CN210803576U - A three-phase AC zero-crossing detection circuit based on optocoupler isolation - Google Patents
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Abstract
本实用新型公开了一种基于光耦隔离的三相交流电过零检测电路，包括与三相交流电源连接的保护电路，所述保护电路与光耦耦合电路连接，所述光耦耦合电路与信号输出电路连接，所述信号输出电路与单片机相连；三相交流电源的电压通过保护电路与光耦耦合电路连接，光耦耦合电路通过隔离转换将220V的交流电转化为对信号输出电路的控制信号，信号输出电路输出与输入交流电频率相同的高低电平信号，单片机通过对高低电平的检测，计算出交流电的过零点时刻，可以大大降低检测的脉动信号电压误差，精确地测出交流电的过零点，本实用新型可以用于交流电的过零点检测。
The utility model discloses a three-phase alternating current zero-crossing detection circuit based on optocoupler isolation. The output circuit is connected, and the signal output circuit is connected with the single-chip microcomputer; the voltage of the three-phase AC power supply is connected with the optocoupler coupling circuit through the protection circuit, and the optocoupler coupling circuit converts the 220V AC power into the control signal for the signal output circuit through isolation conversion, The signal output circuit outputs high and low level signals with the same frequency as the input AC power. The single-chip microcomputer calculates the zero-crossing time of the AC power by detecting the high and low levels, which can greatly reduce the voltage error of the detected pulsating signal and accurately measure the zero-crossing point of the AC power. , the utility model can be used for the zero-crossing detection of alternating current.
Description
技术领域technical field
本实用新型涉及一种检测电路。The utility model relates to a detection circuit.
背景技术：Background technique:
过零检测即利用电子电路检测交流电的过零点时刻。目前存在的传统的检测方法有采用硬件过零比较器来实现,这种方法电路复杂, 比较器需要双电源才能实现过零信号的检测，也有使用光耦，即通过电阻分压当波形从正半周向负半周转换时，经过零位时，取出一个脉动信号电压。采用这种交流电过零检测电路，其电路单一，检测的脉动信号电压误差较大，不能准确的测出交流电的过零点。所以提出一种更加简单、准确的过零检测电路及其检测方法具有重要意义。Zero-crossing detection is to use electronic circuit to detect the zero-crossing moment of alternating current. The existing traditional detection methods are implemented by hardware zero-crossing comparators. This method has a complicated circuit. The comparator needs dual power supplies to realize the detection of zero-crossing signals. There are also optocouplers, that is, when the waveform changes from positive to When the half cycle is converted to the negative half cycle, when the zero position is passed, a pulsating signal voltage is taken out. The use of this alternating current zero-crossing detection circuit has a single circuit, and the detected pulsating signal voltage error is relatively large, and the zero-crossing point of the alternating current cannot be accurately measured. Therefore, it is of great significance to propose a simpler and more accurate zero-crossing detection circuit and its detection method.
实用新型内容Utility model content
本实用新型的目的是提供一种基于光耦隔离的三相交流电过零检测电路，可以大大降低检测的脉动信号电压误差，精确地测出交流电的过零点。The purpose of the utility model is to provide a three-phase alternating current zero-crossing detection circuit based on optocoupler isolation, which can greatly reduce the detected pulsating signal voltage error and accurately measure the zero-crossing point of alternating current.
为实现上述目的，本实用新型提供了一种基于光耦隔离的三相交流电过零检测电路，包括与三相交流电源连接的保护电路，所述保护电路与光耦耦合电路连接，所述光耦耦合电路与信号输出电路连接，所述信号输出电路与单片机相连。In order to achieve the above purpose, the present invention provides a three-phase alternating current zero-crossing detection circuit based on optocoupler isolation, including a protection circuit connected with the three-phase alternating current power supply, the protection circuit is connected with the optocoupler coupling circuit, and the optical The coupling circuit is connected with the signal output circuit, and the signal output circuit is connected with the single-chip microcomputer.
与现有技术相比，本实用新型的有益效果在于，三相交流电源的电压通过保护电路与光耦耦合电路连接，光耦耦合电路通过隔离转换将220V的交流电转化为对信号输出电路的控制信号，信号输出电路输出与输入交流电频率相同的高低电平信号，单片机通过对高低电平的检测，计算出交流电的过零点时刻，可以大大降低检测的脉动信号电压误差，精确地测出交流电的过零点，本实用新型可以用于交流电的过零点检测。Compared with the prior art, the beneficial effect of the utility model is that the voltage of the three-phase AC power supply is connected with the optocoupler coupling circuit through the protection circuit, and the optocoupler coupling circuit converts the 220V AC power into the control of the signal output circuit through isolation conversion. Signal, the signal output circuit outputs high and low level signals with the same frequency as the input AC power. The single-chip microcomputer calculates the zero-crossing time of the AC power by detecting the high and low levels, which can greatly reduce the detected pulsating signal voltage error and accurately measure the AC power. Zero-crossing point, the utility model can be used for the zero-crossing point detection of alternating current.
