CN109905942B - LED dimming signal control circuit and system - Google Patents
LED dimming signal control circuit and system Download PDFInfo
- Publication number
- CN109905942B CN109905942B CN201910241284.6A CN201910241284A CN109905942B CN 109905942 B CN109905942 B CN 109905942B CN 201910241284 A CN201910241284 A CN 201910241284A CN 109905942 B CN109905942 B CN 109905942B
- Authority
- CN
- China
- Prior art keywords
- signal
- resistor
- dimming signal
- module
- terminal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The invention discloses an LED dimming signal control circuit and a system, wherein the LED dimming signal control circuit is connected with a constant current driving circuit and comprises a key detection module, a control module and a signal processing module, the key detection module outputs a corresponding detection signal to the control module when detecting that an external corresponding key is pressed down, the control module outputs a dimming signal to the signal processing module, sets a first parameter value of the dimming signal to be a first preset value according to the detection signal, and outputs a control signal to the signal processing module according to the detection signal; the signal processing module switches a second parameter value of the dimming signal to a second preset value according to the control signal and outputs the dimming signal to the constant current driving circuit, so that flexible setting of parameters of the dimming signal is realized, the constant current driving circuit can obtain the required dimming signal during backlight debugging, and the research and development efficiency of products is improved.
Description
Technical Field
The invention relates to the technical field of LED dimming, in particular to an LED dimming signal control circuit and system.
Background
With the rapid development of technology, consumer electronics products are more and more competitive, and the requirements for the development period and problem analysis capability of the products are higher and higher. In the prior art, only a dimming signal is sent out through a main board for adjustment, but all parameters of the dimming signal cannot be flexibly set; the backlight constant current part of the LED television has different requirements on the characteristics of dimming signals supported by different mainboard schemes, the backlight constant current part is taken as a controlled part, the backlight constant current part cannot provide such adjusting signals, the backlight constant current part must be externally connected with the adjusting signals, the requirements on product development analysis and progress are not facilitated, and the product development efficiency is influenced.
Thus, the prior art has yet to be improved and enhanced.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide an LED dimming signal control circuit and system, which indirectly obtain information set by a user on dimming signal parameters by detecting the working condition of an external key, so as to flexibly set each parameter of the dimming signal, further obtain the dimming signal required in the backlight debugging process, and improve the research and development efficiency of products.
In order to achieve the purpose, the invention adopts the following technical scheme:
an LED dimming signal control circuit is connected with a constant current driving circuit and comprises a key detection module, a control module and a signal processing module, wherein the key detection module outputs a corresponding detection signal to the control module when detecting that an external corresponding key is pressed down, the control module outputs a dimming signal to the signal processing module, sets a first parameter value of the dimming signal to be a first preset value according to the corresponding detection signal, and outputs a control signal to the signal processing module according to the corresponding detection signal; and the signal processing module switches a second parameter value of the dimming signal to a second preset value according to the control signal and outputs the dimming signal to the constant current driving circuit.
The LED dimming signal control circuit further comprises a sampling module and a display module, wherein the sampling module samples the constant current driving circuit and then outputs sampling current and sampling voltage to the control module, and the control module performs analog-to-digital conversion on the sampling voltage and the sampling current and then outputs the sampling voltage and the sampling voltage to the display module for display.
In the LED dimming signal control circuit, the signal processing module includes a first signal processing unit, a second signal processing unit, and a dimming signal input/output unit, the first signal processing unit keeps off according to the control signal, and the second signal processing unit keeps on according to the control signal, so that a second parameter value of the dimming signal output by the dimming signal input/output unit is a second preset value.
In the LED dimming signal control circuit, the sampling module comprises a current sampling unit and a voltage sampling unit, the current sampling unit samples the current output by the constant current driving circuit and outputs the sampled current to the control module, and the voltage sampling unit samples the voltage output by the constant current driving circuit and outputs the sampled voltage to the control module.
In the LED dimming signal control circuit, the first signal processing unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode, a second diode, a first MOS transistor and a first triode, one end of the first resistor and a source electrode of the first MOS transistor are both connected to a 3.3V power supply terminal, the other end of the first resistor and an anode of the first diode are both connected to one end of the second resistor, the other end of the second resistor is connected to a collector of the first triode, an emitter of the first triode and one end of the fourth resistor are both grounded, the other end of the fourth resistor and a base of the first triode are connected to one end of the third resistor, the other end of the third resistor is connected to a cathode of the second diode, and an anode of the second diode is connected to a 3.3VON signal terminal; the negative electrode of the first diode is connected with the grid electrode of the first MOS tube, and the drain electrode of the first MOS tube is connected with the IO _ AMP signal end.
In the LED dimming signal control circuit, the second signal processing unit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a third diode, a fourth diode, a second MOS and a second triode, one end of the fifth resistor and a source electrode of the second MOS are both connected to a 5V power supply terminal, the other end of the fifth resistor and an anode of the third diode are both connected to one end of the sixth resistor, the other end of the sixth resistor is connected to a collector of the second triode, an emitter of the second triode and one end of the eighth resistor are both grounded, the other end of the eighth resistor and a base of the second triode are connected to one end of the seventh resistor, the other end of the seventh resistor is connected to a cathode of the fourth diode, and an anode of the fourth diode is connected to a 5VON signal terminal; and the cathode of the fourth diode is connected with the grid electrode of the second MOS tube, and the drain electrode of the second MOS tube is connected with an IO _ AMP signal end.
