Driving circuit and lamp set

Abstract

The application provides a driving circuit and a lamp set, wherein a DC voltage signal is boosted and converted by a switch power driver control function circuit included in a power regulating circuit, a constant voltage signal can be obtained, the constant voltage signal can be constant current output by a linear constant current circuit, and the constant voltage constant current power supply is used for power supply. The driving circuit has simple structure, can realize higher power density design of the power supply, saves the cost of the driving power supply circuit system, is easier to produce and manufacture, and is modularized and shared in the library design. The driving circuit combines the power regulating circuit and the linear constant current circuit, can realize better line voltage regulation rate and load regulation rate performance, has lower harmonic current value, higher power factor value, and lower output current ripple value and other key performance indicators, can provide constant voltage constant current signals, has wide voltage input and no frequency flash output performance, and can meet the constant voltage constant current power supply demand.

Description

Technical Field

[0001] This invention relates to the field of power supply circuit technology, and in particular to a driving circuit and a lamp assembly. Background Technology

[0002] Light-emitting diodes (LEDs) are widely used in various fields. Due to the inherent characteristics of LEDs, using a constant current driving scheme can protect LEDs from excessive current, which could shorten their lifespan or even cause them to burn out.

[0003] Currently, constant current driving solutions for LEDs typically include switching power supply driving solutions and linear driving solutions. Switching power supply driving solutions usually contain a large number of functional circuits or components, which not only increases the complexity of LED constant current driving but also increases the cost of LED driving. Linear driving solutions typically achieve linear constant current driving of LEDs through operational amplifiers, but this solution cannot meet the performance requirements of wide voltage input and flicker-free output.

[0004] Therefore, there is an urgent need to provide a new driving circuit. Summary of the Invention

[0005] This invention provides a driving circuit and a lamp assembly to overcome the deficiencies in the prior art.

[0006] This invention provides a driving circuit, including: a power regulation circuit and a linear constant current circuit, wherein the power regulation circuit is connected to the linear constant current circuit;

[0007] The power regulation circuit includes a switching power supply driver and a functional circuit connected to the switching power supply driver. The switching power supply driver is used to control the functional circuit to boost the DC voltage signal to obtain a constant voltage signal.

[0008] The linear constant current circuit is used to output the constant voltage signal as a constant current.

[0009] According to a driving circuit provided by the present invention, the linear constant current circuit includes a linear constant current driver and a current sampling resistor;

[0010] The output current setting pin of the linear constant current driver is connected to the current sampling resistor to ground.

[0011] The linear constant current driver outputs a constant current signal through its constant current output pin.

[0012] According to a driving circuit provided by the present invention, the linear constant current circuit further includes a filtering sampling feedback circuit;

[0013] The filtering sampling feedback circuit includes a voltage sampling resistor and a filtering capacitor. The two ends of the voltage sampling resistor are respectively connected to the voltage sampling pins of the power regulation circuit and the linear constant current driver.

[0014] The voltage sampling pin of the linear constant current driver is connected to the filter capacitor and then to ground.

[0015] According to a driving circuit provided by the present invention, the switching power supply driver is a switching power supply driver chip;

[0016] The functional circuit includes an inductor, a boost freewheeling diode, a driver startup power supply circuit, and a driver feedback circuit. One end of the inductor is connected to the DC voltage signal, and the other end of the inductor is connected to the positive terminal of the boost freewheeling diode. The negative terminal of the boost freewheeling diode is connected to the linear constant current circuit.

[0017] The input terminal of the driver startup power supply circuit is connected to the DC voltage signal, and the output terminal of the driver startup power supply circuit is connected to the power supply pin of the switching power supply driver chip.

[0018] The output pin of the power switch transistor built into the switching power supply driver chip is connected to the positive terminal of the boost freewheeling diode.

[0019] The driver feedback circuit is connected to the feedback pin of the switching power supply driver chip and the negative terminal of the boost freewheeling diode, respectively.

[0020] According to a driving circuit provided by the present invention, the driver startup power supply circuit includes a first resistor and a first capacitor;

[0021] One end of the first resistor is connected to the DC voltage signal, and the other end of the first resistor is connected to the power supply pin.

[0022] The power supply pin is connected to the first capacitor and then to ground.

[0023] According to a driving circuit provided by the present invention, the driver feedback circuit includes a second resistor, a third resistor, and a second capacitor;

[0024] The negative terminal of the boost freewheeling diode, the second resistor, and the third resistor are connected in sequence, and the third resistor is grounded;

[0025] The feedback pin is connected to the third resistor to ground, and the second capacitor is connected in parallel with the third resistor.

[0026] According to a driving circuit provided by the present invention, the functional circuit further includes a fourth resistor;

[0027] The primary current sampling pin of the switching power supply driver chip is connected to the fourth resistor to ground.

[0028] According to a driving circuit provided by the present invention, the power regulation circuit further includes an output filter electrolytic capacitor;

[0029] One end of the output filter electrolytic capacitor is connected to the negative terminal of the boost freewheeling diode, and the other end of the output filter electrolytic capacitor is grounded.

[0030] According to a driving circuit provided by the present invention, a rectifier filter protection circuit is further included, wherein the rectifier filter protection circuit is connected to the power regulation circuit;

[0031] The rectifier-filter protection circuit is used to rectify and filter the AC voltage signal to obtain the DC voltage signal.

