A circuit system with a multi-channel PWM signal sharing drive module and its control method

Abstract

The present invention provides a circuit system for a multi-channel PWM signal sharing a driving module, which is applied to a multi-channel LED lamp circuit. It includes: a control module, which includes a micro-control unit. The control module is used to output a PWM total dimming signal and a predetermined number of switch signals. The PWM total dimming signal is composed of PWM sub-dimming signals of a predetermined number of colors, and these sub-dimming signals are paired with the switch signals one by one; a predetermined number of switch modules, which are electrically connected to the control module. These switch modules receive the switch signals one by one and are electrically connected to the lamps in the multi-channel LED lamp circuit one by one. These switch modules cut off or conduct the circuits of their corresponding lamps according to the switch signals; a driving module, which is electrically connected to the control module and the switch modules. The driving module is used to receive and process the PWM total dimming signal and cooperate with the switch modules to drive the lamps for dimming.

Description

Technical Field

[0001] The present invention relates to the field of LED lamp circuit driving, and particularly to a circuit system and a control method for a multi-channel PWM signal sharing driving module. Background Art

[0002] Reference Figure 6 , in the driving circuit of traditional color LED lamps, each color of lamp beads R_LED, G_LED, B_LED... N_LED in the lamp module 4 needs an independent driving module 30R, 30G, 30B... 30N to drive respectively. The control module 10 realizes the dimming effect of the LED lamp by simultaneously outputting corresponding PWM dimming signals 10R, 10G, 10B... 10N to the above driving modules respectively. Since the circuit cost of the driving module is relatively high, when there are multiple colors of lamp beads, multiple independent driving circuits are required, which greatly increases the cost of the lamp circuit, such as the component cost. At the same time, due to the relatively large volume of the driving components, the area of the circuit board increases, resulting in an increase in the structural cost and the manual manufacturing cost. The increase in the number of components also increases the probability of lamp damage. Therefore, improvements are needed. Summary of the Invention

[0003] The present invention provides a circuit system for a multi-channel PWM signal sharing driving module, which uses the same driving module to drive multi-channel LED lamps, simplifying the structure of the multi-channel LED lamp circuit driving system.

[0004] The present invention provides a circuit system for a multi-channel PWM signal sharing driving module, which is applied to a multi-channel LED lamp circuit to realize the dimming control of the lamps in the multi-channel LED lamp circuit. It includes: a control module, which includes a micro control unit, and is used to output a PWM total dimming signal and a predetermined number of switch signals. The PWM total dimming signal is composed of a predetermined number of types of PWM sub-dimming signals, and these sub-dimming signals are paired with the switch signals one by one; a predetermined number of switch modules, which are electrically connected to the control module, and these switch modules respectively receive the switch signals and are respectively electrically connected to the lamps in the multi-channel LED lamp circuit. These switch modules cut off or conduct the circuits of their corresponding lamps according to the switch signals; a driving module, which is electrically connected to the control module and the switch modules, and is used to receive and process the PWM total dimming signal and cooperate with the switch modules to drive the lamps for dimming.

[0005] Preferably, the driving module is a constant voltage driving module, and the constant voltage driving module outputs a driving voltage after receiving and processing the PWM total dimming signal.

[0006] Preferably, the constant voltage driving module includes a switching tube, a resistor connected in series with the switching tube, and a capacitor.

[0007] Preferably, the switching tube includes, but is not limited to, a MOS tube or a triode.

[0008] Preferably, the driving module is a constant current driving module, and the constant current driving module outputs a driving current after receiving and processing the PWM total dimming signal.

[0009] Preferably, the driving module includes a switching tube, a constant current driving chip, an inductor, a resistor, an electrolytic capacitor, and a Schottky diode.

[0010] Preferably, the switching tube includes, but is not limited to, a MOS tube or a triode.

[0011] Preferably, the switching module includes a switching tube, and the switching tube includes, but is not limited to, a MOS tube or a triode.

