Light emitting diode light string control system and signal recognition thereof

Abstract

The application discloses a light emitting diode (LED) lamp string control system and a signal recognition thereof. The LED lamp string control system comprises a control module, a power capacitor and an LED lamp string. The control module switches a direct current voltage to a carrier signal through a power switch according to a light emitting command, and the power capacitor generates a capacitive charge-discharge signal by capacitive charge-discharge of the carrier signal. The LED lamp string comprises at least one LED module. The at least one LED module identifies that a charge-discharge characteristic of the capacitive charge-discharge signal belongs to a first logic, a second logic or a latch instruction, and generates a driving command for controlling a light emitting behavior of the LED lamp string according to the first logic, the second logic and the latch instruction.

Description

TECHNICAL FIELD

[0001] The present application relates to a light emitting diode (LED) string control system and a signal recognition method thereof, and in particular, to a LED string control system with carrier recognition function and a signal recognition method thereof. BACKGROUND

[0002] With the increasing popularity of LED applications and the decreasing cost of manufacturing, LED is more and more widely used in lighting or display. Correspondingly, there are more and more operation and control methods for LED light emitting behavior. In the application of LED string, in order to make the LED string produce visual effect, the light emitting behavior of each LED must be set. Therefore, a controller must be used to control each LED, and each controller must have the function of recognizing signals to determine whether the signal is a specific light emitting command.

[0003] Among them, since the carrier signal received by the existing LED string is mostly high-power and high-frequency switching signal, it is easy to be affected by high-frequency noise interference and affect the stability of signal recognition. Therefore, it is necessary to use more precise recognition circuit or components that can resist noise interference to increase the stability of signal recognition. However, such components or circuits are usually expensive and the operation method is more complex.

[0004] Therefore, how to design a LED string control system with carrier recognition function and a signal recognition method thereof to easily and accurately recognize the carrier signal and enable the LED string to correctly perform the light emitting behavior is a big problem that the present inventor wants to study. SUMMARY

[0005] In order to solve the above problems, the present application provides a LED string control system with carrier recognition function to overcome the problems of known technology. The LED string control system includes a control module, a power capacitor and a LED string. The control module switches the direct current voltage to a carrier signal through a power switch according to a light emitting command. The power capacitor is coupled to the output end of the control module and performs capacitive charging and discharging on the carrier signal to generate a capacitive charging and discharging signal. The LED string is coupled to the power capacitor and includes at least one LED module. The at least one LED module identifies that the charging and discharging characteristics of the capacitive charging and discharging signal belong to a first logic, a second logic or a latch indication, and generates a driving command corresponding to the carrier signal according to the first logic, the second logic and the latch indication. Wherein, the driving command is used to control the light emitting behavior of the LED string.

[0006] To address the aforementioned problems, this invention provides a signal identification method for a light-emitting diode (LED) string control system, overcoming the limitations of known technologies. The signal identification method includes the following steps: (a) switching a DC voltage to a carrier signal according to a light-emitting command. (b) generating a capacitive charge-discharge signal by capacitively charging and discharging the carrier signal. (c) identifying whether the charge-discharge characteristics of the capacitive charge-discharge signal belong to a first logic, a second logic, or a latch indication. (d) generating a drive command corresponding to the carrier signal based on the first logic, the second logic, and the latch indication to control the light-emitting behavior of the LED string.

[0007] The main objective and benefit of this invention is that a power capacitor generates a capacitive charging and discharging signal by capacitively charging and discharging a carrier signal, and a light-emitting diode module identifies the charging and discharging characteristics of the capacitive charging and discharging signal. This achieves the advantages of simple circuit components, easy operation, and accurate identification of the carrier signal to correctly execute the light-emitting behavior.

[0008] To gain a deeper understanding of the techniques, means, and effects employed by this invention to achieve its intended purpose, please refer to the following detailed description and accompanying drawings. It is believed that the purpose, features, and characteristics of this invention can be understood in a thorough and specific manner from these drawings. However, the accompanying drawings are provided for reference and illustration only and are not intended to limit the scope of this invention. Attached Figure Description

[0009] Figure 1 This is a circuit block diagram of the LED string control system with carrier identification function according to the present invention.

