CN212161248U - Three-color LED control circuit, drive integrated circuit board and three-color LED display screen - Google Patents
Three-color LED control circuit, drive integrated circuit board and three-color LED display screen Download PDFInfo
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- CN212161248U CN212161248U CN202020497931.8U CN202020497931U CN212161248U CN 212161248 U CN212161248 U CN 212161248U CN 202020497931 U CN202020497931 U CN 202020497931U CN 212161248 U CN212161248 U CN 212161248U
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Abstract
The utility model relates to a three-colour LED control circuit, drive integrated circuit board and three-colour LED display screen. The utility model discloses a three-color LED control circuit, which comprises a controllable voltage source, an electrical parameter detection circuit and a power control module, wherein the power control module is respectively connected with the controllable voltage source and the electrical parameter detection circuit; the controllable voltage source comprises a voltage output end, and the voltage output end is used for respectively supplying power to a red LED, a blue LED and a green LED in the three-color LED; the electrical parameter detection circuit is used for respectively detecting the electrical parameters of each loop in the red LED, the blue LED and the green LED; the power supply control module comprises a logic controller, a detection signal input end and an adjusting signal output end, wherein the detection signal input end receives a detection signal of the electrical parameter detection circuit, and the logic controller adjusts the output voltage of the controllable voltage source according to a difference value between the detection signal and a preset parameter value. The utility model discloses a three-colour LED control circuit can make three-colour LED when sending the red light, avoids producing extra loss.
Description
Technical Field
The utility model relates to an electronic circuit technical field especially relates to a three-colour LED control circuit, drive integrated circuit board and three-colour LED display screen.
Background
According to the characteristics of light emission of three-color LEDs, the breakover voltage drop of red, green and blue LEDs when the red, green and blue LEDs reach normal brightness is different, the breakover voltage drop of the red LED is generally 1.8-2.2V, the breakover voltage drop of the blue LED (13) is generally 3.0-3.6V, and the voltage of a controllable voltage source is constant, so that the voltage drop of the whole loop is different when different LEDs are gated, when the red LED is conducted, the voltage drop consumed by the whole circuit is about 1V less than that when the blue LED (13) is gated, the voltage about 1V can be forcibly applied to a switching tube or a circuit, extra loss can be caused, and a large amount of loss can be generated for a large array three-color LED.
SUMMERY OF THE UTILITY MODEL
Based on this, the utility model provides a three-colour LED control circuit, drive integrated circuit board and three-colour LED display screen can make three-colour LED when sending the red light, avoids producing extra loss.
In a first aspect, the utility model provides a three-colour LED control circuit, include:
the device comprises a controllable voltage source, an electrical parameter detection circuit and a power supply control module, wherein the power supply control module is respectively connected with the controllable voltage source and the electrical parameter detection circuit;
the controllable voltage source comprises a voltage output end which is used for respectively supplying power to a red LED, a blue LED and a green LED in the three-color LED;
the electrical parameter detection circuit is used for respectively detecting the electrical parameters of each power supply loop in the red LED, the green LED and the blue LED;
the power control module comprises a logic controller, a detection signal input end and an adjustment signal output end, wherein the detection signal input end is used for receiving a detection signal of the electrical parameter detection circuit, the logic controller is used for generating an adjustment signal according to a difference value between the detection signal and a preset parameter value, and the adjustment signal output end is used for outputting the adjustment signal to the power control module so as to adjust the output voltage of the controllable voltage source.
Optionally, the controllable voltage source includes a first switching tube, the adjustment signal output end is connected to the first switching tube, and the adjustment signal is used to adjust the supply voltage of the controllable voltage source by switching the conduction frequency or the duty ratio of the first switching tube.
Optionally, the electrical parameter detection circuit is a current detection circuit, and the current detection circuit is configured to detect currents passing through the red LED, the green LED, and the blue LED respectively;
the logic controller is used for generating the adjusting signal according to the difference value between the current detected by the current detection circuit and a preset current value.
