High-precision circuit for detecting zero-crossing signal
By designing a combination of rectifier module, power supply module, switch module and optocoupler module in the zero-crossing circuit, the conduction path of the optocoupler module is only opened at the zero-crossing point, the problems of low detection accuracy and high power consumption in the traditional circuit are solved, and the problem of low detection accuracy and high power consumption is realized. Higher power control accuracy and safety.
Patent Information
- Application Number
- CN202411264511.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-10
- Publication Date
- 2024-12-13
AI Technical Summary
Traditional zero-crossing circuits have low detection accuracy and high power consumption, resulting in insufficient safety and accuracy of power control.
A circuit for detecting zero-crossing signals with high precision is designed, including a rectifier module, a power supply module, a switching module and an optocoupling module. The AC voltage is rectified into a DC voltage through the rectifier module. The power supply module is used for charging, and the switching module is connected to the power supply module. Only when the AC voltage passes through the zero crossing point, the conduction path of the optocoupler module is turned on to achieve high-precision detection of the zero crossing signal.
Reduces circuit power consumption and improves detection accuracy of zero-crossing signals, ensuring higher power control safety and accuracy.
Smart Images
Figure CN119125661A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of zero-crossing circuits, and in particular to a circuit for detecting zero-crossing signals with high precision. Background Art
[0002] The zero-crossing signal refers to the signal emitted by the point where the voltage value is zero when the waveform passes through the vertical center line during the periodic change of the voltage waveform. This point is the zero-crossing point. The zero-crossing signal can be used to control the power supply and improve the safety of the equipment.
[0003] At present, the zero-crossing signal is generally detected through a zero-crossing circuit. However, in the half-wave or full-wave state, the optical coupler of the traditional zero-crossing circuit is always in the on state, resulting in high circuit power consumption. At the same time, the waveform detected by the traditional zero-crossing detection circuit has a certain offset and the detection accuracy is low. Summary of the invention
[0004] The present invention provides a circuit for detecting zero-crossing signals with high precision, aiming to solve the problems of low detection precision and high power consumption of current zero-crossing circuits.
[0005] The present invention provides a circuit for detecting zero-crossing signals with high precision, comprising a rectifier module, a power supply module, a switch module and an optical coupling module; the rectifier module is connected to a power supply and is used for rectifying an AC voltage provided by the power supply to obtain a DC voltage; the power supply module is connected to the rectifier module and is used for obtaining the DC voltage and charging itself through the DC voltage; the switch module is connected to the power supply module and is used for forming a first loop with the power supply module; the optical coupling module is connected to the switch module and is used for forming a second loop with the switch module; wherein, when the AC voltage passes through a zero-crossing point, the first loop and the second loop are turned on.
[0006] Furthermore, the rectifier module includes a rectifier bridge and a voltage divider circuit; the rectifier bridge is connected to the voltage divider circuit and the power supply module respectively, and the voltage divider circuit is connected to the power supply.
[0007] Further, the voltage divider circuit includes a first resistor, a second resistor and a third resistor; one end of the first resistor is connected to the power supply, and the other end of the first resistor is connected to the rectifier bridge; one end of the second resistor is respectively connected to the rectifier bridge and the power supply module, and the other end of the second resistor is respectively connected to the rectifier bridge, the power supply module and the switch module; one end of the third resistor is connected to the power supply, and the other end of the third resistor is connected to the rectifier bridge.
[0008] Furthermore, the rectifier bridge includes a first diode, a second diode, a third diode and a fourth diode connected end to end in sequence; the anode of the first diode is connected to the first resistor, the anode of the third diode and the anode of the fourth diode are both connected to the second resistor, and the cathode of the third diode is connected to the third resistor.
[0009] Furthermore, the power supply module includes a first capacitor; two ends of the first capacitor are respectively connected to the rectifier module and the switch module.
[0010] Furthermore, the power supply module also includes a fifth diode; the anode of the fifth diode is connected to the first capacitor, and the cathode of the fifth diode is connected to the rectifier module.
[0011] Furthermore, the switch module includes a first switch tube; a controlled end of the first switch tube is connected to the power supply module, a first pole of the first switch tube is connected to the power supply module, and a second pole of the first switch tube is connected to the optocoupler module.
[0012] Furthermore, the first switch tube is a triode, the base of the triode is connected to the power supply module, the emitter of the triode is connected to the power supply module, and the collector of the triode is connected to the optocoupler module.
