Low standby power consumption full-wave zero-crossing circuit of single optocoupler
Through the structure of a single optocoupler combined with diode and transistor, the problems of detection accuracy, isolation performance and standby power consumption of existing zero-crossing circuits are solved, and high-precision full-wave zero-crossing detection and low-cost standby power consumption are achieved.
Patent Information
- Application Number
- CN202421957739.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-14
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-08-14
AI Technical Summary
The existing zero-crossing circuits have shortcomings in detection accuracy, isolation performance, cost and standby power consumption, especially the isolation performance of single optocoupler circuits in high voltage environments, and the dual optocoupler circuits are costly and have large power consumption.
The structure of a single optocouple combined with diode and transistor is adopted to realize full wave zero-crossing detection through the optocouple isolation module and detection output module, and control the power input through a relay during standby to reduce power consumption.
High-precision full-wave zero-crossing detection is realized, providing effective isolation, reducing standby power consumption, and low cost.
Smart Images
Figure CN223155100U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of detection circuits, and particularly relates to a full-wave zero-crossing circuit with a single optocoupler and low standby power consumption. Background Art
[0002] Existing zero-crossing circuits are usually involved in fields such as power electronics, household appliances, intelligent switches, and motor speed regulation. By detecting the zero point of alternating current, devices such as motors, thyristors, and relays are controlled. However, the existing technologies mainly include the following three zero-crossing circuit schemes: ① As shown in Figure 1 the single-transistor zero-crossing circuit shown, this scheme has the following technical defects: 1) Only using a transistor for detection, the zero-crossing detection accuracy is relatively low. 2) As an analog component, the transistor is sensitive to the noise on the power line and is easily interfered. 3) The single-transistor scheme can only be used in non-isolated power supply circuits. ② As shown in Figure 2 the single-optocoupler zero-crossing circuit shown, this scheme has the following technical defects: 1) Improper selection of the voltage-dividing resistor will affect the detection accuracy or increase the power consumption. 2) This circuit can only detect half-wave zero-crossing signals. 3) A single optocoupler may not provide sufficient isolation performance in a high-voltage environment. ③ As shown in Figure 3 the full-wave zero-crossing dual-optocoupler circuit shown, this scheme has the following technical defects: 1) There are many components, and the cost is high. 2) The circuit is relatively complex. 3) The power consumption is large, and the product will continue to consume high energy even when in standby.
[0003] Therefore, it is urgent to propose a full-wave zero-crossing circuit with a single optocoupler and low standby power consumption to solve the above problems. Summary of the Utility Model
[0004] The purpose of the utility model is to provide a full-wave zero-crossing circuit with a single optocoupler and low standby power consumption, so as to provide effective isolation on the premise of detecting accurate zero-crossing signals, reduce power consumption during standby, and take into account the cost.
[0005] To solve the above technical problems, the utility model provides a full-wave zero-crossing circuit with a single optocoupler and low standby power consumption, including:
[0006] An optocoupler isolation module, which is composed of resistors R13 to R15, diodes D16 to D17, and optocoupler U4; two input ends of the optocoupler isolation module are respectively connected to the neutral line ACN and the live line ACL;
[0007] A detection output module, the input end of the detection output module is connected to the output end of the optocoupler isolation module, and the output end of the detection output module is connected to the zero-crossing detection end ZERO.
[0008] Preferably, the circuit connection relationship of the optocoupler isolation module is as follows: the upper end of the resistor R14 is connected to the neutral line ACN and the positive electrode of the diode D16, the lower end of the resistor R14 is connected to the upper end of the resistor R15, the lower end of the resistor R13, and the pin 2 of the optocoupler U4, the lower end of the resistor R15 is connected to the live wire ACL and the positive electrode of the diode D17, and the negative electrodes of the diode D16 and the diode D17 are commonly connected to the upper end of the resistor R13 and the pin 1 of the optocoupler U4.
[0009] Preferably, a relay is further included, and the pins 2 and 1 of the relay are respectively connected between the live wire ACL and the positive electrode of the diode D17.
[0010] Preferably, a 0Ω jumper resistor PR2 is further included, and both ends of the 0Ω jumper resistor PR2 are respectively connected between the live wire ACL and the positive electrode of the diode D17.
