CN218941378U - LED driving circuit and lighting lamp - Google Patents

Abstract

An LED driving circuit, a lighting fixture, the circuit comprising: the constant voltage driving module is used for converting external alternating current into direct current with constant voltage; the constant current module is connected with the constant voltage driving module and used for converting the direct current of the constant voltage into the direct current of the constant current and supplying the direct current of the constant current to an LED load; the power supply switching circuit module is connected in series between the constant voltage driving module and the constant current module; the output open circuit detection module is connected with the constant current module; the control module is connected with the power supply switching circuit module, the output open circuit detection module and the constant current module. The circuit judges whether to cut off the power supply to the constant current module or not, thereby realizing the purpose of reducing energy consumption.

Description

LED driving circuit and lighting lamp

Technical Field

The utility model relates to the technical field of lamp driving, in particular to an LED driving circuit and a lighting lamp.

Background

With the improvement of living standard, the LED illumination is increasingly applied to many scenes, and many LED driving schemes are also appeared, wherein the intelligent control LED driving scheme is widely applied to various application scenes. In general, the intelligent driving is to output multiple paths of PWM signals (usually two paths) by a built-in control module to control different constant current modules, so as to realize the adjustment of output current and color mixing and obtain different color temperatures.

The european ERP (Energy-Related Products) requires driving standby power consumption of less than 0.5W in no-load condition (LED lamp is not connected to drive), and the constant voltage part and the constant current part of the above driving scheme have Energy consumption in no-load condition, and the single constant voltage part or the single constant current part may satisfy standby power consumption of less than 0.5W, but the two parts are easily exceeded if they are combined together.

In addition, the condition of soft off of the lamp can occur in the intelligent dimming driving (for example, alternating current keeps input, the LED lamp keeps connected, the LED lamp is turned off by adjusting the duty ratio of the PWM signal of the constant current module to 0), under the condition, a user aims to require the LED of the lamp to be completely turned off, but the LED continuously has tiny current to flow due to weak leakage current in a driving circuit, so that the LED is slightly on, and the use experience of the user is affected.

The information disclosed in this background section is only for enhancement of understanding of the general background of the utility model and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

Aiming at the problems existing in the prior art, the utility model provides an LED driving circuit and a lighting lamp.

The utility model provides an LED driving circuit, which comprises:

the constant voltage driving module is used for converting external alternating current into direct current with constant voltage;

the constant current module is connected with the constant voltage driving module and used for converting the direct current of the constant voltage into the direct current of the constant current and supplying the direct current of the constant current to an LED load;

the power supply switching circuit module is connected in series between the constant voltage driving module and the constant current module, and can conduct or cut off a circuit from the constant voltage driving module to the constant current module;

the output open circuit detection module is connected with the constant current module and used for detecting the state that the constant current module supplies power to the LED load;

the control module is connected with the power supply switching circuit module, the output open circuit detection module and the constant current module, and outputs PWM signals for controlling the work of the LED load to the constant current module;

when the output open circuit detection module detects that the constant current module is in an idle state or in a soft off state realized by the PWM signal, the control module outputs a first signal to the power supply switching circuit switching module, so that the power supply switching circuit module cuts off a circuit from the constant voltage driving module to the constant current module; otherwise, when the output open circuit detection module detects that the constant current module is in a load state, the control module outputs a second signal to the power supply switching circuit switching module, so that the power supply switching circuit module conducts the constant voltage driving module to a circuit of the constant current module.

According to the LED driving circuit provided by the utility model, the constant current module comprises a warm light constant current module and a cold light constant current module which are mutually connected in parallel and are respectively used for supplying power to a corresponding warm light LED load and a cold light LED load;

correspondingly, the control module outputs a warm light PWM signal to the warm light constant current module, and the control module outputs a cold light PWM signal to the cold light constant current module.