[0013] Furthermore, the switch module also includes a fourth resistor; one end of the fourth resistor is connected to the power supply module, and the other end of the fourth resistor is connected to the optical coupling module.
[0014] Furthermore, the optical coupling module includes a photoelectric coupler, and the photoelectric coupler is connected to the switch module and forms the second loop with the switch module.
[0015] The circuit for detecting zero-crossing signals with high precision disclosed in the present invention comprises a rectifier module, a power supply module, a switch module and an optocoupler module. The rectifier module is used for rectifying the AC voltage provided by the power supply into a DC voltage, and the DC voltage is used for charging the power supply module. The switch module is respectively connected to the power supply module and the optocoupler module, and is used for controlling the conduction of the optocoupler module. When the AC voltage of the power supply passes through the zero-crossing point, the power supply module supplies power to the switch module, and both the first circuit and the second circuit are turned on, that is, the switch module and the optocoupler module are turned on, and the optocoupler module outputs the zero-crossing signal to the control module, which not only realizes the detection of the zero-crossing signal, but also the optocoupler is only turned on at the zero-crossing point, thereby reducing the power consumption of the circuit and improving the detection accuracy at the same time. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.
[0017] Figure 1 is a block diagram of a circuit for detecting zero-crossing signals with high precision provided by an embodiment of the present invention;
[0018] Figure 2 4 is a circuit diagram of a circuit for detecting zero-crossing signals with high precision provided by an embodiment of the present invention. DETAILED DESCRIPTION
[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0020] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, operations, elements, components and / or groups thereof.
[0021] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, the singular forms of "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.
[0022] In addition, the directional terms mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only for reference to the directions of the attached drawings and the use status of the product. Therefore, the directional terms used are used to illustrate and understand the present invention, but not to limit the present invention. In addition, in the drawings, structures with similar or identical structures are represented by the same reference numerals.
[0023] See also Figure 1 and Figure 2 , Figure 11 is a block diagram of a circuit 100 for detecting zero-crossing signals with high precision provided by an embodiment of the present invention; Figure 2 FIG. 1 is a circuit diagram of a circuit 100 for detecting a zero-crossing signal with high precision provided by an embodiment of the present invention. Figure 1 As shown, the circuit 100 for detecting zero-crossing signals with high precision includes a rectifier module 10, a power supply module 20, a switch module 30 and an optical coupling module 40; the rectifier module 10 is connected to the power supply 200, and is used to rectify the AC voltage provided by the power supply 200 to obtain a DC voltage; the power supply module 20 is connected to the rectifier module 10, and is used to obtain the DC voltage and charge itself through the DC voltage; the switch module 30 is connected to the power supply module 20, and is used to form a first loop with the power supply module 20; the optical coupling module 40 is connected to the switch module 30, and is used to form a second loop with the switch module 30; wherein, when the AC voltage passes through the zero-crossing point, the first loop and the second loop are turned on.
[0024] Specifically, the circuit 100 for detecting zero-crossing signals with high precision may include a rectifier module 10, a power supply module 20, a switch module 30, and an optical coupler module 40. The rectifier module 10 is connected to a power supply 200. The power supply 200 may be an AC power supply for providing an AC voltage. The rectifier module 10 is used to convert the AC voltage into a DC voltage and supply power to the power supply module 20. The AC voltage provided by the power supply 200 may be 110V or 240V, and its frequency may be 50Hz or 60Hz.
[0025] The power supply module 20 may include two working modes, the first being a charging mode, in which the rectifier module 10 charges the power supply module 20, and the second being a discharging mode, in which the power supply module 20 supplies power to the switch module 30. Specifically, the alternating current includes a positive half cycle and a negative half cycle, and in the positive half cycle and the negative half cycle, the rectifier module 10 charges the power supply module 20, and the power supply module 20 is in the charging mode, and when the positive half cycle is converted to the negative half cycle, or when the negative half cycle is converted to the positive half cycle, that is, when the alternating current voltage passes through the zero point, the power supply module 20 is in the discharging mode.
[0026] The switch module 30 is connected to the power supply module 20 and the optocoupler module 40 respectively. When the power supply module 20 is in the charging mode, the switch module 30 is turned off. When the power supply module 20 is in the discharging mode, the switch module 30 is turned on. The switch module 30 is used to control the on and off of the optocoupler module 40. When the switch module 30 is turned on, the optocoupler module 40 is turned on. When the switch module 30 is turned off, the optocoupler module 40 is turned off.
