A thyristor drive circuit and a dimming device

Abstract

The present invention provides a thyristor drive circuit and a dimming device. In the thyristor drive circuit, the fourth pin of the transformer is connected to the target voltage terminal for outputting the target voltage, and this target voltage terminal is not only connected to the voltage source of the power integrated circuit, but also connected to the voltage input terminal of the control circuit and the first main terminal of the thyristor. Therefore, in this application, in order to drive the thyristor, it is not necessary to provide a dedicated power supply winding for the power integrated circuit and a dedicated power supply winding for the thyristor on the primary side of the transformer. Instead, the power integrated circuit and the thyristor share the power supply winding, thereby reducing the number of pins on the primary side of the transformer and making the selection range of the transformer model larger.

Description

Technical Field

[0001] The present invention relates to the technical field of dimming, and particularly to a thyristor drive circuit and a dimming device. Background Art

[0002] Thyristors are commonly used components in circuits. For example, bidirectional thyristors can be applied to dimming devices to control and adjust light sources, or to other AC loads such as motors that need to be adjusted.

[0003] In an application circuit, a bidirectional thyristor can be made to operate in a specific quadrant. As Figure 1 shown, in order for the first main terminal A1 of the bidirectional thyristor to have a voltage VDD, a circuit for generating the voltage VDD needs to be specially configured for the first main terminal A1. For example, in Figure 1 a power supply winding including pins 5 and 6 needs to be specially provided on the primary side of the transformer to draw out the voltage source VDD. This results in a relatively large number of pins required on the primary side of the transformer (such as Figure 1 6 pins are required), making it difficult to select a suitable transformer. Summary of the Invention

[0004] In order to solve the problem that a power supply winding for generating the voltage VDD needs to be specially provided in the thyristor drive circuit of a dimming device, resulting in a relatively large number of pins required on the primary side of the transformer and thus difficult transformer selection, the present application provides a thyristor drive circuit that does not require a specially provided power supply winding, and a dimming device having such a thyristor drive circuit.

[0005] To solve the above technical problems, the present invention is implemented as follows:

[0006] In a first aspect, a thyristor drive circuit is provided, including a live wire terminal, a neutral wire terminal, a live wire output terminal, a thyristor, a control circuit, a power integrated circuit, and a transformer;

[0007] The thyristor includes a first main terminal, a second main terminal, and a control electrode. The first main terminal is connected to the live wire terminal, and the second main terminal is connected to the live wire output terminal. The output end of the control circuit is connected to the control electrode and is used to output a trigger signal to the control electrode to turn on the thyristor;

[0008] The transformer includes a primary side, and the primary side includes a first pin, a second pin, a third pin, and a fourth pin. The first pin is connected to the neutral wire terminal, the second pin is connected to the power integrated circuit, and the first pin, the second pin, and the power integrated circuit cooperate to output a stable target voltage between the third pin and the fourth pin. Among them, the third pin is floating ground, and the fourth pin is connected to a target voltage terminal, and the target voltage terminal is used to output the target voltage;

[0009] The target voltage terminal is connected to the voltage input terminal of the power integrated circuit, the voltage input terminal of the control circuit, and the first main terminal.

[0010] For the above-mentioned thyristor drive circuit, the transformer further includes a secondary side. The first pin and the second pin cooperate with the power integrated circuit in a flyback manner to provide a stable output voltage for the secondary side. The turns ratio between the third pin and the fourth pin and the turns of the secondary side is a fixed ratio value to form a stable target voltage between the third pin and the fourth pin.

[0011] For the above-mentioned thyristor drive circuit, a fourth diode is further provided between the target voltage terminal and the fourth pin. The negative electrode of the fourth diode is connected to the target voltage terminal, and the positive electrode of the fourth diode is connected to the fourth pin;

[0012] The thyristor drive circuit further includes a third capacitor. The positive electrode of the third capacitor is connected to the negative electrode of the fourth diode, and the negative electrode of the third capacitor is grounded for protection.