[0032] The switching power supply driver is also used to control the functional circuit to perform power factor correction on the DC voltage signal.

[0033] The present invention also provides a lamp assembly, including a lamp assembly body and the above-mentioned driving circuit, wherein the linear constant current circuit is connected to the lamp assembly body;

[0034] The driving circuit is used to supply power to the lamp assembly body.

[0035] The driving circuit and lamp assembly provided by this invention use a switching power supply driver control circuit included in the power regulation circuit to boost and convert a DC voltage signal into a constant voltage signal. A linear constant current circuit then outputs this constant voltage signal as a constant current power supply. This driving circuit not only has a simple structure and allows for higher power density design, but also saves on the cost of the driving power supply circuit system, making it easier to manufacture and design with a modular shared library. Furthermore, by combining the power regulation circuit with the linear constant current circuit, this driving circuit achieves good line voltage regulation and load regulation performance, exhibiting key performance indicators such as low harmonic current, high power factor, and low output current ripple. It can provide constant voltage and constant current signals, has wide voltage input and flicker-free output performance, and can meet the constant voltage and constant current power supply requirements. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on the drawings described below without creative effort.

[0037] Figure 1This is a schematic diagram of the drive circuit provided by the present invention;

[0038] Figure 2 This is one of the schematic diagrams showing the connection between the linear constant current circuit and the target load in the driving circuit provided by the present invention;

[0039] Figure 3 This is the second schematic diagram showing the connection between the linear constant current circuit and the target load in the driving circuit provided by this invention;

[0040] Figure 4 This is a schematic diagram of the power regulation circuit in the drive circuit provided by the present invention;

[0041] Figure 5 This is a schematic diagram of the rectifier filter protection circuit in the driving circuit provided by the present invention;

[0042] Figure 6 This is the third schematic diagram showing the connection between the linear constant current circuit and the target load in the driving circuit provided by this invention;

[0043] Figure 7 This is the fourth schematic diagram showing the connection between the linear constant current circuit and the target load in the driving circuit provided by this invention;

[0044] Figure 8 This is one of the schematic diagrams of the driving circuit provided by the present invention applied to driving LED lamps;

[0045] Figure 9 This is the second schematic diagram of the driving circuit provided by the present invention applied to driving LED lamps;

[0046] Figure 10 This is a schematic diagram of the structure of the lamp assembly provided by the present invention.

[0047] Figure label:

[0048] 1: Power regulation circuit; 11: Switching power supply driver; 111: Switching power supply driver chip; 12: Functional circuit; 121: Inductor; 122: Boost freewheeling diode; 123: Driver startup power supply circuit; 124: Driver feedback circuit; 1231: First resistor; 1232: First capacitor; 1233: Fourth resistor; 1241: Second resistor; 1242: Third resistor; 1243: Second capacitor; 125: Output filter electrolytic capacitor; 2: Linear constant current circuit; 21: Linear constant current driver; 3: Target load; 31: Reverse diode; 4: Rectifier filter protection circuit; 41: Protection circuit; 42: Rectifier filter circuit; 421: Post-bridge filter energy storage capacitor; 101: Lamp assembly body; 102: Driver circuit. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] Because existing constant current driving schemes for LEDs cannot simultaneously meet the performance requirements of simple structure, wide voltage input, and flicker-free output, this invention provides a new driving circuit that is not only simple in structure but also meets the performance requirements of wide voltage input and flicker-free output.

[0051] Figure 1 This is a schematic diagram of the driving circuit provided in an embodiment of the present invention, such as... Figure 1 As shown, the driving circuit includes: a power regulation circuit 1 and a linear constant current circuit 2, wherein the power regulation circuit 1 is connected to the linear constant current circuit 2;

[0052] The power regulation circuit 1 includes a switching power supply driver 11 and a functional circuit 12 connected to the switching power supply driver 11. The switching power supply driver 11 is used to control the functional circuit 12 to perform boost conversion on the DC voltage signal to obtain a constant voltage signal.

[0053] The linear constant current circuit 2 is used to output the constant voltage signal as a constant current.

[0054] Specifically, in this embodiment of the invention, the driving circuit may include a power regulation circuit 1 and a linear constant current circuit 2 connected together. The input of the power regulation circuit 1 is a DC voltage signal, which may originate from a DC voltage source or be obtained by rectifying and filtering the initial signal output from the power grid; no specific limitation is made here.

[0055] The power regulation circuit 1 can be used to boost the DC voltage signal to obtain and output a constant voltage signal. Here, boost conversion refers to converting the DC voltage signal into a stable constant voltage signal by increasing the voltage, thus providing a stable power supply voltage source for subsequent circuits. In other words, the amplitude of the constant voltage signal is greater than the amplitude of the DC voltage signal.

[0056] The power regulation circuit 1 may include a switching power supply driver 11 and a functional circuit 12 connected to the switching power supply driver 11. The switching power supply driver 11 is used to drive the power regulation circuit 1 to work, that is, to control the functional circuit 12 to perform boost conversion on the DC voltage signal, thereby obtaining a constant voltage signal.

