A method for controlling rectangular wave signal changes of a single signal line

Abstract

The present invention belongs to the field of lighting for color adjustment and dimming of dual-channel LEDs with different color temperatures, and in particular, is a method for controlling the change of a rectangular wave signal of a single signal line. In view of the problem that existing color adjustment and dimming control methods are relatively complicated, the following scheme is proposed, which includes a control unit system, a color adjustment unit system and a dimming unit system. The output end of the control unit system is connected to a power switch unit and an inverter in the color adjustment unit system; the input end of the power switch unit is connected to the output end of the light source; the output end of the power switch unit in the color adjustment unit system is connected to a total power switch unit in the dimming unit system. The present invention utilizes the change of square waves for control, and can adjust the color temperature and brightness of the lamp, thereby improving the controllability, applicability and diversity of the LED lamp, better meeting the needs of actual life, simplifying the complex color adjustment and dimming control methods, and making LED applications more convenient and efficient.

Description

Technical Field

[0001] The present invention relates to the technical field of dual-channel LED color adjustment and dimming lighting, and in particular to a method for controlling changes in a rectangular wave signal of a single signal line. Background Art

[0002] An LED (Light Emitting Diode) is a solid-state semiconductor device that converts electrical energy into visible light. LED lighting typically requires a dedicated driver solution, including dimming or color adjustment. There are generally two types of driver solutions: linear and switching.

[0003] Linear drive applications are the simplest and most direct drive application method. In lighting-grade white light LED applications, although there are problems such as low efficiency and poor adjustability, due to its simple circuit and compact size, it can meet the needs of many specific applications.

[0004] Switching drivers offer excellent current control accuracy and high overall efficiency. They are primarily categorized into two types: buck and boost. Buck switching drivers are ideal for applications where the power supply voltage is higher than the LED terminal voltage, or when multiple LEDs are driven in parallel. Boost switching drivers are ideal for applications where the power supply voltage is lower than the LED terminal voltage, or when multiple LEDs are driven in series.

[0005] To obtain stable lighting, it is necessary to design a drive control circuit that matches the lamp. With the popularity of LED lighting, LED color change has become very common. Usually, the color change is controlled by a signal command (such as the common power switch color change or remote control color change), and an external voltage regulator or power supply is connected to achieve frequency "phase cutting" to achieve dimming.

[0006] In the existing technology, the color adjustment and dimming control methods are relatively complicated. Therefore, we propose a control method for the change of the rectangular wave signal of a single signal line to solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to solve the shortcomings of the existing technology in that the color adjustment and dimming control methods are relatively complicated, and to propose a control method for the change of a rectangular wave signal of a single signal line.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for controlling changes in a rectangular wave signal on a single signal line includes a control unit system, a color adjustment unit system, and a dimming unit system. The output end of the control unit system is connected to a power switch unit and an inverter in the color adjustment unit system; the input end of the power switch unit is connected to the output end of a light source; the output end of the power switch unit in the color adjustment unit system is connected to a total power switch unit in the dimming unit system; and the output end of the power supply is connected to the control unit system, the color adjustment unit system, and the dimming unit system. The control method includes the following steps:

[0010] S1, the color adjustment control of the control unit system is realized by the duty cycle of the rectangular wave signal emitted by the signal generating device;

[0011] S2, the dimming control of the control unit system is achieved by a PWM rectangular wave signal cycle at a recurring time interval;

[0012] S3, the color adjustment of the color adjustment unit system is achieved by the duty cycle of the PWM rectangular wave signal and driving two groups of light sources;

[0013] S4. The dimming of the dimming unit system is realized by controlling the start and end time of a rectangular wave signal cycle generated by the monostable trigger.

[0014] Preferably, the control unit system control command input can be input in various forms, including but not limited to: directly connecting the command signal source with a wire, receiving the command signal by a radio receiving circuit, receiving the command signal by a photoelectric coupling circuit, receiving the voice command signal by a voice recognition circuit, sensing the command signal by an isolation capacitor, or inputting the control command by a key.

