Multi-channel LED drive control system

Abstract

The utility model discloses a multi-channel LED drive control system. The system comprises a plurality of LED units which are connected in parallel; the first end of the LED unit receives a driving voltage; the first end of each control unit is connected with the second end of one LED unit, and the control units are used for measuring the current value of each LED unit; the resistance adjusting unit is connected with the second end of the control unit and used for adjusting the resistance value according to the current value; and the input end of the power converter is connected with a power supply to receive a first voltage, and the output end of the power converter is connected with the resistance adjusting unit and the other end of the plurality of LED units so as to output a driving voltage to the first ends of the plurality of LED units according to the resistance value. The driving voltage of the LED unit can be adjusted in real time.

Description

Technical Field

[0001] The implementation of the utility model relates to the technical field of electronic circuits. Specifically, the application relates to a multi-channel LED drive control system. Background Art

[0002] When driving an LED, a lot of LED heat is required to produce light. Since one or more LEDs must be driven, the driving components generate a lot of heat, which leads to reduced efficiency. In order to improve efficiency, the voltage of the driving circuit needs to be reduced, but if the voltage is too low, it cannot drive the correct current, and the brightness will dim, so the voltage needs to be maintained above a certain voltage. However, the problem now is that the forward bias voltage of the LED used in the prior art is not constant, and it is difficult to determine the specific voltage.

[0003] Therefore, the present invention seeks to provide a system that optimizes thermal efficiency by keeping the drive current constant while using a minimum voltage when using various LEDs. Utility Model Content

[0004] The present application aims to at least solve the problem in the prior art that the forward bias voltage of an LED is difficult to determine. To this end, an example of the present application provides a multi-channel LED drive control system that can adjust the drive voltage of an LED unit in real time.

[0005] The solution of this application example is implemented through the following contents.

[0006] In a first aspect, the present application describes a multi-channel LED driving control system, comprising:

[0007] A plurality of LED units connected in parallel; a first end of each LED unit receives a driving voltage;

[0008] A plurality of control units, each of which has a first end connected to a second end of one of the LED units, for measuring a current value of each of the LED units;

[0009] a resistance adjustment unit, connected to the second end of the control unit, and used for adjusting the resistance value according to the current value;

[0010] A power converter, whose input end is connected to a power source to receive a first voltage, and whose output end is connected to the resistance adjustment unit and the other end of the multiple LED units to output a driving voltage to the first end of the multiple LED units according to the resistance value.

[0011] The multi-channel LED drive control system as described above may optionally further include a current detector, one end of which is connected to all the control units for outputting an adjustment signal according to the current value output by each control unit, and the other end of which is connected to the resistance adjustment unit.

[0012] As described above, the multi-channel LED driving control system, optionally, the control unit includes a first transistor and a current integrated circuit:

[0013] The source of the first transistor is connected to the second end of the LED unit and the first input end of the current integrated circuit, the drain of the first transistor is connected to the first resistor, and the other end of the first resistor is grounded;

[0014] The output end of the current integrated circuit is connected to the current detector, and outputs the current flowing through the LED unit to the resistance adjustment unit.

[0015] In the multi-channel LED driving control system as described above, optionally, the control unit further includes:

[0016] A second transistor, wherein a source of the second transistor is connected to the second input terminal of the current integrated circuit, a drain of the second transistor is connected to a second resistor, and the other end of the second resistor is grounded.

[0017] As the multi-channel LED driving control system described above, optionally, the control unit further includes an operational amplifier and a digital-to-analog converter;

[0018] The in-phase input terminal of the operational amplifier is connected to the digital-to-analog converter, the inverting input terminal of the operational amplifier is connected to the drain of the first transistor, and the output terminal of the operational amplifier is connected to the gate of the first transistor and the gate of the second transistor.

[0019] In the multi-channel LED driving control system as described above, optionally, the operational amplifier includes a programmable amplifier.

[0020] As the multi-channel LED driving control system described above, optionally, the resistance adjustment unit includes a modulation decoder and a sliding resistor;

[0021] The two ends of the sliding rheostat are respectively connected to the reflection end and the output end of the power converter, and the sliding end of the sliding rheostat is connected to the modulation decoder;

[0022] The modulation decoder is connected to the current detector and is used for adjusting the sliding end of the sliding resistor according to the adjustment signal.

