Choking type surge suppression circuit based on Zigbee control

Abstract

The utility model discloses a choke type surge suppression circuit based on Zigbee control, which comprises a surge suppression circuit and a Zigbee module, and a relay driving circuit is arranged between the surge suppression circuit and the Zigbee module for connection. Comprising a load switch and a load, the output end of the load switch is connected with the power end of the surge suppression circuit, and the input end of the load is connected with the output end of the surge suppression circuit. According to the utility model, electricity is not required to be taken from strong electricity, the breakdown risk of a device is solved, time is conveniently configured through software for time delay, a large amount of calculation and debugging are not required, remote field configuration can be realized through software, the time delay control precision is high, and new surge current can be generated when a CBB capacitor at the front end of the strong electricity taking circuit is charged. The surge suppression effect is influenced, the zero-cross detection function is realized, the surge current suppression capability is improved, and the device cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of power equipment protection circuits, in particular to a choke type surge suppression circuit based on Zigbee control. Background Art

[0002] A surge suppressor is an electronic device that provides protection for electronic equipment. When used, a choke-type surge suppressor is connected in series with the protected device, presenting high impedance to surge current pulses and low impedance to normal voltage states. The simplest choke-type surge suppressors include: choke coils, high-pass filters, low-pass filters, NTC resistors, 1 / 4 wavelength short circuits, etc. In smart home scenarios, surge suppressors generally use pure hardware methods, using high-impedance devices to limit current, and then using hardware delay circuits to control relays for switching. This solves the problem of excessive surge currents of hundreds of A at the moment when the power supply device is powered on in smart homes, causing damage to other devices.

[0003] A Chinese patent document with a publication date of May 5, 2023 and a publication number of CN218976559U discloses a surge suppressor and an electrical device, including: a current limiting circuit connecting an AC power supply end and a power consumption end for charging the power consumption end; a switching circuit connected in parallel at both ends of the current limiting circuit 300; and a delay control circuit connected to the switching circuit for controlling the switch to be turned on for a period of time after the AC power supply end is turned on.

[0004] Surge suppressors designed with pure hardware solutions have the following obvious disadvantages:

[0005] 1. The delay circuit draws power from the strong current, and the strong and weak currents are not isolated, which may cause the risk of device breakdown;

[0006] 2. The delay circuit is completed by pure hardware, which requires a lot of calculation and debugging, and the design is relatively complex. In addition, it is debugged in a strong power working environment, which is somewhat dangerous;

[0007] 3. The delay is the time it takes to charge and raise the voltage through the aluminum electrolytic capacitor. The debugging parameters are easily affected by the ambient temperature, resulting in temperature drift errors, which reduces the effect of surge suppression and the delay accuracy is not high.

[0008] 4. When the CBB capacitor at the front end of the high-voltage power supply circuit is charged, a new surge current will be generated, and the surge suppression effect will be affected. Utility Model Content

[0009] The purpose of the utility model is to solve the problems existing in the prior art, such as the risk of device breakdown, pure hardware delay requiring a lot of calculation and debugging, complex design, certain danger in debugging in a strong electric environment, the delay effect being easily affected by the ambient temperature and reducing the surge suppression effect, the delay accuracy being low, and a new surge current being generated when the CBB capacitor at the front end of the strong electric power supply circuit is charged, which affects the surge suppression effect. A choke type surge suppression circuit based on Zigbee control is provided, which has the advantages of not needing to draw power from strong electricity, solving the risk of device breakdown, convenient configuration time of delay through software, no need for a lot of calculation and debugging, and remote on-site configuration can be realized through software, high control delay accuracy, zero-crossing detection function to improve surge current suppression capability, good surge suppression effect without CBB capacitor, and reduced device cost.

[0010] The technical solution adopted by the utility model to solve the above technical problems is a choke type surge suppression circuit based on Zigbee control, including a surge suppression circuit and a Zigbee module, wherein a relay driving circuit is provided between the surge suppression circuit and the Zigbee module for connection; including a load switch and a load, wherein the output end of the load switch is connected to the input end of the surge suppression circuit, and the output end of the surge suppression circuit is connected to the input end of the load. On the basis of the original surge suppression circuit, a Zigbee module and a relay driving circuit are added to control the impedance of the power supply circuit in the circuit. In the initial state of power supply, the load is powered by the NTC resistor, which increases the impedance of the power supply circuit and suppresses the generation of large surge current. After effectively suppressing the surge current, the relay is closed again to short-circuit the NTC resistor, reduce the impedance of the power supply circuit, reduce the working pressure of the NTC resistor, and extend the service life of the NTC resistor. In this way, the utility model solves the existing problems of device breakdown risk, pure hardware delay requiring a lot of calculation and debugging, complex design, strong power environment debugging having certain dangers, delay effect easily affected by ambient temperature to reduce surge suppression effect, low delay accuracy, and new surge current generated when the CBB capacitor at the front end of the strong power supply circuit is charged, which affects the surge suppression effect. The utility model has the advantages of no need to take power from strong electricity, solve the risk of device breakdown, convenient configuration time of delay through software, no need for a lot of calculation and debugging, and remote on-site configuration can be realized through software, high control delay accuracy, better surge suppression effect without CBB capacitor, zero-crossing detection function to improve surge current suppression ability, and reduce device cost.