[0027] The optical coupling module 40 is connected to the control module 300, and is used to output a zero-crossing signal to the control module 300. When the alternating current is in a positive half-cycle or a negative half-cycle, the power supply module 20 is in a charging mode, the switch module 30 is disconnected, and the optical coupling module 40 is disconnected. When the alternating current is converted from a positive half-cycle to a negative half-cycle, or from a negative half-cycle to a positive half-cycle, the power supply module 20 is in a discharge mode, the switch module 30 is turned on, the optical coupling is turned on, and a zero-crossing signal is output to the control module 300, and the control module 300 detects the zero-crossing signal to confirm the zero-crossing point. In the above process, the optical coupling is only turned on when the alternating current is at a zero-crossing point, and is in a disconnected state in other periods, which can not only reduce its own power consumption, but also improve the detection accuracy of the zero-crossing signal.
[0028] As a further embodiment, the rectifier module 10 includes a rectifier bridge BD and a voltage divider circuit; the rectifier bridge BD is connected to the voltage divider circuit and the power supply module 20 respectively, and the voltage divider circuit is connected to the power supply 200 .
[0029] The rectifier module 10 may include a rectifier bridge BD and a voltage divider circuit, the rectifier bridge BD is connected to the voltage divider circuit, and the voltage divider circuit is connected to the power supply 200. The AC power of the power supply 200 is divided by the voltage divider circuit and then input into the rectifier bridge BD, and after being rectified by the rectifier bridge BD, a full-wave rectified voltage waveform is obtained, which is used to charge the power supply module 20.
[0030] See also Figure 2 As a further embodiment, the voltage divider circuit includes a first resistor R1, a second resistor R2 and a third resistor R3; one end of the first resistor R1 is connected to the power supply 200, and the other end of the first resistor R1 is connected to the rectifier bridge BD; one end of the second resistor R2 is respectively connected to the rectifier bridge BD and the power supply module 20, and the other end of the second resistor R2 is respectively connected to the rectifier bridge BD, the power supply module 20 and the switch module 30; one end of the third resistor R3 is connected to the power supply 200, and the other end of the third resistor R3 is connected to the rectifier bridge BD. As a further embodiment, the rectifier bridge BD includes a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4 connected end to end in sequence; the positive electrode of the first diode D1 is connected to the first resistor R1, the positive electrode of the third diode D3 and the positive electrode of the fourth diode D4 are both connected to the second resistor R2, and the negative electrode of the third diode D3 is connected to the third resistor R3.
[0031] The rectifier bridge BD may include a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4 connected end to end, and the voltage divider circuit may include a first resistor R1, a second resistor R2 and a third resistor R3. The first resistor R1 is connected to the anode of the first diode D1 and the cathode of the fourth diode D4, one end of the second resistor R2 is connected to the cathode of the first diode D1, the other end of the second resistor R2 is connected to the anode of the third diode D3 and the anode of the fourth diode D4, and the third resistor R3 is connected to the cathode of the third diode D3.
[0032] like Figure 2 As shown, the circuit can be divided into multiple working loops, and the multiple working loops can include a positive half-cycle working loop and a negative half-cycle working loop. The positive half-cycle working loop can include a first sub-loop and a second sub-loop, the first sub-loop is ACL-first resistor R1-first diode D1-point A-second resistor R2-point B-third diode D3-third resistor R3-ACN, and the second sub-loop is ACL-first resistor R1-first diode D1-point A-power supply module 20-point B-third diode D3-third resistor R3-ACN. That is, when the alternating current is in the positive half cycle, the first sub-loop and the second sub-loop are in working state.
[0033] The negative half-cycle working loop may include a third sub-loop and a fourth sub-loop, the third sub-loop is ACN-third resistor R3-third diode D3-point B-second resistor R2-point A-first diode D1-first resistor R1-ACL, and the fourth sub-loop is ACN-third resistor R3-third diode D3-point B-power supply module 20-point A-first diode D1-first resistor R1-ACL. That is, when the alternating current is in the negative half-cycle, the third sub-loop and the fourth sub-loop are in working state.
[0034] As a further embodiment, the power supply module 20 includes a first capacitor C1; both ends of the first capacitor C1 are respectively connected to the rectifier module 10 and the switch module 30. As a further embodiment, the power supply module 20 also includes a fifth diode D5; the anode of the fifth diode D5 is connected to the first capacitor C1, and the cathode of the fifth diode D5 is connected to the rectifier module 10.