In the LED dimming signal control circuit, the dimming signal input/output unit includes a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a third triode and a fourth triode, one end of the ninth resistor is connected to an IO _ AMP signal terminal, the other end of the ninth resistor is connected to a collector of the third triode and an ENA signal terminal, and a base of the third triode is connected to the ENA0 signal terminal through the tenth resistor; the transmitting end of the third triode is grounded; one end of the eleventh resistor is connected with an IO _ AMP signal end, the other end of the eleventh resistor is connected with a collector electrode and a PWM signal end of the fourth triode, and a base electrode of the fourth triode is connected with the PWM0 signal end through a twelfth resistor; and the transmitting end of the fourth triode is grounded.
In the LED dimming signal control circuit, the current sampling unit includes a first operational amplifier, a thirteenth resistor, a fourteenth resistor, and a fifteenth resistor, a positive power source of the first operational amplifier IS connected to a 5V power source, a negative power source of the first operational amplifier IS grounded, a positive input of the first operational amplifier IS connected to an IS signal end through the thirteenth resistor, an inverting input of the first operational amplifier IS connected to one end of the fifteenth resistor, and the other end of the fifteenth resistor IS grounded; the output end of the first operational amplifier is connected with one end of the fourteenth resistor and the signal end of the ADC1, and the other end of the fourteenth resistor is connected with one end of the fifteenth resistor.
In the LED dimming signal control circuit, the voltage sampling unit includes a second operational amplifier, a sixteenth resistor, a seventeenth resistor and an eighteenth resistor, a positive power source end of the second operational amplifier is connected to a 5V power source end, a negative power source end of the second operational amplifier is grounded, a positive input end of the second operational amplifier is connected to a VS signal end through the sixteenth resistor, an inverting input end of the second operational amplifier is connected to one end of the eighteenth resistor, and the other end of the eighteenth resistor is grounded; the output end of the second operational amplifier is connected with one end of the seventeenth resistor and the signal end of the ADC0, and the other end of the seventeenth resistor is connected with one end of the eighteenth resistor.
An LED dimming signal control system comprises the LED dimming signal control circuit.
Compared with the prior art, the LED dimming signal control circuit and the LED dimming signal control system provided by the invention are connected with the constant current driving circuit and comprise a key detection module, a control module and a signal processing module, wherein the key detection module outputs a corresponding detection signal to the control module when detecting that an external corresponding key is pressed down, the control module outputs a dimming signal to the signal processing module, sets a first parameter value of the dimming signal to be a first preset value according to the detection signal, and outputs a control signal to the signal processing module according to the detection signal; the signal processing module switches a second parameter value of the dimming signal to a second preset value according to the control signal and outputs the dimming signal to the constant current driving circuit, so that flexible setting of parameters of the dimming signal is realized, the constant current driving circuit can obtain the required dimming signal during backlight debugging, and the research and development efficiency of products is improved.
Drawings
Fig. 1 is a block diagram of a structure of an LED dimming signal control circuit and a constant current driving circuit according to the present invention;
fig. 2 is a schematic circuit diagram of a signal processing module in the LED dimming signal control circuit provided by the present invention;
fig. 3 is a schematic circuit diagram of a current sampling unit in the LED dimming signal control circuit provided by the present invention;
fig. 4 is a schematic circuit diagram of a voltage sampling unit in the LED dimming signal control circuit provided by the present invention;
fig. 5 is a schematic circuit diagram of a first key detection unit in the LED dimming signal control circuit according to the present invention;
fig. 6 is a schematic circuit diagram of a second key detection unit in the LED dimming signal control circuit according to the present invention;
fig. 7 is a schematic circuit diagram of a third key detection unit in the LED dimming signal control circuit according to the present invention;
fig. 8 is a schematic circuit diagram of a fourth key detection unit in the LED dimming signal control circuit according to the present invention;
fig. 9 is a schematic circuit diagram of a control module in the LED dimming signal control circuit provided by the present invention;
fig. 10 is a schematic circuit diagram of a first power supply unit in the LED dimming signal control circuit provided by the present invention;
fig. 11 is a schematic circuit diagram of a second power supply unit in the LED dimming signal control circuit provided by the present invention;
fig. 12 is a schematic circuit diagram of a display module in the LED dimming signal control circuit according to the present invention;
fig. 13 is a schematic circuit diagram of an output interface in the LED dimming signal control circuit provided by the present invention;
fig. 14 is a flowchart of signal conditioning of the LED dimming signal control circuit provided by the present invention.
Detailed Description
The invention provides an LED dimming signal control circuit and system, which indirectly acquire information set by a user for dimming signal parameters by detecting the working condition of an external key, realize flexible setting of each parameter of a dimming signal, further acquire a dimming signal required in a backlight debugging process and improve the research and development efficiency of products.
In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The LED dimming signal control circuit provided by the invention is suitable for constant current circuits such as backlight and illumination of a television, and can also be applied to the fields of program control voltage source voltage regulation, direct current motor speed regulation control and the like.
Referring to fig. 1, an LED dimming signal control circuit 20 provided by the present invention is connected to a constant current driving circuit 10, where the LED dimming signal control circuit 20 includes a key detection module 210, a control module 220, a signal processing module 230, and a power supply module 240, the key detection module 210 is connected to the control module 220, the control module 220 is connected to the signal processing module 230, the signal processing module 230 is connected to the constant current driving, and the power supply module 240 is connected to the control module 220, the key detection module 210, and the signal processing module 230; the key detection module 210 outputs a corresponding detection signal to the control module 220 when detecting that an external corresponding key is pressed, the control module 220 outputs a dimming signal to the signal processing module 230, sets a first parameter value of the dimming signal to a first preset value according to the detection signal, and outputs a control signal to the signal processing module 230 according to the detection signal; the signal processing module 230 switches the second parameter value of the dimming signal to a second preset value according to the control signal, and outputs the dimming signal to the constant current driving circuit 10, so that flexible setting of the parameter of the dimming signal is realized, the constant current driving circuit 10 can obtain a required dimming signal during backlight debugging, and research and development efficiency of a product is improved.