[0012] The circuit system of the multi-channel PWM signal sharing driving module provided by the present invention controls a total dimming signal composed of multiple sub-dimming signals and switching signals corresponding to the sub-dimming signals one by one through a control module. Only one driving module receives and processes the total dimming signal, and cooperates with the switching signal to control the cut-off and conduction of the switching module, so as to realize the dimming control of multiple LED lamps in the multi-channel LED lamp circuit. Compared with the traditional multi-channel LED lamp circuit driving system, the structure of this system reduces the number of driving modules, and the cost of the switching module is much lower than that of the driving module, thereby reducing the lamp design cost and maintenance cost. Also, since the number of electronic components used in the switching module is less than that of the driving module, the overall volume of the lamp can be reduced. At the same time, compared with the traditional circuit system, the simple circuit structure of this system makes the circuit easy to maintain, further reducing the maintenance cost and difficulty.

[0013] A control method for a circuit system of a multi-channel PWM signal sharing driving module, which is applied to the circuit system of any one of the above multi-channel PWM signal sharing driving modules. The control method includes the following steps: Step 1, parameter initialization, presetting the output order, duty cycle, and output mark of the PWM sub-dimming signal corresponding to each color; Step 2, timer interruption, entering the PWM total dimming signal output judgment period. If the current PWM total dimming signal output period ends, go to Step 31. If the current PWM total dimming signal output period does not end, go to Step 32;

[0014] Step 31: Reset the judgment period of the PWM total dimming signal output, set the output flag of the PWM sub-dimming signal corresponding to the color output at the beginning of the next period to the output state, and simultaneously output the PWM sub-dimming signal and the switch signal corresponding to the color output at the beginning of the next period, then loop back to Step 2; Step 32: Enter the judgment period of the PWM sub-dimming signal output according to the output flag. If the current PWM sub-dimming signal output is completed, enter Step 5; if the current PWM sub-dimming signal output is not completed, loop back to Step 2. When all output flags are set to the off state, loop back to Step 2.

[0015] Step 5: Turn off the output of the current PWM sub-dimming signal and the current switch signal, set the output flag of the current PWM sub-dimming signal to the off state, and enter Step 6. If the current PWM sub-dimming signal is the last one in the PWM sub-dimming signal output sequence, loop back to Step 2; Step 6: Set the output flag of the PWM sub-dimming signal corresponding to the next output color to the output state, and simultaneously output the PWM sub-dimming signal and the switch signal corresponding to the next output color, then loop back to Step 2.

[0016] The circuit system control method of the multi-channel PWM signal sharing drive module provided by the present invention is applied to the above circuit system, and is a method for realizing the output of a total dimming signal composed of multiple sub-dimming signals. The control method has a concise logic, makes the output of the PWM total dimming signal of the control module more accurate, has a low delay, does not require the control module to add additional auxiliary functional devices, has a low cost, and improves the practicability of the circuit system of the multi-channel PWM signal sharing drive module. Description of the Drawings

[0017] Figure 1 is a circuit system structure diagram of a multi-channel PWM signal sharing drive module provided by an embodiment of the present invention;

[0018] Figure 2 is a PWM total dimming signal output waveform diagram output by the control module provided by an embodiment of the present invention;

[0019] Figure 3 is Figure 2 a regional division diagram of the PWM total dimming signal output waveform diagram in

[0020] Figure 4 is Figure 2 a PWM sub-dimming signal decomposition output waveform diagram of the PWM total dimming signal output waveform diagram in

[0021] Figure 5 is a switch signal output waveform diagram output by the control module;

[0022] Figure 6 is a schematic diagram of the circuit system structure of a traditional color LED lamp;

[0023] Figure 7 is a schematic structural diagram of a constant-voltage driving module;

[0024] Figure 8 is a schematic structural diagram of a constant-current driving module;

[0025] Figure 9 is a partial schematic structural diagram of a switching module;

[0026] Figure 10 is a logic schematic diagram of a circuit system control method for a multi-channel PWM signal sharing driving module provided by the first embodiment of the present invention. Specific Embodiment

[0027] The following further describes the circuit system of a multi-channel PWM signal sharing driving module provided by the present invention with reference to the accompanying drawings. It should be noted that only an optimized technical solution is used here to elaborate in detail on the technical solution and design principle of the present invention.

[0028] Refer to Figure 1 , which is a circuit system of a multi-channel PWM signal sharing driving module provided by the present invention. It includes a control module 1, a driving module 3, switching modules 2R, 2G, 2B... 2N, and lamps of various colors R_LED, G_LED, B_LED... N_LED. Among them, the control module includes a micro-control unit (MCU) and common peripheral circuits of the micro-control unit. The micro-control is used to output a PWM total dimming signal and switching signals 1R, 1G, 1B... 1N. The peripheral circuits of the micro-control unit are well-known technologies and will not be elaborated here one by one. The above switching modules are all electrically connected to the control module 1. The switching modules 2R, 2G, 2B... 2N respectively receive the switching signals 1R, 1G, 1B... 1N, and the switching modules 2R, 2G, 2B... 2N are correspondingly electrically connected to the lamps of various colors R_LED, G_LED, B_LED... N_LED in the lamp module 4. These switching modules cut off or conduct the circuits of their corresponding lamps of different colors according to the switching signals. The driving module 3 is electrically connected to the control module 1 and the switching modules 2R, 2G, 2B... 2N. It is used to receive and process the PWM total dimming signal, and cooperate with the switching modules 2R, 2G, 2B... 2N to drive the lamps R_LED, G_LED, B_LED... N_LED for dimming.

[0029] Next, in combination with Figure 1, in the first embodiment of the present invention, this circuit system will be further introduced based on LED lamps of three colors, red, green, and blue, in combination with specific PWM dimming signals. Among them, in the total PWM dimming signal, the duty cycle of the red lamp R_LED is 30%, the duty cycle of the green lamp G_LED is 10%, and the duty cycle of the blue lamp B_LED is 50%. Refer to Figure 2 , which is the output waveform of the total PWM dimming signal output by the control module 1. Refer to Figure 3 , the single period of this total PWM dimming signal can be decomposed into three output regions, tR, tG, and tB. Representing the three regions tR, tG, and tB of this total PWM dimming signal with the output waveforms of separate PWM dimming signals respectively, we can obtain Figure 4 the PWM sub-dimming signal R (duty cycle 30%), the PWM sub-dimming signal G (duty cycle 10%), and the PWM self-dimming signal B (duty cycle 50%) in Figure 2 . That is to say, the total PWM dimming signal in Figure 5, the control module 1 outputs switching signals 1R, 1G, and 1B to the switching modules 2R, 2G, and 2B respectively. Among them, the switching signal 1R is at a high level during the time period t1 within a single cycle, the switching signal 1G is at a high level during the time period t2 within a single cycle, and the switching signal 1B is at a high level during the time period t3 within a single cycle. When the circuit system is in the time period t1 of a single cycle, the control module 1 outputs the PWM total dimming signal, the switching signal 1R, the switching signal 1G, and the switching signal 1B. And during this time period, the PWM total dimming signal is in a high-level state, the switching signal 1R is in a high-level state, the switching signal 1G and the switching signal 1B are in a low-level state. At this time, the switching module 2R is in a conducting state, and the switching modules 2G and 2B are both in a non-conducting state. The driving module receives and processes the PWM total dimming signal and then outputs a driving voltage or a driving current to the R_LED for red dimming control. When the circuit system is in the time period t2 of a single cycle, the PWM total dimming signal and the switching module 2G are at a high level, and the switching modules 2R and 2B are at a low level. At this time, the switching module 2G is in a conducting state, and the switching modules 2R and 2B are in a non-conducting state. The driving module outputs a driving voltage or a driving current to the G_LED for green dimming control. When the circuit system is in the time period t3 of a single cycle, the PWM total dimming signal and the switching module 2B are at a high level, and the switching modules 2R and 2G are at a low level. At this time, the switching module 2B is in a conducting state, and the switching modules 2R and 2G are in a non-conducting state. The driving module outputs a driving voltage or a driving current to the B_LED for blue dimming control. In this embodiment, the duration of a single cycle T1 = T2 = T3 =... = Tn = 10 ms. Due to the short cycle, in fact, the effect observed by the human eye during the operation of this system is that the lamps of the three colors are dimmed simultaneously, which is the same as the effect shown by the traditional dimming control and will not cause the influence of flicker due to the dimming delay of lamps of different colors.

[0030] Preferably, referring to Figure 1 and Figure 7 , in the circuit system provided by the first embodiment of the present invention, the driving module 3 can be a constant-voltage driving module. This constant-voltage driving module is used to receive and process the PWM total dimming signal and then output a driving voltage. This constant-voltage driving module includes a triode 311, resistors 312, 313, diodes 314, 315, 316, 317, and 318. The base (B) of the triode 311 is sequentially connected to a resistor 312 and the PWM total dimming signal output terminal of the control module 1. The emitter (E) of the triode 311 is grounded. The collector (C) of the triode 311 is sequentially connected to resistors 313, diodes 314, 315, 316, 317, 318, and the power supply. Of course, the triode 311, as a switching tube, can also be replaced by a MOS tube.

[0031] Preferably, referring to Figure 1 and Figure 8 , different from the first embodiment, the driving module 3 may be a constant current driving module, which is used to receive and process the PWM total dimming signal and then output a driving current. The constant current driving module includes a constant current driving chip 321, a triode 322, resistors 323, 324, an inductor 327, electrolytic capacitors 326, 3212, a Schottky diode 325, and diodes 328, 329, 3210, 3211. The ADJ terminal of the constant current driving chip 321 is connected to the collector (C) of the triode 322. The emitter (E) of the triode 322 is connected to the power supply through the electrolytic capacitor 3212. The base (B) of the triode 322 is sequentially connected to the resistor 323 and the PWM total dimming signal output terminal of the control module 1. An electrolytic capacitor 326 and the inductor 327, diodes 328, 329, 3210, 3211, and the power supply voltage connected in series are connected in parallel to the LX terminal and the IS terminal of the constant current driving chip 321. The VIN terminal of the constant current driving chip 321 is connected to the power supply and through an electrolytic capacitor 3212. Of course, the triode 322 as a switching tube can also be replaced by a MOS tube.

[0032] Referring to Figure 1 and Figure 9 , in the circuit system provided by the present invention, each of the switching modules 2R, 2G, and 2B includes a MOS tube N1. The gate (G) of the MOS tube N1 is connected to the switching signal output terminal of the control module 1. The drain (D) of the MOS tube N1 is connected to the driving output terminal of the driving module 3. The source (S) of the MOS tube N1 is connected to the LED lamp. Of course, the switching module can also be replaced by a triode.

[0033] Finally, referring to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 10 , based on the LED lamps of three colors, red, green, and blue, and combined with the specific PWM dimming signal, a further introduction is made to the circuit system control method of sharing the driving module by multiple PWM signals provided by the first embodiment of the present invention. The method specifically includes the following steps:

[0034] Step 1: Parameter initialization. In this embodiment, assume that the output order of the PWM sub-dimming signals corresponding to red, green, and blue is such that red is the first output color, green is the second output color, and blue is the third output color. The duty cycle of the PWM sub-dimming signal R corresponding to red is 30%, the duty cycle of the PWM sub-dimming signal G corresponding to green is 10%, and the duty cycle of the PWM sub-dimming signal B corresponding to blue is 50%. The output flag OUT_R of the PWM sub-dimming signal R is 0, the output flag OUT_G of the PWM sub-dimming signal G is 0, and the output flag OUT_B of the PWM sub-dimming signal B is 0. Here, an output flag of 0 indicates the off state, and an output flag of 1 indicates the output state. The single output period T of the PWM total dimming signal is 10 ms, the timer off interval is 0.1 ms, and the number of timer off times is k. When first powered on, let the number of timer off times k = 99;

[0035] Step 2: Timer interrupt. Enter the PWM total dimming signal output judgment period. When k > 100, the judgment period ends. If the current PWM total dimming signal output period ends, then enter Step 31. When k ≤ 100, the judgment period does not end. If the current PWM total dimming signal output period has not ended, then enter Step 32;

[0036] Step 31: Reset the interrupt count k, let k = 0, set the output flag of the PWM sub-dimming signal R corresponding to red to the output state, i.e., let OUT_R = 1, and simultaneously output the PWM sub-dimming signal R and the switch signal 1R, then loop back to Step 2;

[0037] Step 32: Enter the PWM sub-dimming signal output judgment period according to the output flag. When OUT_R = 1, judge whether the output of the PWM sub-dimming signal R is completed. When OUT_G = 1, judge whether the output of the PWM sub-dimming signal G is completed. When OUT_B = 1, judge whether the output of the PWM sub-dimming signal B is completed. If the current PWM sub-dimming signal output is completed, then enter Step 5. If the current PWM sub-dimming signal output is not completed, then loop back to Step 2. When all output flags are set to the off state, i.e., OUT_R = 0, OUT_G = 0, OUT_B = 0, then directly loop back to Step 2;

[0038] Step 5: Turn off the output of the current PWM sub-dimming signal and the current switch signal, and set the output flag of the current PWM sub-dimming signal to the off state, then enter Step 6. If the current PWM sub-dimming signal is the last one in the PWM sub-dimming signal output order, i.e., when the output of the PWM sub-dimming signal B is completed, then directly loop back to Step 2;

[0039] Step 6: Set the output flag of the PWM sub-dimming signal corresponding to the next output color to the output state, and simultaneously output the PWM sub-dimming signal and the switch signal corresponding to the next output color, and loop back to Step 2.