According to the LED driving circuit provided by the utility model, the output open circuit detection module obtains a first state that the warm light constant current module supplies power to the warm light LED load, and the output open circuit detection module obtains a second state that the cold light constant current module supplies power to the cold light LED load;

based on the first state and the second state, the control module outputs the first signal or the second signal.

According to the present utility model, there is provided an LED driving circuit, the power supply switching circuit module comprising:

the source electrode and the drain electrode of the field effect transistor are connected in series between the constant voltage driving module and the constant current module;

and the collector electrode and the emitter electrode of the triode are connected in series between the grid electrode and the grounding end of the field effect tube, and the base electrode of the triode is connected with the control module to acquire the first signal or the second signal.

According to the utility model, the LED driving circuit is used for detecting the state that the constant current module supplies power to the LED load and comprises the following components:

acquiring the negative electrode potential of the constant current module for supplying power to the LED load;

correspondingly, the control module acquires the negative potential, if the negative potential is low level, the control module outputs a low-level reset signal as the first signal to be sent to the power supply switching circuit switching module, so that the power supply switching circuit module cuts off a circuit from the constant voltage driving module to the constant current module, otherwise, if the negative potential is high level, the control module outputs a high-level reset signal as the second signal to be sent to the power supply switching circuit switching module, so that the power supply switching circuit module conducts the constant voltage driving module to the circuit of the constant current module.

According to the LED driving circuit provided by the utility model, when the duty ratio of the PWM signal is 0 or the LED load is not connected to the circuit, the potential of the negative electrode is low.

According to the LED driving circuit provided by the present utility model, the output open circuit detection module includes:

and the two voltage dividing resistors are connected in series between the negative electrode and the grounding end, and the potential output by the non-grounding end of the resistor close to the grounding end in the two voltage dividing resistors is used as the negative electrode potential.

According to the LED driving circuit provided by the utility model, when the control module is just powered on, the control module outputs a high-level reset signal.

According to the present utility model, there is provided an LED driving circuit, the control module comprising:

a conversion sub-circuit that converts the negative electrode potential from an analog signal to a digital signal;

and the comparison sub-circuit compares the negative electrode potential converted into the digital signal with a preset threshold value and judges whether the negative electrode potential is in a high level or a low level.

The utility model also provides a lighting lamp, which comprises any LED driving circuit.

According to the LED driving circuit and the lighting lamp, whether the power supply to the constant current module is required to be cut off is judged through the circuit, so that the purpose of reducing energy consumption is achieved.

Drawings

In order to more clearly illustrate the utility model or the technical solutions of the prior art, the following brief description will be given of the drawings used in the embodiments or the description of the prior art, it being obvious that the drawings in the following description are some embodiments of the utility model and that other drawings can be obtained from them without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of an LED driving circuit according to the present utility model;

FIG. 2 is a schematic diagram of another LED driving circuit according to the present utility model;

FIG. 3 is a schematic diagram of another LED driving circuit according to the present utility model;

fig. 4 is a schematic diagram of another LED driving circuit according to the present utility model.

Detailed Description

Advantages of the utility model are further illustrated in the following description, taken in conjunction with the accompanying drawings and detailed description.

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the accompanying claims.

The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present disclosure. The word "if" as used herein may be interpreted as "at … …" or "at … …" or "responsive to a determination", depending on the context.

In the description of the present utility model, it should be understood that the terms "longitudinal," "transverse," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

In the description of the present utility model, unless otherwise specified and defined, it should be noted that the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, mechanical or electrical, or may be in communication with each other between two elements, directly or indirectly through intermediaries, as would be understood by those skilled in the art, in view of the specific meaning of the terms described above.

In the following description, suffixes such as "module", "component", or "unit" for representing elements are used only for facilitating the description of the present utility model, and are not of specific significance per se. Thus, "module" and "component" may be used in combination.

The LED driving circuit provided in the embodiment of the present application is described in detail below with reference to the accompanying drawings by means of specific embodiments and application scenarios thereof.