[0013] For the above-mentioned thyristor drive circuit, the control circuit includes a control chip and a control diode. The control chip includes a control voltage input terminal, an output ground terminal, and an output signal terminal. The control diode includes a base, a collector, and an emitter;

[0014] The control voltage input terminal is the voltage input terminal of the control circuit. The output ground terminal is floating ground. The output signal terminal is connected to the base of the control diode and is used to output a signal to control the conduction of the collector and the emitter of the control diode. The emitter is floating ground. The collector is the output terminal of the control circuit and is connected to the control electrode. When the collector and the emitter are conducting, the control diode outputs a trigger signal to the control electrode to turn on the thyristor.

[0015] For the above-mentioned thyristor drive circuit, the power integrated circuit includes an integrated chip, a fourth capacitor, and a third diode. The integrated chip includes a chip voltage input terminal. The positive electrode of the fourth capacitor is connected to the chip voltage input terminal, the negative electrode of the fourth capacitor is grounded for protection. The positive electrode of the third diode is connected to the target voltage terminal, and the negative electrode of the third diode is connected to the chip voltage input terminal.

[0016] For the above-mentioned thyristor drive circuit, the integrated chip further includes a built-in switching transistor and an external source terminal connected to the drain of the switching transistor. The source terminal is connected to the second pin, and an energy storage component is disposed between the first pin and the second pin. After the integrated chip is started, when the switching transistor is turned on, the energy storage component stores electrical energy; when the switching transistor is turned off, the energy storage component releases electrical energy for the secondary side of the transformer to output a voltage.

[0017] For the above-mentioned thyristor drive circuit, the thyristor drive circuit further includes a filtering component, and the filtering component includes a first inductor, a first capacitor and a second capacitor. One end of the first inductor is connected to the neutral terminal and the positive electrode of the first capacitor, and the other end is connected to the positive electrode of the second capacitor and the first pin. The negative electrodes of the first capacitor and the second capacitor are connected to the live terminal.

[0018] For the above-mentioned thyristor drive circuit, it further includes a first diode, and the positive electrode of the first diode is connected to the neutral terminal and the negative electrode is connected to the positive electrode of the first capacitor.

[0019] For the above-mentioned thyristor drive circuit, the thyristor drive circuit further includes a protection inductor, and both ends of the protection inductor are respectively connected to the second main terminal and the live output terminal.

[0020] In a second aspect, the present invention provides a dimming device, including a light source and the thyristor drive circuit as described in any one of the above. The light source is connected between the live terminal and the live output terminal.

[0021] In the thyristor drive circuit provided by the present invention, the fourth pin of the transformer is connected to the target voltage terminal for outputting the target voltage. And this target voltage terminal is not only connected to the voltage source of the power integrated circuit, but also connected to the voltage input terminal of the control circuit and the first main terminal of the thyristor. Therefore, in the present application, in order to drive the thyristor, it is not necessary to provide a dedicated power supply winding for the power integrated circuit and a dedicated power supply winding for the thyristor on the primary side of the transformer. Instead, the power integrated circuit and the thyristor share the power supply winding, thereby reducing the number of pins on the primary side of the transformer and making the selection range of the transformer model larger. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 It is a schematic structural block diagram of a thyristor drive circuit in the prior art;

[0024] Figure 2It is a schematic structural diagram of a thyristor drive circuit provided by an embodiment of the present invention.