作为本实用新型的进一步改进，所述光耦耦合电路包括光电耦合器U1A、光电耦合器U1B以及光电耦合器U1C，所述光电耦合器U1A 的输入端、光电耦合器U1B的输入端以及光电耦合器U1C的输入端与保护电路相连，所述光电耦合器U1A的输出端的集电极、光电耦合器 U1B的输出端的集电极以及光电耦合器U1C的输出端的集电极与5V 电源相连；所述光电耦合器U1A的输出端、光电耦合器U1B的输出端的以及光电耦合器U1C的输出端与信号输出电路相连；所述光电耦合器U1A的输出端的发射级串接电阻R4并接地、光电耦合器U1B的输出端的发射级串接电阻R7并接地，光电耦合器U1C的输出端的发射级串接电阻R6并接地，这样可以通过光耦合器更好地将交流电转化为对信号输入电路的控制信号，使得信号输入电路的导通和截止更精确。As a further improvement of the present invention, the optocoupler coupling circuit includes optocoupler U1A, optocoupler U1B, and optocoupler U1C. The input end of the optocoupler U1A, the input end of the optocoupler U1B, and the optocoupler The input end of the photocoupler U1C is connected to the protection circuit, and the collector of the output end of the photocoupler U1A, the collector electrode of the output end of the photocoupler U1B and the collector electrode of the output end of the photocoupler U1C are connected to the 5V power supply; the photoelectric coupling The output end of the photocoupler U1A, the output end of the photocoupler U1B and the output end of the photocoupler U1C are connected to the signal output circuit; the emitter stage of the output end of the photocoupler U1A is connected to the resistor R4 in series and grounded, and the The emitter stage of the output end is connected to the resistor R7 in series and grounded, and the emitter stage of the output end of the optocoupler U1C is connected to the resistor R6 in series and grounded, so that the AC power can be better converted into the control signal for the signal input circuit through the optocoupler, so that the signal The turn-on and turn-off of the input circuit is more precise.
作为本实用新型的进一步改进，所述信号电路输出电路包括开关三极管Q1、开关三极管Q2以及开关三极管Q3；所述开关三极管Q1 的基极与光电耦合器U1A的输出端的发射级相连，所述开关三极管 Q1的集电极与5V电源相连，所述开关三极管Q1的发射级串接电阻R5并接地；所述开关三极管Q2的基极与光电耦合器U1B的输出端的发射级相连，所述开关三极管Q2的集电极与5V电源相连，所述开关三极管Q2的发射级串接电阻R8并接地；所述开关三极管Q3的基极与光电耦合器U1C的输出端的发射级相连，所述开关三极管Q3的集电极与5V电源相连，所述开关三极管Q3的发射级串接电阻R9并接地；所述电阻R5、电阻R8以及电阻R9的输出端与单片机相连，这样将电阻R5、R8、R9上的电压做为单片机检测三相交流电过零的信号电压，开关三极管输出与输入交流电频率相同的高低电平信号，单片机通过对开关三极管输出的高低电平的检测，计算出交流电的过零点时刻，进一步提升检测精度，减小误差。As a further improvement of the present invention, the signal circuit output circuit includes a switch transistor Q1, a switch transistor Q2 and a switch transistor Q3; the base of the switch transistor Q1 is connected to the emitter stage of the output end of the photocoupler U1A, and the switch The collector of the transistor Q1 is connected to the 5V power supply, and the emitter of the switch transistor Q1 is connected to the resistor R5 in series and grounded; the base of the switch transistor Q2 is connected to the emitter of the output end of the photocoupler U1B, and the switch transistor Q2 The collector of the switch transistor Q2 is connected to the 5V power supply, the emitter stage of the switch transistor Q2 is connected in series with the resistor R8 and grounded; the base electrode of the switch transistor Q3 is connected to the emitter stage of the output end of the photocoupler U1C, and the collector of the switch transistor Q3 The electrode is connected to the 5V power supply, and the emitter stage of the switch transistor Q3 is connected to the resistor R9 in series and grounded; the output terminals of the resistor R5, the resistor R8 and the resistor R9 are connected to the single-chip microcomputer, so that the voltages on the resistors R5, R8 and R9 are For the single-chip microcomputer to detect the signal voltage of the zero-crossing of the three-phase alternating current, the switching transistor outputs a high and low level signal with the same frequency as the input alternating current. accuracy and reduce errors.