Optionally, the electrical parameter detection circuit is a voltage detection circuit, and the voltage detection circuit is configured to detect voltages applied to the red LED, the green LED, and the blue LED respectively;
the logic controller is used for generating the adjusting signal according to the difference value between the voltage detected by the voltage detection circuit and a preset voltage value.
Optionally, the electrical parameter detection circuit is a voltage detection circuit, and the voltage detection circuit is configured to detect voltages loaded at two ends of a second switching tube, a third switching tube and a fourth switching tube, respectively, where the second switching tube is connected in series to the voltage output end and a power supply loop of the red LED, the third switching tube is connected in series to the voltage output end and a power supply loop of the blue LED, and the third switching tube is connected in series to the voltage output end and a power supply loop of the green LED;
the logic controller is used for generating the adjusting signal according to the difference value between the voltage detected by the voltage detection circuit and a preset voltage value.
Optionally, the device further comprises an FPGA chip, a first control end, a second control end and a third control end of the FPGA chip, the first control end is connected with the second switch tube, the second control end is connected with the third switch tube, and the third control end is connected with the fourth switch tube.
Optionally, the FPGA chip further includes a preset parameter output port, and the power control module further includes a preset parameter input port, where the preset current signal input port is configured to receive a preset parameter value input by the preset parameter output port.
Optionally, the FPGA further comprises a fifth switch, the fifth switch is connected in series to the voltage output end and the power supply loop of the three-color LED, and the FPGA chip further comprises a fourth control end, and the fourth control end is connected to the fifth switch.
In a second aspect, the utility model provides a drive integrated circuit board, implement the first aspect including this application three-colour LED control circuit.
Third aspect, the utility model provides a three-colour LED display screen, include:
the LED driving circuit comprises at least one group of three-color LEDs and a three-color LED control circuit according to the first aspect of the embodiment of the application;
the controllable voltage source comprises a voltage output end which is used for respectively supplying power to a red LED, a blue LED and a green LED in the at least one group of three-color LEDs;
the electrical parameter detection circuit is used for respectively detecting the electrical parameters of each power supply loop in the red LEDs, the green LEDs and the blue LEDs of at least one group of three-color LEDs.
The utility model discloses in, detect respectively through electrical parameter detection circuitry red LED green LED with electrical parameter in blue LED's the power supply circuit, and according to electrical parameter and the output voltage who predetermines electrical parameter value and adjust controllable voltage source to when red LED switches on, can reduce the output voltage of controllable voltage source, avoid leading to producing extra loss.
For better understanding and implementation, the technical solutions of the present invention are described in detail below with reference to the accompanying drawings.
Drawings
Fig. 1 is a schematic diagram of a three-color LED control circuit according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a circuit structure of a controllable voltage source according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a three-color LED control circuit according to an embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a current detection circuit according to an embodiment of the present invention;
fig. 5 is a schematic diagram of a three-color LED control circuit according to an embodiment of the present invention;
fig. 6 is a schematic circuit diagram of a voltage detection circuit according to an embodiment of the present invention;
fig. 7 is a schematic diagram of a three-color LED control circuit according to an embodiment of the present invention;
fig. 8 is a schematic diagram of a circuit structure of a power control module according to an embodiment of the present invention;
fig. 9 is a schematic structural view of a driving board card according to an embodiment of the present invention;
fig. 10 is a schematic view of a three-color LED display screen according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the relevant portions of the present invention are shown in the drawings.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, are not to be construed as limiting the present invention.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
In the following, several specific embodiments are given for describing the technical solution of the present application in detail. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.
Fig. 1 is three-colour LED control circuit structure schematic diagram in an exemplary embodiment of this application, the utility model provides a three-colour LED control circuit includes controllable voltage source 2, electrical parameter detection circuitry 3 and power control module 4, power control module 4 respectively with controllable voltage source 2 with electrical parameter detection circuitry 3 connects.