In this embodiment, the power supply module 240 provides working power for the key detection module 210, the control module 220, and the signal processing module 230, the key detection module 210, the control module 220, and the signal processing module 230 work normally, the control module 220 outputs a dimming signal to the signal processing module 230 normally, the signal processing module 230 outputs the dimming signal to the constant current driving circuit 10, and at this time, parameter values of the dimming signal output by the signal processing module 230 are all default values. When the key detection module 210 detects that an external corresponding key is pressed, a corresponding detection signal is output to the control module 220, the control module 220 outputs a control signal to the signal processing module 230 according to the detection signal, the signal processing module 230 adjusts the second parameter value of the dimming signal to the second preset value according to the control signal, and the corresponding control module 220 also adjusts the first parameter value of the dimming signal to the first preset value according to the detection module, so that the constant current driving circuit 10 can obtain a required dimming signal during backlight debugging, and the research and development efficiency of products is improved. Preferably, the first parameter includes a frequency and a duty ratio of the dimming signal and an interval time between the dimming signal and the enable signal, the corresponding first preset value is obtained by a user according to actual needs, the second parameter includes a signal amplitude of the dimming signal, and the second preset value is a signal amplitude of 5V.
Further, the LED dimming signal control circuit 20 further includes a sampling module 250 and a display module 260, the sampling module 250 is connected to the constant current driving circuit 10 and the control module 220, and the display module 260 is connected to the control module 220; the sampling module 250 samples the constant current driving circuit 10 and outputs a sampling current and a sampling voltage to the control module 220, and the control module 220 performs analog-to-digital conversion on the sampling current and the sampling voltage and outputs the sampling voltage and the sampling voltage to the display module 260 for display; after the control module 220 and the signal processing module 230 complete the adjustment of the parameter value of the dimming signal, the signal processing module 230 outputs the dimming signal to the constant current driving circuit 10, which may cause the change of the voltage and the current corresponding to the constant current driving circuit 10, and the specific change is, the sampling module 250 may sample the dimming signal to obtain a sampling current and a sampling voltage to the control module 220, and the control module 220 performs analog-to-digital conversion on the sampling current and the sampling voltage and outputs the sampling current and the sampling voltage to the display module 260 for displaying, so that the change of the voltage and the current can be visually observed through the display module 260. In addition, the control module 220 correspondingly outputs the parameter value of the dimming signal to the display module 260, and the parameter value of the dimming signal is displayed by the display module 260 and visually obtained by people.
Further, referring to fig. 2, the signal processing module 230 includes a first signal processing unit 231, a second signal processing unit 232, and a dimming signal input/output unit 233, the first signal processing unit 231 is connected to the second signal processing unit 232, the control module 220, and the dimming signal input/output unit 233, the second signal output unit is connected to the control module 220 and the dimming signal input/output unit 233, and the dimming signal input/output unit 233 is further connected to the control module 220 and the constant current driving circuit 10; the first signal processing unit 231 keeps being turned off according to the control signal, and the second signal processing unit 232 keeps being turned on according to the control signal, so that a second parameter value of the dimming signal output by the dimming signal input/output unit 233 is a second preset value; when the external key is pressed, a corresponding detection signal is output to the control module 220, the control module 220 outputs a control signal to the first signal processing unit 231 and the second signal processing unit 232, and controls the first signal processing unit 231 to keep the off state, and the second signal processing unit 232 to keep the on state, so that the second parameter value of the dimming signal output by the dimming signal input/output unit 233 is a second preset value, the second parameter is the signal amplitude of the dimming signal, that is, the signal amplitude value of the output dimming signal is 5V, and the signal amplitude of the dimming signal can be effectively adjusted by the signal processing module 230.
Further, referring to fig. 3 and fig. 4, the sampling module 250 includes a current sampling unit 251 and a voltage sampling unit 252, the current sampling unit 251 is connected to the control module 220 and the constant current driving circuit 10, and the voltage sampling unit 252 is connected to the control module 220 and the constant current driving circuit 10; the current sampling unit 251 samples the current output by the constant current driving circuit 10 and outputs the sampled current to the control module 220, the voltage sampling unit 252 samples the voltage output by the constant current driving circuit 10 and outputs the sampled voltage to the control module 220, and the current sampling unit 251 and the voltage sampling unit 252 sample the output current and the output voltage of the constant current driving circuit 10, so that the voltage and the current of the constant current driving circuit 10 can be conveniently contrasted and analyzed, and the dimming signal required by the constant current driving circuit 10 can be conveniently and accurately debugged.
In detail, referring to fig. 2, the first signal processing unit 231 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D1, a second diode D2, a first MOS transistor M1 and a first transistor Q1, one end of the first resistor R1 and the source electrode of the first MOS transistor M1 are both connected with a 3.3V power supply end, the other end of the first resistor R1 and the anode of the first diode D1 are both connected with one end of the second resistor R2, the other end of the second resistor R2 is connected to the collector of the first transistor Q1, the emitter of the first transistor Q1 and one end of the fourth resistor R4 are both grounded, the other end of the fourth resistor R4 and the base of the first triode Q1 are connected with one end of the third resistor R3, the other end of the third resistor R3 is connected with the cathodes of the two diodes, and the anode of the second diode D2 is connected with a 3.3VON signal end; the cathode of the first diode D1 is connected to the gate of the first MOS transistor M1, and the drain of the first MOS transistor M1 is connected to the IO _ AMP signal terminal.
When the external corresponding key is pressed, the key detection module 210 outputs a detection signal, preferably, the detection signal is a low level signal, and at this time, the control module 220 outputs a control signal to the 3.3VON signal end according to the low level signal, so as to control the 3.3VON signal end to be converted from a high level to a low level, thereby stopping the first MOS transistor M1.