[0057] The switching power supply driver 11 can be a switching power supply driver chip, which can be a conventional switching power supply driver chip or a chip with power factor correction function, i.e., an active power factor correction (APFC) chip. For example, it can be a single-stage APFC chip such as UC3854, IR1150, LT1508, ML4819, BP3102, BP3105, BP3108, BP3308, BP3309, BP3336D, etc. There is no specific limitation here.

[0058] The functional circuit 12 connected to the switching power supply driver 11 is a peripheral circuit of the switching power supply driver 11, used to supply power to the switching power supply driver 11, and can work with the switching power supply driver 11 to at least realize the boost conversion function of the power regulation circuit 1.

[0059] The input of the linear constant current circuit 2 is a constant voltage signal. The linear constant current circuit 2 can perform linear constant current control on the constant voltage signal, so that the constant voltage signal is output as a constant current signal. That is, the current signal provided by the constant voltage signal has a low harmonic current value and a low current ripple value, thereby supplying power to the target load with constant voltage and constant current power supply requirements.

[0060] Here, the linear constant current circuit 2 may include a linear constant current driver, or it may be based on the linear constant current driver and introduce external circuits to jointly achieve linear constant current control. No specific limitation is made here.

[0061] The target load can be an LED lamp, or other lamps or devices, without specific limitations. That is, the driving circuit provided in this embodiment can output a constant voltage and constant current signal, which can not only provide a stable electrical signal to the LED lamp, but also power other lamps or devices with constant voltage and constant current power requirements. When the target load is an LED lamp, it can include a single LED lamp, or multiple LED lamps combined in series and parallel.

[0062] The driving circuit provided in this embodiment of the invention includes a connected power regulation circuit and a linear constant current circuit. The DC voltage signal is boosted and converted to a constant voltage signal by the switching power supply driver control function circuit included in the power regulation circuit. The linear constant current circuit then outputs the constant voltage signal as a constant current power supply. This driving circuit not only has a simple structure and can achieve higher power density design, but also saves on the cost of the driving power supply circuit system, making it easier to manufacture and design with a modular shared library. Furthermore, by combining the power regulation circuit and the linear constant current circuit, this driving circuit can achieve good line voltage regulation and load regulation performance, with key performance indicators such as low harmonic current value, high power factor, and low output current ripple value. It can provide constant voltage and constant current signals, has wide voltage input and flicker-free output performance, and can meet the constant voltage and constant current power supply requirements.

[0063] Furthermore, this drive circuit architecture, primarily constructed with power regulation and linear constant current circuits, not only guarantees the inherent technical advantages of a two-stage switching drive scheme, such as constant current and power, high power factor, and flicker-free low output current ripple, but also simplifies the first-stage switching constant current power supply circuit, achieving constant control current through the linear constant current circuit. Simultaneously, due to the relatively simple structure of the linear constant current circuit, it fully enables optoelectronic integration design, thus reducing the size of the drive power supply and facilitating manufacturing and assembly. Therefore, the drive circuit in this embodiment of the invention is applicable to the design of medium-to-high power optoelectronic integrated drive schemes, significantly simplifying the overall circuit architecture design.

[0064] Based on the above embodiments, the driving circuit provided in the embodiments of the present invention includes a linear constant current driver and a current sampling resistor;

[0065] The output current setting pin of the linear constant current driver is connected to the current sampling resistor to ground.

[0066] The linear constant current driver outputs a constant current signal through its constant current output pin.

[0067] Specifically, in this embodiment of the invention, the linear constant current circuit may include a linear constant current driver and a current sampling resistor. The linear constant current driver may be a linear constant current driver chip, such as SM2326PG, SM2091E / T, HM7162AES, etc. The linear constant current driver may integrate functional modules such as a constant current control module and an output port high voltage drive module.

[0068] A linear constant current driver may include an output current setting pin (REXT), a constant current output pin (OUT), a ground pin (GND), and a voltage sampling pin (VT). The output current setting pin (REXT), ground pin (GND), and voltage sampling pin (VT) can be located on the first side of the linear constant current driver, while the constant current output pin (OUT) can be located on the second side. There can be one or more constant current output pins (OUT). One or more floating pins (NC) can be provided on both sides of the linear constant current driver.

[0069] The output current setting pin REXT of the linear constant current driver can be connected to a current sampling resistor R. ext To ground, i.e., the current sampling resistor R in the linear constant current circuit. ext One end can be connected to the output current value setting pin REXT, and the current sampling resistor R ext The other end is grounded. At this time, the other pins on the first side of the linear constant current driver can be grounded as floating pins. The second side of the linear constant current driver can contain only one constant current output pin OUT, and the remaining pins can be connected in series with the constant current output pin OUT as floating pins. The target load to be powered is connected between the constant current output pin OUT and the power regulation circuit.

[0070] It is understandable that the constant voltage signal V output by the power regulation circuit... bus The voltage signal V higher than that of the constant current output pin OUT out Therefore, the current flows from the output of the power regulation circuit to the constant current output pin OUT. Thus, for a target load with a conduction direction restriction, the conduction direction should be the same as the current flow direction when the target load is connected. For a target load without a conduction direction restriction, the target load can be connected at will.

