0-10V dimming control circuit, dimming power supply and controller

Abstract

The utility model discloses a 0-10V dimming control circuit, a dimming power supply and a dimming controller. According to the 0-10V dimming control circuit, when negative logic dimming is carried out and the voltage of a connecting port of a dimmer reaches the maximum, an MCU unit controls a switching device to be switched off so as to disconnect a pull-up resistor and a direct-current power supply, and meanwhile, the MCU unit outputs an excitation voltage to the input end of a voltage follower; the MCU unit judges whether the dimmer connection port is connected with the dimmer according to the magnitude change of the voltage detection signal output by the voltage follower, and further distinguishes whether the maximum voltage of the dimmer connection port is caused by the maximum output of the dimmer or the suspension of the dimmer connection port; the 0-10V dimming control circuit solves the technical problem that a conventional positive logic 0-10V dimming control circuit cannot be compatible with negative logic dimming, can be compatible with positive and negative logic dimming at the same time, is compatible with an active dimmer and a passive dimmer, and is higher in universality.

Description

Technical Field

[0001] The utility model relates to the technical field of lighting equipment, in particular to a 0-10V dimming control circuit, a dimming power supply and a dimming controller. Background Art

[0002] Power supplies based on 0-10V dimming interfaces are widely used in wired dimming systems due to their standardization, high stability and low solution cost. In outdoor dimming systems (such as tunnels), power supplies with positive logic or negative logic dimming interfaces are used. For a positive logic 0-10V dimming power supply, when receiving a 10V voltage, it controls the power supply to adjust the brightness to the maximum value, and when at 0V, it controls the power supply to adjust the brightness to the minimum value. Conversely, for a negative logic 0-10V dimming power supply, when receiving a 10V voltage, it controls the power supply to adjust the brightness to the minimum value, and when at 0V, it controls the power supply to adjust the brightness to the maximum value. At the same time, whether it is a positive logic or negative logic dimming interface, when not connected to a dimmer, that is, when suspended, the dimming power supply should output the maximum brightness value.

[0003] There are mainly two common 0-10V dimming control circuits, such as Figure 1 、 2 shown. Figure 1 What is shown is a conventional positive logic 0-10V dimming control circuit. Figure 2 What is shown is a conventional negative logic 0-10V dimming control circuit.

[0004] Figure 1 The positive logic 0-10V dimming control circuit shown can be connected to an active dimmer or a passive dimmer for positive logic dimming. When the dimmer outputs the maximum or the dimmer connection port is suspended, the voltage at the input end of the voltage follower U1 will be the maximum, that is, the voltage at V1 is the maximum. However, during negative logic dimming, when the dimmer outputs the maximum, the MCU unit U2 should control the duty cycle of the output PWM signal to the minimum value; and when the dimmer connection port is suspended, the MCU unit U2 should control the duty cycle of the output PWM signal to the maximum value. Obviously, these two are contradictory. Therefore, the conventional positive logic 0-10V dimming control circuit cannot perform negative logic dimming.

[0005] Figure 2 The negative logic 0-10V dimming control circuit shown can be connected to an active dimmer for negative logic dimming. When it is connected to a passive dimmer, no matter how the resistance value of the dimmer is adjusted, the input voltage at V1 is 0V, and the circuit cannot work properly. Therefore, the conventional negative logic 0-10V dimming control circuit cannot be compatible with passive dimmers.

[0006] In summary, the conventional positive logic 0-10V dimming control circuit can only perform positive logic dimming and cannot be compatible with negative logic dimming; the conventional negative logic 0-10V dimming control circuit can only be connected to an active dimmer for negative logic dimming and cannot use a passive dimmer for negative logic dimming. Based on this, designing a 0-10V dimming control circuit that can be compatible with both positive and negative logic dimming and is suitable for active and passive dimmers is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0007] The technical problem to be solved by the present utility model is to provide a 0-10V dimming control circuit, a dimming power supply, and a dimming controller that can be compatible with both positive and negative logic dimming and are suitable for active and passive dimmers.