The controllable voltage source 2 comprises a voltage output end 21, and the voltage output end 21 is used for respectively supplying power to a red LED (11), a green LED (12) and a blue LED (13) in the three-color LED (1).
The controllable voltage source 2 is used for converting the input voltage Vin, and changing the output value of the output voltage Vout by changing the frequency, duty ratio, etc. of the driving signal with a fixed voltage value Vin, in some examples, the controllable voltage source 2 may also filter the input voltage Vin.
In some examples, the voltage output terminal 21 of the controllable voltage source 2 is connected to the three-color LED (1) through a fifth switch S5, so that the controllable voltage source 2 can supply power to multiple three-color LEDs through multiple switches, and the fifth switch S5 can be a switch tube.
The electrical parameter detection circuit 3 is used for respectively detecting the electrical parameters of each power supply loop in the red LED (11), the green LED (12) and the blue LED (13).
The electrical parameter is a parameter indicating electrical characteristics of the power supply circuits of the red LED (11), the green LED (12) and the blue LED (13), and may be electrical parameters of the red LED (11), the green LED (12) and the blue LED (13) themselves, or electrical parameters of a second switch S2, a third switch S3 or a fourth switch S4 connected in series in the power supply circuits of the red LED (11), the green LED (12) and the blue LED (13), respectively. Under the condition that the same controllable voltage source 2 outputs voltage, the current passing through the red LED is different from that passing through the blue LED and the green LED, the voltage applied to the red LED is different from that applied to the blue LED and the green LED, and the voltage applied to the second switch S2, the third switch S3 and the fourth switch S4 is different from that applied to the blue LED and the green LED, so that the electrical parameter may be specifically current or voltage, and the electrical parameter detection circuit 3 may be a current detection circuit or a voltage detection circuit.
The power control module 4 comprises a logic controller 41, a detection signal input end 42 and an adjustment signal output end 43, the detection signal input end 42 is used for receiving the detection signal of the electrical parameter detection circuit 3, the logic controller 41 is used for generating an adjustment signal according to the difference between the detection signal and a preset parameter value, and the adjustment signal output end 43 is used for outputting the adjustment signal to the power control module 2 so as to adjust the output voltage of the controllable voltage source 2.
The logic controller 41 is a signal processing chip, and may be integrated with a feedback driving circuit commonly used in the prior art for adjusting current or voltage, and the feedback driving circuit is configured to adjust output according to a difference between a detected value and a standard value or a preset value, so that the detected value meets a preset requirement. In the embodiment of the present invention, the logic controller 41 generates the adjusting signal according to the difference between the detection signal and the preset parameter value, and the adjusting signal changes the output value of the output voltage Vout by changing the frequency, duty ratio, etc. of the driving signal of the input voltage Vin of the controllable voltage source 2.
The preset parameter value may be a value written in advance in the logic controller 41, or may be a value input to the logic controller 41 through an external device such as the FPGA chip 5. As shown in fig. 2, if the preset current value is input through an external device, such as an FPGA chip 5, the power control module 4 may further include a preset parameter input port, and the FPGA chip further includes a preset parameter output port.
In one embodiment, to realize the separate power supply of the red LED (11), the green LED (12) and the blue LED (13), a second switch S2 is further connected in series in the power supply loop of the red LED (11), a third switch S3 is further connected in series in the power supply loop of the green LED (12), a fourth switch S4 is further connected in series in the power supply loop of the blue LED (13), the second switch S2, the third switch S3 and the fourth switch S4 are respectively controlled by the FPGA chip 5, and the second switch S2, the third switch S3 and the fourth switch S4 may be transistors, switching devices such as switching tubes, or the like.