[0011] Preferably, the detection output module includes: resistors R16 to R19, a triode Q3, and a capacitor C6; the upper end of the resistor R16 is connected to the power supply +5V and the pin 4 of the optocoupler U4, the pin 3 of the optocoupler U4 is connected to the left end of the resistor R17, the right end of the resistor R17 is connected to the upper end of the resistor R18 and the base of the triode Q3, the emitter of the triode Q3 is connected to the lower end of the resistor R18 and grounded to GND, the collector of the triode Q3 is connected to the lower end of the resistor R16 and the left end of the resistor R19, the right end of the resistor R19 is connected to the upper end of the capacitor C6 and the zero-crossing detection end ZERO, and the lower end of the capacitor C6 is grounded to GND.
[0012] Compared with the prior art, the present invention has the following beneficial effects:
[0013] The present invention still takes the zero-crossing point before rectification, adds a diode to each of the live and neutral lines, and cancels an optocoupler. Since the price of the optocoupler is more expensive than the sum of the two diodes, the cost can be saved after replacement. Using the optocoupler plus triode scheme can ensure effective isolation; only one optocoupler can achieve full-wave zero-crossing detection, and the cost is more optimal; through the use of its own relay control, standby low power consumption can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 is a schematic diagram of a prior art single-triode zero-crossing circuit solution.
[0015] Figure 2 is a schematic diagram of a prior art single-optocoupler zero-crossing circuit solution.
[0016] Figure 3 is a schematic diagram of a prior art full-wave zero-crossing double-optocoupler solution.
[0017] Figure 4 is a schematic diagram of the full-wave zero-crossing single-optocoupler solution of the present invention.
[0018] Figure 5 This is the waveform diagram of the two pins of the optocoupler of the present utility model with respect to the live wire and the neutral wire.
[0019] Figure 6 This is the waveform diagram of the optocoupler conduction of the present utility model.
[0020] Figure 7 This is the zero-crossing signal waveform diagram of the present utility model. Specific embodiments
[0021] The present utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present utility model will be clearer. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise scales, only for the purpose of conveniently and clearly assisting in explaining the embodiments of the present utility model.
[0022] As Figure 4 shown, the embodiment of the present utility model specifically provides a single-optocoupler low standby power consumption full-wave zero-crossing circuit, including:
[0023] An optocoupler isolation module, which is composed of resistors R13 to R15, diodes D16 to D17, and optocoupler U4; the two input ends of the optocoupler isolation module are respectively connected to the neutral wire ACN and the live wire ACL;
[0024] A detection output module, the input end of the detection output module is connected to the output end of the optocoupler isolation module, and the output end of the detection output module is connected to the zero-crossing detection end ZERO.
[0025] The circuit connection relationship of the optocoupler isolation module includes: the upper end of the resistor R14 is connected to the neutral wire ACN and the positive pole of the diode D16, the lower end of the resistor R14 is connected to the upper end of the resistor R15, the lower end of the resistor R13, and the 2nd pin of the optocoupler U4, the lower end of the resistor R15 is connected to the live wire ACL and the positive pole of the diode D17, and the negative poles of the diode D16 and the diode D17 are commonly connected to the upper end of the resistor R13 and the 1st pin of the optocoupler U4.
[0026] It further includes a relay, and the 2nd pin and the 1st pin of the relay are respectively connected between the live wire ACL and the positive pole of the diode D17.
[0027] It further includes a 0Ω jumper resistor PR2, and both ends of the 0Ω jumper resistor PR2 are respectively connected between the live wire ACL and the positive pole of the diode D17.
[0028] The detection output module includes: resistors R16 to R19, a triode Q3, and a capacitor C6; the upper end of the resistor R16 is connected to the power supply +5V and the pin 4 of the optocoupler U4, the pin 3 of the optocoupler U4 is connected to the left end of the resistor R17, the right end of the resistor R17 is connected to the upper end of the resistor R18 and the base of the triode Q3, the emitter of the triode Q3 is connected to the lower end of the resistor R18 and grounded to GND, the collector of the triode Q3 is connected to the lower end of the resistor R16 and the left end of the resistor R19, the right end of the resistor R19 is connected to the upper end of the capacitor C6 and the zero-crossing detection terminal ZERO, and the lower end of the capacitor C6 is grounded to GND.