[0008] To solve the above technical problem, the present utility model adopts the following technical solutions:

[0009] A 0-10V dimming control circuit includes: a dimmer connection port for connecting a dimmer, where the dimmer is an active dimmer or a passive dimmer; a voltage follower, whose input terminal is connected to the dimmer connection port for outputting a voltage detection signal according to the voltage of the dimmer connection port; a pull-up resistor R1 and a switching device Q1, one end of the pull-up resistor R1 is connected to the dimmer connection port, and the other end of the pull-up resistor R1 is connected to a DC power supply through the switching device Q1; a dimming logic switching module for outputting a dimming logic switching signal; an MCU unit, which is respectively connected to the output terminal of the voltage follower, the control terminal of the switching device Q1, and the dimming logic switching module, and the MCU unit is also connected to the input terminal of the voltage follower through a resistor R6;

[0010] The MCU unit switches the dimming logic according to the dimming logic switching signal. The dimming logic includes positive logic dimming and negative logic dimming. The MCU unit also outputs a PWM signal with a corresponding duty cycle according to the dimming logic and the magnitude of the voltage detection signal to control the power supply for dimming; during negative logic dimming, if the voltage of the dimmer connection port reaches the maximum value, the MCU unit controls the switching device Q1 to turn off and outputs an excitation voltage, and this excitation voltage is output to the input terminal of the voltage follower through the resistor R6 to adjust the magnitude of the voltage detection signal output by the voltage follower. The MCU unit determines whether a dimmer is connected to the dimmer connection port according to the magnitude of the adjusted voltage detection signal and outputs a PWM signal with the maximum or minimum duty cycle according to the judgment result.

[0011] A dimming power supply includes the above 0-10V dimming control circuit.

[0012] A dimming controller includes the above-mentioned 0-10V dimming control circuit.

[0013] The beneficial technical effects of the present utility model are as follows: For the above-mentioned 0-10V dimming control circuit, when dimming in negative logic and the voltage at the dimming controller connection port reaches the maximum value, the MCU unit controls the switching device to turn off to disconnect the connection between the pull-up resistor and the DC power supply. At the same time, the MCU unit outputs an excitation voltage to the input terminal of the voltage follower. The MCU unit can determine whether a dimming controller is connected to the dimming controller connection port according to the magnitude change of the voltage detection signal output by the voltage follower, and further distinguish whether the maximum voltage at the dimming controller connection port is caused by the maximum output of the dimming controller or the dimming controller connection port being suspended, solving the technical problem that the conventional positive logic 0-10V dimming control circuit can only perform positive logic dimming and cannot be compatible with negative logic dimming. Moreover, when connecting a passive dimming controller for negative logic dimming, before the voltage at the dimming controller connection port reaches the maximum value, the DC power supply provides an input voltage to the input terminal of the voltage follower through the pull-up resistor; when the voltage at the dimming controller connection port reaches the maximum value, the MCU unit outputs an excitation voltage to provide an input voltage to the input terminal of the voltage follower, thus solving the technical problem that the conventional negative logic 0-10V dimming control circuit cannot use a passive dimming controller for negative logic dimming. In summary, the 0-10V dimming control circuit of the present utility model can be compatible with both positive and negative logic dimming, is compatible with active and passive dimming controllers, can adapt to more dimming controllers, and has stronger versatility. Description of the Drawings

[0014] Figure 1 is the circuit schematic diagram of the positive logic 0-10V dimming control circuit in the prior art;

[0015] Figure 2 is the circuit schematic diagram of the negative logic 0-10V dimming control circuit in the prior art;

[0016] Figure 3 is the circuit schematic diagram of the 0-10V dimming control circuit in the present utility model;

[0017] Figure 4 is Figure 3 the circuit schematic diagram when the 0-10V dimming control circuit in

[0018] Figure 5 is Figure 3 the circuit schematic diagram when the 0-10V dimming control circuit in Detailed Embodiments

[0019] To enable those of ordinary skill in the art to more clearly understand the purpose, technical solution, and advantages of the present utility model, the following further elaborates on the present utility model in conjunction with the accompanying drawings and embodiments.