The working process of the embodiment is as follows:
when the switch S5 is closed and any one of the switches S2, S3 and S4 is closed, the controllable voltage source 2 supplies power to one of the red LED (11), the green LED (12) and the blue LED (13), the electrical parameter detection circuit 3 detects an electrical parameter in a power supply loop and sends the electrical parameter to the power control module 4, and the logic controller 41 outputs a regulation signal to regulate the output voltage of the controllable voltage source 2 according to a difference between the detected electrical parameter and a predicted electrical parameter. Specifically, if the initial voltage of the controllable voltage source is 5V, when the detected electrical parameter is the electrical parameter (voltage is lower or current is larger) of the red LED (11), the output voltage of the controllable voltage source 2 is reduced, when the detected electrical parameter is the voltage across the second switch S2, if the voltage across the second switch S2 is greater than 1V, the output voltage of the controllable voltage source 2 is also reduced, and when the detected electrical parameter is the electrical parameter of the green LED (12), the blue LED (13), the third switch S3, and the fourth switch S4, the output voltage of the controllable voltage source 2 is maintained.
The utility model discloses in, detect respectively through electrical parameter detection circuitry red LED green LED with blue LED's power supply circuit's electrical parameter, and according to electrical parameter and the output voltage who predetermines electrical parameter value and adjust controllable voltage source to when red LED switches on, can reduce controllable voltage source's output voltage, avoid leading to producing extra loss.
As shown in fig. 2, the controllable voltage source comprises a first switch S1, the first switch S1 is connected in series in a main power supply loop of the controllable voltage source S1, the adjusting signal output end 43 is connected with the first switch S1, and the adjusting signal is used for adjusting the power supply voltage of the controllable voltage source 2 by switching the conducting frequency or duty cycle of the first switch S1.
In a specific example, the first switch S1 is a switch tube.
As shown in fig. 2, the controllable voltage source 2 further includes an inductor L1 and a filter capacitor C1, the first inductor L1 is connected in series in a main power supply loop of the controllable voltage source, the filter capacitor C1 is connected in parallel with the inductor L1, and the power control module 4 controls the on/off time of the first switch S1 by changing the frequency, duty ratio, and the like of the driving signal, so as to control how much energy is stored in the inductor to change the magnitude of the Vout voltage.
As shown in fig. 3, in one embodiment, the electrical parameter detection circuit 3 is a current detection circuit 31, and the current detection circuit 31 is used for detecting the current passing through the red LED (11), the green LED (12) and the blue LED (13), respectively.
In this embodiment, the logic controller 41 is configured to generate the adjustment signal according to a difference between the current detected by the current detecting circuit 31 and a preset current value.
The preset current value may be a value pre-stored in the logic controller 41, or may be an externally input value, for example, a value input through the FPGA chip 5.
The input end of the current detection circuit 31 is connected to the power supply circuit of the red LED (11), the green LED (12) and the blue LED (13), respectively, as shown in fig. 4, in one embodiment, the current detection circuit 31 includes a differential operational amplifier UB1, the forward input end of the differential operational amplifier UB1 is connected to the current sampling point connected in series to the power supply circuit of the red LED (11), the green LED (12) or the blue LED (13) through a resistor R3, the inverting input end of the differential operational amplifier UB1 is connected to the current sampling point through a resistor R2 and a resistor R1, the inverting input end of the differential operational amplifier UB1 is further connected to the output end of the differential operational amplifier UB1 through a resistor R5, and the output end of the differential operational amplifier UB1 is connected to the power supply control module 4 through a resistor R6.
In this embodiment, it is assumed that the initial voltage of the controllable voltage source 2 is 3V, the conduction voltage drop and the line impedance voltage drop of the fifth switch S5 are 1V, the conduction voltage drop required when the red LED (11) reaches the rated current is 2V, the conduction voltage drop required when the green LED (12) and the blue LED (13) reach the rated current is 3V, the conduction voltage drops of the switches S2, S3, and S4 are 0.7V, respectively, and the preset current value is 20 mA. When the red LED (11) is required to work, the switch S2 is turned on, and the switches S3 and S4 are turned off. The voltage drop distribution of the whole power loop at steady state is as follows: the voltage drop of the switch S5 is 1V, the conduction voltage drop of the red LED (11) is 2V, and the conduction voltage drop of the switch S2 is 0.7V. The total voltage is 1V +2V +0.7V — 3.7V.
