coil L5. The first end of the first coil L2 and the first end of the third coil L4 are both coupled to the first DC voltage path DC1, that is, the first end of the first coil L2 and the first end of the third coil L4 can both receive the first voltage of the DC power supply 10 through the first DC voltage path DC1 and the protection circuit 330 (marked as "+" in fig. 5). The second end of the first coil L2 is coupled to the first end of the second coil L3. A second end of the third coil L4 is coupled to a first end of the first filament 21 of the hot cathode tube 20.

A first terminal of switch Q1 is coupled to a first DC voltage path DC 1. The second terminal of the switch Q1 is coupled to the second DC voltage path DC2, i.e., the second terminal of the switch Q1 can receive the second voltage (labeled as "") of the DC power supply 10 through the second DC voltage path DC2 and the protection circuit 330. A control terminal of the switch Q1 is coupled to the second terminal of the first coil L2 and the first terminal of the fourth coil L5. The cathode of diode D1 is coupled to a first DC voltage path DC 1. The anode of the diode D1 is coupled to the second direct voltage path DC 2. A first terminal of capacitor C3 is coupled to a first DC voltage path DC 1. A second terminal of the capacitor C3 is coupled to a second terminal of the second coil L3 and a first terminal of the second filament 22 of the hot cathode tube 20. A first terminal of the switch Q2 is coupled to a second terminal of the capacitor C3. A second terminal of the switch Q2 is coupled to the second direct voltage path DC 2. A control terminal of the switch Q2 is coupled to the second terminal of the fourth coil L5. The cathode of the diode D2 is coupled to the second terminal of the capacitor C3. The anode of the diode D2 is coupled to the second direct voltage path DC 2.

In the embodiment shown in fig. 5, the adjustable ballast 300 further includes a capacitor C2. A first terminal of the capacitor C2 is coupled to a second terminal of the first filament 21 of the hot cathode tube 20. A second terminal of the capacitor C2 is coupled to a second terminal of the second filament 22 of the hot cathode tube 20. The capacitor C2 can maintain the voltage difference between the first filament 21 and the second filament 22.

The first coil L2, the second coil L3, and the third coil L4 shown in fig. 5 may also be members of the resonance circuit 311. In addition, the resonant circuit 311 further includes an inductor L1 and a capacitor C1. A first terminal of inductor L1 is coupled to first direct current path DC 1. A second terminal of the inductor L1 is coupled to a second terminal of the first coil L2. One or more of the inductor L1, the coil L2, the coil L3 and the coil L4 may include a variable coil (variable inductor) according to design requirements. The variable coil (variable inductor) can be analogized by referring to the description of the inductor L1 shown in fig. 4, and thus, the description thereof is omitted. The power control circuit 322 of the feedback control circuit 320 may adjust the inductance of one or more of the inductor L1, the first coil L2, the second coil L3, and the third coil L4 according to the feedback information. For example, the power control circuit 322 of the feedback control circuit 320 may adjust the frequency (or resonant frequency) of the electric energy EE by changing the inductance value of one or more of the inductance L1, the first coil L2, the second coil L3, and the third coil L4.

A first terminal of the capacitor C1 is coupled to a second terminal of the third coil L4. The second terminal of the capacitor C1 is coupled to the first terminal of the first filament 21 of the hot cathode tube 20. The power control circuit 322 of the feedback control circuit 320 may adjust the capacitance of the capacitor C1 according to the feedback information. For example, the power control circuit 322 of the feedback control circuit 320 can adjust the current of the power EE (or the current of the filament) by changing the capacitance value of the capacitor C1.