Further, the second signal processing unit 232 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a third diode D3, a fourth diode D4, a second MOS transistor M2, and a second transistor Q2, one end of the fifth resistor R5 and the source electrode of the second MOS transistor M2 are both connected with a 5V power supply end, the other end of the fifth resistor R5 and the anode of the third diode D3 are both connected with one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected to the collector of the second transistor Q2, the emitter of the second transistor Q2 and one end of the eighth resistor R8 are both grounded, the other end of the eighth resistor R8 and the base of the second triode Q2 are connected with one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected with the cathode of the fourth diode D4, and the anode of the fourth diode D4 is connected with a 5VON signal end; the cathode of the fourth diode D4 is connected to the gate of the second MOS transistor M2, and the drain of the second MOS transistor M2 is connected to the IO _ AMP signal terminal.
When an external corresponding key is pressed, the key detection module 210 outputs a detection signal, preferably, the detection signal is a low level signal, and at this time, the control module 220 outputs a control signal to the 5VON signal end according to the low level signal to control the 5VON signal end to be converted from a low level to a high level, so that the second MOS transistor M2 is turned on, and the signal amplitude IO _ AMP of the dimming signal is 5V. When the external key is not normally pressed, the key detection module 210 correspondingly outputs a high level signal, the 3.3VON is in a high level state, the first MOS transistor M1 is turned on, the 5VON is in a low level state, the second MOS transistor M2 is turned off, and the signal amplitude IO _ AMP of the dimming signal is 3.3V, that is, the key detection module 210 detects the working condition of the external key, so that the signal amplitude of the dimming signal can be effectively adjusted.
Further, the dimming signal input/output unit 233 includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a third transistor Q3 and a fourth transistor Q4, one end of the ninth resistor R9 is connected to an IO _ AMP signal terminal, the other end of the ninth resistor R9 is connected to a collector of the third transistor Q3 and an ENA signal terminal, and a base of the third transistor Q3 is connected to the ENA signal terminal through the tenth resistor R100A signal terminal; the transmitting end of the third triode Q3 is grounded; one end of the eleventh resistor R11 is connected to an IO _ AMP signal terminal, the other end of the eleventh resistor R11 is connected to a collector of the fourth transistor Q4 and a PWM signal terminal, and a base of the fourth transistor Q4 is connected to the PWM0 signal terminal through a twelfth resistor R12; the transmitting end of the fourth triode Q4 is grounded, receives the dimming signal and the enable signal output by the control module 220 through the adjustment signal input/output unit, and outputs the dimming signal with the set parameter information to the constant current driving circuit 10.
Further, with reference to fig. 3, the current sampling unit 251 includes a first operational amplifier U1, a thirteenth resistor R13, a fourteenth resistor R14 and a fifteenth resistor R15, a positive power terminal of the first operational amplifier U1 IS connected to the 5V power terminal, a negative power terminal of the first operational amplifier U1 IS grounded, a non-inverting input terminal of the first operational amplifier U1 IS connected to the IS signal terminal through the thirteenth resistor R13, an inverting input terminal of the first operational amplifier U1 IS connected to one end of the fifteenth resistor R15, and the other end of the fifteenth resistor R15 IS grounded; the output end of the first operational amplifier U1 is connected to one end of the fourteenth resistor R14 and the signal end of the ADC1, the other end of the fourteenth resistor R14 is connected to one end of the fifteenth resistor R15, the voltage sampling unit 252 amplifies the current signal output by the constant current driving circuit 10 by the second operational amplifier U2 and outputs a sampling current to the control module 220, and the sampling current is transmitted to the display module 260 for real-time display after analog-to-digital conversion by the control module 220.
Further, with reference to fig. 4, the voltage sampling unit 252 includes a second operational amplifier U2, a sixteenth resistor R16, a seventeenth resistor R17 and an eighteenth resistor R18, wherein a positive power terminal of the second operational amplifier U2 IS connected to the 5V power terminal, a negative power terminal of the second operational amplifier U2 IS grounded, a non-inverting input terminal of the second operational amplifier U2 IS connected to the IS signal terminal through the sixteenth resistor R16, an inverting input terminal of the second operational amplifier U2 IS connected to one end of the eighteenth resistor R18, and the other end of the eighteenth resistor R18 IS grounded; the output end of the second operational amplifier U2 is connected to one end of the seventeenth resistor R17 and the signal end of the ADC0, the other end of the seventeenth resistor R17 is connected to one end of the eighteenth resistor R18, the voltage sampling unit 252 amplifies the voltage signal output by the constant current driving circuit 10 by the second operational amplifier U2 and outputs a sampling voltage to the control module 220, and the sampling voltage is transmitted to the display module 260 for real-time display after analog-to-digital conversion by the control module 220.
Further, referring to fig. 5, fig. 6, fig. 7 and fig. 8, the key detection module 210 includes a plurality of key detection units, each of which can independently output detection information to the control module 220, and each of which includes an independent key, a pull-up resistor and a debounce capacitor. Preferably, the key detection module 210 in this embodiment includes a first key detection unit 211, a second key detection unit 212, a third key detection unit 213, a fourth key detection unit 214, a fifth key detection unit, and a sixth key detection unit.