[0071] Finally, the linear constant current driver outputs a constant current signal to the target load through the constant current output pin OUT. The linear constant current driver can integrate wired voltage compensation, which, within the rated input voltage range, supplies power to the target load through an external current sampling resistor R. ext The output current is adjusted to maintain a constant input power. The operating current on the target load remains constant under all conditions (e.g., when the input DC voltage signal changes due to mains voltage adjustments), without flickering or current fluctuations.

[0072] like Figure 2 As shown, taking a target load consisting of n LED lights connected in series as an example, the DC voltage signal V in After passing through the power regulation circuit, a constant voltage signal V is output. bus Constant voltage signal V busThe linear constant current driver 21 and the current sampling resistor R in the linear constant current circuit 2 ext The output constant current signal then powers the target load 3.

[0073] The principle of linear constant current circuit to achieve linear constant current is to effectively control the voltage signal of the constant current output pin OUT of linear constant current driver 21, which has the following mathematical expression relationship:

[0074] V out ≥V bus -V LED

[0075] Among them, V LED For the target load voltage, the linear constant current circuit needs to maintain the voltage signal at the constant current output pin OUT of the linear constant current driver (pin 21) greater than or equal to the constant voltage signal V. bus The voltage difference between the target load and the target load, V out =V bus -V LED This is usually referred to as the constant current inflection point voltage. Below this value, the linear constant current driver 21 will be unable to maintain a constant current state.

[0076] In this embodiment of the invention, a constant current signal is output by using a linear constant current driver and a current sampling resistor, which can provide a constant voltage and constant current signal to the target load, simplifying the structure of the driving circuit and reducing the driving cost of the target load.

[0077] Based on the above embodiments, the driving circuit provided in the embodiments of the present invention further includes a filter sampling feedback circuit;

[0078] The filtering sampling feedback circuit includes a voltage sampling resistor and a filtering capacitor. The two ends of the voltage sampling resistor are respectively connected to the voltage sampling pins of the power regulation circuit and the linear constant current driver.

[0079] The voltage sampling pin of the linear constant current driver is connected to the filter capacitor and then to ground.

[0080] Specifically, in the embodiments of the present invention, such as Figure 3 As shown, the linear constant current circuit 2 includes a linear constant current driver 21 and a current sampling resistor R. ext In addition, a filter sampling feedback circuit may be included. This filter sampling feedback circuit may include a voltage sampling resistor R. VT and filter capacitor C c Voltage sampling resistor R VT The two ends are connected to the power regulation circuit and the voltage sampling pin VT of the linear constant current driver 21, respectively.

[0081] Here, the voltage sampling resistor RVT It can be a single resistor with a large resistance value, or it can be formed by connecting several resistors with even larger resistance values ​​in parallel, or by connecting several resistors with smaller resistance values ​​in series. No specific limitation is made here.

[0082] The voltage sampling pin VT of the linear constant current driver 21 is connected to a filter capacitor C. c To ground, i.e., the filter capacitor C c One end is connected to the voltage sampling pin VT, and the filter capacitor C c The other end is grounded.

[0083] Under normal operating conditions of the linear constant current circuit, the linear constant current driver 21 is also in saturation, operating at a constant current. Due to the introduction of the filter sampling feedback circuit, when the DC voltage signal V... in When an anomaly occurs, such as rapid fluctuations, the power regulation circuit affects the DC voltage signal V. in The response adjustment process for rapidly changing conditions is relatively slow, resulting in a constant voltage signal V. bus Overshoot occurs, meaning the input voltage of the linear constant current circuit changes abruptly. In this case, the constant voltage signal V output by the power regulation circuit can be compensated by a filtered sampling feedback circuit. bus The current flowing through the target load fluctuates greatly due to the deep fluctuations.

[0084] At this point, the voltage relationship of the linear constant current circuit can be expressed as:

[0085]

[0086] Among them, V rext The voltage sampling resistor R is after adding a filter sampling feedback circuit. VT The corresponding current control threshold voltage; V ref K1, K2, and K3 are the threshold voltages of the current control terminals when there is no internal filtering sampling feedback circuit in the linear constant current driver 21; K1, K2, and K3 are all fixed constant values ​​inside the linear constant current driver 21.

[0087] From the above formula, we can see that V bus With V rext Negative correlation, while V rext =I out *R ext I out The current at pin REXT is set to the output current value of the linear constant current driver 21, which is also the current at the constant current output pin OUT of the linear constant current driver 21. Therefore, V bus with I out Also negatively correlated, therefore when V bus When the value deviates from the center value of the rated design, the voltage sampling resistor R in the filter sampling feedback circuit can be used to mitigate this.VT Make corrections to optimize the DC voltage signal V in The problem of current fluctuations in the target load and increased power loss of the linear constant current driver during the mutation process is addressed.

[0088] It is understandable that the DC voltage signal V in During the mutation process, V bus When it suddenly drops, via R VT The compensation current decreases, thus compensating for I. out The decline. And V bus When the voltage suddenly increases, the voltage signal V at the constant current output pin OUT of the linear constant current driver... out Increase, via R VT The compensation current also increases, but I out However, the loss decreases due to the increase in compensation current. At this time, the increasing trend of loss of the linear constant current driver is effectively suppressed to protect the reliability of the linear constant current driver.