In the embodiment shown in fig. 5, the feedback circuit 321 of the feedback control circuit 320 includes a capacitor C4, a capacitor C5, and a capacitor C6. The first terminal of the capacitor C4 is coupled to the second terminal of the first filament 21 of the ccfl 20 to receive the signal S1. A second terminal of the capacitor C4 is coupled to the power control circuit 322. The first terminal of the capacitor C5 is coupled to the first terminal of the second filament 22 of the ccfl 20 to receive the signal S2. A second terminal of the capacitor C5 is coupled to the power control circuit 322. The first terminal of the capacitor C6 is coupled to the control terminal of the switch Q1 to receive the signal S3. The power control circuit 322 shown in fig. 5 is further coupled to a control terminal of the switch Q1 for receiving the signal S3. The second terminal of the capacitor C6 is coupled to a reference voltage (e.g., ground or other fixed voltage).

The power control circuit 322 may calculate the control signal CL and/or the control signal CC according to the signal S1, the signal S2, and/or the signal S3. The power control circuit 322 may output a control signal CL to the inductor L1 to adjust the inductance value of the inductor L1. The power control circuit 322 may output a control signal CC to the capacitor C1 to adjust the capacitance value of the capacitor C1. By adjusting the inductance of the inductor L1 and/or the capacitance of the capacitor C1, the frequency and current of the power EE can be changed, thereby dynamically adjusting the power consumption of the ccfl 20. In other words, the power control circuit 322 can control the resonant circuit 311 and/or the inverter circuit 312 according to the signal S1, the signal S2 and/or the signal S3 to adjust the frequency and the current of the power EE.

The power control circuit 322 of the feedback control circuit 320 may also be coupled to the user interface circuit 30 and the fan module 40 according to design requirements. The embodiment of the user interface circuit 30 and the fan module 40 is not limited. For example, the user interface circuit 30 may be an existing user interface circuit or other user interface circuit, and the fan module 40 may be an existing fan circuit or other fan circuit/component. The power control circuit 322 of the feedback control circuit 320 may control the speed of the fan module 40 according to the wind speed command from the user interface circuit 30.

The power control circuit 322 of the feedback control circuit 320 can also correspondingly control the driving circuit 310 according to the rotation speed of the fan module 40 to adjust the frequency and the current of the electric energy EE. When the rotation speed of the fan module 40 increases, the power control circuit 322 of the feedback control circuit 320 can adjust the frequency and the current of the electric energy EE to increase the output power of the hctube 20. When the rotation speed of the fan module 40 decreases, the power control circuit 322 of the feedback control circuit 320 can adjust the frequency and the current of the power EE to decrease the output power of the ccfl 20. Therefore, in some applications, the power control circuit 322 can adjust the ozone yield of the uv lamp (the ccfl 20) in real time to maintain the device outlet ozone concentration within an effective and safe range, without causing the outlet ozone concentration to be too high or too low due to the change of the air volume.

The blocks of the power Control circuit 322 can be implemented by a logic circuit (hardware) formed on an integrated circuit (integrated circuit), or can be implemented by a Central Processing Unit (CPU) or a Micro-controller (MCU) and a software program for controlling the logic circuit. In the latter case, the related functions of the power control circuit 322 may be implemented as programming codes of software (i.e., programs). The power control circuit 322 is implemented, for example, by programming in a general programming language (e.g., C or C + +) or a combination language of the MCU's instruction set. The software (i.e., program) can be Read by a microcomputer (CPU or MCU) and can be recorded/stored in a non-volatile Memory such as a Read Only Memory (ROM) or an Electrically Erasable Programmable Read-Only Memory (EEPROM) or a FLASH Memory (FLASH). And, the program is read from the recording medium and executed by a microcomputer (CPU or MCU), thereby achieving the related functions. As the recording medium, a "non-transitory computer readable medium" may be used, and for example, a tape (tape), a disk (disk), a card (card), a semiconductor memory, a programmable logic circuit, or the like may be used. The program may be supplied to the microcomputer (CPU or MCU) via any transmission medium (communication network, broadcast wave, etc.). Such as the Internet, wired communication, wireless communication, or other communication media.

