A constant voltage dimming circuit

Abstract

The present invention discloses a constant voltage dimming circuit, comprising an adjustable constant voltage output module and a processing module, wherein the processing module comprises a detection end, an adjustment end and an output end, wherein the detection end of the processing module is connected to the output end of the adjustable constant voltage output module to obtain an output voltage signal, the adjustment end of the processing module can obtain an external dimming control signal, the output end of the processing module can output a feedback control signal obtained by integrating and processing the output voltage signal and the dimming control signal, the output end of the processing module is connected to the controlled end of the adjustable constant voltage output module to control the adjustable constant voltage output module to adjust the size of the output voltage, and the dimming of the design is stable and can reduce the flicker of the light source.

Description

Technical Field

[0001] The invention relates to the technical field of lighting dimming, and in particular to a constant voltage dimming circuit. Background Art

[0002] Traditional constant voltage dimming circuits are generally composed of a constant voltage output module, a control chip and a switch module. By modulating the constant voltage output module, a suitable voltage level is output, and the light source is powered by the switch module. The control chip then outputs a PWM duty cycle signal according to the user's dimming requirements, and controls the switch module to adjust the opening time, thereby adjusting the output voltage for powering the light source to achieve the dimming purpose. However, the previous dimming circuit structure has a relatively serious problem of light source flicker in the low-voltage range that is difficult to solve. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a constant voltage dimming circuit with stable dimming.

[0004] According to a first aspect of the present invention, a constant voltage dimming circuit includes: an adjustable constant voltage output module; a processing module, including a detection end, an adjustment end and an output end, the detection end of the processing module is connected to the output end of the adjustable constant voltage output module to obtain an output voltage signal, the adjustment end of the processing module can obtain an external dimming control signal, the output end of the processing module can output a feedback control signal obtained by integrating and processing the output voltage signal and the dimming control signal, and the output end of the processing module is connected to the controlled end of the adjustable constant voltage output module to control the adjustable constant voltage output module to adjust the output voltage.

[0005] A constant voltage dimming circuit according to an embodiment of the present invention has at least the following beneficial effects:

[0006] The constant voltage dimming circuit of the present invention can output constant voltages of different levels by controlling an adjustable constant voltage output module. When the adjustable constant voltage output module is connected to a light source load and is powered for operation, a detection end of a processing module is connected to an output end of the adjustable constant voltage output module to obtain the output voltage at this time, and an adjustment end of the processing module can obtain a dimming control signal input and set by a user. After processing, it is determined whether the output voltage meets the user's dimming requirements, and then the processing module outputs a related feedback control signal to the adjustable constant voltage output module, controls the adjustable constant voltage output module to adjust the size of the output constant voltage to achieve the purpose of dimming, and the dimming is stable, and the light source flicker can be reduced.

[0007] According to some embodiments of the present invention, the processing module is a comparison module, which includes a detection end, an adjustment end and an output end. The detection end of the comparison module is connected to the output end of the adjustable constant voltage output module to obtain an output voltage signal, the adjustment end of the comparison module can obtain an external dimming control signal, the output end of the comparison module can output a feedback control signal obtained by comparing the output voltage signal and the dimming control signal, and the output end of the comparison module is connected to the controlled end of the adjustable constant voltage output module to control the adjustable constant voltage output module to adjust the output voltage.

[0008] According to some embodiments of the present invention, the comparison module includes a photoelectric coupler and a signal voltage regulating unit, the signal voltage regulating unit can obtain an external dimming control signal and form a reference voltage according to the dimming control signal, the photoelectric coupler includes a light emitter and a light receiver, the anode of the light emitter is connected to the output end of the adjustable constant voltage output module, the cathode of the light emitter is connected to the output end of the signal voltage regulating unit, and the light receiver is connected to the controlled end of the adjustable constant voltage output module.

[0009] According to some embodiments of the present invention, the signal voltage regulating unit is an operational amplifier circuit.

[0010] According to some embodiments of the present invention, the signal voltage regulating unit includes an operational amplifier U2, a diode D1, a resistor R5, a resistor R6, a resistor R12, a resistor R34, a resistor R55, a resistor R13, an adjustable voltage source U5 and a capacitor C15, the anode of the diode D1 is connected to the cathode of the light emitter, the output end of the operational amplifier U2 is respectively connected to the cathode of the diode D1 and one end of the capacitor C15, the other end of the capacitor C15 is connected to one end of the resistor R6, and the other end of the resistor R6 is respectively connected to the first end of the operational amplifier U2 The input end, one end of the resistor R34 and one end of the resistor R55 are connected, the second input end of the operational amplifier U2 is respectively connected to one end of the resistor R12 and one end of the resistor R13, the other end of the resistor R13 can obtain an external dimming control signal, the other end of the resistor R12 is respectively connected to one end of the resistor R5, the controlled electrode of the adjustable voltage-stabilizing source U5 and the cathode of the adjustable voltage-stabilizing source U5, the other end of the resistor R34 and the other end of the resistor R5 are both connected to an external power supply, and the other end of the resistor R55 and the anode of the adjustable voltage-stabilizing source U5 are both grounded.

[0011] According to some embodiments of the present invention, an overcurrent protection module is also included, which is connected to the output end of the adjustable constant voltage output module to detect the working current, and the overcurrent protection module is connected to the controlled end of the adjustable constant voltage output module to control the adjustable constant voltage output module to adjust the output voltage.

[0012] According to some embodiments of the present invention, the overcurrent protection module is connected to the cathode of the light emitter.

[0013] According to some embodiments of the present invention, the overcurrent protection module includes a comparator U6, a resistor R4, a resistor R8, a resistor R28, a resistor R46, a capacitor C1, a capacitor C2, a controllable voltage regulator U4 and a diode D2, the anode of the diode D2 is connected to the cathode of the light emitter, the cathode of the diode D2 is respectively connected to the output end of the comparator U6 and one end of the capacitor C2, the other end of the capacitor C2 is connected to one end of the resistor R46, the other end of the resistor R46 is respectively connected to one end of the capacitor C1, the first input end of the comparator U6 and the output end of the adjustable constant voltage output module, the second input end of the comparator U6 is respectively connected to one end of the resistor R8 and one end of the resistor R4, the other end of the resistor R4 is respectively connected to the controlled pole of the controllable voltage regulator U4, the cathode of the controllable voltage regulator U4 and one end of the resistor R28, the other end of the resistor R28 is connected to an external power supply, and the anode of the controllable voltage regulator U4, the other end of the capacitor C1 and the other end of the resistor R8 are all grounded.

[0014] According to some embodiments of the present invention, the adjustable constant voltage output module includes a main control unit and a constant voltage modulation unit, the output end of the processing module is connected to the main control unit, the main control unit is connected to the constant voltage modulation unit to control the constant voltage modulation unit to adjust the output voltage, and the detection end of the processing module is connected to the output end of the constant voltage modulation unit.

[0015] According to some embodiments of the present invention, a control module and a power supply module are further included. The power supply module is connected to the control module to supply power. A variety of dimming control signals can be generated through the control module. The control module is connected to the adjustment end of the processing module.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 It is a principle structure block diagram of one embodiment of the constant voltage dimming circuit of the present invention;

[0019] Figure 2 A schematic diagram of an adjustable constant voltage output module and a filter module circuit of one embodiment of the constant voltage dimming circuit of the present invention;

[0020] Figure 3 A schematic diagram of a processing module circuit of one embodiment of a constant voltage dimming circuit of the present invention;

[0021] Figure 4 The figure is a schematic diagram of a power supply module circuit of one embodiment of the constant voltage dimming circuit of the present invention.

[0022] Reference numerals:

[0023] Adjustable constant voltage output module 100, main control unit 110, constant voltage modulation unit 120, processing module 200, optocoupler 210, signal voltage regulation unit 220, control module 300, energy supply module 400, voltage stabilization module 500, overcurrent protection module 600. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0025] In the description of the present invention, it should be understood that descriptions involving orientation, such as the orientations or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside” and “outside” are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0026] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] like Figure 1-4 As shown, a constant voltage dimming circuit according to an embodiment of the first aspect of the present invention includes an adjustable constant voltage output module 100 and a processing module 200, the processing module 200 includes a detection end, an adjustment end and an output end, the detection end of the processing module 200 is connected to the output end of the adjustable constant voltage output module 100 to obtain an output voltage signal, the adjustment end of the processing module 200 can obtain an external dimming control signal, the output end of the processing module 200 can output a feedback control signal obtained by integrating and processing the output voltage signal and the dimming control signal, and the output end of the processing module 200 is connected to the controlled end of the adjustable constant voltage output module 100 to control the adjustable constant voltage output module 100 to adjust the output voltage.

[0029] Among them, in some embodiments of the present invention, the adjustable constant voltage output module 100 includes a main control unit 110 and a constant voltage modulation unit 120, the output end of the processing module 200 is connected to the main control unit 110, the main control unit 110 is connected to the constant voltage modulation unit 120 to control the constant voltage modulation unit 120 to adjust the output voltage, and the detection end of the processing module 200 is connected to the output end of the constant voltage modulation unit 120.

[0030] The main control unit 110 may be composed of a CPU, an MCU or other processing chips and their peripheral circuits, and the constant voltage modulation unit 120 may be selected from a conventional constant voltage modulation circuit or an integrated adjustable digital constant voltage source.

[0031] In some embodiments of the present invention, a control module 300 and a power supply module 400 are also included. The power supply module 400 is connected to the control module 300 to supply power. A variety of dimming control signals can be generated through the control module 300. The control module 300 is connected to the adjustment end of the processing module 200.

[0032] The control module 300 may be an encoder or a multi-position resistive knob, etc., and the energy supply module 400 may be Figure 4 As shown, it can be a constant voltage circuit, which outputs a voltage of, for example, 10V, to the control module 300 . The user can form different voltage levels through the control module 300 as dimming control signals to be output to the processing module 200 .

[0033] like Figure 2 As shown, in some embodiments of the present invention, the output end of the adjustable constant voltage output module 100 can also be connected to components such as a voltage stabilizing module 500 and a common mode inductor LF4, and is connected to the light source for power supply through the voltage stabilizing module 500 and the common mode inductor LF4.

[0034] The constant voltage dimming circuit of the present invention can output constant voltages of different levels by controlling the adjustable constant voltage output module 100. When the adjustable constant voltage output module 100 is connected to a light source load and is powered for operation, the detection end of the processing module 200 is connected to the output end of the adjustable constant voltage output module 100 to obtain the output voltage at this time, and the adjustment end of the processing module 200 can obtain the dimming control signal input and set by the user. After processing, it is determined whether the output voltage meets the user's dimming requirements, and then the processing module 200 outputs a related feedback control signal to the adjustable constant voltage output module 100, and controls the adjustable constant voltage output module 100 to adjust the output constant voltage to achieve the dimming purpose. The dimming is stable and the light source flicker can be reduced.

[0035] In some embodiments of the present invention, the processing module 200 is a comparison module, which includes a detection end, an adjustment end and an output end. The detection end of the comparison module is connected to the output end of the adjustable constant voltage output module 100 to obtain an output voltage signal, the adjustment end of the comparison module can obtain an external dimming control signal, and the output end of the comparison module can output a feedback control signal obtained by comparing the output voltage signal and the dimming control signal. The output end of the comparison module is connected to the controlled end of the adjustable constant voltage output module 100 to control the adjustable constant voltage output module 100 to adjust the output voltage.

[0036] In some embodiments of the present invention, the processing module 200 may also be a processing chip that performs logic judgment on the dimming control signal and the output voltage signal.

[0037] In the embodiment where the processing module 200 is a comparison module, Figure 3 As shown, the adjustment end of the comparison module can obtain the dimming control signal, and the voltage level that the user needs to set is known from the dimming control signal. The detection end of the comparison module obtains the output voltage signal. When the output voltage signal is higher than the set voltage level, the adjustable constant voltage output module 100 is controlled to continue to reduce the output voltage.

[0038] In some embodiments of the present invention, the comparison module includes a photoelectric coupler 210 and a signal voltage regulating unit 220. The signal voltage regulating unit 220 can obtain an external dimming control signal and form different levels of reference voltage according to the dimming control signal. The photoelectric coupler 210 includes a light emitter and a light receiver. The anode of the light emitter is connected to the output end of the adjustable constant voltage output module 100, the cathode of the light emitter is connected to the output end of the signal voltage regulating unit 220, and the light receiver is connected to the controlled end of the adjustable constant voltage output module 100.

[0039] In some embodiments of the present invention, the comparison module may also be composed of a comparator, and the first input terminal and the second input terminal of the comparator are respectively connected to the dimming control signal and the output voltage signal, and the output voltage signal is output after comparison.

[0040] In some embodiments of the present invention, the signal voltage regulating unit 220 is an operational amplifier circuit, and different dimming control signals form reference voltages of different levels by operationally amplifying the dimming control signal.

[0041] Specifically, the signal voltage regulating unit 220 includes an operational amplifier U2, a diode D1, a resistor R5, a resistor R6, a resistor R12, a resistor R34, a resistor R55, a resistor R13, an adjustable voltage source U5 and a capacitor C15. The anode of the diode D1 is connected to the cathode of the light emitter, the output end of the operational amplifier U2 is respectively connected to the cathode of the diode D1 and one end of the capacitor C15, the other end of the capacitor C15 is connected to one end of the resistor R6, and the other end of the resistor R6 is respectively connected to the first input end of the operational amplifier U2, the cathode of the diode D1 and one end of the capacitor C15. One end of the resistor R34 is connected to one end of the resistor R55, the second input end of the operational amplifier U2 is respectively connected to one end of the resistor R12 and one end of the resistor R13, the other end of the resistor R13 can obtain an external dimming control signal, the other end of the resistor R12 is respectively connected to one end of the resistor R5, the controlled electrode of the adjustable voltage-stabilizing source U5 and the cathode of the adjustable voltage-stabilizing source U5, the other end of the resistor R34 and the other end of the resistor R5 are both connected to an external power supply, and the other end of the resistor R55 and the anode of the adjustable voltage-stabilizing source U5 are both grounded.

[0042] Furthermore, the other end of the resistor R13 is connected to the control module 300 after being divided by the resistors R14 and R15. For example, the control module 300 can input a 0-10V voltage at one end of the resistor R14 as a dimming control signal. After operational amplification by the operational amplifier U2, a voltage level corresponding to the dimming control signal is formed and provided to the optocoupler 210 as a reference voltage for comparison.

[0043] In some embodiments of the present invention, an overcurrent protection module 600 is also included. The overcurrent protection module 600 is connected to the output end of the adjustable constant voltage output module 100 to detect the working current, and the overcurrent protection module 600 is connected to the controlled end of the adjustable constant voltage output module 100 to control the adjustable constant voltage output module 100 to adjust the output voltage.

[0044] Among them, the overcurrent protection module 600 can be connected to the output end of the adjustable constant voltage output module 100 and the power supply circuit of the light source through the resistor R33. When the detected current is too large, the signal can be fed back to the adjustable constant voltage output module 100 to lower the output voltage and thus reduce the current.

[0045] In some embodiments of the present invention, the overcurrent protection module 600 can be connected to the cathode of the light emitter. When the current is too large, the voltage of the cathode of the light emitter can be lowered, so that the light emitter is turned on and lights up, thereby feeding back the signal to the adjustable constant voltage output module 100.

[0046] In some embodiments of the present invention, the overcurrent protection module 600 may also be directly connected to the adjustable constant voltage output module 100 to directly feed back the signal to the adjustable constant voltage output module 100 .

[0047] Specifically, Figure 3 The overcurrent protection module 600 includes a comparator U6, a resistor R4, a resistor R8, a resistor R28, a resistor R46, a capacitor C1, a capacitor C2, a controllable voltage regulator U4 and a diode D2, wherein the anode of the diode D2 is connected to the cathode of the light emitter, the cathode of the diode D2 is respectively connected to the output end of the comparator U6 and one end of the capacitor C2, the other end of the capacitor C2 is connected to one end of the resistor R46, the other end of the resistor R46 is respectively connected to one end of the capacitor C1, the first input end of the comparator U6 and the output end of the adjustable constant voltage output module 100, the second input end of the comparator U6 is respectively connected to one end of the resistor R8 and one end of the resistor R4, the other end of the resistor R4 is respectively connected to the controlled pole of the controllable voltage regulator U4, the cathode of the controllable voltage regulator U4 and one end of the resistor R28, the other end of the resistor R28 is connected to an external power supply (specifically, it can be connected to the output end of the adjustable constant voltage output module 100), and the anode of the controllable voltage regulator U4, the other end of the capacitor C1 and the other end of the resistor R8 are all grounded.

[0048] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A constant voltage dimming circuit, characterized in that: include: Adjustable constant voltage output module; A processing module, comprising a detection end, a regulating end and an output end, wherein the detection end of the processing module is connected to the output end of the adjustable constant voltage output module to obtain an output voltage signal, the regulating end of the processing module can obtain an external dimming control signal, the output end of the processing module can output a feedback control signal obtained by integrating and processing the output voltage signal and the dimming control signal, and the output end of the processing module is connected to the controlled end of the adjustable constant voltage output module to control the adjustable constant voltage output module to adjust the output voltage; The processing module is a comparison module, which includes a detection end, an adjustment end and an output end. The detection end of the comparison module is connected to the output end of the adjustable constant voltage output module to obtain an output voltage signal. The adjustment end of the comparison module can obtain an external dimming control signal. The output end of the comparison module can output a feedback control signal obtained by comparing the output voltage signal and the dimming control signal. The output end of the comparison module is connected to the controlled end of the adjustable constant voltage output module to control the adjustable constant voltage output module to adjust the output voltage. The comparison module includes a photoelectric coupler and a signal voltage regulating unit. The signal voltage regulating unit can obtain an external dimming control signal and form a reference voltage according to the dimming control signal. The photoelectric coupler includes a light emitter and a light receiver. The anode of the light emitter is connected to the output end of the adjustable constant voltage output module, the cathode of the light emitter is connected to the output end of the signal voltage regulating unit, and the light receiver is connected to the controlled end of the adjustable constant voltage output module. The signal voltage regulating unit is an operational amplifier circuit; The signal voltage regulating unit includes an operational amplifier U2, a diode D1, a resistor R5, a resistor R6, a resistor R12, a resistor R34, a resistor R55, a resistor R13, an adjustable voltage source U5 and a capacitor C15. The anode of the diode D1 is connected to the cathode of the light emitter, the output end of the operational amplifier U2 is respectively connected to the cathode of the diode D1 and one end of the capacitor C15, the other end of the capacitor C15 is connected to one end of the resistor R6, and the other end of the resistor R6 is respectively connected to the first input end of the operational amplifier U2, the resistor One end of R34 is connected to one end of the resistor R55, the second input end of the operational amplifier U2 is respectively connected to one end of the resistor R12 and one end of the resistor R13, the other end of the resistor R13 can obtain an external dimming control signal, the other end of the resistor R12 is respectively connected to one end of the resistor R5, the controlled electrode of the adjustable voltage-stabilizing source U5 and the cathode of the adjustable voltage-stabilizing source U5, the other end of the resistor R34 and the other end of the resistor R5 are both connected to an external power supply, and the other end of the resistor R55 and the anode of the adjustable voltage-stabilizing source U5 are both grounded.

2. A constant voltage dimming circuit according to claim 1, characterized in that: It also includes an overcurrent protection module, which is connected to the output end of the adjustable constant voltage output module to detect the working current, and the overcurrent protection module is connected to the controlled end of the adjustable constant voltage output module to control the adjustable constant voltage output module to adjust the output voltage.

3. A constant voltage dimming circuit according to claim 2, characterized in that: The overcurrent protection module is connected to the cathode of the light emitter.

4. The constant voltage dimming circuit according to claim 3, characterized in that: The overcurrent protection module includes a comparator U6, a resistor R4, a resistor R8, a resistor R28, a resistor R46, a capacitor C1, a capacitor C2, a controllable voltage regulator U4 and a diode D2, wherein the anode of the diode D2 is connected to the cathode of the light emitter, the cathode of the diode D2 is respectively connected to the output end of the comparator U6 and one end of the capacitor C2, the other end of the capacitor C2 is connected to one end of the resistor R46, the other end of the resistor R46 is respectively connected to one end of the capacitor C1, the first input end of the comparator U6 and the output end of the adjustable constant voltage output module, the second input end of the comparator U6 is respectively connected to one end of the resistor R8 and one end of the resistor R4, the other end of the resistor R4 is respectively connected to the controlled pole of the controllable voltage regulator U4, the cathode of the controllable voltage regulator U4 and one end of the resistor R28, the other end of the resistor R28 is connected to an external power supply, and the anode of the controllable voltage regulator U4, the other end of the capacitor C1 and the other end of the resistor R8 are all grounded.

5. The constant voltage dimming circuit according to claim 1, characterized in that: The adjustable constant voltage output module includes a main control unit and a constant voltage modulation unit. The output end of the processing module is connected to the main control unit. The main control unit is connected to the constant voltage modulation unit to control the constant voltage modulation unit to adjust the output voltage. The detection end of the processing module is connected to the output end of the constant voltage modulation unit.

6. The constant voltage dimming circuit according to claim 1, characterized in that: It also includes a control module and a power supply module. The power supply module is connected to the control module to supply power. A variety of dimming control signals can be generated through the control module. The control module is connected to the adjustment end of the processing module.

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