[0015] Preferably, the control unit system PWM signal is generated by the control unit algorithm, and PWM signals of different states are output according to the control instruction requirements. The PWM signal can be connected to the color adjustment unit system and the dimming unit system through the control unit's built-in I / O port, transistor, photocoupler, TTL circuit, and CMOS circuit.

[0016] Preferably, the control unit system color adjustment control is achieved through the duty cycle of the rectangular wave signal, and the change of the signal duty cycle controls the same change in the conduction time of the two LEDs with different color temperatures to produce different color temperatures.

[0017] Preferably, the color adjustment of the color adjustment unit system is achieved by adjusting the duty cycle of the PWM rectangular wave signal and driving the two groups of light sources, which has a specific relationship with the control signal of the control unit system, either in phase or in antiphase.

[0018] Preferably, the color adjustment method for implementing the color adjustment unit system can generate an inverted PWMB signal by the first power switch, without the need for an inverter to generate the PWMB signal.

[0019] Preferably, the control unit system dimming control is achieved through a PWM rectangular wave signal cycle (time) at a recurring time interval. The smaller the recurring time interval of the rectangular wave signal (when the minimum recurring time interval is "0"), the more rectangular wave signals there are per unit time, the more specific duty cycles of the two LEDs with different color temperatures are turned on per unit time, and the higher the brightness.

[0020] Preferably, the dimming of the dimming unit system is achieved by generating a rectangular wave signal through a monostable trigger to generate the start and end time of a rectangular wave signal cycle (time), the start time is the same as the start time of a rectangular wave signal cycle (time) "1" of the control unit system, and the end time is the same as the end time of a rectangular wave signal cycle (time) signal "0" of the control unit system.

[0021] Preferably, the dimming control of the dimming unit system is controlled by the control of the main power switch, and its real-time current size can be set when it is turned on.

[0022] In the present invention, the beneficial effects of the control method for the change of the rectangular wave signal of a single signal line are:

[0023] The present invention utilizes the change of square waves for control, and can adjust the color temperature and brightness of the lamp, thereby improving the controllability, applicability and diversity of LED lamps, better meeting the needs of actual life, simplifying complex color adjustment and dimming control methods, and making LED applications more convenient and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a two-cycle square wave signal diagram of a method for controlling changes in a rectangular wave signal of a single signal line proposed by the present invention;

[0025] Figure 2 This is a flowchart for implementing dual light source color adjustment and dimming in a method for controlling changes in a rectangular wave signal on a single signal line proposed by the present invention;

[0026] Figure 3 A PWM color adjustment (color temperature) circuit form 1 of a control method for a rectangular wave signal change of a single signal line proposed by the present invention;

[0027] Figure 4 This is a PWM color adjustment (color temperature) circuit form 2 of a control method for a rectangular wave signal change on a single signal line proposed by the present invention;

[0028] Figure 5 This is a circuit diagram of the connection between the first power switch, the second power switch and the total power switch unit in the dimming system in a method for controlling the change of a rectangular wave signal on a single signal line proposed by the present invention;

[0029] Figure 6 This is a signal relationship diagram of dual light source color adjustment and dimming in a method for controlling changes in a rectangular wave signal of a single signal line proposed by the present invention. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] Reference Figure 1-6 A method for controlling changes in a rectangular wave signal on a single signal line includes a control unit system, a color adjustment unit system, and a dimming unit system. The output end of the control unit system is connected to a power switch unit and an inverter in the color adjustment unit system; the input end of the power switch unit is connected to the output end of a light source; the output end of the power switch unit in the color adjustment unit system is connected to a total power switch unit in the dimming unit system; the output end of a power supply is connected to the control unit system, the color adjustment unit system, and the dimming unit system. The power supply is a DC power supply composed of an electronic circuit or a DC power supply provided by a battery. The control unit system is composed of a control instruction input circuit, a control unit, and a PWM signal output circuit. The control method includes the following steps:

[0032] S1, the color adjustment control of the control unit system is realized by the duty cycle of the rectangular wave signal emitted by the signal generating device;

[0033] S2, the dimming control of the control unit system is achieved by a PWM rectangular wave signal cycle at a recurring time interval;

[0034] S3, the color adjustment of the color adjustment unit system is achieved by the duty cycle of the PWM rectangular wave signal and driving two groups of light sources;

[0035] S4. The dimming of the dimming unit system is realized by controlling the start and end time of a rectangular wave signal cycle generated by the monostable trigger.

[0036] In this embodiment, the control unit system control command input can be input in various forms, including but not limited to: directly connecting the command signal source by a wire, receiving the command signal by a radio receiving circuit, receiving the command signal by an optoelectronic coupling circuit, receiving the voice command signal by a voice recognition circuit, sensing the command signal by an isolation capacitor, or inputting the control command by a key.

[0037] In this embodiment, the control unit system PWM signal is generated by the algorithm of the control unit, and PWM signals of different states are output according to the control instruction requirements. The PWM signal can be connected to the color adjustment unit system and the dimming unit system through the built-in I / O port, transistor, photocoupler, TTL circuit, and CMOS circuit of the control unit.

[0038] In this embodiment, the control unit system color adjustment control is achieved through the duty cycle of the rectangular wave signal. The change of the signal duty cycle controls the same change in the conduction time of the two LEDs with different color temperatures, thereby generating different color temperatures.

[0039] In this embodiment, the color adjustment of the color adjustment unit system is achieved by adjusting the duty cycle of the PWM rectangular wave signal and driving the two groups of light sources, which has a specific relationship with the control signal of the control unit system, either in phase or in antiphase.

[0040] In this embodiment, the method for implementing color adjustment in the color adjustment unit system can generate an inverted PWMB signal by the first power switch, without the need for an inverter to generate the PWMB signal.

[0041] In this embodiment, the control unit system dimming control is achieved through a PWM rectangular wave signal cycle (time) at a recurring time interval. The smaller the recurring time interval of the rectangular wave signal (when the minimum recurring time interval is "0"), the more rectangular wave signals there are per unit time, the more specific duty cycles of the two LEDs with different color temperatures are turned on per unit time, and the higher the brightness.

[0042] In this embodiment, the dimming of the dimming unit system is realized by generating the start and end time of a rectangular wave signal cycle (time) of a rectangular wave signal by a monostable trigger. The start time is the same as the start time of a rectangular wave signal cycle (time) "1" of the control unit system, and the end time is the same as the end time of a rectangular wave signal cycle (time) signal "0" of the control unit system.

[0043] In this embodiment, the dimming control of the dimming unit system is achieved by controlling the main power switch, and the real-time current level of the main power switch can be set when the main power switch is turned on.

[0044] The control instruction input circuit can be directly connected to the instruction signal source by a wire, the control instruction input circuit can receive the instruction signal by a radio receiving circuit, the control instruction input circuit can receive the instruction signal by a photoelectric coupling circuit, the control instruction input circuit can receive the voice instruction signal by a voice recognition circuit, the control instruction input circuit can sense the instruction signal by an isolation capacitor, the control unit can be composed of an MCU (micro control unit, containing I / O ports), the control unit can be composed of an IoT module, the control unit can be composed of a Bluetooth module, the control unit can be composed of a WIFI module, the PWM signal is generated by the algorithm of the control unit, the PWM signal can be directly output by the built-in I / O port of the control unit, the PWM signal can be connected to the color adjustment unit system and the dimming unit system through a transistor, the PWM signal can be connected to the color adjustment unit system and the dimming unit system through a photoelectric coupler, the PWM signal can be connected to the color adjustment unit system and the dimming unit system through a TTL circuit, and the PWM signal can be connected to the color adjustment unit system and the dimming unit system through a CMOS circuit.