In different application scenarios, the related functions of the power control circuit 322 may be implemented as firmware or hardware using a general programming language (e.g., C, C + + or combinatorial language), a hardware description language (e.g., Verilog HDL or VHDL), or other suitable programming languages. For a hardware implementation, various logic blocks, modules, and circuits within one or more controllers, microcontrollers, microprocessors, Application-specific integrated circuits (ASICs), Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), and/or other processing units may be used to implement or perform the functions described in the embodiments herein. Additionally, the apparatus and methods of the present invention may be implemented by a combination of hardware, firmware, and/or software.

Fig. 6 is a circuit diagram illustrating the resonant circuit 311, the inverter circuit 312 and the feedback circuit 321 shown in fig. 3 according to another embodiment of the invention. The adjustable ballast 300 includes an inverter circuit 312, a feedback control circuit 320, a protection circuit 330, an inductor L1, a capacitor C1, and a capacitor C2. In the embodiment shown in fig. 6, the inverter circuit 312 includes a transformer T1, a Solid State Relay (SSR) 1, a SSR2, a diode D3, a diode D4, a capacitor C7, and a resistor R1. The transformer T1 has a first coil L2, a second coil L3, a third coil L4 and a fourth coil L5. The inductor L1, the first coil L2, the second coil L3, the third coil L4 and the capacitor C1 shown in fig. 6 can be used as components of the resonant circuit 311 shown in fig. 3. The transformer T1, the feedback control circuit 320, the protection circuit 330, the inductor L1, the capacitor C1, and the capacitor C2 shown in fig. 6 can be analogized with reference to the related descriptions of fig. 3 and fig. 5, and therefore, the description thereof is omitted.

A cathode of the diode D3 and a first terminal of the capacitor C7 are coupled to the first DC voltage path DC 1. The cathode of the diode D4 is coupled to the second terminal of the capacitor C7, the second terminal of the second coil L3, and the first terminal of the second filament 22 of the hot cathode fluorescent lamp 20. A first terminal of the resistor R1 is coupled to the anode of the diode D3 and the anode of the diode D4. The second terminal of the resistor R1 is coupled to the second DC voltage path DC2, i.e., the second terminal of the resistor R1 can receive the second voltage (labeled as "-") of the DC power supply 10 via the second DC voltage path DC2 and the protection circuit 330.

A first end of the solid state relay SSR1 is coupled to a first DC voltage path DC 1. The control terminal of the solid state relay SSR1 is coupled to the second terminal of the first coil L2 and the first terminal of the fourth coil L5. The second terminal of the solid state relay SSR1 is coupled to the anode of the diode D3, the anode of the diode D4, and the first terminal of the resistor R1. The first terminal of the solid state relay SSR2 is coupled to the second terminal of the capacitor C7. A second terminal of the solid state relay SSR2 is coupled to the second direct voltage path DC 2. The control terminal of the solid state relay SSR2 is coupled to the second terminal of the fourth coil L5.

In the embodiment shown in fig. 6, the feedback circuit 321 of the feedback control circuit 320 includes a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a capacitor C8, and a capacitor C9. The first terminal of the resistor R2 is coupled to the second terminal of the first filament 21 of the ccfl 20 to receive the signal S1. A second terminal of the resistor R2 is coupled to the power control circuit 322. The first terminal of the resistor R3 is coupled to the second terminal of the resistor R2. A second terminal of the resistor R3 is coupled to the second direct voltage path DC 2. A first terminal of the resistor R4 is coupled to a first terminal of the second filament 22 of the ccfl 20 to receive the signal S2. The second terminal of the resistor R4 is coupled to the first terminal of the capacitor C8. A second terminal of the capacitor C8 is coupled to the power control circuit 322. The first terminal of the resistor R5 is coupled to the second terminal of the resistor R4. A second terminal of the resistor R5 is coupled to the second direct voltage path DC 2. A first terminal of the resistor R6 is coupled to the control terminal of the solid state relay SSR1 to receive the signal S3. The second terminal of the resistor R6 is coupled to the first terminal of the capacitor C9. A second terminal of the capacitor C9 is coupled to the power control circuit 322. The first terminal of the resistor R7 is coupled to the second terminal of the resistor R6. A second terminal of the resistor R7 is coupled to the second direct voltage path DC 2. The power control circuit 322 shown in fig. 6 can be analogized with reference to the related descriptions of fig. 3 and fig. 5, and therefore, the description thereof is omitted.