[0089] In this embodiment of the invention, by adding a filtering sampling feedback circuit to the linear constant current circuit, it is possible not only to compensate for the fluctuating current flowing through the target load caused by the deep fluctuation of the constant voltage signal, but also to optimize the problems of current fluctuation in the target load and increased power loss of the linear constant current driver during the sudden change of the DC voltage signal, thereby further improving the stability of the target load and the reliability of the linear constant current driver.

[0090] Based on the above embodiments, the driving circuit provided in this embodiment of the invention includes a switching power supply driver chip.

[0091] The functional circuit includes an inductor, a boost freewheeling diode, a driver startup power supply circuit, and a driver feedback circuit. One end of the inductor is connected to the DC voltage signal, and the other end of the inductor is connected to the positive terminal of the boost freewheeling diode. The negative terminal of the boost freewheeling diode is connected to the linear constant current circuit.

[0092] The input terminal of the driver startup power supply circuit is connected to the DC voltage signal, and the output terminal of the driver startup power supply circuit is connected to the power supply pin of the switching power supply driver chip.

[0093] The output pin of the power switch transistor built into the switching power supply driver chip is connected to the positive terminal of the boost freewheeling diode.

[0094] The driver feedback circuit is connected to the feedback pin of the switching power supply driver chip and the negative terminal of the boost freewheeling diode, respectively.

[0095] Specifically, such as Figure 4As shown, the switching power supply driver is a switching power supply driver chip. In the power regulation circuit 1, the functional circuit 12 connected to the switching power supply driver chip 111 may include an inductor 121, a boost freewheeling diode 122, a driver startup power supply circuit 123, and a driver feedback circuit 124. One end of the inductor 121 is connected to a DC voltage signal V. in The other end of inductor 121 is connected to the positive terminal of boost freewheeling diode 122, and the negative terminal of boost freewheeling diode 122 is connected to the linear constant current circuit, outputting V. bus .

[0096] A DC voltage signal V is connected to the input terminal of the driver startup power supply circuit 123. in The output terminal of the driver startup power supply circuit 123 is connected to the power supply pin VCC of the switching power supply driver chip 111. To protect the driver startup power supply circuit 123, it is grounded.

[0097] The output pin DRAIN of the power switch transistor built into the switching power supply driver chip 111 is connected to the positive terminal of the boost freewheeling diode 122. Here, the power switch transistor can be a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0098] The driver feedback circuit 124 is connected to the feedback pin FB of the switching power supply driver chip 111 and the negative terminal of the boost freewheeling diode 122, respectively.

[0099] Understandably, for Figure 4 Other devices or connections not appearing in the embodiments of the present invention are not necessary for the embodiments of the present invention, that is, they can be used. Figure 4 The devices or connections mentioned can also be implemented using other devices or connections, therefore no specific limitations are made in the embodiments of the present invention.

[0100] The operating principle of the switching power supply driver chip 111 and the functional circuit 12 connected thereto is as follows: When the voltage signal connected to the power supply pin VCC of the switching power supply driver chip 111 reaches the start-up voltage of the switching power supply driver chip 111, the switching power supply driver chip 111 sends a drive signal to drive the built-in power switching transistor into the conduction state. At this time, a certain amount of operating current flows through the inductor 121, and the electrical energy is stored in the coil of the inductor 121 in the form of magnetic energy.

[0101] When the power switch transistor built into the switching power supply driver chip 111 is turned off, the inductor 121 releases its stored energy, generating a self-induced electromotive force with opposite polarity across the inductor 121. At this time, the voltage at the positive terminal of the boost freewheeling diode 122 will be continuously raised. After the boost freewheeling diode 122 is forward-biased, V is output from the negative terminal of the boost freewheeling diode 122. bus It provides operating current for subsequent circuits.

[0102] Furthermore, through the driver feedback circuit 124, the switching power supply driver chip 111 can precisely control the magnitude of the constant voltage signal output by the power regulation circuit, providing voltage power to the target load and linear constant current circuit in the subsequent stage.

[0103] In this embodiment of the invention, by combining a switching power supply driver chip with a functional circuit, it is possible not only to accurately control the magnitude of the constant voltage signal output by the power regulation circuit, providing voltage power to the target load and linear constant current circuit in the subsequent stage, but also to perform boost conversion to achieve the effect of constant voltage.

[0104] Based on the above embodiments, the driving circuit provided in the embodiments of the present invention includes a first resistor and a first capacitor in the driver startup power supply circuit.

[0105] One end of the first resistor is connected to the DC voltage signal, and the other end of the first resistor is connected to the power supply pin.

[0106] The power supply pin is connected to the first capacitor and then to ground.

[0107] Specifically, in the embodiments of the present invention, such as Figure 4 As shown, the driver startup power supply circuit 123 may include a first resistor 1231 and a first capacitor 1232, one end of which is connected to a DC voltage signal V. in The other end of the first resistor 1231 is connected to the power supply pin VCC of the switching power supply driver chip 111.

[0108] One end of the first capacitor 1232 is connected to the power supply pin VCC of the switching power supply driver chip 111, and the other end of the first capacitor 1232 is grounded.

[0109] When the voltage signal across the first capacitor 1232 reaches the startup voltage of the switching power supply driver chip 111, the switching power supply driver chip 111 sends a drive signal. That is, the voltage signal across the first capacitor 1232 is the voltage signal connected to the power supply pin VCC of the switching power supply driver chip 111.