Preferably, the first key detecting unit 211 includes a first key S1, a nineteenth resistor R19 and a first capacitor C1, the 1 st pin of the first key S1, the 2 nd pin of the first key S1 and the 5 th pin of the first key S1 are all grounded, the 3 rd pin of the first key S1 and the 4 th pin of the first key S1 are connected to the end of the nineteenth resistor R19 and one end of a first capacitor C1, the other end of the first capacitor C1 is grounded, and the other end of the nineteenth resistor R19 is connected to a 3.3V power supply terminal; after the first key S1 is pressed, the first key detection unit 211 outputs a corresponding detection signal, i.e., a low level signal, to the control module 220, the control module 220 outputs a control signal to the 3.3VON signal end of the first signal processing unit 231 and the 5VON signal end of the second signal processing unit 232 according to the detection signal, so that the 3.3VON signal end is changed from a high level to a low level, the 5VON signal end is changed from a low level to a high level, at this time, the first MOS transistor M1 is turned off, the second MOS transistor M2 is turned on, and further, the signal amplitude IO _ AMP of the dimming signal is 5V, thereby flexibly setting the signal amplitude of the dimming signal.
Preferably, the second key detecting unit 212 includes a second key S2, a twentieth resistor R20 and a second capacitor C2, the 1 st pin of the second key S2, the 2 nd pin of the second key S2 and the 5 th pin of the second key S2 are all grounded, the 3 rd pin of the second key S2 and the 4 th pin of the second key S2 are connected to the end of the twentieth resistor R20 and one end of the second capacitor C2, the other end of the second capacitor C2 is grounded, and the other end of the twentieth resistor R20 is connected to a 3.3V power supply terminal; the second key detection unit 212 is configured to set an interval time between the output of the dimming signal and the output of the enable signal, after the second key S2 is pressed, the second key detection unit 212 outputs a corresponding detection signal, i.e., a low level signal, to the control module 220, and the control module 220 may automatically set the interval time between the output of the dimming signal and the output of the enable signal according to the detection signal, so as to flexibly set the interval time between the output of the dimming signal and the output of the enable signal.
Preferably, the third key detecting unit 213 includes a third key S3, a twenty-first resistor R21 and a third capacitor C3, the 1 st pin of the third key S3, the 2 nd pin of the third key S3 and the 5 th pin of the third key S3 are all grounded, the 3 rd pin of the third key S3 and the 4 th pin of the third key S3 are connected to the end of the twenty-first resistor R21 and one end of the third capacitor C3, the other end of the third capacitor C3 is grounded, and the other end of the twenty-first resistor R21 is connected to a 3.3V power supply end; the third key detecting unit 213 can be used to adjust the frequency of the dimming signal, and the control module 220 can be triggered to set the frequency value of the dimming signal by controlling the third key S3, so as to output the dimming signal required for debugging.
Further preferably, the fourth key detecting unit 214 includes a fourth key S4, a twenty-second resistor R22 and a fourth capacitor C4, wherein the 1 st pin of the fourth key S4, the 2 nd pin of the fourth key S4 and the 5 th pin of the fourth key S4 are all grounded, the 3 rd pin of the fourth key S4 and the 4 th pin of the fourth key S4 are connected to the end of the twenty-second resistor R22 and one end of the fourth capacitor C4, the other end of the fourth capacitor C4 is grounded, and the other end of the twenty-second resistor R22 is connected to a 3.3V power supply terminal; the fourth key detecting unit 214 may be configured to adjust a duty ratio of the dimming signal, that is, the control module 220 may be triggered to set a frequency value of the dimming signal by controlling the fourth key S4, and then output the dimming signal for debugging.
Further, referring to fig. 9, the control module 220 includes a control chip U3, the 7 th pin of the control chip U3 is connected to the 5VON signal terminal, the 8 th pin of the control chip U3 is connected to the 3.3VON signal terminal, and the 11 th pin of the control chip U3 is connected to the PWM signal terminal0A 12 th pin of the control chip U3 is connected with the ADC0 signal terminal, a 13 th pin of the control chip U3 is connected with the ADC1 signal terminalTerminal, the 14 th pin of the control chip U3 is connected with the ENA0A 16 th pin of the control chip U3 is connected with the 3 rd pin and the 4 th pin of the first key S1, a 17 th pin of the control chip U3 is connected with the 3 rd pin and the 4 th pin of the second key S2, an 18 th pin of the control chip U3 is connected with the 3 rd pin and the 4 th pin of the third key S3, and a 19 th pin of the control chip U3 is connected with the 3 rd pin and the 4 th pin of the fourth key S4; the control chip U3 combines an RC oscillator, a self-contained multi-channel analog-to-digital converter, a PWM timer and the like integrated in the control chip U3 according to the detection signals of all keys to complete the setting of the frequency, the duty ratio and the output interval time of the dimming signal and the enabling signal; meanwhile, the control chip U3 is also integrated with a charged erasable programmable read-only memory for storing data, so that the current data can be kept after power failure, and the data information of the previous setting can be directly called after next power-on, thereby improving the reliability and the flexibility of the setting of the circuit. Preferably, the model of the control chip U3 is STC12C5a60S2, although in other embodiments, other control chips U3 with the same function may also be adopted, and the invention is not limited thereto.
Further, referring to fig. 10 and fig. 11, the power supply module 240 includes a first power supply unit 241 and a second power supply unit 242, the first power supply unit 241 is powered by USB5V dc, and is connected to the circuit through a USB socket interface to provide 5V power for the voltage sampling unit 252, the current sampling unit 251, the control chip U3 and the signal processing module 230; the second power supply unit 242 provides a 3.3V power supply for the signal processing module 230 and the key detection module 210, so as to ensure the stability and reliability of the operation of the LED dimming signal control circuit 20.
Preferably, the first power supply unit 241 includes a USB interface J1 and a fifth capacitor C5, one end of the fifth capacitor C5 is connected to the 4 th pin of the USB interface J1 and the ground, and the other end of the fifth capacitor C5 is connected to the 1 st pin of the USB interface J1 and the 5V power supply terminal.