At this time, the power control module 4 continuously collects the current passing through the red LED (11) through the current detection circuit 31, because in the initial state, the output voltage 3V of the controllable voltage source 2 is less than 3.7V, and therefore the current passing through the red LED (11) is less than 20mA, at this time, the power control module 4 continuously increases the duty ratio of the adjustment signal to continuously increase the voltage of the controllable voltage source 2, and when the current increases to be slightly greater than 3.7V, the current passing through the red LED (11) is approximately equal to or slightly greater than 20 mA. At this time, the power control module 4 continuously decreases the duty cycle of the adjustment signal, so that the output voltage of the controllable voltage source 2 is continuously decreased, and is decreased to be slightly less than 3.7V (e.g. 3.6V). The current through the red LED (11) is now again less than 20mA, which again requires an increase in the output voltage of the controllable voltage source 2. Finally, the output voltage of the controllable voltage source 2 maintains the voltage dynamic balance of about 3.7V.
In the second state, the blue LED (13) is switched to the on state, the switch S4 is turned on, and the switches S2 and S3 are turned off. If output needs to be guaranteed, the voltage drop distribution of the whole power loop is as follows: the voltage drop of the switch tube S1 is 1V, the conduction voltage drop of the blue LED (13) is 3V, and the conduction voltage drop of the switch S4 is 0.7V. The total voltage is 1V +3V +0.7V ═ 4.7V. The power control module 4 continuously collects the voltage of the passing current blue LED (13) through the current detection circuit 31, and the current passing through the blue LED (13) is less than 20mA because the output voltage of the controllable voltage source 2 is 3.7V <4.7V in the last state. The power control module 4 will increase the duty cycle of the adjustment signal continuously to increase the output voltage of the controllable voltage source 2, and when the output voltage increases to be slightly larger than 4.7V, the current passing through the green LED (12) is equal to or slightly larger than 20 mA. At this time, the power control module 4 continuously reduces the duty ratio of the adjustment signal to continuously reduce the voltage of the controllable voltage source 2, and when the voltage is reduced to be slightly less than 4.7V (for example, 4.6V), the current passing through the blue LED (13) is smaller than 20mA, and at this time, the output voltage of the controllable voltage source 2 needs to be increased. Finally, the controllable voltage source 2 maintains the voltage dynamic balance of about 4.7V. The green LED (12) and the blue LED (13) work in the same way, and are not described in detail.
In the third state, the LED is required to be switched back to the on state of the red LED (11), at which time the switch S2 is turned on and S3 and S4 are turned off. If output needs to be guaranteed, the voltage drop distribution of the whole power loop is as follows: the voltage drop of the switching tube S1 is 1V; the conduction voltage drop of the red LED (11) is 2V, and the conduction voltage drop of the switch S2 is 0.7V. The total voltage is 1V +2V +0.7V — 3.7V. The power control module continuously collects the current passing through the LED through the current sampling module, and the current passing through the red LED (11) is equal to 20mA because the voltage of the controllable voltage source is 4.7V >3.7V in the last state. The power control module 4 will decrease the duty cycle of the adjustment signal to decrease the output voltage of the controllable voltage source 2 to slightly less than 3.7V (e.g. 3.6V). The current through the red LED (11) is now again less than 20mA, which again requires an increase in the voltage of the controllable voltage source 2. Finally, the controllable voltage source 2 maintains the voltage dynamic balance of about 3.7V.
As shown in fig. 5, in one embodiment, the electrical parameter detection circuit 3 is a voltage detection circuit 32, and the voltage detection circuit 32 is configured to detect voltages applied to two ends of the red LED (11), the green LED (12) and the blue LED (13), respectively.