[0025] Reference numerals:

[0026] 100 - Thyristor drive circuit;

[0027] 10 - Control circuit; 20 - Power integrated circuit; 30 - Filter component;

[0028] T11 - First pin; T12 - Second pin; T13 - Third pin; T14 - Fourth pin;

[0029] L - Live wire terminal; N - Neutral wire terminal; Lout - Live wire output terminal;

[0030] Q1 - Thyristor; A1 - First main terminal; A2 - Second main terminal; G - Control electrode;

[0031] Q2 - Control diode;

[0032] T1 - Transformer;

[0033] D1 - First diode; D3 - Third diode; D4 - Fourth diode;

[0034] CE1 - First capacitor; CE2 - Second capacitor; CE3 - Third capacitor; C4 - Fourth capacitor;

[0035] R1 - First resistor; R2 - Second resistor;

[0036] U1 - Integrated chip; U3 - Control chip;

[0037] V1 - Chip voltage input terminal; V3 - Control voltage input terminal; GND - Output ground terminal; P1.1 - Output signal terminal;

[0038] Drain - Source terminal;

[0039] L1 - First inductor. Detailed implementation manners

[0040] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] As Figure 1As shown, it is the current thyristor drive circuit. In this thyristor drive circuit, the primary side of the transformer includes six pins and three sets of windings. The uppermost winding serves as the primary winding, which can supply power to the secondary side of the transformer. The middle winding is used to supply power to the integrated chip in the power integrated circuit, and the smallest section of the winding is used to supply power to the thyristor. It can be seen that Figure 1 the primary side of the transformer in

[0042] Embodiment 1

[0043] To solve the above technical problems, Embodiment 1 of the present invention provides a thyristor drive circuit 100. As Figure 2 shown, in this thyristor drive circuit 100, there is no need to specifically provide a power supply winding for driving the thyristor Q1 on the primary side of the transformer T1, thereby reducing the number of windings on the primary side of the transformer T1 and also reducing the number of pins on the primary side of the transformer T1.

[0044] In the thyristor drive circuit 100 provided by the embodiment of the present invention, it includes a live wire terminal L, a neutral wire terminal N, a live wire output terminal Lout, a thyristor Q1, a control circuit 10, a power integrated circuit 20, and a transformer T1.

[0045] In the thyristor Q1 of the embodiment of the present invention, a bidirectional thyristor Q1 is taken as an example. Of course, the case of a unidirectional thyristor Q1 is not excluded. Among them, the thyristor Q1 may include a first main terminal A1, a second main terminal A2, and a control electrode G. The first main terminal A1 is connected to the live wire terminal L, the second main terminal A2 is connected to the live wire output terminal Lout, and the output terminal of the control circuit 10 is used for this control electrode G to output a trigger signal to the control electrode G to turn on the thyristor Q1.

[0046] The transformer T1 may include a relatively arranged primary side and a secondary side. The primary side includes a first pin T11, a second pin T12, a third pin T13, and a fourth pin T14. The first pin T11 is connected to the neutral wire terminal N, the second pin T12 is connected to the power integrated circuit 20, and the first pin T11, the second pin T12, and the power integrated circuit 20 cooperate to output a stable target voltage between the third pin T13 and the fourth pin T14. Among them, the third pin T13 may be floating ground, and the fourth pin T14 is connected to the target voltage terminal, and this target voltage terminal can be used to output the target voltage.

[0047] For the transformer T1 of the embodiment of the present invention, the arrangement of its first pin T11, second pin T12, third pin T13, and fourth pin T14 refers to Figure 2 , in Figure 2Among them, they are arranged in order from top to bottom as the first pin T11, the second pin T12, the fourth pin T14, and the third pin T13.

[0048] The target voltage terminal is connected to the input voltage terminal of the power integrated circuit 20, the voltage input terminal of the control circuit 10, and the first main terminal A1 of the thyristor Q1. That is, the target voltage output by the target voltage terminal provides voltage for both the integrated circuit and the control circuit 10 and the thyristor Q1. In other words, in the embodiment of the present invention, there is no need to provide a dedicated power supply winding for the power integrated circuit 20 and a dedicated power supply winding for the thyristor Q1 on the primary side of the transformer T1. Instead, the power integrated circuit 20 and the thyristor Q1 share the power supply winding, thereby reducing the number of pins on the primary side of the transformer T1 and making the selection range of the model of the transformer T1 larger.