[0023] In the multi-channel LED driving control system as described above, optionally, the power converter includes a BUCK converter.

[0024] The multi-channel LED driving control system as described above may optionally further include an inductor and a capacitor;

[0025] The first end of the inductor is connected to the output end of the BUCK converter, and the second end of the inductor is connected to one end of the sliding rheostat and the first end of the LED unit;

[0026] The first end of the capacitor is connected to the second end of the inductor, and the second end of the capacitor is grounded.

[0027] As described above, in the multi-channel LED driving control system, optionally, the LED unit includes a plurality of LED tubes connected in series.

[0028] Beneficial effects:

[0029] The present application receives a first voltage output through a power converter to drive a driving voltage for multiple LED units, and then adjusts the resistance value of the output end connected to the power converter according to the current value of the output end of the multiple LED units through a control unit and a resistance adjustment unit, so as to adjust the driving voltage applied to the multiple LED units in real time and make the driving voltage flowing through the LED units as low as possible, thereby reducing the heat generation while still being able to generate light of sufficient brightness. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present application will become easy to understand. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0031] Figure 1 The circuit diagram of the multi-channel LED driving control system of the present application embodiment is shown in FIG. Figure 1 ;

[0032] Figure 2 The circuit diagram of the multi-channel LED driving control system of the embodiment of the present application is shown in FIG. Figure 2 . DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0034] As attached Figure 1 The circuit diagram of the multi-channel LED driving control system shown in the figure, the embodiment of the present application provides a multi-channel LED driving control system, including multiple LED units connected in series, multiple control units, a resistance adjustment unit and a power converter; wherein the first end of the multiple LED units connected in parallel is connected to the power converter, and operates according to the driving voltage output by the power converter, the second end of the LED unit is connected to the first end of the control unit and grounded, the first end of the control unit is connected to the second end of the LED unit for measuring the current value in the LED unit, and the control unit transmits the current value to the resistance adjustment unit through the second end; then the resistance adjustment unit adjusts the resistance according to the current value, so that when the power converter connected to the resistance adjustment unit outputs the driving voltage through the output end, the driving voltage is adjusted by the resistance.

[0035] The number of control units is the same as the number of LED units, and each control unit is connected to the second end of each LED unit and measures the current value flowing through the LED unit. The current value flowing through the LED can directly drive the LED unit to work and maintain stable brightness.

[0036] A first voltage output is received through a power converter to drive a driving voltage of multiple LED units, and then a control unit and a resistance adjustment unit adjust the resistance value connected to the output end of the power converter according to the current value of the output end of the multiple LED units, thereby adjusting the driving voltage applied to the multiple LED units.

[0037] As attached Figure 2 As shown, in this embodiment, a current detector is also included, one end of which is connected to all the control units and is used to output an adjustment signal according to the current value output by each control unit, and the other end of the current detector is connected to the resistance adjustment unit.

[0038] A control unit is used to measure the current flowing through each LED unit, and the current values ​​of all LED units are transmitted to a current detector. The current detector stores a target current value, and the current value transmitted by the control unit is compared with the target current value. When the received current value is greater than the target current value or less than the target current value, the driving voltage of the LED unit needs to be adjusted. Specifically, the current detector outputs a corresponding adjustment signal to the resistance adjustment unit, and the resistance value is adjusted by the resistance adjustment unit, thereby realizing the adjustment of the driving voltage of the LED unit, and realizing real-time adjustment of the driving voltage of the LED unit.

[0039] As attached Figure 2As shown, the control unit includes a first transistor M1, a second transistor M2 and a current integrated circuit; wherein the source of the first transistor M1 is connected to the second end of the LED unit and the first input end of the current integrated circuit, the drain of the first transistor M1 is connected to the first resistor R1, and the other end of the first resistor R1 is grounded; the source of the second transistor M2 is connected to the second input end of the current integrated circuit, the drain of the second transistor M2 is connected to the second resistor, and the other end of the second resistor R2 is grounded; the output end of the current integrated circuit is connected to the current detector, and outputs the current flowing through the LED unit to the resistance adjustment unit.