In summary, the adjustable ballast and the driving method thereof according to the embodiments of the invention can obtain feedback information related to the light energy EL from the ccfl 20. According to the feedback information, the feedback control circuit can dynamically control the driving circuit to adjust the frequency and current of the driving power EE of the ccfl 20. Therefore, the adjustable ballast can feedback and adjust the output power of the hot cathode fluorescent lamp 20.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. An adjustable ballast for driving a hot cathode tube to generate light energy, the adjustable ballast comprising:

the driving circuit is used for providing electric energy to drive the hot cathode lamp tube; and

a feedback control circuit coupled to the driving circuit, wherein the feedback control circuit is used for obtaining feedback information related to the light energy from the hot cathode fluorescent lamp, and the feedback control circuit controls the driving circuit to adjust the frequency and the current of the electric energy according to the feedback information.

2. The adjustable ballast according to claim 1, wherein the driving circuit comprises:

a resonant circuit; and

an inverter circuit coupled to the resonant circuit for driving the hot cathode fluorescent lamp;

wherein the feedback control circuit adjusts one or more of at least one inductance value and at least one capacitance value of the resonant circuit according to the feedback information to adjust the frequency and the current of the electrical energy.

3. The adjustable ballast of claim 2, wherein the resonant circuit comprises:

an inductor, wherein the feedback control circuit adjusts an inductance value of the inductor according to the feedback information; and

a first capacitor having a first terminal coupled to the first terminal of the inductor, wherein a second terminal of the first capacitor is configured to be coupled to a first filament of the hot cathode tube, and the feedback control circuit adjusts a capacitance of the first capacitor according to the feedback information.

4. The adjustable ballast of claim 3, wherein said resonant circuit further comprises:

a second capacitor having a first terminal coupled to the first filament of the hot cathode tube, wherein a second terminal of the second capacitor is coupled to a second filament of the hot cathode tube.

5. The adjustable ballast according to claim 2, wherein the inverter circuit comprises:

a transformer having a first coil, a second coil, a third coil and a fourth coil, wherein a first end of the first coil is coupled to a first direct current voltage path, a second end of the first coil is coupled to a first end of the second coil, a first end of the third coil is coupled to the first direct current voltage path, and a second end of the third coil is coupled to a first end of a first filament of the hot cathode tube;

a first switch having a first terminal coupled to the first DC voltage path, wherein a second terminal of the first switch is coupled to a second DC voltage path, and a control terminal of the first switch is coupled to the second terminal of the first coil and a first terminal of the fourth coil;

a first diode having a cathode coupled to the first DC voltage path, wherein an anode of the first diode is coupled to the second DC voltage path;

a first capacitor having a first terminal coupled to the first DC voltage path, wherein a second terminal of the first capacitor is coupled to a second terminal of the second coil and a first terminal of a second filament of the hot cathode tube;

a second switch having a first terminal coupled to the second terminal of the first capacitor, wherein a second terminal of the second switch is coupled to the second DC voltage path, and a control terminal of the second switch is coupled to a second terminal of the fourth coil; and

a second diode having a cathode coupled to the second end of the first capacitor, wherein an anode of the second diode is coupled to the second DC voltage path.

6. The adjustable ballast of claim 5, wherein the resonant circuit comprises:

an inductor having a first end coupled to the first DC voltage path, wherein a second end of the inductor is coupled to the second end of the first coil;

the first coil;

the second coil;

the third coil, wherein the feedback control circuit adjusts an inductance value of one or more of the inductance, the first coil, the second coil, and the third coil based on the feedback information; and

a second capacitor having a first terminal coupled to the second terminal of the third coil, wherein a second terminal of the second capacitor is coupled to the first terminal of the first filament of the hot cathode tube, and the feedback control circuit adjusts a capacitance value of the second capacitor according to the feedback information.