[0035] The power supply module 20 may include a first capacitor C1 and a fifth diode D5. When the alternating current is in a positive half cycle, the first capacitor C1 is in a charging state, and when the alternating current is in a negative half cycle, the first capacitor C1 is in a discharging state. The power supply module 20, the rectifier module 10, and the switch module 30 form a first loop, and the power supply module 20, the switch module 30, and the optical coupling module 40 form a second loop. When the alternating current is converted from a positive half cycle to a negative half cycle, or from a negative half cycle to a positive half cycle, the first loop and the second loop are turned on.
[0036] As a further embodiment, the switch module 30 includes a first switch tube Q1; the controlled end of the first switch tube Q1 is connected to the power supply module 20, the first electrode of the first switch tube Q1 is connected to the power supply module 20, and the second electrode of the first switch tube Q1 is connected to the optical coupling module 40. As a further embodiment, the first switch tube Q1 is a triode, the base of the triode is connected to the power supply module 20, the emitter of the triode is connected to the power supply module 20, and the collector of the triode is connected to the optical coupling module 40. As a further embodiment, the switch module 30 also includes a fourth resistor R4; one end of the fourth resistor R4 is connected to the power supply module 20, and the other end of the fourth resistor R4 is connected to the optical coupling module 40.
[0037] Among them, the switch module 30 may include a first switch tube Q1, the first switch tube Q1 may be a triode, the base of the triode is connected to the power supply module 20, the emitter of the triode is connected to the power supply module 20, and the collector of the triode is connected to the optocoupler module 40. The rectifier module 10, the power supply module 20 and the first switch tube Q1 constitute a first loop, and the power supply module 20, the first switch tube Q1 and the optocoupler module 40 constitute a second loop. When the alternating current is converted from a positive half-cycle to a negative half-cycle, or from a negative half-cycle to a positive half-cycle, the first loop and the second loop are turned on. When the first loop and the second loop are turned on, the optocoupler module 40 is turned on and outputs a zero-crossing signal to the control module 300.
[0038] As a further embodiment, the optical coupling module 40 includes a photoelectric coupler U1 , which is connected to the switch module 30 and forms the second loop with the switch module 30 .
[0039] The optical coupling module 40 may include a photoelectric coupler U1, a fifth resistor R5, a sixth resistor R6 and a second capacitor C2, one end of the photoelectric coupler U1 is connected to the switch module 30, the other end of the photoelectric coupler U1 is connected to the fifth resistor R5, one end of the sixth resistor R6 is connected to the fifth resistor R5, the other end of the sixth resistor R6 is connected to the control module 300 and one end of the second capacitor C2, respectively, and the other end of the second capacitor C2 is grounded. When the switch module 30 is turned on, the second loop is turned on, the 3rd and 4th pins of the photoelectric coupler U1 are connected, and the zero-crossing signal is converted from a high level to a low level.
[0040] The following is an overall description of the circuit principle. Figure 2 As shown, Figure 2 The circuit shown may include a positive half-cycle working loop, a negative half-cycle working loop, a first loop and a second loop. The positive half-cycle working loop includes a first sub-loop and a second sub-loop, and the negative half-cycle working loop includes a third sub-loop and a fourth sub-loop. The first sub-loop is ACL-first resistor R1-first diode D1-point A-second resistor R2-point B-third diode D3-third resistor R3-ACN, and the second sub-loop is ACL-first resistor R1-first diode D1-point A-power supply module 20-point B-third diode D3-third resistor R3-ACN. N, the third sub-loop is ACN-third resistor R3-third diode D3-point B-second resistor R2-point A-first diode D1-first resistor R1-ACL, the fourth sub-loop is ACN-third resistor R3-third diode D3-point B-power supply module 20-point A-first diode D1-first resistor R1-ACL, the first loop is the first capacitor C1-point A-second resistor R2-point B-first switch tube Q1-first capacitor C1, and the second loop is the first capacitor C1-first resistor R1-photocoupler U1-first switch tube Q1-first capacitor C1.