作为本实用新型的进一步改进，所述保护电路包括二极管D1、二极管D2以及二极管D3，所述二极管D1的负极与光电耦合器U1A 的输入端的正极相连，所述二极管D1的正极与光电耦合器U1A的输入端的负极相连，所述二极管D2的负极与光电耦合器U1B的输入端的正极相连，所述二极管D2的正极与光电耦合器U1B的输入端的负极相连，所述二极管D3的负极与光电耦合器U1C的输入端的正极相连，所述二极管D3的正极与光电耦合器U1C的输入端的负极相连，这样在交流电路为负半周时二极管导通，防止光电耦合器被反向击穿。As a further improvement of the present invention, the protection circuit includes a diode D1, a diode D2 and a diode D3. The cathode of the diode D1 is connected to the anode of the input end of the photocoupler U1A, and the anode of the diode D1 is connected to the photocoupler U1A. The negative electrode of the input end of the diode D2 is connected to the negative electrode of the input end of the photocoupler U1B, the positive electrode of the diode D2 is connected to the negative electrode of the input end of the photocoupler U1B, the negative electrode of the diode D3 is connected to the photocoupler The anode of the input terminal of U1C is connected to the anode of the diode D3, and the anode of the diode D3 is connected to the cathode of the input terminal of the optocoupler U1C, so that the diode is turned on when the AC circuit is in the negative half cycle, preventing the optocoupler from being reversely broken down.
作为本实用新型的进一步改进，所述保护电路还包括限流电阻 R1、限流电阻R2以及限流电阻R3，所述限流电阻R1的一端与三相交流电源相连，所述限流电阻R1的另一端与二极管D1的负极相连，所述限流电阻R2的一端与三相交流电源相连，所述限流电阻R2的另一端与二极管D2的负极相连，所述限流电阻R3的一端与三相交流电源相连，所述限流电阻R1的另一端与二极管D3的负极相连，这样通过限流电阻来防止电流过大，使光电耦合器烧毁。As a further improvement of the present invention, the protection circuit further includes a current limiting resistor R1, a current limiting resistor R2 and a current limiting resistor R3, one end of the current limiting resistor R1 is connected to the three-phase AC power supply, and the current limiting resistor R1 The other end of the current limiting resistor R2 is connected to the negative electrode of the diode D1, one end of the current limiting resistor R2 is connected to the three-phase AC power supply, the other end of the current limiting resistor R2 is connected to the negative electrode of the diode D2, and one end of the current limiting resistor R3 is connected to the The three-phase AC power supply is connected, and the other end of the current limiting resistor R1 is connected to the negative electrode of the diode D3, so that the current limiting resistor is used to prevent the current from being too large and the photocoupler from being burned.
作为本实用新型的进一步改进，所述开关三极管Q1的发射级与示波器的A+接口相连，所述示波器的A-接口接地，这样可以通过示波器对信号波形进行实时检测。As a further improvement of the present invention, the transmitting stage of the switching transistor Q1 is connected to the A+ interface of the oscilloscope, and the A- interface of the oscilloscope is grounded, so that the signal waveform can be detected in real time by the oscilloscope.
附图说明Description of drawings
图1是本实用新型电路图。Fig. 1 is the circuit diagram of the utility model.
图2是本实用新型波形图。Figure 2 is a waveform diagram of the present utility model.
具体实施方式Detailed ways
如图1-2所示的一种基于光耦隔离的三相交流电过零检测电路，包括与三相交流电源连接的保护电路，保护电路与光耦耦合电路连接，光耦耦合电路与信号输出电路连接，信号输出电路与单片机相连。As shown in Figure 1-2, a three-phase AC zero-crossing detection circuit based on optocoupler isolation includes a protection circuit connected to the three-phase AC power supply, the protection circuit is connected to the optocoupler coupling circuit, and the optocoupler coupling circuit is connected to the signal output The circuit is connected, and the signal output circuit is connected with the single-chip microcomputer.