[0045] A color adjustment unit system realizes the change of LED color temperature by adjusting the duty cycle of a PWM rectangular wave signal and driving two groups of light sources. The first switch unit and the second switch unit are used to control the conduction and cutoff of the first light source and the second light source respectively. The power switch unit is a semiconductor switch. The control end of the first power switch is connected to the PWM output end of the control unit, and the control end of the second power switch is connected to the output end of the inverter. The first power switch can be regarded as the inverter function of the second power switch. The first light source and the second light source are commonly connected to the current output end. The first light source and the second light source are respectively connected to the first power switch and the second power switch. The output ends of the first power switch and the second power switch are connected to the total power switch unit in the dimming system. The input ends of the first power switch, the inverter, and the monostable trigger are commonly connected to the PWM signal output of the control unit system. The processing module detects the conduction time and cutoff time of the DC power output by the rectifier unit through the extraction module.

[0046] The dimming unit system is connected to the color adjustment unit system and the control unit system respectively.

[0047] The monostable trigger uses the control unit system's PWM rectangular wave signal as a clock, generating a regular monostable square wave with a constant frequency and width. However, when the light source power is increased, the drive signal operates at full frequency. When the light source power is reduced, the drive signal skips some switching cycles. During these skipped cycles, the total power switching unit remains in the off state. When the load changes, the number of skipped cycles is changed to achieve system adjustment and control.

[0048] The on and off of the monostable trigger respectively control the on and off of the total power switch. When the total power switch is on, it has a constant current function when passing a reference voltage or a reference current. The on time of the total power switch is the sum of the passing time of the first power switch and the second power switch.

[0049] The control unit controls the regular change of the PWM signal, and the first power switch and the second power switch are turned on and off respectively according to the proportion of the PWM signal, thereby realizing the color change of the LED light source.

[0050] When the PWM signal is implemented with a PWM rectangular wave signal cycle (time) at a recurring time interval, the smaller the recurring time interval of the rectangular wave signal (when the minimum recurring time interval is "0"), the more rectangular wave signals there are per unit time, and the more specific duty cycles of the two LEDs with different color temperatures are turned on per unit time, the higher the brightness.

[0051] To better illustrate the dimming principle, a complete PWM signal is fixed-width, and the frequency of one PWB signal and the next PWM signal is fixed-frequency. When the light source power is at its maximum, one PWB signal and the next PWM signal operate at full frequency. When the light source power is reduced, the drive signal skips some switching cycles. During the skipped cycles, the main power switch unit remains in the off state. When adjusting the LED brightness, the output power is adjusted by changing the number of skip cycles to determine whether the PWM signal and the main switch tube are operating within a cycle. The PWM signal is ultimately used to control the first power switch, the second power switch, and the main power switch.

[0052] In this embodiment, the control unit includes but is not limited to: an MCU (micro control unit, including an I / O port), an IoT module, a Bluetooth module, and a WIFI module group.

[0053] In this embodiment, the PWM signal is generated by the algorithm of the control unit, and the PWM signal of different states is output according to the control instruction requirements. The PWM signal can be connected to the color adjustment unit system and the dimming unit system through the built-in I / O port, transistor, photocoupler, TTL circuit, and CMOS circuit of the control unit.

[0054] In this embodiment, the color mixing unit system is shown in FIG. Figure 2 , realize the duty cycle of PWM rectangular wave signal and drive two sets of light sources to achieve LED color temperature change, see Figure 3Circuit presentation. The first and second light sources are connected to the first and second power switches, respectively. PWM color temperature adjustment involves mixing light strings with cool and warm color temperatures and adjusting their brightness separately. After averaging, the color temperature can be adjusted. PWM color temperature adjustment technology uses a pair of complementary PWM signals (the PWMB signal is implemented by an inverter): PWM and PWMB, to control LED light strings with corresponding color temperatures. For example, PWM controls cool white LEDs, while PWMB controls warm white LEDs. The PWMB signal is the inverse of the PWM signal, so only one LED is illuminated at a time. This balances the two, so when the cool white LED is illuminated for a longer period, the warm white LED is illuminated for a shorter period, resulting in a cooler overall light appearance. When the cool white LED is illuminated for a shorter period, the warm white LED is illuminated for a longer period, resulting in a warmer overall light appearance.