[0041] When the alternating current is in the positive half cycle, the first sub-circuit and the second sub-circuit are in working state, when the alternating current is in the negative half cycle, the third sub-circuit and the fourth sub-circuit are in working state, when the alternating current is converted from the positive half cycle to the negative half cycle, or when the alternating current is converted from the negative half cycle to the positive half cycle, the first circuit and the second circuit are in working state. When the alternating current is in the positive half cycle and the negative half cycle, the first circuit and the second circuit are turned off, and the photoelectric coupler U1 is not turned on. When the alternating current is converted from the positive half cycle to the negative half cycle, or when the alternating current is converted from the negative half cycle to the positive half cycle, the first circuit and the second circuit are turned on, and the photoelectric coupler U1 is turned on, so that the power consumption of the circuit can be reduced and the accuracy of detecting the zero-crossing signal can be improved.
[0042] In the circuit for detecting zero-crossing signals with high precision disclosed by the present invention, when the alternating current is in the positive half-cycle and the negative half-cycle, the photoelectric coupler is not turned on, and when the alternating current is converted from the positive half-cycle to the negative half-cycle, or from the negative half-cycle to the positive half-cycle, the photoelectric coupler is turned on, thereby reducing circuit power consumption and improving detection accuracy.
[0043] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.
Claims
1. A circuit for detecting zero-crossing signals with high precision. It is characterized in that include: A rectifier module, the rectifier module is connected to the power supply and is used to rectify the AC voltage provided by the power supply to obtain a DC voltage; A power supply module, the power supply module is connected to the rectifier module and is used to obtain the DC voltage and charge itself through the DC voltage; A switch module, the switch module is connected to the power supply module and is used to form a first loop with the power supply module; An optical coupling module, the optical coupling module is connected to the switch module and the control module respectively, and is used to form a second loop with the switch module; When the AC voltage passes through a zero point, the first loop and the second loop are connected.
2. The circuit for detecting zero-crossing signals with high precision as claimed in claim 1, It is characterized in that The rectifier module includes a rectifier bridge and a voltage divider circuit; The rectifier bridge is connected to the voltage divider circuit and the power supply module respectively, and the voltage divider circuit is connected to the power supply.
3. The circuit for detecting zero-crossing signals with high precision as claimed in claim 2, It is characterized in that The voltage divider circuit includes a first resistor, a second resistor and a third resistor; One end of the first resistor is connected to the power supply, and the other end of the first resistor is connected to the rectifier bridge; One end of the second resistor is connected to the rectifier bridge and the power supply module respectively, and the other end of the second resistor is connected to the rectifier bridge, the power supply module and the switch module respectively; One end of the third resistor is connected to the power supply, and the other end of the third resistor is connected to the rectifier bridge.
4. The circuit for detecting zero-crossing signals with high precision as claimed in claim 3, It is characterized in that The rectifier bridge comprises a first diode, a second diode, a third diode and a fourth diode which are connected end to end in sequence; An anode of the first diode is connected to the first resistor, an anode of the third diode and an anode of the fourth diode are both connected to the second resistor, and a cathode of the third diode is connected to the third resistor.
5. The circuit for detecting zero-crossing signals with high precision as claimed in claim 1, It is characterized in that The power supply module includes a first capacitor; Two ends of the first capacitor are connected to the rectifier module and the switch module respectively.
6. The circuit for detecting zero-crossing signals with high precision as claimed in claim 4, It is characterized in that The power supply module also includes a fifth diode; The anode of the fifth diode is connected to the first capacitor, and the cathode of the fifth diode is connected to the rectifier module.
7. The circuit for detecting zero-crossing signals with high precision as claimed in claim 1, It is characterized in that The switch module includes a first switch tube; The controlled end of the first switch tube is connected to the power supply module, the first pole of the first switch tube is connected to the power supply module, and the second pole of the first switch tube is connected to the optical coupling module.
8. The circuit for detecting zero-crossing signals with high precision as claimed in claim 7, It is characterized in that The first switch tube is a triode, the base of the triode is connected to the power supply module, the emitter of the triode is connected to the power supply module, and the collector of the triode is connected to the optical coupling module.
9. The circuit for detecting zero-crossing signals with high precision as claimed in claim 7, It is characterized in that The switch module further includes a fourth resistor; One end of the fourth resistor is connected to the power supply module, and the other end of the fourth resistor is connected to the optical coupling module.
10. The circuit for detecting zero-crossing signals with high precision as claimed in claim 1, It is characterized in that The optical coupling module includes a photoelectric coupler, which is connected to the switch module and the control module respectively, and forms the second loop with the switch module.