[0049] Among them, the first pin T11 and the second pin T12 of the transformer T1 are in flyback cooperation with the road integrated circuit to provide a stable output voltage for the secondary side of the transformer T1. Since the number of turns between the third pin T13 and the fourth pin T14 and the number of turns of the secondary side have a fixed ratio value, a stable target voltage is formed between the third pin T13 and the fourth pin T14. That is, the third pin T13 is floating ground set, and the voltage of the target voltage terminal connected to the fourth pin T14 remains stable. Among them, the fact that the number of turns between the third pin T13 and the fourth pin T14 and the number of turns of the secondary side have a fixed ratio value means that after the model of the transformer T1 is selected, this ratio value is fixed. In practice, the model of the transformer T1 can be changed according to needs to change this ratio value. Of course, as a variation, in some embodiments, the first pin T11 and the second pin T12 of the transformer T1 and the road integrated circuit can be in forward cooperation to provide a stable output voltage for the secondary side of the transformer T1.

[0050] In the thyristor drive circuit 100 provided in the embodiment of the present invention, a fourth diode D4 is further provided between the target voltage terminal and the fourth pin T14. The negative electrode of the fourth diode D4 is connected to the target voltage terminal, and the positive electrode of the fourth diode D4 is connected to the fourth pin T14 to prevent current from flowing from the target voltage terminal to the fourth pin T14. The thyristor Q1 further includes a third capacitor CE3. The positive electrode of the third capacitor CE3 is connected to the negative electrode of the fourth diode D4, that is, connected to the target voltage terminal, and the negative electrode of the third capacitor CE3 is grounded for protection setting to store the energy of the target voltage terminal.

[0051] In an embodiment of the present invention, the control circuit 10 may include a control chip U3 and a control diode Q2. The control chip U3 may include a control voltage input terminal V3, an output ground terminal GND, and an output signal terminal P1.1. The control diode Q2 may include a base, a collector, and an emitter. Among them, the control voltage input terminal V3 of the control chip U3 is the voltage input terminal of the control circuit 10 and is used to connect to a target voltage terminal. The voltage output from the target voltage terminal provides power for the control chip U3. The output ground terminal GND of the control chip U3 is set floating. The output signal terminal P1.1 of the control chip U3 is connected to the base of the control diode Q2 and is used to output a signal to control the conduction of the collector and emitter of the control diode Q2. The emitter is set floating, and the collector serves as the output terminal of the control circuit 10 and is connected to the control electrode G of the thyristor Q1. When the collector and emitter are conducting, the control diode Q2 outputs a trigger signal to the control electrode G to turn on the thyristor Q1.

[0052] Among them, the power integrated circuit 20 may include an integrated chip U1, a fourth capacitor C4, and a third diode D3. The integrated chip U1 may include a chip voltage input terminal V1. The positive electrode of the fourth capacitor C4 is connected to the chip voltage input terminal V1, and the negative electrode of the fourth capacitor C4 is grounded for protection. The positive electrode of the third diode D3 is connected to the target voltage terminal, and the negative electrode of the third diode D3 is connected to the chip voltage input terminal V1. The setting of the third diode D3 can prevent current from flowing from the chip voltage output terminal to the target voltage terminal, ensuring that the target voltage terminal can supply power to the integrated chip U1. Moreover, the fourth capacitor C4 is used to ensure that the chip voltage input terminal V1 can be maintained in a non-grounded state. The third diode D3 and the fourth capacitor C4 cooperate to enable the integrated chip U1 to start smoothly.

[0053] Among them, the integrated chip U1 may further include an internal switch tube and an external source terminal Drain connected to the drain of the switch tube. The at least one source terminal Drain is connected to the second pin T12. Figure 2 It is possible that the right 4 pins of the integrated chip U1 are all source terminals Drain. A energy storage element (not shown in the figure) is provided between the first pin T11 and the second pin T12 of the transformer T1. After the integrated chip U1 is started and the switch tube inside the integrated chip U1 is conducting, the energy storage component stores electrical energy. When the switch tube is turned off, the energy storage component releases electrical energy for the secondary side of the transformer T1 to output a voltage, and then a target voltage is output between the third pin T13 and the fourth pin T14.