[0110] It is understandable that the first resistor 1231 can be a single resistor with a large resistance value, or it can be composed of multiple resistors with even larger resistance values ​​connected in parallel, or multiple resistors with smaller resistance values ​​connected in series. No specific limitation is made here.

[0111] In this embodiment of the invention, the driver startup power supply circuit includes a first resistor and a first capacitor. It has a simple structure and low cost, and can quickly realize the startup and power supply of the switching power supply driver chip.

[0112] Based on the above embodiments, the driving circuit provided in the embodiments of the present invention includes a second resistor, a third resistor, and a second capacitor;

[0113] The negative terminal of the boost freewheeling diode, the second resistor, and the third resistor are connected in sequence, and the third resistor is grounded;

[0114] The feedback pin is connected to the third resistor to ground, and the second capacitor is connected in parallel with the third resistor.

[0115] Specifically, in the embodiments of the present invention, such as Figure 4 As shown, the driver feedback circuit 124 may include a second resistor 1241, a third resistor 1242 and a second capacitor 1243. The negative terminal of the boost freewheeling diode 122, the second resistor 1241 and the third resistor 1242 are connected in sequence, and the third resistor 1242 is grounded.

[0116] One end of the third resistor 1242 is connected to the feedback pin FB of the switching power supply driver chip 111, and the other end of the third resistor 1242 is grounded. The second capacitor 1243 is connected in parallel across the third resistor 1242. At this time, the feedback pin FB of the switching power supply driver chip 111 can acquire the voltage across the third resistor 1242.

[0117] It is understandable that the second resistor 1241 can be a resistor with a large resistance value, or it can be composed of multiple resistors with even larger resistance values ​​connected in parallel or multiple resistors with smaller resistance values ​​connected in series. No specific limitation is made here.

[0118] At this time, V bus It can satisfy the following mathematical relationship:

[0119]

[0120] Among them, V FB R is the reference voltage set internally by the switching power supply driver chip 111, serving as the reference voltage for external voltage sampling feedback of the switching power supply driver chip 111. 1241 R is the resistance value of the second resistor 1241. 1242The resistance value of the third resistor 1242 is given. The second resistor 1241 and the third resistor 1242 together serve as an external resistor to V. bus Voltage sampling resistor.

[0121] In this embodiment of the invention, the driver feedback circuit includes a second resistor, a third resistor, and a second capacitor. It has a simple structure and low cost, and can quickly enable the startup and power supply of the switching power supply driver chip.

[0122] Based on the above embodiments, the driving circuit provided in this embodiment of the invention further includes a fourth resistor;

[0123] The primary current sampling pin of the switching power supply driver chip is connected to the fourth resistor to ground.

[0124] Specifically, in the embodiments of the present invention, such as Figure 4 As shown, the functional circuit 12 also includes a fourth resistor 1233. One end of the fourth resistor 1233 is connected to the primary current sampling pin CS of the switching power supply driver chip 111, and the other end of the fourth resistor 1233 is grounded.

[0125] It is understandable that the fourth resistor 1233 can be a resistor with a large resistance value, or it can be composed of multiple resistors with even larger resistance values ​​connected in parallel, or it can be composed of multiple resistors with smaller resistance values ​​connected in series. No specific limitation is made here.

[0126] In this embodiment of the invention, a fourth resistor is connected to the primary current sampling pin of the switching power supply driver chip, which ensures that none of the pins of the switching power supply driver chip are idle, thus guaranteeing full utilization of the switching power supply driver chip.

[0127] Based on the above embodiments, the driving circuit provided in this embodiment of the invention further includes an output filter electrolytic capacitor in the power regulation circuit;

[0128] One end of the output filter electrolytic capacitor is connected to the negative terminal of the boost freewheeling diode, and the other end of the output filter electrolytic capacitor is grounded.

[0129] Specifically, in the embodiments of the present invention, such as Figure 4 As shown, the power regulation circuit 1 also includes an output filter electrolytic capacitor 125. One end of the output filter electrolytic capacitor 125 is connected to the negative terminal of the boost freewheeling diode 122, and the other end of the output filter electrolytic capacitor 125 is grounded.

[0130] It is understandable that after the boost freewheeling diode 122 is forward-biased, V is output from the negative terminal of the boost freewheeling diode 122. bus It provides operating current for subsequent circuits. Meanwhile, V bus Charge the output filter electrolytic capacitor 125 to achieve voltage regulation.

[0131] Based on the above embodiments, the driving circuit provided in the embodiments of the present invention further includes a rectifier filter protection circuit, which is connected to the power regulation circuit.

[0132] The rectifier-filter-protection circuit is used to rectify and filter the AC voltage signal to obtain the DC voltage signal.

[0133] The switching power supply driver is also used to control the functional circuit to perform power factor correction on the DC voltage signal.

[0134] Specifically, in this embodiment of the invention, the AC voltage signal can be the grid voltage signal. Through the rectifier, filter and protection circuit, the AC voltage signal can be rectified, filtered and protected to obtain a DC voltage signal. Then, through the subsequent power regulation circuit and linear constant current circuit, a constant voltage and constant current signal is obtained to supply power to the target load.