[0010] Figure 2 This is a circuit block diagram of the light-emitting diode module of the present invention;

[0011] Figure 3A This is a waveform diagram of the present invention for identifying charging and discharging characteristics using a predetermined threshold.

[0012] Figure 3B The waveform diagram used in this invention to identify charge and discharge characteristics using time width; and

[0013] Figure 4 This is a flowchart of the signal identification method for a light-emitting diode string control system according to the present invention.

[0014] Explanation of symbols in the attached diagram:

[0015] 100 LED string control system;

[0016] 1. Rectifier;

[0017] 2. Control module;

[0018] 20 Power switches;

[0019] 22 controller;

[0020] C power capacitor;

[0021] 3 light emitting diode light string;

[0022] 30 light emitting diode module;

[0023] 32 light emitting diode;

[0024] 34 detection circuit;

[0025] 36 logic circuit;

[0026] 38 controller;

[0027] 40 filter circuit;

[0028] Vin input voltage;

[0029] Vdc direct current voltage;

[0030] Cl light emitting command;

[0031] Cd drive command;

[0032] Scr carrier signal;

[0033] Scd capacitive charge-discharge signal;

[0034] Sc control signal;

[0035] Slg logic signal;

[0036] Slg1-Slg3 first logic signal-third logic signal;

[0037] V1-V3 first threshold-third threshold;

[0038] V predetermined threshold;

[0039] H first voltage level;

[0040] L second voltage level;

[0041] 0 first logic;

[0042] 1 second logic;

[0043] LK latch indication. DETAILED DESCRIPTION

[0044] The technical content and detailed description of the present application are described as follows in conjunction with the drawings:

[0045] Please refer to Figure 1A circuit block diagram of a light emitting diode (LED) string control system with carrier recognition function. The LED string control system 100 receives an input voltage Vin through an input terminal, and includes a rectifier 1, a control module 2, a power capacitor C, and an LED string 3. The control module 2 is coupled between the rectifier 1 and the LED string 3, and the power capacitor C is coupled between the control module 2 and the LED string 3. The rectifier 1 rectifies the input voltage Vin from an alternating current (AC) to a direct current (DC) voltage Vdc, and the control module 2 switches the DC voltage Vdc to a carrier signal Scr according to a light emitting command Cl provided externally. The power capacitor C is coupled to an output terminal of the control module 2, and performs capacitive charging and discharging on the carrier signal Scr to generate a capacitive charging and discharging signal Scd. The LED string 3 is coupled to the power capacitor C, and includes at least one LED module 30. The LED module 30 includes at least one LED 32, and controls the light emitting behavior of the LED 32 in the LED string 3 according to the carrier signal Scr. When the LED module 30 is a plurality of LED modules (a plurality of LED modules are shown in the embodiment), the LED modules 30 can be coupled in series or in parallel (not shown in the figure). It is worth mentioning that in an embodiment of the present application, the LED string control system 100 can also not include the rectifier 1, and the input voltage Vin received by the LED string control system 100 is the DC voltage Vdc. Alternatively, the rectifier 1 can be replaced by a DC converter. The DC converter receives the input voltage Vin in a DC form, and converts the input voltage Vin to the DC voltage Vdc.

[0046] The control module 2 includes a power switch 20 and a controller 22, and the power switch 20 is coupled between the rectifier 1 and the power capacitor C. The controller 22 is coupled to a control terminal of the power switch 20, and provides a control signal Sc to control the conduction or non-conduction of the power switch 20 according to the light emitting command Cl, so as to switch the DC voltage Vdc to the carrier signal Scr by controlling the conduction or non-conduction of the power switch 20. The controller 22 can not include a conventional light emitting signal generator inside, and only generates the carrier signal Scr with high and low voltage levels by controlling the conduction or non-conduction of the power switch 20.