光耦耦合电路包括光电耦合器U1A、光电耦合器U1B以及光电耦合器U1C，光电耦合器U1A的输入端、光电耦合器U1B的输入端以及光电耦合器U1C的输入端与保护电路相连，光电耦合器U1A的输出端的集电极、光电耦合器U1B的输出端的集电极以及光电耦合器U1C的输出端的集电极与5V电源相连；光电耦合器U1A的输出端、光电耦合器U1B的输出端的以及光电耦合器U1C的输出端与信号输出电路相连；光电耦合器U1A的输出端的发射级串接电阻R4并接地、光电耦合器U1B的输出端的发射级串接电阻R7并接地，光电耦合器U1C的输出端的发射级串接电阻R6并接地。The optocoupler coupling circuit includes optocoupler U1A, optocoupler U1B and optocoupler U1C. The input end of optocoupler U1A, the input end of optocoupler U1B and the input end of optocoupler U1C are connected to the protection circuit, and the optocoupler is connected to the protection circuit. The collector of the output of the photocoupler U1A, the collector of the output of the photocoupler U1B and the collector of the output of the photocoupler U1C are connected to the 5V power supply; the output of the photocoupler U1A, the output of the photocoupler U1B and the photocoupler The output end of the photocoupler U1C is connected to the signal output circuit; the emitter stage of the output end of the optocoupler U1A is connected to the resistor R4 and grounded, the emitter stage of the output end of the optocoupler U1B is connected to the resistor R7 and grounded, and the output end of the optocoupler U1C is connected to the ground. The transmitter stage is connected to resistor R6 in series and grounded.
信号电路输出电路包括开关三极管Q1、开关三极管Q2以及开关三极管Q3；开关三极管Q1的基极与光电耦合器U1A的输出端的发射级相连，开关三极管Q1的集电极与5V电源相连，开关三极管Q1的发射级串接电阻R5并接地；开关三极管Q2的基极与光电耦合器U1B的输出端的发射级相连，开关三极管Q2的集电极与5V电源相连，开关三极管Q2的发射级串接电阻R8并接地；开关三极管Q3的基极与光电耦合器U1C的输出端的发射级相连，开关三极管Q3的集电极与 5V电源相连，开关三极管Q3的发射级串接电阻R9并接地；电阻R5、电阻R8以及电阻R9的输出端与单片机相连。The output circuit of the signal circuit includes a switching transistor Q1, a switching transistor Q2 and a switching transistor Q3; the base of the switching transistor Q1 is connected to the emitter of the output end of the photocoupler U1A, the collector of the switching transistor Q1 is connected to the 5V power supply, and the The emitter stage is connected to the resistor R5 in series and grounded; the base of the switch transistor Q2 is connected to the emitter stage of the output end of the photocoupler U1B, the collector of the switch transistor Q2 is connected to the 5V power supply, and the emitter stage of the switch transistor Q2 is connected to the resistor R8 in series and grounded ; The base of the switching transistor Q3 is connected with the emitter stage of the output end of the photocoupler U1C, the collector of the switching transistor Q3 is connected with the 5V power supply, and the emitter stage of the switching transistor Q3 is connected in series with the resistor R9 and grounded; the resistor R5, the resistor R8 and the resistor The output end of R9 is connected with the microcontroller.
保护电路包括二极管D1、二极管D2以及二极管D3，二极管D1 的负极与光电耦合器U1A的输入端的正极相连，二极管D1的正极与光电耦合器U1A的输入端的负极相连，二极管D2的负极与光电耦合器U1B的输入端的正极相连，二极管D2的正极与光电耦合器U1B的输入端的负极相连，二极管D3的负极与光电耦合器U1C的输入端的正极相连，二极管D3的正极与光电耦合器U1C的输入端的负极相连。The protection circuit includes a diode D1, a diode D2 and a diode D3. The cathode of the diode D1 is connected to the anode of the input end of the optocoupler U1A, the anode of the diode D1 is connected to the cathode of the input end of the optocoupler U1A, and the cathode of the diode D2 is connected to the optocoupler. The anode of the input terminal of U1B is connected to the anode of the input terminal of U1B, the anode of the diode D2 is connected to the cathode of the input terminal of the optocoupler U1B, the cathode of the diode D3 is connected to the anode of the input terminal of the optocoupler U1C, and the anode of the diode D3 is connected to the cathode of the input terminal of the optocoupler U1C. connected.