Preferably, the second power supply unit 242 includes a voltage regulator chip U4, a sixth capacitor C6 and a seventh capacitor C7, one end of the 3 rd pin of the voltage regulator chip U4 and one end of the sixth capacitor C6 are both connected to the input end of the 3.3V power supply terminal, the other end of the sixth capacitor C6 is grounded, the 1 st pin of the voltage regulator chip U4 is grounded, the 4 th pin of the voltage regulator chip U4 and one end of the seventh capacitor C7 are both connected to the output end of the 3.3V power supply terminal, and the other end of the seventh capacitor C7 is grounded. Preferably, the model of the regulator chip U4 is AS1117L, but in other embodiments, other regulator chips U4 having the same function may be used, and the invention is not limited thereto.
Further preferably, referring to fig. 12, the display module 260 includes a display chip U5 and a twenty-third resistor R23, the 1 st pin of the display chip U5 is connected with the 2 nd pin of the control chip U3, the 2 nd pin of the display chip U5 is connected with the 3 rd pin of the control chip U3, the pin 3 of the display chip U5 is connected with the pin 4 of the control chip U3, the pin 4 of the display chip U5 is connected with the pin 5 of the control chip U3, the 5 th pin of the display chip U5 is connected with the 6 th pin of the control chip U3, the 6 th pin of the display chip U5 is connected with the 8 th pin of the display chip U5 through a twenty-second twelve resistor R22, the 7 th pin of the display module 260 is connected with the 5V power supply end, through the display module 260 can intuitively display each parameter value, sampling voltage and sampling current value of the dimming signal, and then is convenient for data adjustment. Preferably, the model number NOKIA5110 of the display chip U5 is, but in other embodiments, other display chips U5 with the same function may be adopted, the present invention is not limited thereto, and the display chip U5 adopted in this embodiment may enable the display module 260 to display 4 rows of chinese characters and perform universal selection with the control chip U3 through a serial interface.
Further, referring to fig. 13, the LED dimming signal control circuit 20 further includes an output interface 270, a 1 st pin of the output interface 270 IS connected to the PWM signal terminal, a 2 nd pin, a 4 th pin and a6 th pin of the output interface 270 are all grounded, a 3 rd pin of the output interface 270 IS connected to an ENA signal terminal, a5 th pin of the output interface 270 IS connected to the VS signal terminal, and a 7 th pin of the output interface 270 IS connected to the IS signal terminal; the dimming signal of the signal processing module 230 is output to the constant current driving circuit 10 through the output port; and the voltage and the circuit output by the constant current driving circuit 10 are output to the voltage sampling unit 252 and the current sampling unit 251 through the output port, so that the output of the dimming signal and the sampling work of the voltage signal and the current signal are realized.
For better understanding the working principle of the LED dimming signal control circuit provided by the present invention, please refer to fig. 14, and the working process of the LED dimming signal control circuit provided by the present invention is described in detail according to the application embodiment, that is, the dimming signal adjusting steps of the LED dimming signal control circuit are as follows:
s10, initializing a control chip;
s11, setting default values;
s12, judging whether the second key is pressed, if so, executing a step S13, otherwise, executing a step S14;
s13, setting the interval time of the dimming signal and the enabling signal;
s14, judging whether the first key is pressed, if so, executing a step S15, otherwise, executing a step S16;
s15, setting the signal amplitude to be 5V;
s16, judging whether the third key is pressed, if so, executing a step S17, otherwise, executing a step S18;
s17, adjusting the frequency of the dimming signal;
s18, judging whether the fourth key is pressed, if yes, executing the step S19, otherwise, executing the step S20;
s19, adjusting the duty ratio of the dimming signal;
s20, outputting a dimming signal according to default parameters;
and S21, storing each parameter value of the current dimming signal.
After the LED dimming signal control circuit is powered on and enters a working state, the control chip is initialized, a main function in the control chip and sub-functions of the key detection units are initialized correspondingly, and at the moment, all parameters of the dimming signal are output as default values; then, whether the second key is pressed down is judged by the control module, namely whether the control chip receives a detection signal corresponding to the second key detection unit, if so, the interval time between the output of the dimming signal and the output of the enabling signal is set, and then whether the first key is pressed down is judged; otherwise, the control chip directly judges whether the first case is pressed, that is, whether the control chip receives the detection signal output by the second key detection unit, if so, the corresponding signal processing module is controlled to switch the default 3.3V of the signal amplitude of the dimming signal to 5V, and then the third key is judged to be pressed; otherwise, the control chip directly judges whether the fourth key is pressed down, if so, the control chip adjusts the duty ratio of the dimming signal according to the detection signal output by the fourth key detection unit, otherwise, the dimming signal is output to the constant current driving circuit through an output port according to the set default parameter value, and the control chip stores each parameter value of the currently set dimming signal, so that the flexible setting of the dimming signal parameter is realized, the constant current driving circuit can obtain the required dimming signal during backlight debugging, and the research and development efficiency of the product is improved.
The invention also provides an LED dimming signal control system, which comprises the LED dimming signal control circuit, and the LED dimming signal control circuit is described in detail above and is not repeated herein.
In summary, the present invention provides an LED dimming signal control circuit and system, where the LED dimming signal control circuit is connected to a constant current driving circuit, and includes a key detection module, a control module and a signal processing module, where the key detection module outputs a corresponding detection signal to the control module when detecting that an external corresponding key is pressed, the control module outputs a dimming signal to the signal processing module, sets a first parameter value of the dimming signal to a first preset value according to the detection signal, and outputs a control signal to the signal processing module according to the detection signal; the signal processing module switches a second parameter value of the dimming signal to a second preset value according to the control signal and outputs the dimming signal to the constant current driving circuit, so that flexible setting of parameters of the dimming signal is realized, the constant current driving circuit can obtain the required dimming signal during backlight debugging, and the research and development efficiency of products is improved.