Fig. 1 is a schematic diagram of an LED driving circuit according to the present utility model, as shown in fig. 1, where the circuit includes:

the constant voltage driving module is used for converting external alternating current into direct current with constant voltage;

the constant current module is connected with the constant voltage driving module and used for converting the direct current of constant voltage into the direct current of constant current and supplying the direct current of constant current to the LED load;

the power supply switching circuit module is connected in series between the constant voltage driving module and the constant current module, and can conduct or cut off the circuit from the constant voltage driving module to the constant current module;

the control module is connected with the power supply switching circuit module, the output open circuit detection module and the constant current module, and outputs PWM signals for controlling the work of the LED load to the constant current module, and preferably, the control module is a single chip Microcomputer (MCU);

when the output open circuit detection module detects that the constant current module is in an idle state or in a soft off state realized by PWM signals, the control module outputs a first signal to the power supply switching circuit switching module, so that the power supply switching circuit module cuts off a circuit from the constant voltage driving module to the constant current module; otherwise, when the output open circuit detection module detects that the constant current module is in a load state, the control module outputs a second signal to the power supply switching circuit switching module, so that the power supply switching circuit module conducts the constant voltage driving module to the circuit of the constant current module.

The embodiment judges whether the power supply to the constant current module needs to be cut off or not through the circuit, thereby achieving the purpose of reducing energy consumption.

Preferably, fig. 2 is a schematic diagram of another LED driving circuit according to the present utility model, as shown in fig. 2, the constant current module has a DIM pin for adjusting its own output current according to the PWM signal output from the control module. It should be noted that, the constant voltage driving module adopts an IW3627 chip (high PF isolation constant voltage scheme) of the dialogs company, the constant current module adopts an SM32108E (buck DC-DC constant current dimming scheme) of the bright microelectronics, and the single-path output is not used for dimming, and only the current is regulated.

Optionally, fig. 3 is a schematic diagram of another LED driving circuit provided in the present utility model, where, as shown in fig. 3, the constant current module includes a warm light constant current module and a cold light constant current module connected in parallel, and the warm light constant current module and the cold light constant current module are respectively used to supply power to a corresponding warm light LED load and a corresponding cold light LED load;

correspondingly, the control module outputs a warm light PWM signal (PWMW) to the warm light constant current module, and the control module outputs a cold light PWM signal (PWMC) to the cold light constant current module.

Optionally, the output open circuit detection module obtains a first state that the warm light constant current module supplies power to the warm light LED load, and the output open circuit detection module obtains a second state that the cold light constant current module supplies power to the cold light LED load;

based on the first state and the second state, the control module outputs the first signal or the second signal.

The control module outputs the first signal or the second signal based on the first state and the second state through the internal judgment logic of the control module.

Further, the soft off state realized by the no-load state and the PWM signal is summarized as the off state, and the internal judgment logic includes: and the control module outputs a first signal only when the first state and the second state are in the light-off state so as to cut off the circuit from the constant voltage driving module to the constant current module, otherwise, the control module outputs a second signal only when any one of the first state and the second state is not in the light-off state so as to maintain the circuit from the constant voltage driving module to the constant current module. As another alternative parallel scheme, the aforementioned internal judgment logic includes: and the control module outputs a first signal to cut off a circuit from the constant voltage driving module to the constant current module.

It should be noted that the control module is used for outputting 2 paths of PWM signals to control the module to work according to the program setting and the external adjustment requirements. And the control module can output signals to control the work of the power supply switching circuit module. In general, the control module in the LED intelligent lighting can also realize various intelligent controls by combining various communication protocols with ICs with functions of Bluetooth, wifi and the like, and the functions of the control module in the diagram are only described in the function description of the constant current module power supply switching circuit, the output state ADC detection and the PWM signal output control, and other functions are not described in detail.