[0054] In the embodiment of the present invention, the thyristor drive circuit 100 may further include a filtering component 30. The filtering component 30 may include a first inductor L1, a first capacitor CE1, and a second capacitor CE2. One end of the first inductor L1 is connected to the neutral terminal N and the positive electrode of the first capacitor CE1, and the other end is connected to the positive electrode of the second capacitor CE2 and the first pin T11. The negative electrodes of the first capacitor CE1 and the second capacitor CE2 are both connected to the live terminal L. A first diode D1 may also be included between the filtering component 30 and the neutral terminal N. The positive electrode of the first diode D1 is connected to the neutral terminal N, and the negative electrode is connected to the positive electrode of the first capacitor CE1. The first diode D1 is used to prevent reverse conduction.

[0055] Among them, the first capacitor CE1, the second capacitor CE2, and the third capacitor CE3 in the embodiment of the present invention may be electrolytic capacitors.

[0056] The thyristor drive circuit 100 may further include a protection inductor (not shown in the figure). The two ends of the protection inductor are respectively connected to the second main terminal A2 and the live output terminal Lout, which is used to suppress the sudden change of the current of the load and protect the thyristor Q1 to prevent the thyristor Q1 from being mis-triggered or damaged.

[0057] In addition, a resistor is also included in the thyristor drive circuit 100 of the embodiment of the present invention. One end of the resistor is connected to the positive electrode of the second capacitor CE2, and the other end is connected to the input voltage terminal of the integrated chip U1. The resistor may be formed by connecting a first resistor R1 and a second resistor R2 in series.

[0058] In the thyristor drive circuit 100 of the embodiment of the present invention, an AC load may be connected between the live terminal L and the live output terminal Lout. Thus, the thyristor Q1 can be used to drive the AC load. The AC load includes but is not limited to light sources, motors, etc.

[0059] Embodiment 2

[0060] The embodiment 2 of the present invention provides a dimming device, which includes a light source and the thyristor drive circuit 100 in Embodiment 1. The light source may be connected between the live terminal L and the live output terminal Lout. The light source is driven by the thyristor drive circuit 100, and the dimming purpose is achieved by using the thyristor Q1.

[0061] The above are only the embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A thyristor drive circuit, characterized in that, It includes a live wire terminal (L), a neutral wire terminal (N), a live wire output terminal (Lout), a thyristor (Q1), a control circuit (10), a power integrated circuit (20), and a transformer (T1); The thyristor (Q1) includes a first main terminal (A1), a second main terminal (A2), and a control electrode (G). The first main terminal (A1) is connected to the live wire terminal (L), and the second main terminal (A2) is connected to the live wire output terminal (Lout). The output end of the control circuit (10) is connected to the control electrode (G) and is used to output a trigger signal to the control electrode (G) to turn on the thyristor (Q1); The transformer (T1) includes a primary side. The primary side includes a first pin (T11), a second pin (T12), a third pin (T13), and a fourth pin (T14). The first pin (T11) is connected to the neutral wire terminal (N), the second pin (T12) is connected to the power integrated circuit (20), and the first pin (T11), the second pin (T12), and the power integrated circuit (20) cooperate to output a stable target voltage between the third pin (T13) and the fourth pin (T14). Among them, the third pin (T13) is directly grounded, and the fourth pin (T14) is connected to the target voltage terminal, and the target voltage terminal is used to output the target voltage; The target voltage terminal is directly connected to the voltage input end of the power integrated circuit (20), the voltage input end of the control circuit (10), and the first main terminal (A1).