[0020] As Figure 3 shown, in an embodiment of the present utility model, the 0 - 10V dimming control circuit includes a dimming controller connection port J1, a voltage follower U1, a pull-up resistor R1, a switching device Q1, a dimming logic switching module, and an MCU unit U2. The dimming controller connection port J1 is used to connect to a dimming controller; the input terminal of the voltage follower U1 is connected to the dimming controller connection port J1, and is used to output a voltage detection signal according to the voltage of the dimming controller connection port J1; one end of the pull-up resistor R1 is connected to the dimming controller connection port J1, and the other end of the pull-up resistor R1 is connected to a DC power supply (VCC) through the switching device Q1; the dimming logic switching module is used to output a dimming logic switching signal; the MCU unit U2 is respectively connected to the output terminal of the voltage follower U1, the control terminal of the switching device Q1, and the dimming logic switching module, and the MCU unit U2 is also connected to the input terminal of the voltage follower U1 through a resistor R6.

[0021] The MCU unit U2 switches the dimming logic according to the dimming logic switching signal. The dimming logic includes positive logic dimming and negative logic dimming. The MCU unit U2 also outputs a PWM signal with a corresponding duty cycle according to the dimming logic and the magnitude of the voltage detection signal to control the power supply for dimming; in negative logic dimming, if the voltage of the dimming controller connection port J1 reaches the maximum value, the MCU unit U2 controls the switching device Q1 to turn off and outputs an excitation voltage, and this excitation voltage is output to the input terminal of the voltage follower U1 through the resistor R6 to adjust the magnitude of the voltage detection signal output by the voltage follower U1. The MCU unit U2 determines whether a dimming controller is connected to the dimming controller connection port J1 according to the magnitude of the adjusted voltage detection signal, and outputs a PWM signal with the maximum or minimum duty cycle according to the judgment result.

[0022] As Figure 4 、 5 shown, the input terminal of the voltage follower U1 is connected to the dimming controller connection port J1, and the dimming controller connection port J1 is connected to an active dimming controller or a passive dimming controller. The signal output by the dimming controller is input to the input terminal of the voltage follower U1 through the dimming controller connection port J1. In this way, the voltage follower U1 receives the voltage signal output by the dimming controller, and its output voltage (i.e., the voltage detection signal) follows the change of the input voltage. The MCU unit U2 can determine the change of the voltage output by the dimming controller according to the received voltage detection signal, and thus output a PWM signal with a corresponding duty cycle to control the power supply for dimming.

[0023] A voltage stabilizing diode D2 is connected between the dimming controller connection port J1 and the ground (GND). The function of the voltage stabilizing diode D2 is to protect the input end of the voltage follower U1 and prevent the voltage follower U1 from being damaged by excessive voltage.

[0024] A resistor R2 and a resistor R3 are arranged at the output end of the voltage follower U1. The voltage detection signal output by the voltage follower U1 is divided by the resistor R2 and the resistor R3 and then output to the MCU unit U2. In this embodiment, the resistance values of the resistor R2 and the resistor R3 are equal; of course, in other embodiments, the resistor R2 and the resistor R3 can adopt resistors with unequal resistance values.

[0025] In this embodiment, the switching device Q1 uses a Pmos transistor. The source electrode of the switching device Q1 is connected to the DC power supply VCC. The drain electrode of the switching device Q1 is connected to the other end of the pull-up resistor R1. The gate electrode of the switching device Q1 is connected to the MCU unit U2. A resistor R5 is connected between the gate electrode of the switching device Q1 and the ground. The MCU unit U2 outputs high and low levels to control the on and off of the switching device Q1. In other embodiments, the switching device Q1 can also adopt other switching devices such as thyristors and triodes.

[0026] A voltage stabilizing diode D3 is connected between the connection point of the resistor R6 and the MCU unit U2 and the ground. The voltage stabilizing diode D3 can limit the voltage transmitted from the dimming controller connection port J1 to the MCU unit U2 through the resistor R6, and avoid burning out the MCU unit U2 when the voltage at the dimming controller connection port J1 is too large.

[0027] The dimming logic switching module includes a resistor R4 and a DIP switch K1. One end of the resistor R4 is grounded, and the other end of the resistor R4 is connected to the MCU unit U2 through the DIP switch K1. In other embodiments, a push-button switch can also be used to replace the DIP switch K1. The 0-10V dimming control circuit performs switching control of the dimming logic through the dimming logic switching module. When the DIP switch K1 is toggled to connect the resistor R4 to the MCU unit U2, the MCU unit U2 runs the positive logic dimming program, and the circuit performs positive logic dimming; when the DIP switch K1 is toggled to disconnect the resistor R4 from the MCU unit U2, the MCU unit U2 runs the negative logic dimming program, and the circuit performs negative logic dimming.

[0028] The working process of the 0-10V dimming control circuit in this embodiment when connected to an active dimming controller is as follows:

[0029] As Figure 4 shown, first, the dimming logic of the circuit is switched through the DIP switch K1 to switch the dimming logic to positive logic dimming.

[0030] When the circuit performs positive logic dimming, the MCU unit U2 controls the switching device Q1 to remain conducting. The DC power supply VCC is connected to the pull-up resistor R1. The active dimmer outputs a 0 - 10V voltage to the dimmer connection port J1 (i.e., at V1). The voltage at V4 changes following the voltage at V1. The MCU unit U2 runs the positive logic dimming program and outputs a PWM signal with a corresponding duty cycle according to the voltage at V1 to control the power supply for dimming. When the voltage at V1 is 0V, the MCU unit U2 outputs a PWM signal with the minimum duty cycle; when the voltage at V1 is 10V, the MCU unit U2 outputs a PWM signal with the maximum duty cycle; when the dimmer connection port J1 is floating, since the pull-up resistor R1 pulls up to the DC power supply VCC (VCC ≥ 10V), at this time the voltage at V1 ≥ 10V, and the MCU unit U2 outputs a PWM signal with the maximum duty cycle.

[0031] When the circuit performs negative logic dimming, the MCU unit U2 first controls the switching device Q1 to remain conducting. The DC power supply VCC is connected to the pull-up resistor R1. The active dimmer outputs a 0 - 10V voltage to the dimmer connection port J1 (i.e., at V1). The voltage at V4 changes following the voltage at V1. The MCU unit U2 runs the negative logic dimming program and outputs a PWM signal with a corresponding duty cycle according to the voltage at V1 to control the power supply for dimming. When the voltage at V1 is 0V, the voltage at V4 is the minimum, and the MCU unit U2 outputs a PWM signal with the maximum duty cycle. When the voltage at V1 is the maximum, the voltage at V4 is also the maximum. There are two cases that can cause the voltage at V1 to be the maximum: not connecting the dimmer and the active dimmer outputting the maximum voltage. However, the result we want is: when the active dimmer is connected and the active dimmer outputs the maximum voltage, the MCU unit U2 should output a PWM signal with the minimum duty cycle; when the dimmer is not connected (i.e., the dimmer connection port J1 is floating), the MCU unit U2 should output a PWM signal with the maximum duty cycle.

[0032] Therefore, when the voltage at V1 is the maximum, it is necessary to first determine whether there is an active dimmer connected to the dimmer connection port J1, and then output a PWM signal with the maximum or minimum duty cycle according to the judgment result. The specific processing process is as follows:

[0033] Suppose that the maximum voltage output by the active dimmer causes the voltage at V1 to be the maximum: when the voltage at V1 is the maximum, the MCU unit U2 controls the switching device Q1 to disconnect, and the M2 pin of the MCU unit U2 outputs an excitation voltage (such as a 5V high level). This excitation voltage is output to the input terminal of the voltage follower U1 through the resistor R6. Since the input voltage at V1 is 10V and the excitation voltage value (5V) is less than the active dimmer output voltage value, the current direction on the resistor R6 is from left to right. The voltage at V1 is the voltage value output by the active dimmer, V1 = V2 = 10V, and the voltage at V4 is 5V (R2 = R3).

[0034] Assume that not connecting the dimmer results in the maximum voltage at V1: When the voltage at V1 is maximum, the MCU unit U2 controls the switch device Q1 to disconnect, and the M2 pin of the MCU unit U2 outputs an excitation voltage (e.g., 5V high level). This excitation voltage is output to the input terminal of the voltage follower U1 through the resistor R6. Since the dimmer is not connected, the current direction on the resistor R6 is from right to left. The excitation voltage is input to the voltage follower U1 through the resistor R6, and the voltage at V1 is equal to the excitation voltage (5V), i.e., V1 = V2 = 5V, and the voltage at V4 is 2.5V (R2 = R3).

[0035] After the MCU unit U2 controls the switch device Q1 to disconnect, the MCU unit U2 outputs an excitation voltage to the input terminal of the voltage follower U1 through the resistor R6. For the two cases of connecting an active dimmer and not connecting a dimmer, the magnitudes of the voltage detection signals output by the voltage follower U1 are different. Therefore, it is possible to determine whether an active dimmer is connected to the dimmer connection port according to the magnitude of the adjusted voltage detection signal, that is, it is possible to determine whether an active dimmer is connected to the dimmer connection port according to the voltage magnitude at V4. When the voltage at V4 is 5V, the MCU unit will determine that an active dimmer is connected to the dimmer connection port. The active dimmer outputs the maximum voltage, resulting in the maximum voltage at V1, and the MCU unit U2 outputs a PWM signal with the minimum duty cycle. When the voltage at V4 is 2.5V, the MCU unit will determine that no dimmer is connected to the dimmer connection port. The dimmer connection port is floating, resulting in the maximum voltage at V1, and the MCU unit U2 outputs a PWM signal with the maximum duty cycle.

[0036] It should be noted that the voltage value of the excitation voltage output by the M2 pin of the MCU unit U2 can be adjusted according to the actual situation, which can be 5V, or 3.3V or other values. The resistance values of the resistor R2 and the resistor R3 can also be adjusted according to the actual situation, and the two resistance values can be unequal. The voltage at V4 changes according to the voltage at V1 and the resistance values of the resistor R2 and the resistor R3. When determining whether an active dimmer is connected to the dimmer connection port, the MCU unit U2 can preset a first preset value and a second preset value correspondingly. Among them, the first preset value is the voltage at V4 after the control switch device Q1 is disconnected and the M2 pin of the MCU unit U2 outputs an excitation voltage when an active dimmer is connected; the second preset value is the voltage at V4 after the control switch device Q1 is disconnected and the M2 pin of the MCU unit U2 outputs an excitation voltage when no dimmer is connected. By comparing the voltage at V4 with the first preset value and the second preset value, it is possible to determine whether an active dimmer is connected to the dimmer connection port.

[0037] The working process of the 0 - 10V dimming control circuit in this embodiment when connecting a passive dimmer is as follows:

[0038] As Figure 5 shown, first, the dimming logic of the circuit is switched by the DIP switch K1.

[0039] When the circuit performs positive logic dimming, the MCU unit U2 controls the switch device Q1 to remain conducting. The DC power supply VCC is connected to the pull-up resistor R1. The resistance value of the passive dimmer is adjusted to change the voltage at V1, and the voltage at V4 changes following the voltage at V1. The MCU unit U2 runs the positive logic dimming program and outputs a PWM signal with a corresponding duty cycle according to the voltage magnitude at V1 to control the power supply for dimming. When the resistance value of the passive dimmer is adjusted to the minimum, due to the voltage division of the pull-up resistor R1 and the equivalent resistance of the passive dimmer at V1, the voltage at V1 is the minimum at this time, the voltage at V4 is the minimum, and the MCU unit U2 outputs a PWM signal with the minimum duty cycle; when the resistance value of the passive dimmer is adjusted to the maximum, the voltage at V1 is the maximum at this time, the voltage at V4 is the maximum, and the MCU unit U2 outputs a PWM signal with the maximum duty cycle; when no dimmer is connected (i.e., the dimmer connection port J1 is floating), since the pull-up resistor R1 is pulled up to the DC power supply VCC, the voltage at V1 is the maximum at this time, the voltage at V4 is the maximum, and the MCU unit U2 outputs a PWM signal with the maximum duty cycle.

[0040] When the circuit performs negative logic dimming, the MCU unit U2 first controls the switch device Q1 to remain conducting. The DC power supply VCC is connected to the pull-up resistor R1. The resistance value of the passive dimmer is adjusted to change the voltage at V1, and the voltage at V4 changes following the voltage at V1. The MCU unit U2 runs the negative logic dimming program and outputs a PWM signal with a corresponding duty cycle according to the voltage magnitude at V1 to control the power supply for dimming. When the resistance value of the passive dimmer is adjusted to the minimum, the voltage at V1 is the minimum at this time, the voltage at V4 is the minimum, and the MCU unit U2 outputs a PWM signal with the maximum duty cycle. When the resistance value of the passive dimmer is adjusted to the maximum, the voltage at V1 is the maximum at this time, and the voltage at V4 is also the maximum. There are two cases that can cause the voltage at V1 to be the maximum here: no dimmer is connected and the resistance value of the passive dimmer is adjusted to the maximum. However, the result we want is: when a passive dimmer is connected and the resistance value of the passive dimmer is adjusted to the maximum, the MCU unit U2 should output a PWM signal with the minimum duty cycle; when no dimmer is connected (i.e., the dimmer connection port J1 is floating), the MCU unit U2 should output a PWM signal with the maximum duty cycle.

[0041] Therefore, when the voltage at V1 is the maximum, it is necessary to first determine whether a passive dimmer is connected to the dimmer connection port J1, and then output a PWM signal with the maximum or minimum duty cycle according to the judgment result. The specific processing process is as follows:

[0042] Assume that the resistance of the passive dimmer is adjusted to the maximum, resulting in the maximum voltage at V1: When the voltage at V1 is the maximum, the MCU unit U2 controls the switch device Q1 to disconnect, and the M2 pin of the MCU unit U2 outputs an excitation voltage (such as a 5V high level). This excitation voltage is output to the input terminal of the voltage follower U1 through the resistor R6. The excitation voltage will generate a voltage division through the resistor R6 and the equivalent resistance of the passive dimmer, and this voltage division serves as the input voltage of the voltage follower U1. Here, it is selected that R6 is equal to the maximum value of the dimmer range, V1 = 2.5V, and the voltage at V4 = 1.25V (R2 = R3).

[0043] Assume that not connecting the dimmer results in the maximum voltage at V1: When the voltage at V1 is the maximum, the MCU unit U2 controls the switch device Q1 to disconnect, and the M2 pin of the MCU unit U2 outputs an excitation voltage (such as a 5V high level). This excitation voltage is output to the input terminal of the voltage follower U1 through the resistor R6, and this excitation voltage serves as the input voltage of the voltage follower U1, V1 = 5V, and the voltage at V4 = 2.5V (R2 = R3).

[0044] After the MCU unit U2 controls the switch device Q1 to disconnect, the MCU unit U2 outputs an excitation voltage to the input terminal of the voltage follower U1 through the resistor R6. For the two cases of connecting the passive dimmer and not connecting the dimmer, the magnitudes of the voltage detection signals output by the voltage follower U1 are different. Therefore, it is possible to determine whether a passive dimmer is connected to the dimmer connection port according to the magnitude of the adjusted voltage detection signal, that is, it is possible to determine whether a passive dimmer is connected to the dimmer connection port according to the magnitude of the voltage at V4. When the voltage at V4 is 1.25V, the MCU unit will determine that a passive dimmer is connected to the dimmer connection port. The resistance of the passive dimmer is adjusted to the maximum, resulting in the maximum voltage at V1, and the MCU unit U2 outputs a PWM signal with the minimum duty cycle; when the voltage at V4 is 2.5V, the MCU unit will determine that no dimmer is connected to the dimmer connection port. The dimmer connection port is left floating, resulting in the maximum voltage at V1, and the MCU unit U2 outputs a PWM signal with the maximum duty cycle.

[0045] It should be noted that the voltage value of the excitation voltage output by the M2 pin of the MCU unit U2 can be adjusted according to the actual situation, which can be 5V, 3.3V or other values. The resistance values of the resistor R2 and the resistor R3 can also be adjusted according to the actual situation, and the two resistance values can be unequal. The voltage at V4 changes according to the voltage at V1 and the resistance values of the resistor R2 and the resistor R3. When judging whether a passive dimmer is connected to the dimmer connection port, the MCU unit U2 can preset a second preset value and a third preset value correspondingly, where the second preset value is the voltage at V4 after the control switch device Q1 is turned off and the MCU unit U2 outputs an excitation voltage when no dimmer is connected; the third preset value is the voltage at V4 after the control switch device Q1 is turned off and the MCU unit U2 outputs an excitation voltage when a passive dimmer is connected. By comparing the voltage at V4 with the second preset value and the third preset value, it can be judged whether a dimmer is connected to the dimmer connection port.

[0046] For the 0-10V dimming control circuit of the present invention, when dimming in negative logic and the voltage at the dimmer connection port reaches the maximum value, the MCU unit controls the switch device Q1 to turn off to disconnect the pull-up resistor from the DC power supply. At the same time, the MCU unit outputs an excitation voltage to the input end of the voltage follower. The MCU unit can judge whether a dimmer is connected to the dimmer connection port according to the change in the magnitude of the voltage detection signal output by the voltage follower, and further distinguish whether the maximum voltage at the dimmer connection port is caused by the dimmer outputting the maximum or the dimmer connection port being suspended, which solves the technical problem that the conventional positive logic 0-10V dimming control circuit can only perform positive logic dimming and cannot be compatible with negative logic dimming. Moreover, when connecting a passive dimmer for negative logic dimming, before the voltage at the dimmer connection port reaches the maximum value, the DC power supply provides an input voltage to the input end of the voltage follower through the pull-up resistor; when the voltage at the dimmer connection port reaches the maximum value, the MCU unit outputs an excitation voltage to provide an input voltage to the input end of the voltage follower, thus solving the technical problem that the conventional negative logic 0-10V dimming control circuit cannot use a passive dimmer for negative logic dimming.

[0047] In summary, the 0-10V dimming control circuit of the present invention can be compatible with both positive and negative logic dimming, compatible with active dimmers and passive dimmers, can adapt to more dimmers, and has stronger versatility.

[0048] Based on Figures 3 - 5 the 0-10V dimming control circuit in the embodiment shown, the present invention also provides a dimming power supply, which includes Figures 3 - 5 the 0-10V dimming control circuit in the embodiment shown.

[0049] Based on Figures 3 - 5For the 0-10V dimming control circuit in the illustrated embodiment, the present utility model further provides a dimming controller, which includes Figures 3 - 5 the 0-10V dimming control circuit in the illustrated embodiment.

[0050] Based on Figures 3 - 5 the 0-10V dimming control circuit in the illustrated embodiment, the present utility model further provides a dimming method.

[0051] The dimming method includes the following steps:

[0052] S1. The MCU unit switches the dimming logic according to the dimming logic switching signal output by the dimming logic switching module. The dimming logic includes positive logic dimming and negative logic dimming. The MCU unit also outputs a PWM signal with a corresponding duty cycle according to the dimming logic and the magnitude of the voltage detection signal to control the power supply for dimming.

[0053] S2. During negative logic dimming, if the voltage at the dimming device connection port reaches the maximum value, the MCU unit controls the switch device Q1 to turn off and outputs an excitation voltage, which is output to the input end of the voltage follower to adjust the magnitude of the voltage detection signal output by the voltage follower. The MCU unit determines whether a dimming device is connected to the dimming device connection port according to the magnitude of the adjusted voltage detection signal, and outputs a PWM signal with the maximum or minimum duty cycle according to the determination result.