Preferably, the output open circuit detection module is capable of detecting the working condition of the LED load and providing the working condition to the control module for judgment.

Optionally, the power supply switching circuit module includes:

the source electrode and the drain electrode of the field effect transistor are connected in series between the constant voltage driving module and the constant current module;

and the collector electrode and the emitter electrode of the triode are connected in series between the grid electrode and the grounding end of the field effect transistor, and the base electrode of the triode is connected with the control module to acquire a first signal or a second signal.

Optionally, the method for detecting a state that the constant current module supplies power to the LED load includes:

acquiring the negative electrode potential of the constant current module for supplying power to the LED load;

correspondingly, the control module acquires the negative electrode potential, if the negative electrode potential is low level, the control module outputs a low-level reset signal as the first signal to be sent to the power supply switching circuit switching module, so that the power supply switching circuit module cuts off a circuit from the constant voltage driving module to the constant current module, otherwise, if the negative electrode potential is high level, the control module outputs a high-level reset signal as the second signal to be sent to the power supply switching circuit switching module, so that the power supply switching circuit module conducts the circuit from the constant voltage driving module to the constant current module.

Alternatively, when the PWM signal duty ratio is 0, the negative electrode potential is low level. The requirement that the LED can not be slightly lightened under the soft-off condition is met.

Alternatively, when the LED load is not connected to the circuit, the negative potential is low. Under the no-load condition, the power supply of the constant current module is automatically cut off to reduce the energy loss, thereby meeting the requirement that the power consumption of the no-load circuit is less than 0.5W.

Optionally, the output open circuit detection module includes:

and the two voltage dividing resistors are connected in series between the negative electrode and the grounding end, and the potential output by the non-grounding end of the resistor close to the grounding end in the two voltage dividing resistors is used as the potential of the negative electrode.

Optionally, the control module outputs a high level reset signal upon power up.

Optionally, the control module includes:

a conversion sub-circuit that converts the negative electrode potential from an analog signal to a digital signal;

and the comparison sub-circuit compares the negative electrode potential converted into the digital signal with a preset threshold value and judges whether the negative electrode potential is at a high level or a low level.

It should be noted that, as shown in fig. 3, the constant voltage driving module converts AC mains supply into Constant Voltage (CV), in this example, the constant voltage driving module uses an IW3627 chip U1 manufactured by dialog semiconductor company, the driving is a high PF isolation constant voltage scheme, and the constant current module uses a dimmable LEDBUCK constant current control chip U2 manufactured by Ming microelectronics corporation, the model is SM32108E. A dc voltage of 50V is generated across the electrolytic capacitor EC1 (50V is illustrated, and is designed according to the requirements in practical applications).

The constant current module is used for converting 50V direct current into 36V constant current to provide the constant current for the LED lamp (36V is a condition illustrating the LED load, and different voltages are possible in practical application). The whole constant current module is of a BUCK type BUCK power supply topological structure. The constant current module has two paths of modules in parallel connection: cold light constant current module and warm light constant current module. And the LED lamp beads with corresponding color temperatures are respectively connected. The cold light constant current module is connected with cold color LED lamp beads (5700K or other cold color LED lamp beads), and the warm light constant current module is connected with warm color LED lamp beads (2700K or other warm color LED lamp beads). The two paths of constant current modules work under different currents and can mix colors to obtain different color temperatures and currents.

The two paths 36VLED lamp beads are normally connected, the control module U3 outputs a warm light PWM signal to control the warm color constant current module, and outputs a cold light PWM signal to control the cold color constant current module. The voltage of the EC1 end is 50V, the voltage of the negative end of the electrolytic capacitor EC3 on the warm color road is CV voltage 50V, the voltage is 14V after subtracting the LED load voltage 36, the 14V is divided by R5 and R6 and reaches the PIN11 PIN of the control module U3, the voltage of the negative end of the electrolytic capacitor EC4 on the cold color road is CV voltage 50V, the voltage is 14V after subtracting the LED load voltage 36, and the 14V is divided by R7 and R8 and reaches the PIN10 PIN of the control module U3. The control module is used for carrying out ADC conversion (analog to digital) on the collected analog signals, comparing the analog signals with an internal threshold value, outputting high potential through a PIN2 PIN MRST, conducting an NPN triode Q2, pulling down the G pole of an N channel MOS tube Q1 after the Q2 is conducted, conducting the Q1, enabling 50V direct current to flow into Vin ports of U2 and U4, enabling the U2 and the U4 to work normally, and outputting the lamp normally.