In this embodiment, the logic controller 41 is configured to generate the adjustment signal according to a difference between the voltage detected by the voltage detection circuit 32 and a preset voltage value.
The preset voltage value may be a value pre-stored in the logic controller 41, or may be an externally input value, for example, a value input through the FPGA chip 5.
The input terminals of the voltage detection circuit 32 are respectively connected to the power supply loops of the red LED (11), the green LED (12) and the blue LED (13), as shown in fig. 6, in one embodiment, the voltage detection circuit 32 includes a differential operational amplifier UB2, a positive input terminal of the differential operational amplifier UB2 is connected to the voltage sampling point 1 through a resistor R1, the inverting input of the differential operational amplifier UB2 is connected to voltage sampling point 2 through resistor R3, wherein the voltage sampling point 1 and the voltage sampling point 2 are respectively connected to two ends of a power supply loop of the red LED (11), the green LED (12) or the blue LED (13), the inverting input terminal of the differential operational amplifier UB2 is further connected to the output terminal of the differential operational amplifier UB2 through a parallel circuit of a resistor R4 and a capacitor C2, the output of the differential operational amplifier UB2 is connected to the power control module 4 through a resistor R5.
In this embodiment, it is assumed that the basic parameters of the circuit are as follows: the conduction voltage drop and the line impedance voltage drop of the fifth switch S5 are 1V; the conduction voltage drop required when the red LED reaches the rated current is 2V, the conduction voltage drop required when the blue LED (13) reaches the rated current is 3V, and the preset voltage value can be any value which is larger than 2V and smaller than 3V, such as 2.5V; the conduction voltage drops of the switches S2, S3 and S4 are 0.7V respectively. When the red LED lamp is operated, the total voltage required by the branch is 1V +2V +0.7V — 3.7V. When the blue LED (13) lamp works, the total voltage required by the branch circuit is 1V +3V + 0.7V-4.7V. The embodiment is detecting
In the first state, the system requires the red LED lamp (11) to operate. The voltage of the controllable voltage source is controlled to be 4.7V by default by the system. At this point, the fifth switch S5 is turned on, the switch S2 is turned on, and the switches S3 and S4 are turned off. When the circuit is conducted, the voltage at two ends of the red LED is 2V. At this time, the voltage detected by the voltage detection circuit 32 at the two ends of the LED is 2V, which is smaller than the preset voltage value 2.5V, and the power control module 4 starts to reduce the duty ratio of the adjustment signal, and at this time, the output voltage of the controllable voltage source 2 starts to be continuously reduced. The power control module 4 can compare the voltage across the red LED (11) with a reference voltage of 2V through a comparison circuit, and according to the comparison result, the output voltage of the controllable voltage source is limited to be reduced to be slightly lower than 3.7V and not reduced any more. In other examples, when the output voltage of the controllable voltage source decreases below 3.7V, the voltage detection circuit 32 detects that the voltage across the red LED (11) is less than 2V. At this time, the power control module 4 slightly increases the output voltage of the controllable voltage source 2, so as to achieve a dynamic balance state.
In the second state, the blue LED (13) is switched to the on state, the switch S4 is turned on, and the switches S2 and S3 are turned off. The system receives the switch signal, and the system controls the voltage of the controllable voltage source to be 4.7V by default. At this moment, the voltage detection circuit 32 acquires that the voltage across the LED is 3V, which is greater than the preset voltage value of 2.5V, and then the controllable voltage source 2 maintains the voltage to continue outputting. The green LED (12) and the blue LED (13) work in the same way, and are not described in detail.
As shown in fig. 7, in another embodiment, the voltage detection circuit 32 may be further configured to detect voltages applied to two ends of the second switch S2, the third switch S3 and the fourth switch S4, respectively.