[0047] Further, since the carrier signal Scr is mostly composed of pulses with different widths, the width represents a specific logic meaning. Since the pulses with different widths are affected by the charging and discharging of the power capacitor C, different charging and discharging characteristics are generated. Therefore, the light emitting diode module 30 is designed to identify the charging and discharging characteristics of the capacitive charging and discharging signal Scd as a first logic (such as but not limited to logic "0"), a second logic (such as but not limited to logic "1") or a latch indication (usually at the end of a pulse, indicating that the corresponding light emitting diode module 30 can perform a latch action), and generate a driving command corresponding to the carrier signal Scr according to the first logic, the second logic and the latch indication, so as to control the light emitting behavior of the light emitting diode module 30 (the light emitting diode 32). Wherein, the driving command can include at least one of address data and light emitting data, which can be selectively matched according to actual needs (such as only light emitting data, or both). The address data mainly specifies at least one of the light emitting diode module 30. When the light emitting diode module 30 is singular, the address data is specified for the only one light emitting diode module 30. When the light emitting diode module 30 is plural, the address data can be specified for one or more of the light emitting diode modules 30. The light emitting data specifies the light emitting behavior of the light emitting diode 32 in the corresponding light emitting diode module 30. When the light emitting diode module 30 is singular, the light emitting data is specified for the light emitting behavior of the light emitting diode 32 in the only one light emitting diode module 30. When the light emitting diode module 30 is plural, the light emitting data can be specified for the light emitting behavior of the light emitting diode 32 in one or more of the light emitting diode modules 30.

[0048] Please refer to Figure 2 The circuit block diagram of the light emitting diode module of the present application is shown in FIG. 1, and the circuit block diagram of the light emitting diode module of the present application is shown in FIG. 2. Figure 1The light emitting diode module 30 includes at least one light emitting diode 32, a detection circuit 34, a logic circuit 36, and a controller 38. The detection circuit 34 is coupled to the power capacitor C and detects the capacitive charge-discharge signal Scd to generate a logic signal Slg according to the charge-discharge characteristics of the capacitive charge-discharge signal Scd. The logic circuit 36 is coupled to the detection circuit 34 and identifies whether the logic signal Slg belongs to a first logic, a second logic, or a latch indication to correspondingly generate a driving command Cd. The logic signal Slg can include a plurality of logic combinations (such as but not limited to "1011"), and the logic circuit 36 identifies the logic combination "1011" to generate a corresponding driving command Cd. The controller 38 is coupled to the logic circuit 36 and the light emitting diode 32 and receives the driving command Cd to store the driving command Cd in an internal memory unit (not shown). In this way, the controller 38 can control the light emitting behavior of the light emitting diode 32 according to the driving command Cd. When there are a plurality of light emitting diode modules 30, the light emitting behavior of the light emitting diode lamp string 3 as a whole can be varied, such as but not limited to sequential light emission, sequential flickering, and the like, because the driving command Cd of each light emitting diode module 30 can be different.

[0049] Further, the light emitting diode module 30 includes at least two ways of identifying the charge-discharge characteristics. One of them is that the light emitting diode module 30 identifies the charge-discharge characteristics using predetermined thresholds, and the other is that the light emitting diode module 30 identifies the charge-discharge characteristics using time width. When the charge-discharge characteristics are identified using predetermined thresholds, the detection circuit 34 is designed to compare the size of the capacitive charge-discharge signal Scd with the thresholds. Specifically, the detection circuit 34 sets a first threshold, a second threshold, and a third threshold, and the thresholds are in order from large to small, i.e., the first threshold, the second threshold, and the third threshold. When the voltage value of the capacitive charge-discharge signal Scd triggers the first threshold, the second threshold, and the third threshold, the detection circuit 34 correspondingly generates a first logic signal, a second logic signal, and a third logic signal (the sum of which is the logic signal Slg). The logic circuit 36 identifies whether this segment of signal belongs to a first logic, a second logic, or a latch indication according to the first logic signal, the second logic signal, and the third logic signal. For example, but not limited to, when the first logic signal, the second logic signal, and the third logic signal appear in order within a certain time, it can be judged that this waveform of the capacitive charge-discharge signal Scd refers to a latch indication (and so on).

[0050] In using the time width to identify the charge-discharge characteristics, the detection circuit 34 is designed to generate the charge-discharge time width of the capacitive charge-discharge signal Scd when the signal discharges to the same voltage level as when it charges. Specifically, the detection circuit 34 sets a predetermined threshold, and generates a logic signal Slg according to the capacitive charge-discharge signal Scd discharging to less than or equal to the predetermined threshold and charging to greater than or equal to the predetermined threshold. The logic circuit 36 judges the logic signal Slg to belong to the first logic, the second logic or the latch indication according to the time width maintained by the logic signal Slg. For example, but not limited to, the longest time width maintained can be judged as the capacitive charge-discharge signal Scd indicating the latch indication (by analogy).