It should be understood that equivalents and modifications of the technical solution and inventive concept thereof may occur to those skilled in the art, and all such modifications and alterations should fall within the scope of the appended claims.
Claims (9)
1. An LED dimming signal control circuit is connected with a constant current driving circuit and is characterized by comprising a key detection module, a control module and a signal processing module, wherein the key detection module outputs a corresponding detection signal to the control module when detecting that an external corresponding key is pressed down, the control module outputs a dimming signal to the signal processing module, sets a first parameter value of the dimming signal to be a first preset value according to the corresponding detection signal, and outputs a control signal to the signal processing module according to the corresponding detection signal; the signal processing module switches a second parameter value of the dimming signal to a second preset value according to the control signal and outputs the dimming signal to the constant current driving circuit; the first parameters comprise the frequency and the duty ratio of the dimming signal and the interval time between the dimming signal and the enabling signal; the second parameter comprises a signal amplitude of the dimming signal;
the signal processing module comprises a first signal processing unit, a second signal processing unit and a dimming signal input and output unit, wherein the first signal processing unit keeps off according to the control signal, and the second signal processing unit keeps on according to the control signal, so that a second parameter value of the dimming signal output by the dimming signal input and output unit is a second preset value;
the key detection module comprises a first key detection unit and a second key detection unit;
the control module judges whether a detection signal corresponding to the second key detection unit is received or not, if so, the interval time between the output of the dimming signal and the output of the enabling signal is set, and then whether the detection signal output by the first key detection unit is received or not is judged; otherwise, the control module directly judges whether the detection signal output by the first key detection unit is received, and if so, the signal processing module is correspondingly controlled to switch the second parameter value of the dimming signal to a second preset value.
2. The LED dimming signal control circuit according to claim 1, further comprising a sampling module and a display module, wherein the sampling module samples the constant current driving circuit and outputs a sampling current and a sampling voltage to the control module, and the control module performs analog-to-digital conversion on the sampling voltage and the sampling current and outputs the sampling voltage and the sampling voltage to the display module for display.
3. The LED dimming signal control circuit according to claim 2, wherein the sampling module comprises a current sampling unit and a voltage sampling unit, the current sampling unit samples the current output by the constant current driving circuit and outputs the sampled current to the control module, and the voltage sampling unit samples the voltage output by the constant current driving circuit and outputs the sampled voltage to the control module.
4. The LED dimming signal control circuit of claim 1, wherein the first signal processing unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode, a second diode, a first MOS transistor and a first triode, one end of the first resistor and the source electrode of the first MOS tube are both connected with a 3.3V power supply end, the other end of the first resistor and the anode of the first diode are both connected with one end of the second resistor, the other end of the second resistor is connected with the collector of the first triode, the emitter of the first triode and one end of the fourth resistor are both grounded, the other end of the fourth resistor and the base electrode of the first triode are connected with one end of the third resistor, the other end of the third resistor is connected with the cathode of the second diode, and the anode of the second diode is connected with a 3.3VON signal end; the negative electrode of the first diode is connected with the grid electrode of the first MOS tube, and the drain electrode of the first MOS tube is connected with an IO _ AMP signal end.
5. The LED dimming signal control circuit of claim 1, wherein the second signal processing unit comprises a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a third diode, a fourth diode, a second MOS transistor and a second triode, one end of the fifth resistor and the source electrode of the second MOS tube are both connected with a 5V power supply end, the other end of the fifth resistor and the anode of the third diode are both connected with one end of the sixth resistor, the other end of the sixth resistor is connected with the collector of the second triode, the emitter of the second triode and one end of the eighth resistor are both grounded, the other end of the eighth resistor and the base electrode of the second triode are connected with one end of the seventh resistor, the other end of the seventh resistor is connected with the cathode of the fourth diode, and the anode of the fourth diode is connected with the 5VON signal end; and the cathode of the fourth diode is connected with the grid electrode of the second MOS tube, and the drain electrode of the second MOS tube is connected with an IO _ AMP signal end.
6. The LED dimming signal control circuit of claim 1, wherein the dimming signal input/output unit comprises a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a third transistor and a fourth transistor, one end of the ninth resistor is connected to an IO _ AMP signal terminal, the other end of the ninth resistor is connected to a collector of the third transistor and an ENA signal terminal, and a base of the third transistor is connected to the ENA signal terminal through the tenth resistor0A signal terminal; the transmitting end of the third triode is grounded; one end of the eleventh resistor is connected with an IO _ AMP signal end, the other end of the eleventh resistor is connected with a collector electrode and a PWM signal end of the fourth triode, and a base electrode of the fourth triode is connected with PWM through a twelfth resistor0A signal terminal; and the transmitting end of the fourth triode is grounded.
7. The LED dimming signal control circuit according to claim 3, wherein the current sampling unit comprises a first operational amplifier, a thirteenth resistor, a fourteenth resistor and a fifteenth resistor, wherein a positive power source terminal of the first operational amplifier IS connected to a 5V power source terminal, a negative power source terminal of the first operational amplifier IS grounded, a positive input terminal of the first operational amplifier IS connected to an IS signal terminal through the thirteenth resistor, an inverting input terminal of the first operational amplifier IS connected to one terminal of the fifteenth resistor, and the other terminal of the fifteenth resistor IS grounded; the output end of the first operational amplifier is connected with one end of the fourteenth resistor and the signal end of the ADC1, and the other end of the fourteenth resistor is connected with one end of the fifteenth resistor.