[0055] In this embodiment Figure 4 In the circuit color adjustment method, the PWMB signal is directly generated by the first power switch, and an inverter is not required to generate the PWMB signal.

[0056] In this embodiment, the first switch unit and the second switch unit are used to control the on and off of the first light source (cold light source) and the second light source (warm light source) respectively.

[0057] In this embodiment, the power switch unit is a semiconductor switch.

[0058] In this embodiment, the control terminal of the first power switch is connected to the PWM output terminal of the control unit.

[0059] In this embodiment, the control terminal of the second power switch is connected to the output terminal of the inverter. In some applications, the first power switch can be regarded as the inverter function of the second power switch. When the first power switch can be regarded as the inverter function of the second power switch, the circuit form should meet the parameter requirements and settings of the driving voltage and driving current of the second power switch.

[0060] In this embodiment, the first light source and the second light source are commonly connected to the current output terminal.

[0061] In this embodiment, the output ends of the first power switch and the second power switch are connected to the total power switch unit in the dimming system. Figure 5 The total power switch is controlled to be turned on or off by a monostable signal. When turned on, the conduction time of the total power switch is the sum of the passing time of the first power switch and the second power switch, and the current flowing therethrough is controlled by the current limit setting device, so that the LED light source operates at a constant current.

[0062] In the embodiment, when the PWM signal is implemented in a PWM rectangular wave signal cycle (time) at a recurring time interval, the smaller the recurring time interval of the rectangular wave signal (when the minimum recurring time interval is "0"), the more rectangular wave signals there are per unit time, the more specific duty cycles of the two LEDs with different color temperatures are turned on per unit time, and the higher the brightness. To better illustrate the dimming principle, a complete PWM signal is fixed at a "fixed width", and the frequency of a PWB signal and the next PWM signal is a "fixed frequency". When the light source power is increased, a PWB signal and the next PWM signal work at full frequency. When the light source power is reduced, the drive signal will skip some switching cycles. During the skipped cycles, the total power switch unit remains in the off state. When adjusting the LED brightness, the output power is adjusted by changing the number of times the cross-cycle occurs to realize whether the PWM signal and the control main switch tube work within a cycle. Refer to Figure 6 .

[0063] In this embodiment, this solution mainly uses the change of square wave for control;

[0064] A square wave is a non-sinusoidal waveform (e.g. Figure 1 A square wave signal with a 2-cycle period is commonly encountered in electronics and signal processing. An ideal square wave has only two values: "high" and "low." A signal with a rectangular current or voltage waveform is called a rectangular wave. The ratio of the time the high level lasts within one waveform cycle is called the duty cycle, which can also be understood as the ratio of the effective release time of energy in a circuit to the total release time. A rectangular wave with a 50% duty cycle is called a square wave. Square waves can have either a low level of zero or a negative value. "Low level is zero" or "Low level is negative" can be used to describe these when necessary. The duty cycle is the ratio of the time the square wave value "1" lasts within one cycle. A true square wave has a duty cycle of 50%—meaning the high and low values ​​occupy an equal amount of time. The average value of a square wave is determined by the duty cycle. Therefore, by varying the on and off periods and then taking the average, it is possible to represent any value between two limiting levels. This is the basis of pulse-width modulation (Pulse-Width Modulation).