[0040] The sources of the first transistor M1 and the second transistor M2 are both connected to the second end of the LED unit, and are grounded through the first resistor R1 and the second resistor R2 respectively to realize circuit grounding, thereby measuring the current value of the LED unit. In addition, the source of the second transistor M2 is connected to the second input end of the current integrated circuit through the third resistor R3; the current integrated circuit can detect the current value of the LED unit by detecting the first transistor M1, and can also detect the current value of the LED unit by detecting the second transistor M2 to realize the measurement of the current value of the LED unit.

[0041] The first transistor M1 and the second transistor M2 are both MOS transistors, and NMOS transistors are used as an example.

[0042] Continue as attached Figure 2 As shown, each control unit also includes an operational amplifier OP1 and a digital-to-analog converter. The in-phase input terminal of the operational amplifier OP1 is connected to the digital-to-analog converter, and the digital-to-analog converter provides an input signal to the operational amplifier OP1. The reverse input terminal of the operational amplifier OP1 is connected to the drain of the first transistor M1, and the output terminal of the operational amplifier OP1 is connected to the gate of the first transistor M1 and the gate of the second transistor M2. The gate voltages of the first transistor M1 and the second transistor M2 are controlled by the operational amplifier OP1 to control the switches of the first transistor M1 and the second transistor M2, thereby realizing the control of one LED unit.

[0043] In this embodiment, the operational amplifier OP1 adopts a programmable operational amplifier, and the drive signal output to the gate of the first transistor M1 and the second transistor M2 can be adjusted by programming. The operational amplifier OP1 is an input deviation programmable operational amplifier. By calibrating the output signal by n-bit deviation, the input deviation voltage (or input offset voltage) of the operational amplifier can be changed. The input deviation of the operational amplifier OP1 is calibrated to a very small value by the corresponding offset calibration circuit, for example, within 1mV. After calibration, it can be ensured that the voltage deviation of the output end is very small.

[0044] As attached Figure 2As shown, the resistance adjustment unit includes a modulation decoder and a sliding resistor R4; wherein, the two ends of the sliding resistor R4 are respectively connected to the reflection end and the output end of the power converter, and the sliding end of the sliding resistor R4 is connected to the modulation decoder; the modulation decoder is connected to the current detector, which is used to adjust the sliding end of the sliding resistor R4 according to the adjustment signal.

[0045] A modulation decoder is used to adjust the sliding end of the sliding rheostat R4 according to the adjustment signal to achieve resistance adjustment of the sliding rheostat R4, and the reflection end and the output end of the power converter are respectively connected to the two ends of the sliding rheostat R4. When the resistance of the sliding rheostat R4 changes, the driving voltage output by the output end of the power converter will also change synchronously, and the driving voltage of the LED unit can be adjusted in real time, and the driving voltage flowing through the LED unit can be made as low as possible, thereby reducing the heat generation while generating light of sufficient brightness.

[0046] As attached Figure 2 As shown, in one embodiment, the power converter includes a BUCK converter, and the multi-channel LED drive control system also includes an inductor L1 and a capacitor C1; wherein, the first end of the inductor L1 is connected to the output end of the BUCK converter, and the second end of the inductor L1 is connected to one end of the sliding rheostat and the first end of the LED unit; the first end of the capacitor C1 is connected to the second end of the inductor L1, and the second end of the capacitor C1 is grounded.

[0047] In this embodiment, each LED unit includes a plurality of LED tubes connected in series. The number of LED tubes connected in series in each LED unit is determined according to application requirements.

[0048] In the above description of the present application, unless otherwise clearly specified and limited, the terms "fixed", "installed", "connected" or "connected" and the like should be understood in a broad sense. For example, with regard to the term "connection", it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. Therefore, unless otherwise clearly defined in the present application, those skilled in the art can understand the specific meanings of the above terms in the present application according to the specific circumstances.