2. The thyristor drive circuit according to claim 1, characterized in that, The transformer (T1) further includes a secondary side. The first pin (T11) and the second pin (T12) cooperate with the power integrated circuit (20) in flyback to provide a stable output voltage for the secondary side. The turns ratio between the third pin (T13) and the fourth pin (T14) and the turns of the secondary side is a fixed ratio value to form a stable target voltage between the third pin (T13) and the fourth pin (T14).

3. The thyristor drive circuit according to claim 1, characterized in that A fourth diode (D4) is further provided between the target voltage terminal and the fourth pin (T14). The negative electrode of the fourth diode (D4) is connected to the target voltage terminal, and the positive electrode of the fourth diode (D4) is connected to the fourth pin (T14); The thyristor drive circuit (100) further includes a third capacitor (CE3). The positive electrode of the third capacitor (CE3) is connected to the negative electrode of the fourth diode (D4), and the negative electrode of the third capacitor (CE3) is grounded for protection.

4. The thyristor drive circuit according to claim 1, characterized in that, The control circuit (10) includes a control chip (U3) and a control diode (Q2). The control chip (U3) includes a control voltage input end (V3), an output ground end (GND), and an output signal end (P1.1). The control diode (Q2) includes a base, a collector, and an emitter; The control voltage input terminal (V3) is the voltage input terminal of the control circuit (10), the output ground terminal (GND) is floating ground, and the output signal terminal (P1.1) is connected to the base of the control diode (Q2) for outputting a signal to control the conduction of the collector and the emitter of the control diode (Q2). The emitter is floating ground, the collector is the output terminal of the control circuit (10) and is connected to the control terminal (G). When the collector and the emitter are conducting, the control diode (Q2) outputs a trigger signal to the control terminal (G) to turn on the thyristor (Q1).

5. The thyristor drive circuit according to claim 1, characterized in that, The power integrated circuit (20) includes an integrated chip (U1), a fourth capacitor (C4) and a third diode (D3). The integrated chip (U1) includes a chip voltage input terminal (V1); the positive electrode of the fourth capacitor (C4) is connected to the chip voltage input terminal (V1), the negative electrode of the fourth capacitor (C4) is grounded for protection, the positive electrode of the third diode (D3) is connected to the target voltage terminal, and the negative electrode of the third diode (D3) is connected to the chip voltage input terminal (V1).

6. The thyristor drive circuit according to claim 5, wherein The integrated chip (U1) further includes a built-in switching transistor and an external source terminal (Drain) connected to the drain of the switching transistor. The source terminal (Drain) is connected to the second pin (T12), and an energy storage component is provided between the first pin (T11) and the second pin (T12). After the integrated chip (U1) is started, when the switching transistor is conducting, the energy storage component stores electrical energy; when the switching transistor is off, the energy storage component releases electrical energy for the secondary side of the transformer (T1) to output a voltage.

7. The thyristor drive circuit according to claim 1, characterized in that, The thyristor drive circuit (100) further includes a filtering component (30). The filtering component (30) includes a first inductor (L1), a first capacitor (CE1) and a second capacitor (CE2). One end of the first inductor (L1) is connected to the neutral terminal (N) and the positive electrode of the first capacitor (CE1), and the other end is connected to the positive electrode of the second capacitor (CE2) and the first pin (T11). The negative electrodes of the first capacitor (CE1) and the second capacitor (CE2) are connected to the live terminal (L).

8. The thyristor drive circuit according to claim 7, characterized in that It further includes a first diode (D1). The positive electrode of the first diode (D1) is connected to the neutral terminal (N), and the negative electrode is connected to the positive electrode of the first capacitor (CE1).

9. The thyristor drive circuit according to claim 1, characterized in that, The thyristor drive circuit (100) further includes a protection inductor. The two ends of the protection inductor are respectively connected to the second main terminal (A2) and the live output terminal (Lout).

10. A dimming device, characterized in that, It includes a light source and the thyristor drive circuit (100) according to any one of claims 1-9. The light source is connected between the live terminal (L) and the live output terminal (Lout).

Images