The two paths 36VLED are not connected in at the same time, namely, under the no-load condition, the voltage of the end of EC1 is 50V, the voltage of the negative ends of electrolytic capacitors EC3 and EC4 is 0V, the voltage is divided by R5 and R6 and then sent to the PIN11 PIN of U3, the voltage is divided by R7 and R8 and then sent to the PIN10 PIN of U3, the control module carries out ADC conversion (analog to digital) on the collected analog signals, the analog signals are compared with the internal threshold value, the analog signals are lower than the internal threshold value, the two paths are low at the same time, the control module judges that the lamp is not connected in, the control module outputs low potential through the PIN2 PIN, Q2 is not conducted, the G of Q1 is extremely high, Q1 is not conducted, 50V direct current can not flow into the Vin ports of U2 and U4, and U2 and U4 stop working. The 2-way module has no power consumption at this time. The power consumption of the whole driving is no-load power consumption of the constant voltage driving part. Thus, the requirement that the standby power consumption of the circuit is smaller than 0.5W can be met.

The user enables Pin10 and Pin11 of the control module to output low potential through adjusting PWM signals, and the situation of soft-off of the LED lamp is achieved. After the control module outputs a warm light PWM signal and a cold light PWM signal for a certain time at the same time, the control module program judges that the control module is in a soft-off state, at the moment, the control module outputs low potential through a PIN2 PIN, Q2 is not conducted, G of Q1 is extremely high potential, Q1 is not conducted, at the moment, 50V direct current cannot flow into Vin ports of U2 and U4, and U2 and U4 stop working.

Further, it should be noted that, after the circuit is initially powered on, the control module outputs a high level directly through the MRST pin without making a logic judgment, after the Q1 is powered on, the CV has 50V, after the LED is turned on, the sampling is judged through the partial voltages of R5 and R6, if the sampling is a high level, and if the sampling is higher than the internal threshold, the MRST outputs a high level continuously. If the sample goes low, the MRST output is low, turning off Q1.

The utility model does not limit whether to isolate and what power supply topology is adopted for constant voltage driving, and only can generate a direct current constant voltage power for the constant voltage driving module. The constant current module is not limited by the power supply topology and the dimming mode, only a dimming interface is limited, and a negative electrode (LED-end) for supplying power to the LED load cannot be in the same network with a ground end (GND), so that the potential of the negative electrode can be detected. The number of bits of the used control module is not limited, and the control module only has an ADC sampling function, a PWM signal outputting function and a high-low level outputting function.

Fig. 4 is a schematic diagram showing another LED driving circuit according to the present utility model, in which, as shown in fig. 4, HFC0100HS (low PF secondary side feedback isolation constant voltage scheme) is adopted in the constant voltage driving module, and H5112A (buck DC-DC constant current dimming scheme) of the semiconductor limited of the Dongguan city is adopted in the constant current module.

The utility model further provides a lighting lamp, which comprises any LED driving circuit.

It should be noted that the embodiments of the present utility model are preferred and not limited in any way, and any person skilled in the art may make use of the above-disclosed technical content to change or modify the same into equivalent effective embodiments without departing from the technical scope of the present utility model, and any modification or equivalent change and modification of the above-described embodiments according to the technical substance of the present utility model still falls within the scope of the technical scope of the present utility model.