[0051] Referring to Figure 2 Each light emitting diode module 30 further includes a filter circuit 40, and if analog filtering, the filter circuit 40 is coupled between the detection circuit 34 and the power capacitor C, and if digital filtering, the filter circuit 40 is coupled between the detection circuit 34 and the logic circuit 36. Since there are two implementations, it is represented by a dashed line. The filter circuit 40 is used to filter the capacitive charge-discharge signal Scd. Specifically, since the capacitive charge-discharge signal Scd is a high-power signal, and the power switch 20 is high-frequency switching, the capacitive charge-discharge signal Scd will generate more edge or switching spikes. If there is no filter circuit 40 to filter the capacitive charge-discharge signal Scd, the edge or switching spike will affect the detection accuracy of the capacitive charge-discharge signal Scd by the detection circuit 34. Therefore, using the filter circuit 40 to filter the capacitive charge-discharge signal Scd is a preferred implementation of the light emitting diode lamp string control system 100.

[0052] Referring to Figure 3A For the waveform diagram of the present application using a predetermined threshold to identify the charge-discharge characteristics, referring to Figures 1-2 In Figure 3AIn the embodiment, Scd is a capacitive charge-discharge signal, V1~V3 are first threshold value~third threshold value, Slg is a logic signal, Slg1~Slg3 are first logic signal~third logic signal, Cd is a drive command, and "0", "1", "LK" are first logic, second logic, and latch indication respectively. When the voltage value of the capacitive charge-discharge signal Scd is lower than the first threshold value V1, the second threshold value V2, and the third threshold value V3 respectively, the detection circuit 34 generates the first logic signal Slg1, the second logic signal Slg2, and the third logic signal Slg3 respectively. The logic circuit 36 generates the first logic "0" according to the logic signal Slg with only the first logic signal Slg1, and generates the second logic "1" according to the logic signal Slg with the first logic signal Slg1 and the second logic signal Slg2. When the logic signal Slg contains the first logic signal Slg1~the third logic signal Slg3, it represents the latch indication "LK". The corresponding controller 38 uses the arrangement combination of the logic "0" and "1" as the drive command Cd, and stores it in the internal memory unit (not shown). In this way, the carrier signal Scr can be accurately identified and the light emitting behavior can be correctly performed.

[0053] It is worth mentioning that in an embodiment of the present application, the way of identifying the charge-discharge characteristics using predetermined threshold values is not limited to the above-mentioned way. Any way of using set voltage threshold values to judge the logic signal (such as but not limited to positive edge or negative edge triggering) should be included in the scope of this embodiment. In addition, the logic "0" and the logic "1" can be mutually adjusted (for example, the logic circuit 36 generates the first logic "1" according to the logic signal Slg with only the first logic signal Slg1, and is not limited to only the logic "0"). In addition, in an embodiment of the present application, the latch indication "LK" can be a longer discharge of the capacitive charge-discharge signal Scd or a potential of the latch indication "LK" with a longer high potential.

[0054] Please refer to Figure 3B The waveform diagram of the present application using time width to identify the charge-discharge characteristics, please refer to Figures 1-3A In Figure 3BIn the equation, Scd is the capacitive charge-discharge signal, V is the predetermined threshold, Slg is the logic signal, Cd is the driving command, and "0", "1", and "LK" are the first logic, the second logic, and the latch indication, respectively. When the capacitive charge-discharge signal Scd is discharged to be less than or equal to the predetermined threshold V, the logic signal Slg changes to the first voltage level H (i.e., the high level), and when the capacitive charge-discharge signal Scd is charged to be greater than or equal to the predetermined threshold V, the logic signal Slg changes to the second voltage level L (i.e., the low level). The logic circuit 36 determines whether the signal belongs to the first logic "0", the second logic "1", or the latch indication "LK" according to the time width of the logic signal Slg at the first voltage level. When the time width of the logic signal Slg at the first voltage level is short, it is determined to be the first logic "0", and when the time width of the logic signal Slg at the first voltage level is long, it is determined to be the second logic "1". When the time width of the logic signal Slg at the first voltage level is the longest, it represents the latch indication "LK". The corresponding controller 38 uses the arrangement combination of the aforementioned logic "0" and "1" as the driving command Cd, and stores it in the internal memory unit (not shown). In this way, the carrier signal Scr can be accurately recognized to correctly perform the light emitting behavior.