[0029] The working principle is as follows:
[0030] When the electricity enters from the live wire ACL, the current path is: ACL - D17 - U4 generates a zero-crossing signal - R14 - ACN; when the electricity enters from the neutral wire ACN, the current path is: ACN - D16 - U4 generates a zero-crossing signal - R15 - ACL; if the present utility model has its own relay, then borrow this relay, take the live wire ACL behind the relay, and control the power input of the zero-crossing circuit. When in standby, disconnect the relay to reduce power consumption, thereby achieving low standby power consumption. If it does not have a relay itself, then take the live wire ACL behind the 0Ω jumper resistor PR2 to control the power input of the zero-crossing circuit. When using the above relay and 0Ω jumper resistor PR2, only one of them can be selected for use.
[0031] Moreover, by using the structure of the optocoupler U4 plus the triode Q3, effective isolation is ensured; when the voltage is divided by the resistors R14 and R15, the current direction is controlled by the diodes D16 and D17; the pin 2 of the optocoupler U4 is connected between the resistors R14 and R15. When the alternating current is at zero point, the optocoupler U4 is not conducting, and the subsequent triode Q3 is also not conducting, and the chip port will detect a high-level pulse width. When it is at other times than the zero point of the alternating current, the optocoupler U4 is conducting, and the subsequent triode Q3 is also conducting, and the chip port will detect a low level. That is, the present utility model controls the current to flow through the optocoupler U4 through two diodes after voltage division on the live and neutral wires; by connecting the pin 2 of the optocoupler U4 between the resistors R14 and R15 to form a voltage drop and turn on the optocoupler U4, thereby achieving the advantage of being able to detect the zero-crossing signal with one optocoupler.
[0032] The above description is only a description of the preferred embodiments of the present utility model, and does not limit the scope of the present utility model in any way. Any changes and modifications made by those of ordinary skill in the field of the present utility model according to the above disclosure shall fall within the protection scope of the claims.
Claims
1. A single optocoupler low standby power full-wave zero-crossing circuit, characterized in that, Comprising: An optocoupler isolation module, which is composed of resistors R13 to R15, diodes D16 to D17 and optocoupler U4; two input ends of the optocoupler isolation module are respectively connected to the neutral line ACN and the live line ACL. A detection output module, the input end of the detection output module is connected to the output end of the optocoupler isolation module, and the output end of the detection output module is connected to the zero-crossing detection end ZERO.
2. The single-opto-coupler low standby power full-wave zero-crossing circuit according to claim 1, characterized in that, The circuit connection relationship of the optocoupler isolation module includes: the upper end of the resistor R14 is connected to the neutral line ACN and the positive electrode of the diode D16, the lower end of the resistor R14 is connected to the upper end of the resistor R15, the lower end of the resistor R13, and the pin 2 of the optocoupler U4, the lower end of the resistor R15 is connected to the live line ACL and the positive electrode of the diode D17, and the negative electrodes of the diode D16 and the diode D17 are commonly connected to the upper end of the resistor R13 and the pin 1 of the optocoupler U4.
3. The full-wave zero-crossing circuit with a single optocoupler and low standby power consumption according to claim 2, characterized in that, It further includes a relay, and the pin 2 and pin 1 of the relay are respectively connected between the live line ACL and the positive electrode of the diode D17.
4. The single-optical-coupler low standby power consumption full-wave zero-crossing circuit according to claim 2, wherein It further includes a 0Ω jumper resistor PR2, and both ends of the 0Ω jumper resistor PR2 are respectively connected between the live line ACL and the positive electrode of the diode D17.
5. The full-wave zero-crossing circuit with a single optocoupler and low standby power consumption as described in claim 1, wherein The detection output module includes: resistors R16 to R19, a triode Q3 and a capacitor C6; the upper end of the resistor R16 is connected to the power supply +5V and the pin 4 of the optocoupler U4, the pin 3 of the optocoupler U4 is connected to the left end of the resistor R17, the right end of the resistor R17 is connected to the upper end of the resistor R18 and the base of the triode Q3, the emitter of the triode Q3 is connected to the lower end of the resistor R18 and grounded to GND, the collector of the triode Q3 is connected to the lower end of the resistor R16 and the left end of the resistor R19, the right end of the resistor R19 is connected to the upper end of the capacitor C6 and the zero-crossing detection end ZERO, and the lower end of the capacitor C6 is grounded to GND.