Claims (10)

1. An LED driving circuit, the circuit comprising:

the constant voltage driving module is used for converting external alternating current into direct current with constant voltage;

the constant current module is connected with the constant voltage driving module and used for converting the direct current of the constant voltage into the direct current of the constant current and supplying the direct current of the constant current to an LED load;

the power supply switching circuit module is connected in series between the constant voltage driving module and the constant current module, and can conduct or cut off a circuit from the constant voltage driving module to the constant current module;

the output open circuit detection module is connected with the constant current module and used for detecting the state that the constant current module supplies power to the LED load;

the control module is connected with the power supply switching circuit module, the output open circuit detection module and the constant current module, and outputs PWM signals for controlling the work of the LED load to the constant current module;

when the output open circuit detection module detects that the constant current module is in an idle state or in a soft off state realized by the PWM signal, the control module outputs a first signal to the power supply switching circuit switching module, so that the power supply switching circuit module cuts off a circuit from the constant voltage driving module to the constant current module; otherwise, when the output open circuit detection module detects that the constant current module is in a load state, the control module outputs a second signal to the power supply switching circuit switching module, so that the power supply switching circuit module conducts the constant voltage driving module to a circuit of the constant current module.

2. The LED driving circuit of claim 1, wherein the constant current module comprises a warm light constant current module and a cool light constant current module connected in parallel to each other for supplying power to the corresponding warm light LED load and cool light LED load, respectively;

correspondingly, the control module outputs a warm light PWM signal to the warm light constant current module, and the control module outputs a cold light PWM signal to the cold light constant current module.

3. The LED driver circuit of claim 2, wherein the output open circuit detection module obtains a first state in which the warm light constant current module supplies power to the warm light LED load, and wherein the output open circuit detection module obtains a second state in which the cool light constant current module supplies power to the cool light LED load;

based on the first state and the second state, the control module outputs the first signal or the second signal.

4. The LED driving circuit of claim 1, wherein the power supply switching line module comprises:

the source electrode and the drain electrode of the field effect transistor are connected in series between the constant voltage driving module and the constant current module;

and the collector electrode and the emitter electrode of the triode are connected in series between the grid electrode and the grounding end of the field effect tube, and the base electrode of the triode is connected with the control module to acquire the first signal or the second signal.

5. The LED driving circuit of claim 1, wherein detecting the state of the constant current module supplying power to the LED load comprises:

acquiring the negative electrode potential of the constant current module for supplying power to the LED load;

correspondingly, the control module acquires the negative potential, if the negative potential is low level, the control module outputs a low-level reset signal as the first signal to be sent to the power supply switching circuit switching module, so that the power supply switching circuit module cuts off a circuit from the constant voltage driving module to the constant current module, otherwise, if the negative potential is high level, the control module outputs a high-level reset signal as the second signal to be sent to the power supply switching circuit switching module, so that the power supply switching circuit module conducts the constant voltage driving module to the circuit of the constant current module.

6. The LED driving circuit according to claim 5, wherein the negative electrode potential is low level when the PWM signal duty ratio is 0 or when the LED load is not connected to the circuit.

7. The LED driving circuit of claim 5, wherein the output open circuit detection module comprises:

and the two voltage dividing resistors are connected in series between the negative electrode and the grounding end, and the potential output by the non-grounding end of the resistor close to the grounding end in the two voltage dividing resistors is used as the negative electrode potential.

8. The LED driving circuit according to claim 5, wherein the control module outputs a high-level reset signal upon power-up.

9. The LED driving circuit of claim 5, wherein the control module comprises:

a conversion sub-circuit that converts the negative electrode potential from an analog signal to a digital signal;

and the comparison sub-circuit compares the negative electrode potential converted into the digital signal with a preset threshold value and judges whether the negative electrode potential is in a high level or a low level.

10. A lighting fixture, characterized in that it comprises the LED driving circuit of any one of claims 1-9.

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