[0055] It is worth mentioning that in an embodiment of the present application, the way of recognizing the charge-discharge characteristics using the time width is not limited to the above-mentioned way. Any way of using the calculated time width to determine the logic signal should be included in the scope of the present embodiment. In addition, the widths corresponding to the logic "0" and the logic "1" can be mutually adjusted.

[0056] Please refer to Figure 4 The method flowchart of the signal recognition method for the light emitting diode lamp string control system of the present application is shown in FIG. 4, and please refer to Figures 1-3BThe signal recognition method comprises switching the direct current voltage to a carrier signal according to the light emitting command (S100). Preferably, the controller 22 provides a control signal Sc to control the on or off of the power switch 20 according to the light emitting command Cl, so as to switch the direct current voltage Vdc to the carrier signal Scr by controlling the on or off of the power switch 20. Then, the carrier signal is capacitively charged and discharged to generate a capacitive charge and discharge signal (S120). Preferably, the power capacitor C is used to capacitively charge and discharge the carrier signal Scr to generate the capacitive charge and discharge signal Scd. Then, the charge and discharge characteristics of the capacitive charge and discharge signal are identified to belong to the first logic, the second logic or the latch indication (S140). Preferably, the light emitting diode module 30 is used to identify the charge and discharge characteristics of the capacitive charge and discharge signal Scd to belong to the first logic, the second logic or the latch indication. Specifically, the capacitive charge and discharge signal Scd can be detected to generate a logic signal Slg according to the charge and discharge characteristics of the capacitive charge and discharge signal Scd, and then the logic circuit 36 is used to identify the logic signal Slg to belong to the first logic, the second logic or the latch indication.

[0057] The light emitting diode module 30 comprises at least two recognition methods for the charge and discharge characteristics. One of them is that the light emitting diode module 30 uses a predetermined threshold to recognize the charge and discharge characteristics, and the other is that the light emitting diode module 30 uses the time width to recognize the charge and discharge characteristics. When the predetermined threshold is used to recognize the charge and discharge characteristics, the capacitive charge and discharge signal Scd is preferably compared with the first threshold V1, the second threshold V2 and the third threshold V3 to correspondingly generate the logic signal Slg. When the time width is used to recognize the charge and discharge characteristics, the logic signal Slg is preferably generated according to the capacitive charge and discharge signal Scd from discharging to less than or equal to the predetermined threshold V to charging to greater than or equal to the predetermined threshold V. Then, the drive command corresponding to the carrier signal is generated according to the first logic, the second logic and the latch indication to control the light emitting behavior of the light emitting diode lamp string (S160). Preferably, the logic circuit 36 is used to generate the drive command Cd corresponding to the carrier signal Scr according to the first logic, the second logic and the latch indication. Then, the controller 38 is used to store the drive command Cd in the internal memory unit (not shown). In this way, when all the light emitting diode modules 30 in the light emitting diode lamp string 3 have latched the drive command Cd, the drive command Cd can be used to control the light emitting behavior of the light emitting diode lamp string 3.

[0058] To avoid the influence of the more ragged or switching surge generated by the power generation capacitive charge-discharge signal Scd on the judgment accuracy of the detection circuit 34 on the capacitive charge-discharge signal Scd, after step (S120), the capacitive charge-discharge signal can be filtered (S180). The preferred embodiment is to use a filter circuit 40 to filter the capacitive charge-discharge signal Scd to avoid affecting the judgment accuracy of the detection circuit 34 on the capacitive charge-discharge signal Scd.

[0059] The above is only a detailed description of the preferred embodiments of the application and the drawings, but the features of the application are not limited to this, and are not intended to limit the application. The scope of the application should be based on the following patent claims, and any embodiments similar to the application within the scope of the application should be included in the scope of the application. Any changes or modifications that can be easily thought of by those skilled in the art in the field of the application can be covered by the patent range of the case.