[0135] like Figure 5 As shown, the rectifier filter protection circuit 4 may include a protection circuit 41 and a rectifier filter circuit 42. The protection circuit 41 includes a fuse resistor F1, a common-mode filter inductor FL1, a differential-mode capacitor CX1, and a differential-mode inductor L1. The fuse resistor F1 is connected to the grid terminal L and one input terminal of the common-mode filter inductor FL1, respectively. The other input terminal of the common-mode filter inductor FL1 is connected to the grid terminal N.

[0136] The differential-mode inductor L1 is connected to one output pin of the common-mode filter inductor FL1, and the differential-mode capacitor CX1 is connected between the two output terminals of the common-mode filter inductor FL1. The rectifier-filter circuit 42 is connected to both output terminals of the common-mode filter inductor FL1 and the power regulation circuit 1 to provide a DC voltage signal V to the power regulation circuit. in .

[0137] The rectifier-filter circuit 42 includes a rectifier bridge DB1 and a post-bridge filter energy storage capacitor 421. The two input terminals of the rectifier bridge DB1 are connected to the two output terminals of the common-mode filter inductor FL1, and the two output terminals of the rectifier bridge DB1 are connected to the two ends of the post-bridge filter energy storage capacitor 421. The post-bridge filter energy storage capacitor 421 is connected in parallel with the power regulation circuit.

[0138] When a DC voltage signal is obtained by rectifying and filtering an AC voltage signal, the DC voltage signal is actually a pulsating voltage signal. Therefore, the current signal provided by this DC voltage signal will contain harmonics, reactive current, etc., which will reduce the quality of AC power supply and reduce the utilization rate of AC voltage signal.

[0139] Therefore, in this embodiment of the invention, the power regulation circuit is also equipped with a power factor correction function, that is, the power factor correction is performed on the DC voltage signal obtained by rectifying and filtering the AC voltage signal through the switching power supply driver control function circuit.

[0140] Power factor correction refers to correcting the current signal provided by the DC voltage signal obtained by rectifying and filtering the AC voltage signal into a current signal with a phase close to and a small phase difference with the AC voltage signal, so as to improve the power factor of the drive circuit, eliminate harmonics, reactive current or line damage, and improve the power supply quality of the power grid.

[0141] Here, "phase close" means that the difference in phase angles is within a first preset range, and "phase difference" means that the difference in phases is within a second preset range. The first and second preset ranges can be set as needed, and no specific limitation is made here.

[0142] As can be understood, the power factor (PF) is the ratio of active power (P) to apparent power (S), which is also the cosine of the angular displacement of the current and voltage sinusoidal waves. The power factor ranges from 0 to 1, due to inductive and capacitive effects in the circuit. Power factor correction aims to bring the power factor as close to 1 as possible. When the power factor is 1, there is no phase difference between the current and voltage waveforms. At this point, the circuit connected to the output of power regulation circuit 1 can be considered a purely resistive circuit, resulting in the best AC power supply quality and the highest utilization of the AC voltage signal.

[0143] In this embodiment of the invention, a rectifier-filter protection circuit is introduced. This circuit converts the grid voltage signal into a relatively clean pulsating DC voltage signal through a series of filtering, modulation, and rectification transformations. This provides a stable and clean input voltage source for subsequent circuits, improving grid quality and reducing electromagnetic compatibility interference in the power supply system. Furthermore, the power regulation circuit also has a power factor correction function, which can improve the power factor of the drive circuit, eliminate harmonics, reactive current, or line damage, and improve the quality of grid power supply.

[0144] Based on the above embodiments, in the driving circuit provided in this embodiment of the invention, if the target load is an LED lamp group, a reverse diode is also connected between the power regulation circuit and the constant current output pin, and the connection direction of the reverse diode is opposite to the connection direction of the LED lamp group.

[0145] Specifically, such as Figure 6 and Figure 7 As shown, the floating pin NC on the side where the constant current output pin of the linear constant current driver 21 is located can be designated as the constant current output pin OUT1, and the constant current output pin connected to the target load can be designated as OUT2. At this time, the positive terminal of the reverse diode 31 can be connected to the constant current output pin OUT1, and the negative terminal of the reverse diode 31 can be connected to V.bus .

[0146] In this embodiment of the invention, a reverse diode is introduced to provide overvoltage protection for the target load, thereby enhancing the reliability of the linear constant current driver. When the voltage signal V at the constant current output pins OUT1 and OUT2 of the linear constant current driver... out When an abnormal overvoltage occurs, i.e., V out >V bus The forward conduction of the reverse diode 31 will convert the voltage signal V at the constant current output pins OUT1 and OUT2. out Clamped in V bus +V d V d The voltage drop across the forward-biased diode is the voltage signal V at the constant current output pins OUT1 and OUT2 of the linear constant current driver. out It will be effectively protected from damage caused by overvoltage.

[0147] like Figure 8 , 9 The figures shown are schematic diagrams illustrating the application of the driving circuit provided in the embodiments of the present invention to drive LED lamps. Figure 8 Depend on Figure 5 , Figure 4 as well as Figure 6 It is pieced together. Figure 9 Depend on Figure 5 , Figure 4 as well as Figure 7 It is pieced together. Among them are:

[0148] R 1231 =R1+R2+R3

[0149] R 1241 =R6+R7+R8

[0150] R VT =R9+R10

[0151] The first resistor 1231 is obtained by connecting resistors R1, R2, and R3 in series; the second resistor 1241 is obtained by connecting resistors R6, R7, and R8 in series; and the fourth resistor 1233 is obtained by connecting resistors R4 and R5 in parallel. VT It is obtained by connecting R9 and R10 in series.