[0065] An inverter (not gate) reverses the phase of an input signal by 180 degrees. This circuit is used in analog circuits, such as audio amplifiers and clock oscillators. Inverters are frequently used in electronic circuit design. A CMOS inverter circuit consists of two enhancement-mode MOS field-effect transistors. A typical TTL NAND gate circuit (consists of an input stage, an intermediate stage, and an output stage) is shown.

[0066] A monostable trigger has only one stable state and one transient state. Under the influence of an external pulse, the monostable trigger can flip from a stable state to a transient state. For example, the charge and discharge time of an RC circuit can be realized (due to the RC delay element in the circuit, the transient state persists for a period of time before returning to the original stable state. The duration of the transient state depends on the RC parameter value).

[0067] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for controlling the change of a rectangular wave signal of a single signal line, characterized in that: The following steps are involved: S1, the color adjustment of the control unit system is achieved by the duty cycle of the PWM signal sent by the control unit; S2. The dimming of the control unit system is achieved by adjusting the frequency of the dimming control signal, specifically by changing the number of repetitions of the dimming control signal within one cycle of the PWM signal; S3, the color adjustment of the color adjustment unit system is achieved by driving two groups of light sources through the duty cycle of the PWM signal; S4. The dimming of the dimming unit system is achieved by a monostable trigger, and multiple synchronized dimming control signals are generated within one cycle of the PWM signal output by the control unit. The start time of the first dimming control signal is synchronized with the high level start time of one cycle of the PWM signal, and the end time of the last dimming control signal is synchronized with the low level end time of one cycle of the PWM signal. The output end of the control unit system is connected to the first power switch unit and one end of the inverter in the color adjustment unit system, and the other end of the inverter is connected to the second power switch unit; the two power switch units are connected to the light source; the two power switch units in the color adjustment unit system are also connected to the total power switch unit in the dimming unit system; the output end of the power supply is connected to the control unit system, the color adjustment unit system and the dimming unit system.

2. The method for controlling the change of a rectangular wave signal of a single signal line according to claim 1, characterized in that: The control unit system control command input includes various forms, including: directly connecting the command signal source with a wire, receiving the command signal by a radio receiving circuit, receiving the command signal by a photoelectric coupling circuit, receiving the voice command signal by a voice recognition circuit, sensing the command signal by an isolation capacitor, or inputting the control command by a key.

3. The method for controlling the change of a rectangular wave signal of a single signal line according to claim 2, characterized in that: The PWM signal of the control unit system is generated by the algorithm of the control unit, and the PWM signal of the corresponding state is output according to the control instruction; the PWM signal is output through the built-in I / O port of the control unit and transmitted to the color adjustment unit system and the dimming unit system via at least one element selected from transistors, photocouplers, TTL circuits or CMOS circuits.

4. The method for controlling the change of a rectangular wave signal of a single signal line according to claim 3, characterized in that: The control unit system color adjustment is achieved through the duty cycle of the PWM signal. The change of the signal duty cycle controls the first LED conduction time to increase and the second LED conduction time to decrease accordingly, or vice versa, thereby adjusting the mixed color temperature.

5. The method for controlling the change of a rectangular wave signal of a single signal line according to claim 4, characterized in that: The first power switch unit receives the PWM signal to control the first LED, and the second power switch unit receives the PWM signal through the inverter to control the second LED.

6. The method for controlling the change of a rectangular wave signal of a single signal line according to claim 5, characterized in that: The color adjustment unit system also controls the second power switch unit by outputting a signal opposite to the PWM signal through the first power switch unit, without requiring an inverter.

7. The method for controlling the change of a rectangular wave signal of a single signal line according to claim 6, characterized in that: The control unit system dimming is achieved by adjusting the frequency of the dimming control signal within one cycle of the PWM signal: when the frequency increases, the duty cycle remains unchanged, the total LED conduction time ratio increases, and the brightness is improved.

8. The method for controlling the change of a rectangular wave signal of a single signal line according to claim 7, characterized in that: The dimming control of the dimming unit system controls the real-time current size through the total power switch.

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