Claims

1. A light emitting diode light string control system, characterized by, The application comprises: a control module for switching a direct current voltage to a carrier signal through a power switch according to a light emitting command; a power capacitor coupled to an output terminal of the control module and performing a capacitive charging and discharging on the carrier signal to generate a capacitive charging and discharging signal; and a light emitting diode (LED) string coupled to the power capacitor and comprising at least one LED module; the at least one LED module identifies that a charging and discharging feature of the capacitive charging and discharging signal belongs to a first logic, a second logic or a latch instruction, and generates a driving command corresponding to the carrier signal according to the first logic, the second logic and the latch instruction; wherein the driving command is used to control a light emitting behavior of the LED string; wherein the at least one LED module comprises a detection circuit coupled to the power capacitor and generating a logic signal according to the charging and discharging feature of the capacitive charging and discharging signal; and wherein the at least one LED module uses a voltage threshold to identify the charging and discharging feature, and the detection circuit compares the capacitive charging and discharging signal with a first voltage threshold, a second voltage threshold and a third voltage threshold to correspondingly generate the logic signal; or wherein the at least one LED module uses a time width to identify the charging and discharging feature, and the time width is a time difference from a time point when the capacitive charging and discharging signal is discharged to a time point when the capacitive charging and discharging signal is charged to a predetermined voltage threshold, and the detection circuit correspondingly generates the logic signal according to the time difference.

2. The light emitting diode lamp string control system of claim 1, wherein, The at least one LED module further comprises: a logic circuit coupled to the detection circuit and identifying that the logic signal belongs to the first logic, the second logic or the latch instruction to correspondingly generate the driving command; and a controller coupled to the logic circuit and a LED and receiving the driving command to control a light emitting behavior of the LED.

3. The light emitting diode lamp string control system of claim 2, wherein, The at least one LED module further comprises: a filter circuit coupled to the detection circuit; wherein the filter circuit performs noise filtering on the capacitive charging and discharging signal.

4. The light emitting diode lamp string control system of claim 1, wherein, The driving command comprises at least one of an address data and a light emitting data, and the address data specifies at least one of the at least one LED module, and the light emitting data specifies the light emitting behavior of at least one of the at least one LED module.

5. The light emitting diode lamp string control system of claim 1, wherein, The control module comprises: a power switch receiving the direct current voltage and coupled to the power capacitor; and a controller coupled to the power switch and receiving the light emitting command; wherein the controller provides a control signal to control on or off of the power switch according to the light emitting command, so as to switch the direct current voltage to the carrier signal through controlling on or off of the power switch.

6. The light emitting diode lamp string control system of claim 1, wherein, The at least one LED module is a plurality of LED modules, and the LED modules are coupled in series or coupled in parallel.

7. A method for signal recognition for a light emitting diode light string control system, comprising: The application comprises the following steps: switching a direct current voltage to a carrier signal according to a light emitting command; performing a capacitive charging and discharging on the carrier signal to generate a capacitive charging and discharging signal; identifying that a charging and discharging feature of the capacitive charging and discharging signal belongs to a first logic, a second logic or a latch instruction; According to the first logic, the second logic and the latch indication, a driving command corresponding to the carrier signal is generated to control a light emitting behavior of a light emitting diode (LED) string; According to the charging and discharging characteristics of the capacitive charging and discharging signal, a logic signal is generated; And The logic signal is generated by comparing the capacitive charging and discharging signal with a first voltage threshold, a second voltage threshold and a third voltage threshold; Or The logic signal is generated according to a time difference from a time point when the capacitive charging and discharging signal is discharged to a time point when the capacitive charging and discharging signal is charged to a voltage equal to or greater than a predetermined voltage threshold.

8. The signal recognition method of claim 7, wherein, Further comprising the following steps: The logic signal is identified as the first logic, the second logic or the latch indication to correspondingly generate the driving command.

9. The signal recognition method of claim 7, wherein, Further comprising the following steps: The capacitive charging and discharging signal is subjected to noise filtering.

10. The signal recognition method of claim 7, wherein, Further comprising the following steps: According to the light emitting command, a control signal is provided to control the on or off of a power switch, so as to switch the direct current voltage to the carrier signal by controlling the on or off of the power switch.

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