7. The adjustable stabilizer according to claim 5, further comprising:

a second capacitor having a first terminal coupled to a second terminal of the first filament of the hot cathode tube, wherein a second terminal of the second capacitor is coupled to a second terminal of the second filament of the hot cathode tube.

8. The adjustable ballast according to claim 2, wherein the inverter circuit comprises:

a first solid state relay having a first terminal, a second terminal, and a control terminal, wherein the first terminal of the first solid state relay is coupled to the first DC voltage path, and the control terminal of the first solid state relay is coupled to the second terminal of the first coil and a first terminal of the fourth coil;

a first diode having a cathode coupled to the first DC voltage path, wherein an anode of the first diode is coupled to the second terminal of the first solid state relay;

a second solid state relay having a first terminal, a second terminal, and a control terminal, wherein the first terminal of the second solid state relay is coupled to the second terminal of the first capacitor, the second terminal of the second solid state relay is coupled to a second DC voltage path, and the control terminal of the second solid state relay is coupled to a second terminal of the fourth coil;

a second diode having a cathode coupled to the second terminal of the first capacitor, wherein an anode of the second diode is coupled to the anode of the first diode; and

a resistor having a first terminal coupled to the anode of the first diode, wherein a second terminal of the resistor is coupled to the second DC voltage path.

9. The adjustable ballast according to claim 1, wherein the feedback control circuit comprises:

a feedback circuit coupled to the CCFL to obtain the feedback information related to the light energy; and

a power control circuit coupled to the feedback circuit to receive the feedback information, wherein the power control circuit controls the driving circuit according to the feedback information to adjust the frequency and the current of the electric energy.

10. The adjustable ballast as claimed in claim 1, wherein the feedback control circuit further controls the driving circuit to adjust the frequency and the current of the electrical energy according to a rotation speed of a fan module.

11. The adjustable stabilizer according to claim 10,

when the rotating speed of the fan module is increased, the feedback control circuit adjusts the frequency and the current of the electric energy so as to increase the output power of the hot cathode lamp tube; and

when the rotating speed of the fan module is reduced, the feedback control circuit adjusts the frequency and the current of the electric energy so as to reduce the output power of the hot cathode fluorescent lamp.

12. The adjustable stabilizer according to claim 10, wherein the feedback control circuit further controls the rotation speed of the fan module according to a wind speed command from a user interface circuit.

13. A driving method of an adjustable ballast, wherein the adjustable ballast is used for driving a hot cathode fluorescent lamp to generate light energy, the driving method comprising:

providing electric energy by a driving circuit to drive the hot cathode lamp tube;

obtaining feedback information relating to the light energy from the hot cathode tube by a feedback control circuit; and

and the feedback control circuit controls the driving circuit according to the feedback information to adjust the frequency and the current of the electric energy.

14. The driving method according to claim 13, wherein the step of controlling the driving circuit includes:

adjusting, by the feedback control circuit, one or more of at least one inductance value and at least one capacitance value of a resonant circuit of the driving circuit according to the feedback information to adjust the frequency and the current of the electrical energy.

15. The driving method according to claim 13, further comprising:

and controlling the driving circuit by the feedback control circuit according to the rotating speed of the fan module so as to adjust the frequency and the current of the electric energy.

16. The driving method according to claim 15, wherein the step of controlling the driving circuit in accordance with the rotation speed of the fan module includes:

when the rotating speed of the fan module is increased, the frequency and the current of the electric energy are adjusted by the feedback control circuit, so that the output power of the hot cathode lamp tube is increased; and

when the rotating speed of the fan module is reduced, the frequency and the current of the electric energy are adjusted by the feedback control circuit, so that the output power of the hot cathode fluorescent lamp is reduced.

17. The driving method according to claim 15, further comprising:

the feedback control circuit controls the rotating speed of the fan module according to a wind speed instruction of the user interface circuit.