In this embodiment, it is assumed that the basic parameters of the circuit are as follows: the conduction voltage drop and the line impedance voltage drop of the fifth switch S5 are 1V; the conduction voltage drop required when the red LED reaches the rated current is 2V, the conduction voltage drop required when the blue LED (13) reaches the rated current is 3V, the conduction voltage drops of the switches S2, S3 and S4 are respectively 0.7V, and then the preset voltage value can be 0.7V. When the red LED lamp is operated, the total voltage required by the branch is 1V +2V +0.7V — 3.7V. When the blue LED (13) lamp works, the total voltage required by the branch circuit is 1V +3V + 0.7V-4.7V.
In the first state, the system requires the red LED lamp (11) to operate. The voltage of the controllable voltage source is controlled to be 4.7V by default by the system. At this point, the fifth switch S5 is turned on, the switch S2 is turned on, and the switches S3 and S4 are turned off. When the circuit is turned on, the voltage across the red LED is 2V, the voltage across the switching tube Q1, the second switch S2 and the line reaches 2.7V, and at this time, the voltage across the second switch S2 is greater than the conduction voltage drop by 0.7V. At this time, the voltage detection circuit 32 acquires that the voltage across the second switch S2 is greater than 0.7V, and the power control module 4 starts to decrease the duty ratio of the adjustment signal, and at this time, the output voltage of the controllable voltage source 2 starts to decrease continuously. Until the output voltage of the controllable voltage source decreases to 3.7V, the voltage across the second switch S2 is equal to the conduction voltage drop of 0.7V.
In the second state, the blue LED (13) is switched to the on state, the switch S4 is turned on, and the switches S2 and S3 are turned off. The system receives the switch signal, and the system controls the voltage of the controllable voltage source to be 4.7V by default. At this moment, the voltage detection circuit 32 detects that the voltage across the fourth switch S4 is 0.7V, and the controllable voltage source 2 maintains the voltage to continue outputting. The green LED (12) and the blue LED (13) work in the same way, and are not described in detail.
As shown in fig. 8, in an embodiment, the power control module 4 specifically includes: the power control module 4 may further include a logic controller 41, a detection signal input terminal 42, an adjustment signal output terminal 43, an analog-to-digital conversion circuit, a first operational amplifier, and an amplifier, and when the preset parameter value is input from the outside, the power control module 4 may further include a preset parameter input port 44 and a second operational amplifier.
Fig. 9 is a schematic structural diagram of the driving board provided by the present invention. The drive integrated circuit board 800 includes the embodiment of the utility model provides an arbitrary three-colour LED control circuit.
Fig. 9 is a schematic structural diagram of a three-color LED display screen 900 provided in the present application, where the three-color LED display screen 900 includes at least one set of three-color LEDs (1) and the three-color LED control circuit described in any one of the above embodiments, where the controllable voltage source 2 includes a voltage output end 21, and the voltage output end 21 is used to respectively supply power to the red LEDs (11), the green LEDs (12), and the blue LEDs (13) in the at least one set of three-color LEDs (1);
the electrical parameter detection circuit 3 is used for respectively detecting electrical parameters of the red LED (11), the green LED (12) and the blue LED (13) in at least one group of three-color LEDs (1).
The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention.
Claims (10)
1. A three-color LED control circuit, comprising:
the device comprises a controllable voltage source, an electrical parameter detection circuit and a power supply control module, wherein the power supply control module is respectively connected with the controllable voltage source and the electrical parameter detection circuit;
the controllable voltage source comprises a voltage output end which is used for respectively supplying power to a red LED, a blue LED and a green LED in the three-color LED;
the electrical parameter detection circuit is used for respectively detecting the electrical parameters of each power supply loop in the red LED, the green LED and the blue LED;
the power control module comprises a logic controller, a detection signal input end and an adjustment signal output end, wherein the detection signal input end is used for receiving a detection signal of the electrical parameter detection circuit, the logic controller is used for generating an adjustment signal according to a difference value between the detection signal and a preset parameter value, and the adjustment signal output end is used for outputting the adjustment signal to the power control module so as to adjust the output voltage of the controllable voltage source.