8. The LED dimming signal control circuit according to claim 3, wherein the voltage sampling unit comprises a second operational amplifier, a sixteenth resistor, a seventeenth resistor and an eighteenth resistor, wherein a positive power supply terminal of the second operational amplifier is connected to a 5V power supply terminal, a negative power supply terminal of the second operational amplifier is grounded, a positive input terminal of the second operational amplifier is connected to a VS signal terminal through the sixteenth resistor, an inverted input terminal of the second operational amplifier is connected to one terminal of the eighteenth resistor, and the other terminal of the eighteenth resistor is grounded; the output end of the second operational amplifier is connected with one end of the seventeenth resistor and the signal end of the ADC0, and the other end of the seventeenth resistor is connected with one end of the eighteenth resistor.
9. An LED dimming signal control system comprising the LED dimming signal control circuit of any one of claims 1-8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910241284.6A CN109905942B (en) | 2019-03-28 | 2019-03-28 | LED dimming signal control circuit and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910241284.6A CN109905942B (en) | 2019-03-28 | 2019-03-28 | LED dimming signal control circuit and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109905942A CN109905942A (en) | 2019-06-18 |
| CN109905942B true CN109905942B (en) | 2021-05-18 |
Family
ID=66953616
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910241284.6A Active CN109905942B (en) | 2019-03-28 | 2019-03-28 | LED dimming signal control circuit and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109905942B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110461059A (en) * | 2019-07-29 | 2019-11-15 | 深圳市明微电子股份有限公司 | A kind of digital dimming control chip, digital dimming control circuit and control method |
| CN112437516B (en) * | 2020-12-08 | 2023-06-27 | 宁波恒达高智能科技股份有限公司 | Digital timing dimmer control circuit |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1577194A (en) * | 2003-07-29 | 2005-02-09 | 珠海爱圣特电子科技有限公司 | Programmable lamp controller |
| CN203015241U (en) * | 2013-01-21 | 2013-06-19 | 浙江我芯我能科技有限公司 | Stroboflash-free LED desk lamp having storage function |
| CN203279262U (en) * | 2013-04-16 | 2013-11-06 | 天津津亚电子有限公司 | Intelligent dimmer switch |
| CN207099382U (en) * | 2017-07-28 | 2018-03-13 | 东莞科视自动化科技有限公司 | A kind of light-source brightness automatic compensating controller |
| CN207638953U (en) * | 2017-10-25 | 2018-07-20 | 上海海梵控制系统有限公司 | A kind of lamp dimmer based on DMX512 agreements and Art-Net agreements |
| CN108601153A (en) * | 2018-06-12 | 2018-09-28 | 常州信息职业技术学院 | Tetra- color LED mixed light control methods of RGBW |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015024074A1 (en) * | 2013-08-19 | 2015-02-26 | Automatic Technology (Australia) Pty Ltd | Remote control device and controller |
-
2019
- 2019-03-28 CN CN201910241284.6A patent/CN109905942B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1577194A (en) * | 2003-07-29 | 2005-02-09 | 珠海爱圣特电子科技有限公司 | Programmable lamp controller |
| CN203015241U (en) * | 2013-01-21 | 2013-06-19 | 浙江我芯我能科技有限公司 | Stroboflash-free LED desk lamp having storage function |
| CN203279262U (en) * | 2013-04-16 | 2013-11-06 | 天津津亚电子有限公司 | Intelligent dimmer switch |
| CN207099382U (en) * | 2017-07-28 | 2018-03-13 | 东莞科视自动化科技有限公司 | A kind of light-source brightness automatic compensating controller |
| CN207638953U (en) * | 2017-10-25 | 2018-07-20 | 上海海梵控制系统有限公司 | A kind of lamp dimmer based on DMX512 agreements and Art-Net agreements |
| CN108601153A (en) * | 2018-06-12 | 2018-09-28 | 常州信息职业技术学院 | Tetra- color LED mixed light control methods of RGBW |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109905942A (en) | 2019-06-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109905942B (en) | LED dimming signal control circuit and system | |
| US20010004207A1 (en) | CPU core voltage switching circuit | |
| US20060132199A1 (en) | Supply voltage switching circuit | |
| CN202257349U (en) | Current generating circuit | |
| CN102654967A (en) | Automatic power supply abnormality detection apparatus, drive circuit and display device | |
| CN1991664A (en) | Over-frequency control circuit | |
| CN106371475B (en) | Multi-channel temperature control system based on STM32 exploitations | |
| US20060139829A1 (en) | Supply voltage switching circuit | |
| CN203813867U (en) | Reset circuit and television set | |
| CN115951603A (en) | MCU main control chip circuit board | |
| CN107464404A (en) | A kind of PCM switch alarms device | |
| CN102314209B (en) | Control circuit of mainboard power supply | |
| CN214540752U (en) | Ordinary adapter changes PD power conversion control circuit and device | |
| CN210605633U (en) | Board card awakened intelligently in standby mode | |
| CN215350499U (en) | Inflatable massager circuit | |
| CN216210581U (en) | DP interface awakens receiving equipment's circuit up | |
| CN213185869U (en) | Power failure accelerating circuit, power supply circuit, driving board card and electronic equipment | |
| CN220985648U (en) | Input/output interface variable circuit and embedded device including the same | |
| CN220043397U (en) | Continuous output control circuit based on sampling signal comparison | |
| CN218103100U (en) | Switch control circuit of main control circuit and electronic equipment | |
| CN216387790U (en) | Switching on and shutting down circuit and electrical equipment | |
| CN211786806U (en) | Signal generator for temperature control | |
| CN213043881U (en) | Computer power supply circuit integrating ARGB programmable light adjusting function | |
| CN213305371U (en) | Low power consumption mobile phone | |
| CN219843441U (en) | Power supply control circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |