Low-cost silicon controlled rectifier dimming circuit applied to two-wire lamp strip

Abstract

The utility model discloses a low-cost silicon controlled rectifier dimming circuit applied to a two-wire lamp strip, which comprises a main control module, a power failure detection module, an H-bridge color modulation module and a power supply module, and is characterized in that a mains supply is electrically connected with the input end of the power supply module and the input end of the power failure detection module respectively through a silicon controlled rectifier dimmer; the output end of the power supply module is electrically connected with the Y input end and the W input end of the two-wire lamp strip respectively; the silicon controlled rectifier dimmer controls the positive and negative polarities of the output end of the power supply module so as to control the W lamp bead / Y lamp bead to be lightened; the power failure detection module is used for detecting a power failure signal, the output end of the power failure detection module is electrically connected with the input end of the main control module, and the main control module controls to output two paths of PWM signals according to the power failure signal so as to drive the H-bridge color modulation module; the H-bridge toning module can output a W toning signal and a Y toning signal to be input into the W input end and the Y input end of the two-line lamp strip respectively, and therefore W + Y toning is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of LED dimming, in particular to a low-cost thyristor dimming circuit applied to a two-wire light strip. Background Art

[0002] Thyristor dimming is currently the most widely used dimming method for LEDs. Thyristor dimming is a physical dimming method. Starting at AC phase 0, the input voltage is chopped until the thyristor conducts, and then voltage is applied again. The operating principle is to chop the input voltage waveform by the conduction angle, generating a tangential output voltage waveform. Applying this tangential principle reduces the effective value of the output voltage, thereby reducing the power applied to common loads (resistive loads). Existing conventional thyristor constant-voltage power supplies generally only have dimming functions to save costs. Power supplies with color adjustment functions are expensive and require only pre-set color temperatures, which cannot be changed after installation, resulting in a poor user experience. Utility Model Content

[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a low-cost thyristor dimming circuit for a two-wire light strip that can achieve stepless dimming and color temperature adjustment.

[0004] According to an embodiment of the utility model, a low-cost thyristor dimming circuit applied to a two-wire light strip includes a main control module, a power-off detection module, an H-bridge color adjustment module and a power supply module. The two-wire light strip includes a Y input terminal and a W input terminal. The mains power is electrically connected to the input terminal of the power supply module and the input terminal of the power-off detection module respectively through a thyristor dimmer. The output terminal of the power supply module is electrically connected to the Y input terminal and the W input terminal of the two-wire light strip respectively. The thyristor dimmer controls the positive and negative polarity of the output terminal of the power supply module to control the lighting of the W lamp beads / Y lamp beads; the power-off detection module is used to detect a power-off signal, and the output terminal of the power-off detection module is electrically connected to the input terminal of the main control module. The main control module controls the output of two PWM signals to drive the H-bridge color adjustment module according to the number of times the power-off signal is detected. The H-bridge color adjustment module can output a W color adjustment signal and a Y color adjustment signal to input the W input terminal and the Y input terminal of the two-wire light strip respectively, thereby realizing W+Y color adjustment.

[0005] The low-cost thyristor dimming circuit applied to the two-wire light strip according to the embodiment of the present invention has at least the following beneficial effects: the existing two-wire light strip is composed of two color temperature lamp beads (such as white light lamp beads and yellow light lamp beads) with opposite polarity connected in parallel. The thyristor dimmer generally has a physical switch and a dimming potentiometer. The present application adds a power-off detection module and an H-bridge color adjustment module on the basis of the existing thyristor dimming power supply circuit. Before power is turned on, the initial W light (white light) output can be defaulted. After the physical switch of the thyristor dimmer is initially powered on, the power supply voltage output by the power module is positive at the W input end and negative at the Y output end, so that the W lamp beads are lit, and the dimming potentiometer can be used without The brightness of the W lamp bead can be infinitely adjusted; if it is switched on and off again within a certain period of time, the power-off detection module detects a power-off signal, and the main control module can control the supply voltage output by the power supply module to be positive at the Y input end and negative at the W output end, so that the Y lamp bead is lit, and the dimming potentiometer can infinitely adjust the brightness of the Y lamp bead; if it is switched on and off again within a certain period of time, the power-off detection module detects a second power-off signal, and the main control module outputs a color adjustment drive signal to control the H-bridge color adjustment module to output W color adjustment signal and Y color adjustment signal, so that the W lamp bead and the Y lamp bead are lit at the same time, realizing W+Y neutral color temperature adjustment, and the dimming potentiometer can infinitely adjust the brightness; the structure is simple, cost-saving, and user experience is good.

[0006] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The following is a further description of the specific embodiments of the present invention in conjunction with the accompanying drawings;

[0008] Figure 1 It is the structural block diagram of the dimming circuit;

[0009] Figure 2 This is a partial schematic diagram of the dimming circuit;

[0010] Figure 3 This is the schematic diagram of the main control module and power module of the dimming circuit. DETAILED DESCRIPTION

[0011] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0012] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They 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. Therefore, they cannot be understood as limitations on the present invention.

[0013] In the description of this utility model, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0014] Reference Figures 1 to 3The utility model discloses a low-cost thyristor dimming circuit for a two-wire light strip, comprising a main control module 10, a power-off detection module 11, an H-bridge color adjustment module 12, and a power module 13. The two-wire light strip 20 comprises a Y input terminal and a W input terminal. The mains power is electrically connected to the input terminal of the power module 13 and the input terminal of the power-off detection module 11 respectively through a thyristor dimmer 100. The output terminal of the power module 13 is electrically connected to the Y input terminal and the W input terminal of the two-wire light strip 20 respectively. The thyristor dimmer 100 controls The positive and negative polarity of the output end of the power supply module 13 is used to control the lighting of the W lamp bead / Y lamp bead; the power-off detection module 11 is used to detect the power-off signal, and the output end of the power-off detection module 11 is electrically connected to the input end of the main control module 10. The main control module 10 controls the output of two PWM signals to drive the H-bridge color adjustment module 12 according to the number of power-off signals detected. The H-bridge color adjustment module 12 can output W color adjustment signals and Y color adjustment signals to input the W input end and Y input end of the two-wire light strip 20 respectively, thereby realizing W+Y color adjustment. The existing two-wire light strip 20 is composed of two color temperature lamp beads (such as white light lamp beads and yellow light lamp beads, or cold light lamp beads and warm light lamp beads) with opposite polarity connected in parallel. The thyristor dimmer 100 generally has a physical switch and a dimming potentiometer. The present application adds a power-off detection module 11 and an H-bridge color adjustment module 12 on the basis of the existing thyristor dimming power supply circuit. Before power is turned on, the initial W light (white light) output can be defaulted. After the physical switch of the thyristor dimmer 100 is initially powered on, the power supply voltage output by the power module 13 is positive at the W input end and negative at the Y output end, so that the W lamp bead is lit, and the dimming potentiometer can infinitely adjust the brightness of the W lamp bead; in one The switch is switched on and off again within a certain time, and the power-off detection module 11 detects a power-off signal. The main control module 10 can control the power supply voltage output by the power supply module 13 to be positive at the Y input terminal and negative at the W output terminal, so that the Y lamp bead is lit, and the dimming potentiometer can steplessly adjust the brightness of the Y lamp bead; the switch is switched on and off again within a certain time, and the power-off detection module 11 detects a second power-off signal. The main control module 10 outputs a color adjustment drive signal to control the H-bridge color adjustment module 12 to output a W color adjustment signal and a Y color adjustment signal, so that the W lamp bead and the Y lamp bead are lit at the same time, realizing W+Y neutral color temperature color adjustment, and the dimming potentiometer can steplessly adjust the brightness; the structure is simple, cost-saving, and user experience is good.

[0015] like Figure 2The power-off detection module 11 includes a MOS transistor Q1, a transistor Q2, a transistor Q3, a voltage regulator ZD1, a resistor R1, and an optocoupler U2. The source of the MOS transistor Q1 is electrically connected to the output end of the thyristor dimmer 100, the gate of the MOS transistor Q1 is electrically connected to the cathode of the voltage regulator ZD1 and the collector of the transistor Q2, the drain of the MOS transistor Q1 is electrically connected to the anode of the voltage regulator ZD1, one end of the capacitor C1, and the anode of the diode D1, the other end of the capacitor C1 and the cathode of the diode D1 are electrically connected to the base of the transistor Q2, the emitter of the transistor Q2 is grounded, and the base of the transistor Q3 is electrically connected to the cathode of the diode D1. The source of the MOS tube Q1 is electrically connected to the series resistor, and the collector of the transistor Q3 is electrically connected to one end of the resistor R1 and the input end of the optocoupler U2 respectively. The other end of the resistor R1 and the power supply end of the optocoupler U2 are respectively connected to the working voltage. The output end of the optocoupler U2 is electrically connected to the main control module 10. When there is power, the optocoupler U2 is turned on. When the power is off, the optocoupler U2 is turned off. The power-off signal is the cut-off signal of the optocoupler U2. When the main control module 10 detects the cut-off signal of the optocoupler U2, it controls the positive and negative polarity of the output end of the power supply module 13 or controls the output of two PWM signals to drive the H-bridge color adjustment module 12 to light up the W lamp beads and the Y lamp beads.

[0016] like Figure 2In some embodiments, the main control module 10 includes a main control chip U1. The input end of the main control chip U1 is electrically connected to the output end of the optocoupler U2. The output end of the main control chip U1 can output two PWM signals, namely OUTA signal and OUTB signal. In order to ensure that the brightness remains unchanged when the W+Y two-way color mixing is performed, the two PWM signals can be output complementary. The H-bridge color adjustment module 12 includes a transistor Q41, a transistor Q42, a transistor Q43, a transistor Q44, a transistor Q45, a transistor Q46, a resistor R2, and a resistor R3. The OUTA signal is input to the base of the transistor Q41 and the base of the transistor Q45 respectively, and the OUTB signal is input to the base of the transistor Q43 and the base of the transistor Q46 respectively. The collector of the transistor Q41 is electrically connected to one end of the resistor R2 and the base of the transistor Q42 respectively. The emitter of the transistor Q2 is electrically connected to the other end of the resistor R2, the emitter of the transistor Q44, one end of the resistor R3, and the power module 13 respectively. The base of the transistor Q44 is electrically connected to the base of the resistor R3 respectively. The other end is electrically connected to the collector of the transistor Q46, the emitters of the transistors Q41, Q43, Q45, and Q46 are grounded respectively, the collector of the transistor Q42 is electrically connected to the collector of the transistor Q43 to form a W color adjustment signal output end, the collector of the transistor Q44 is electrically connected to the collector of the transistor Q45 to form a Y color adjustment signal output end, and the main control chip controls the H-bridge color adjustment module 12 through two PWM signals to synchronously output the Y color adjustment signal and the W color adjustment signal to light up the W lamp beads and the Y lamp beads at the same time. By adjusting the duty cycle of the two PWM signals, different degrees of color mixing of the two-color lamp beads can be achieved.

[0017] In certain embodiments, as Figure 3 The main control module 10 includes a digital isolation chip U01 electrically connected to the output end of the main control chip, and a level conversion chip U02 electrically connected to the output end of the digital isolation chip U01. The OUTA signal and the OUTB signal are output after being isolated by the digital isolation chip U01 and protected by the overcurrent protection and short-circuit protection of the level conversion chip U02 respectively.

[0018] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above preferred embodiments can be freely combined and superimposed.

[0019] The above are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the utility model concept, or directly or indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A low-cost thyristor dimming circuit for a two-wire light strip, characterized in that: include: A main control module (10), a power failure detection module (11), an H-bridge color adjustment module (12) and a power supply module (13); a two-wire light strip (20) includes a Y input terminal and a W input terminal; the mains power is electrically connected to the input terminal of the power supply module (13) and the input terminal of the power failure detection module (11) via a thyristor dimmer (100); the output terminal of the power supply module (13) is electrically connected to the Y input terminal and the W input terminal of the two-wire light strip (20); the thyristor dimmer (100) controls the positive and negative polarity of the output terminal of the power supply module (13) to control the lighting of the W lamp bead / Y lamp bead; The power-off detection module (11) is used to detect a power-off signal. The output end of the power-off detection module (11) is electrically connected to the input end of the main control module (10). The main control module (10) controls the output of two PWM signals to drive the H-bridge color adjustment module (12) according to the number of times the power-off signal is detected. The H-bridge color adjustment module (12) can output a W color adjustment signal and a Y color adjustment signal to be respectively input into the W input end and the Y input end of the two-wire light strip (20), thereby realizing W+Y color adjustment.

2. The low-cost thyristor dimming circuit for a two-wire light strip according to claim 1, characterized in that: The power-off detection module (11) comprises a MOS tube Q1, a triode Q2, a triode Q3, a voltage regulator ZD1, a resistor R1 and an optocoupler U2, wherein the source of the MOS tube Q1 is electrically connected to the output end of the thyristor dimmer (100), the gate of the MOS tube Q1 is electrically connected to the cathode of the voltage regulator ZD1 and the collector of the triode Q2, the drain of the MOS tube Q1 is electrically connected to the anode of the voltage regulator ZD1, one end of the capacitor C1 and the anode of the diode D1, and the gate of the capacitor C1 is electrically connected to the cathode of the voltage regulator ZD1 and the collector of the triode Q2. The other end and the cathode of the diode D1 are electrically connected to the base of the transistor Q2, the emitter of the transistor Q2 is grounded, the base of the transistor Q3 is electrically connected to the source of the MOS tube Q1 via a series resistor, the collector of the transistor Q3 is electrically connected to one end of the resistor R1 and the input end of the optocoupler U2, respectively, the other end of the resistor R1 and the power supply end of the optocoupler U2 are respectively connected to the working voltage, the output end of the optocoupler U2 is electrically connected to the main control module (10), and the power-off signal is the cut-off signal of the optocoupler U2.

3. The low-cost thyristor dimming circuit for a two-wire light strip according to claim 2, characterized in that: The main control module (10) comprises a main control chip U1, the input end of the main control chip U1 is electrically connected to the output end of the optical coupler U2, and the output end of the main control chip U1 can output two PWM signals, namely an OUTA signal and an OUTB signal.

4. The low-cost thyristor dimming circuit for a two-wire light strip according to claim 3, characterized in that: The main control module (10) comprises a digital isolation chip U01 electrically connected to the output end of the main control chip, and a level conversion chip U02 electrically connected to the output end of the digital isolation chip U01. The OUTA signal and the OUTB signal are output after being isolated by the digital isolation chip U01 and protected by overcurrent and short circuit protection of the level conversion chip U02.

5. The low-cost thyristor dimming circuit for a two-wire light strip according to claim 3, characterized in that: The H-bridge color adjustment module (12) comprises a transistor Q41, a transistor Q42, a transistor Q43, a transistor Q44, a transistor Q45, a transistor Q46, a resistor R2 and a resistor R3, the OUTA signal is respectively input to the base of the transistor Q41 and the base of the transistor Q45, the OUTB signal is respectively input to the base of the transistor Q43 and the base of the transistor Q46, the collector of the transistor Q41 is respectively electrically connected to one end of the resistor R2 and the base of the transistor Q42, the emitter of the transistor Q2 is respectively electrically connected to the other end of the resistor R2 and the base of the transistor Q4 4, one end of the resistor R3 and the power module (13) are electrically connected, the base of the transistor Q44 is electrically connected to the other end of the resistor R3 and the collector of the transistor Q46 respectively, the emitter of the transistor Q41, the emitter of the transistor Q43, the emitter of the transistor Q45 and the emitter of the transistor Q46 are grounded respectively, the collector of the transistor Q42 and the collector of the transistor Q43 are electrically connected to form the W color modulation signal output end, and the collector of the transistor Q44 and the collector of the transistor Q45 are electrically connected to form the Y color modulation signal output end.

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