[0049] According to the above description of the present application, those skilled in the art may also understand that the terms used below, such as "upper", "lower", "length", "width", "top", "bottom", "inside", "outside", "axial", "longitudinal", "horizontal", "clockwise" or "counterclockwise", etc., which indicate the orientation or position relationship, are based on the orientation or position relationship shown in the drawings of the present application. It is only for the purpose of facilitating the explanation of the scheme of the present application and simplifying the description, rather than explicitly or implicitly indicating that the device or element involved must have the specific orientation, be constructed and operate in a specific orientation, so the above-mentioned orientation or position relationship terms cannot be understood or interpreted as limiting the scheme of the present application.

[0050] In addition, the terms "first" or "second" used in this application to refer to numbers or ordinals are only used for convenience of description and cannot be understood as explicitly or implicitly indicating relative importance or implicitly indicating the number of technical features indicated. At the same time, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, the meaning of "plurality" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

[0051] Although multiple embodiments of the present application have been shown and described herein, it will be appreciated by those skilled in the art that such embodiments are provided only by way of example. Those skilled in the art may think of many changes, modifications and alternatives without departing from the thought and spirit of the present application. It should be understood that in the process of practicing the present application, various alternatives to the embodiments of the present application described herein may be adopted. The attached claims are intended to define the scope of protection of the present application, and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A multi-channel LED drive control system, characterized in that: include: A plurality of LED units connected in parallel; a first end of each LED unit receives a driving voltage; A plurality of control units, each of which has a first end connected to a second end of one of the LED units, for measuring a current value of each of the LED units; a resistance adjustment unit, connected to the second end of the control unit, and used for adjusting the resistance value according to the current value; A power converter, whose input end is connected to a power source to receive a first voltage, and whose output end is connected to the resistance adjustment unit and the other end of the multiple LED units to output a driving voltage to the first end of the multiple LED units according to the resistance value.

2. The multi-channel LED driving control system according to claim 1, characterized in that: It also includes a current detector, one end of which is connected to all the control units and is used to output an adjustment signal according to the current value output by each control unit, and the other end of the current detector is connected to the resistance adjustment unit.

3. The multi-channel LED driving control system according to claim 2, characterized in that: The control unit comprises a first transistor and a current integrated circuit: The source of the first transistor is connected to the second end of the LED unit and the first input end of the current integrated circuit, the drain of the first transistor is connected to the first resistor, and the other end of the first resistor is grounded; The output end of the current integrated circuit is connected to the current detector, and outputs the current flowing through the LED unit to the resistance adjustment unit.

4. The multi-channel LED driving control system according to claim 3, characterized in that: The control unit also includes: A second transistor, wherein a source of the second transistor is connected to the second input terminal of the current integrated circuit, a drain of the second transistor is connected to a second resistor, and the other end of the second resistor is grounded.

5. The multi-channel LED driving control system according to claim 4, characterized in that: The control unit also includes an operational amplifier and a digital-to-analog converter; The in-phase input terminal of the operational amplifier is connected to the digital-to-analog converter, the inverting input terminal of the operational amplifier is connected to the drain of the first transistor, and the output terminal of the operational amplifier is connected to the gate of the first transistor and the gate of the second transistor.

6. The multi-channel LED driving control system according to claim 5, characterized in that: The operational amplifier comprises a programmable amplifier.

7. The multi-channel LED driving control system according to claim 2, characterized in that: The resistance adjustment unit includes a modulation decoder and a sliding resistor; The two ends of the sliding rheostat are respectively connected to the reflection end and the output end of the power converter, and the sliding end of the sliding rheostat is connected to the modulation decoder; The modulation decoder is connected to the current detector and is used for adjusting the sliding end of the sliding resistor according to the adjustment signal.

8. The multi-channel LED driving control system according to claim 7, characterized in that: The power converter includes a BUCK converter.

9. The multi-channel LED driving control system according to claim 8, characterized in that: It also includes inductance and capacitance; The first end of the inductor is connected to the output end of the BUCK converter, and the second end of the inductor is connected to one end of the sliding rheostat and the first end of the LED unit; The first end of the capacitor is connected to the second end of the inductor, and the second end of the capacitor is grounded.

10. The multi-channel LED driving control system according to claim 9, characterized in that: The LED unit includes a plurality of LED tubes connected in series.

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