[0152] In addition, a capacitor C3 and a diode D1 are connected in parallel between the input and output terminals of the power regulation circuit 1 to achieve voltage regulation and filtering of the power regulation circuit 1.

[0153] Based on the above embodiments, such as Figure 10As shown, an embodiment of the present invention provides a lamp assembly, including a lamp assembly body 101 and a driving circuit 102 provided in the above embodiments. The driving circuit 102 is connected to the lamp assembly body 101 through a linear constant current circuit therein.

[0154] The drive circuit 102 can be used to power the lamp assembly body 101.

[0155] Specifically, the lamp body 101 can be an LED lamp, and the specific structural diagram of the lamp assembly can be as follows: Figure 8 , 9 As shown, the brightness of the LED lights in this light group remains stable throughout.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A driving circuit, characterized in that, include: A power regulation circuit and a linear constant current circuit, wherein the power regulation circuit is connected to the linear constant current circuit; The power regulation circuit includes a switching power supply driver and a functional circuit connected to the switching power supply driver. The switching power supply driver is used to control the functional circuit to boost the DC voltage signal to obtain a constant voltage signal. The linear constant current circuit is used to output the constant voltage signal as a constant current. The linear constant current circuit includes a linear constant current driver, a current sampling resistor, and a filter sampling feedback circuit. The filtering sampling feedback circuit includes a voltage sampling resistor and a filtering capacitor. The two ends of the voltage sampling resistor are respectively connected to the voltage sampling pins of the power regulation circuit and the linear constant current driver. The voltage sampling pin of the linear constant current driver is connected to the filter capacitor to ground; The voltage relationship of the linear constant current circuit is as follows: ； Among them, V rext After adding the aforementioned filter sampling feedback circuit, the voltage sampling resistor R VT The corresponding current control threshold voltage; V ref This is the threshold voltage at the current control terminal when the linear constant current driver does not have the filtering sampling feedback circuit inside; K1, K2, and K3 are all fixed constant values ​​inside the linear constant current driver; V bus It is the constant voltage signal; The current relationship of the linear constant current circuit is as follows: I out =V rext / R ext ; Among them, I out R is the current at the constant current output pin of the linear constant current driver. ext The current sampling resistor is the resistor mentioned above.

2. The driving circuit according to claim 1, characterized in that, The output current setting pin of the linear constant current driver is connected to the current sampling resistor to ground. The linear constant current driver outputs a constant current signal through its constant current output pin.

3. The driving circuit according to claim 1, characterized in that, The switching power supply driver is a switching power supply driver chip; The functional circuit includes an inductor, a boost freewheeling diode, a driver startup power supply circuit, and a driver feedback circuit. One end of the inductor is connected to the DC voltage signal, and the other end of the inductor is connected to the positive terminal of the boost freewheeling diode. The negative terminal of the boost freewheeling diode is connected to the linear constant current circuit. The input terminal of the driver startup power supply circuit is connected to the DC voltage signal, and the output terminal of the driver startup power supply circuit is connected to the power supply pin of the switching power supply driver chip. The output pin of the power switch transistor built into the switching power supply driver chip is connected to the positive terminal of the boost freewheeling diode. The driver feedback circuit is connected to the feedback pin of the switching power supply driver chip and the negative terminal of the boost freewheeling diode, respectively.

4. The driving circuit according to claim 3, characterized in that, The driver startup power supply circuit includes a first resistor and a first capacitor; One end of the first resistor is connected to the DC voltage signal, and the other end of the first resistor is connected to the power supply pin. The power supply pin is connected to the first capacitor and then to ground.

5. The driving circuit according to claim 3, characterized in that, The driver feedback circuit includes a second resistor, a third resistor, and a second capacitor; The negative terminal of the boost freewheeling diode, the second resistor, and the third resistor are connected in sequence, and the third resistor is grounded; The feedback pin is connected to the third resistor to ground, and the second capacitor is connected in parallel with the third resistor.

6. The driving circuit according to claim 3, characterized in that, The functional circuit also includes a fourth resistor; The primary current sampling pin of the switching power supply driver chip is connected to the fourth resistor to ground.

7. The driving circuit according to claim 3, characterized in that, The power regulation circuit also includes an output filter electrolytic capacitor; One end of the output filter electrolytic capacitor is connected to the negative terminal of the boost freewheeling diode, and the other end of the output filter electrolytic capacitor is grounded.

8. The driving circuit according to any one of claims 1-7, characterized in that, It also includes a rectifier filter protection circuit, which is connected to the power regulation circuit; The rectifier-filter protection circuit is used to rectify and filter the AC voltage signal to obtain the DC voltage signal. The switching power supply driver is also used to control the functional circuit to perform power factor correction on the DC voltage signal.

9. A lamp assembly, characterized in that, Includes a lamp assembly body and a driving circuit as described in any one of claims 1-8, wherein the linear constant current circuit is connected to the lamp assembly body; The driving circuit is used to supply power to the lamp assembly body.

Images