2. The tristimulus LED control circuit of claim 1, wherein:
the controllable voltage source comprises a first switch tube, the adjusting signal output end is connected with the first switch tube, and the adjusting signal is used for adjusting the supply voltage of the controllable voltage source by switching the conduction frequency or the duty ratio of the first switch tube.
3. The tristimulus LED control circuit of claim 1 or 2, wherein:
the electrical parameter detection circuit is a current detection circuit for respectively detecting currents passing through the red LED, the green LED and the blue LED;
the logic controller is used for generating the adjusting signal according to the difference value between the current detected by the current detection circuit and a preset current value.
4. The tristimulus LED control circuit of claim 1 or 2, wherein:
the electrical parameter detection circuit is a voltage detection circuit for detecting voltages loaded on the red LED, the green LED and the blue LED, respectively;
the logic controller is used for generating the adjusting signal according to the difference value between the voltage detected by the voltage detection circuit and a preset voltage value.
5. The tristimulus LED control circuit of claim 1 or 2, wherein:
the electric parameter detection circuit is a voltage detection circuit, and the voltage detection circuit is used for respectively detecting voltages loaded at two ends of a second switching tube, a third switching tube and a fourth switching tube, wherein the second switching tube is connected in series with the voltage output end and a power supply loop of the red LED, the third switching tube is connected in series with the voltage output end and a power supply loop of the blue LED, and the third switching tube is connected in series with the voltage output end and a power supply loop of the green LED;
the logic controller is used for generating the adjusting signal according to the difference value between the voltage detected by the voltage detection circuit and a preset voltage value.
6. The tristimulus LED control circuit of claim 5, wherein:
still include the FPGA chip, FPGA chip first control end, second control end and third control end, first control end with the second switch union coupling, the second control end with the third switch union coupling, the third control end with the fourth switch union coupling.
7. The tristimulus LED control circuit of claim 6, wherein:
the FPGA chip further comprises a preset parameter output port, the power supply control module further comprises a preset parameter input port, and the preset current signal input port is used for receiving a preset parameter value input by the preset parameter output port.
8. The tristimulus LED control circuit of claim 6, wherein:
the FPGA chip further comprises a fourth control end, and the fourth control end is connected with the fifth switch.
9. A drive integrated circuit board, its characterized in that:
comprising the tristimulus LED control circuit of any of claims 1 to 8.
10. The utility model provides a three-colour LED display screen which characterized in that:
comprising at least one set of tristimulus LEDs and the tristimulus LED control circuit of any of claims 1 to 8;
the controllable voltage source comprises a voltage output end which is used for respectively supplying power to a red LED, a blue LED and a green LED in the at least one group of three-color LEDs;
the electrical parameter detection circuit is used for respectively detecting the electrical parameters of each power supply loop in the red LEDs, the green LEDs and the blue LEDs of at least one group of three-color LEDs.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202020497931.8U CN212161248U (en) | 2020-04-07 | 2020-04-07 | Three-color LED control circuit, drive integrated circuit board and three-color LED display screen |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020497931.8U CN212161248U (en) | 2020-04-07 | 2020-04-07 | Three-color LED control circuit, drive integrated circuit board and three-color LED display screen |
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| CN212161248U true CN212161248U (en) | 2020-12-15 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115116382A (en) * | 2021-03-22 | 2022-09-27 | 西安青松光电技术有限公司 | LED display |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115116382A (en) * | 2021-03-22 | 2022-09-27 | 西安青松光电技术有限公司 | LED display |
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Effective date of registration: 20220629 Address after: 710086 floor 12, northwest regional headquarters of Shiyuan Co., Ltd., north of Fengdong 2nd Road and east of FengHao Avenue, Fengdong new town, Xi'an City, Shaanxi Province Patentee after: QSTECH Co.,Ltd. Address before: 510530 No. 6, Yun Po four road, Whampoa District, Guangzhou, Guangdong. Patentee before: Guangzhou Shiyuan Electronic Technology Company Limited |