[0054] The MCU unit determines whether a dimming device is connected to the dimming device connection port according to the magnitude of the adjusted voltage detection signal, and outputs a PWM signal with the maximum or minimum duty cycle further includes:

[0055] If the magnitude of the adjusted voltage detection signal is a first preset value, the MCU unit determines that an active dimming device is connected to the dimming device connection port, and the MCU unit outputs a PWM signal with the minimum duty cycle;

[0056] If the magnitude of the adjusted voltage detection signal is a second preset value, the MCU unit determines that no dimming device is connected to the dimming device connection port, and the MCU unit outputs a PWM signal with the maximum duty cycle;

[0057] If the magnitude of the adjusted voltage detection signal is a third preset value, the MCU unit determines that a passive dimming device is connected to the dimming device connection port, and the MCU unit outputs a PWM signal with the minimum duty cycle.

[0058] The above are only the preferred embodiments of the present utility model, and do not impose any form of limitation on the present utility model. Those skilled in the art can make various equivalent changes and improvements based on the above embodiments. Any equivalent changes or modifications made within the scope of the claims shall fall within the protection scope of the present utility model.

Claims

1. A 0-10V dimming control circuit, characterized in that: Included are: a dimmer connection port, which is used to connect a dimmer, wherein the dimmer is an active dimmer or a passive dimmer; a voltage follower, whose input end is connected to the dimmer connection port, and is used to output a voltage detection signal according to the voltage of the dimmer connection port; A pull-up resistor R1 and a switch device Q1, wherein one end of the pull-up resistor R1 is connected to the dimmer connection port, and the other end of the pull-up resistor R1 is connected to a DC power source through the switch device Q1; A dimming logic switching module, used for outputting a dimming logic switching signal; an MCU unit, which is respectively connected to the output end of the voltage follower, the control end of the switch device Q1 and the dimming logic switching module, and the MCU unit is also connected to the input end of the voltage follower through a resistor R6; The MCU unit switches the dimming logic according to the dimming logic switching signal, the dimming logic includes positive logic dimming and negative logic dimming, and the MCU unit also outputs a PWM signal with a corresponding duty cycle according to the dimming logic and the voltage detection signal to control the power supply to dim; During negative logic dimming, if the voltage at the dimmer connection port reaches the maximum value, the MCU unit controls the switch device Q1 to turn off and outputs an excitation voltage, which is output to the input end of the voltage follower through the resistor R6 to adjust the size of the voltage detection signal output by the voltage follower. The MCU unit determines whether the dimmer is connected to the dimmer connection port based on the size of the adjusted voltage detection signal, and outputs a PWM signal with a maximum or minimum duty cycle based on the judgment result.

2. The 0-10V dimming control circuit according to claim 1, characterized in that: A voltage stabilizing diode D2 is connected between the dimmer connection port and the ground.

3. The 0-10V dimming control circuit according to claim 1, characterized in that: The output end of the voltage follower is provided with a resistor R2 and a resistor R3. The voltage detection signal output by the voltage follower is output to the MCU unit after being divided by the resistors R2 and R3.

4. The 0-10V dimming control circuit as claimed in claim 3, characterized in that: The resistance values ​​of the resistor R2 and the resistor R3 are equal.

5. The 0-10V dimming control circuit according to any one of claims 1 to 4, characterized in that: The switch device Q1 adopts a Pmos tube, the source of the switch device Q1 is connected to the DC power supply, the drain of the switch device Q1 is connected to the other end of the pull-up resistor R1, and the gate of the switch device Q1 is connected to the MCU unit.

6. The 0-10V dimming control circuit as claimed in claim 5, characterized in that: A resistor R5 is connected between the gate of the switch device Q1 and the ground.

7. The 0-10V dimming control circuit according to any one of claims 1 to 4, characterized in that: A voltage stabilizing diode D3 is connected between the connection point between the resistor R6 and the MCU unit and the ground.

8. The 0-10V dimming control circuit according to any one of claims 1 to 4, characterized in that: The dimming logic switching module includes a resistor R4 and a dip switch. One end of the resistor R4 is grounded, and the other end of the resistor R4 is connected to the MCU unit through the dip switch.

9. A dimming power supply, characterized in that: It comprises the 0-10V dimming control circuit as described in any one of claims 1-8.

10. A dimming controller, characterized in that: It comprises the 0-10V dimming control circuit as described in any one of claims 1-8.

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