[0040] The circuit system of the multi-PWM signal shared driving module provided by the present invention realizes the production of multi-channel LED lamp circuits with low cost and small volume through the mode of sharing one driver for multiple PWM signals.

[0041] The above are only the preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as a limitation of the present invention. The protection scope of the present invention should be defined by the scope of the claims. For those of ordinary skill in the art, without departing from the spirit and scope of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A circuit system with a shared driving module for multi-channel PWM signals, which is applied to a multi-channel LED lighting circuit to achieve dimming control of the lamps in the multi-channel LED lighting circuit. Characterized in that, It includes: A control module, which includes a micro control unit. The control module is used to output a PWM total dimming signal and a predetermined number of switching signals. The PWM total dimming signal is composed of PWM sub-dimming signals with different duty cycles corresponding to a predetermined number of colors. These sub-dimming signals are paired with the switching signals one by one; A predetermined number of switching modules, which are electrically connected to the control module. These switching modules receive the switching signals one by one and are electrically connected to the lamps in the multi-channel LED lighting circuit one by one. These switching modules cut off or conduct the circuits of their corresponding lamps according to the switching signals; A driving module, which is electrically connected to the control module and the switching module. The driving module is used to receive and process the PWM total dimming signal and cooperate with the switching module to drive the lamps for dimming; The switching module includes a switching tube, and the switching tube includes a MOS tube or a triode.

2. A circuit system with a shared driving module for multi-channel PWM signals according to claim 1, Characterized in that, The driving module is a constant voltage driving module, and the constant voltage driving module outputs a driving voltage after receiving and processing the PWM total dimming signal.

3. A circuit system with a shared driving module for multi-channel PWM signals according to claim 2, Characterized in that, The constant voltage driving module includes a switching tube, a resistor connected in series with the switch, and a capacitor.

4. A circuit system with a shared driving module for multi-channel PWM signals according to claim 1, Characterized in that, The driving module is a constant current driving module, and the constant current driving module outputs a driving current after receiving and processing the PWM total dimming signal.

5. A circuit system with a shared driving module for multi-channel PWM signals according to claim 4, Characterized in that, The driving module includes a switching tube, a constant current driving chip, an inductor, a resistor, an electrolytic capacitor, and a Schottky diode.

6. A control method for a circuit system with a shared driving module for multi-channel PWM signals, Characterized in that, This control method is applied to the circuit system with a shared driving module for multi-channel PWM signals as described in any one of claims 1 to 5. This control method includes the following steps: Step 1, parameter initialization, preset the output order of the PWM sub-dimming signals corresponding to each color, the duty cycle of the PWM sub-dimming signals, and the output mark of the PWM sub-dimming signals; Step 2, timer interruption, enter the judgment period of the PWM total dimming signal output. If the current PWM total dimming signal output period ends, enter step 31. If the current PWM total dimming signal output period has not ended, enter step 32; Step 31, reset the judgment period of the PWM total dimming signal output, set the output mark of the PWM sub-dimming signal corresponding to the first output color in the next period to the output state, and simultaneously output the PWM sub-dimming signal corresponding to the first output color in the next period and the switching signal, and loop to step 2; Step 32: Enter the PWM sub-dimming signal output judgment period according to the output flag. If the current PWM sub-dimming signal output is completed, go to Step 5. If the current PWM sub-dimming signal output is not completed, loop back to Step 2. When all output flags are in the off state, loop back to Step 2; Step 5: Turn off the output of the current PWM sub-dimming signal and the current switch signal, and set the current PWM sub-dimming signal output flag to the off state. Enter Step 6. If the current PWM sub-dimming signal is the last one in the PWM sub-dimming signal output sequence, loop back to Step 2; Step 6: Set the PWM sub-dimming signal output flag corresponding to the next output color to the output state, and at the same time output the PWM sub-dimming signal and the switch signal corresponding to the next output color, and loop back to Step 2.

Images