保护电路还包括限流电阻R1、限流电阻R2以及限流电阻R3，限流电阻R1的一端与三相交流电源相连，限流电阻R1的另一端与二极管D1的负极相连，限流电阻R2的一端与三相交流电源相连，限流电阻R2的另一端与二极管D2的负极相连，限流电阻R3的一端与三相交流电源相连，限流电阻R1的另一端与二极管D3的负极相连；开关三极管Q1的发射级与示波器的A+接口相连，示波器的A-接口接地。The protection circuit also includes a current-limiting resistor R1, a current-limiting resistor R2 and a current-limiting resistor R3. One end of the current-limiting resistor R1 is connected to the three-phase AC power supply, and the other end of the current-limiting resistor R1 is connected to the negative electrode of the diode D1. The current-limiting resistor R2 One end of the current limiting resistor R2 is connected to the three-phase AC power supply, the other end of the current limiting resistor R2 is connected to the negative electrode of the diode D2, one end of the current limiting resistor R3 is connected to the three-phase AC power supply, and the other end of the current limiting resistor R1 is connected to the negative electrode of the diode D3; The transmitting stage of the switching transistor Q1 is connected with the A+ interface of the oscilloscope, and the A- interface of the oscilloscope is grounded.
工作时，限流电阻R1、R2和R3进行限流分压，给光电耦合器 U1A、U1B、U1C提供工作点偏置电压；当交流电处于负半周时二极管D1、D2、D3导通，光电耦合器截止，防止光电耦合器被反向击穿；通过光电耦合器的隔离转换，光电耦合器将220V交流电转变为对开关三极管的控制信号，控制开关三极管的导通与截止；通过开关三极管的导通与截止，开关三极管输出单片机可以检测的高低电平信号，当交流电为正半周时过零检测电路输出为高电平，当交流电为负半周时过零检测电路输出为低电平；在过零检测电路的一个周期内，单片机检测过零检测电路的高低电平。设一个周期内电平从低到高时刻为 0点，电平从高到低为t1时刻，电平再次从低到高时刻为t2时刻。When working, the current limiting resistors R1, R2 and R3 limit the current and divide the voltage to provide the working point bias voltage for the photocouplers U1A, U1B and U1C; when the alternating current is in the negative half cycle, the diodes D1, D2 and D3 are turned on, and the photoelectric coupling Through the isolation conversion of the photocoupler, the photocoupler converts the 220V alternating current into a control signal for the switching triode to control the on and off of the switching triode; through the conduction of the switching triode On and off, the switching transistor outputs high and low level signals that can be detected by the single-chip microcomputer. When the alternating current is a positive half cycle, the output of the zero-crossing detection circuit is high, and when the alternating current is a negative half cycle, the output of the zero-crossing detection circuit is low. In one cycle of the zero detection circuit, the single-chip microcomputer detects the high and low levels of the zero-crossing detection circuit. Assume that the time when the level changes from low to high in a cycle is 0 point, the time when the level changes from high to low is time t1 , and the time when the level changes from low to high again is time t2 .
这样交流电一个周期：One cycle of alternating current like this:
T＝t2；T=t 2 ;
在这一个周期的正弦波中正峰值时刻Positive peak moment in the sine wave of this cycle
得到交流电零点时刻为：The time of AC zero point is obtained as:
同理，三相交流电中的B相、C相检测原理与A相相同。In the same way, the detection principle of B-phase and C-phase in three-phase alternating current is the same as that of A-phase.
本实用新型不局限于上述实施例，在本公开的技术方案的基础上，本领域的技术人员根据所公开的技术内容，不需要创造性的劳动就对其中的一些技术特征作出一些替换和变形，这些替换和变形均在本实用新型的保护范围内。The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solutions of the present disclosure, those skilled in the art can make some replacements and modifications to some of the technical features according to the disclosed technical content without creative work. These replacements and modifications are all within the protection scope of the present invention.
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| CN111969999A (en) * | 2020-06-28 | 2020-11-20 | 上海宇航系统工程研究所 | Reliable carrier rocket separation signal isolation detection and self-locking circuit |
| CN112415260A (en) * | 2020-12-02 | 2021-02-26 | 中山市优胜电子科技有限公司 | An isolated single-chip microcomputer AC zero-crossing signal detection circuit |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111969999A (en) * | 2020-06-28 | 2020-11-20 | 上海宇航系统工程研究所 | Reliable carrier rocket separation signal isolation detection and self-locking circuit |
| CN111969999B (en) * | 2020-06-28 | 2023-08-11 | 上海宇航系统工程研究所 | A Reliable Carrier Vehicle Separation Signal Isolation Detection and Self-Locking Circuit |
| CN112415260A (en) * | 2020-12-02 | 2021-02-26 | 中山市优胜电子科技有限公司 | An isolated single-chip microcomputer AC zero-crossing signal detection circuit |
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