[0011] Preferably, the surge suppression circuit comprises an NTC resistor and a relay, the input end of the surge suppression circuit is connected to the output end of the surge suppression circuit via the NTC resistor; and the relay is connected in parallel at both ends of the NTC circuit.

[0012] Preferably, when the relay is disconnected, current passes through the NTC resistor, and when the relay is closed, the NTC resistor is bypassed.

[0013] Preferably, the NTC resistor is a negative temperature coefficient thermistor.

[0014] Preferably, the surge suppression circuit comprises a zero-crossing detection unit, and the zero-crossing detection unit delays the control of closing of the load switch.

[0015] Preferably, the Zigbee module includes an MCU to transmit high and low level signals to the relay drive circuit.

[0016] Preferably, the relay drive circuit comprises a transistor switch drive circuit, and the transistor switch drive circuit is controlled by the MCU; the control end of the transistor switch drive circuit is connected to an IO port of the MCU that outputs high and low levels.

[0017] Preferably, the MCU has 26 pins.

[0018] The beneficial effects of the utility model are that there is no need to draw power from a strong current, the risk of device breakdown is low, the delay time configuration is convenient through software, there is no need for a lot of calculation and debugging, and remote on-site configuration can be achieved through software, the control delay is highly accurate, the surge suppression effect is better without the CBB capacitor, and the zero-crossing detection function improves the surge current suppression capability and reduces the device cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a module flow chart of a choke type surge suppression circuit based on Zigbee control in the utility model;

[0020] Figure 2 This is a partial circuit diagram of a surge suppression circuit of a choke type surge suppression circuit based on Zigbee control in the utility model;

[0021] Figure 3 This is a circuit diagram of a zero-crossing detection unit of a choke-type surge suppression circuit based on Zigbee control in the utility model;

[0022] Figure 4 This is an MCU circuit diagram of a Zigbee module of a choke type surge suppression circuit based on Zigbee control in the utility model;

[0023] Figure 5 This is a transistor switch driving circuit diagram in a relay driving circuit of a choke type surge suppression circuit based on Zigbee control of the utility model;

[0024] Figure 6This is a realization method of a choke type surge suppression circuit based on Zigbee control in the utility model;

[0025] In the figure: 1. Surge suppression circuit, 2. Zigbee module, 3. Relay drive circuit, 4. Load switch, 5. Load. DETAILED DESCRIPTION

[0026] The specific implementation of the technical solution of the utility model is further described below through examples and in conjunction with the accompanying drawings.

[0027] According to one aspect of the present application, the utility model provides a choke type surge suppression circuit based on Zigbee control, including a surge suppression circuit and a Zigbee module, wherein a relay drive circuit is provided between the surge suppression circuit and the Zigbee module for connection; including a load switch and a load, wherein the output end of the load switch is connected to the input end of the surge suppression circuit, and the output end of the surge suppression circuit is connected to the input end of the load switch. A Zigbee module and a relay drive circuit are added to the original surge suppression circuit to control the impedance of the power supply circuit in the circuit, and in the initial state of power supply, the load is supplied with power through an NTC resistor, thereby increasing the impedance of the power supply circuit and suppressing the generation of large surge currents. After effectively suppressing the surge current, the relay is closed again to short-circuit the NTC resistor, thereby reducing the impedance of the power supply circuit, reducing the working pressure of the NTC resistor, and extending the service life of the NTC resistor.

[0028] In this embodiment, the AC power is input to the load switch, and then the AC live wire is connected to the surge suppression circuit. After the surge current is suppressed by the surge suppression circuit, the AC live wire is output and flows into the load.

[0029] Through the above settings, the surge current in the circuit is suppressed, which firstly greatly improves the stability of the power system. The suppression of surge current can prevent sudden changes in current, ensure the smooth operation of the power system, and reduce the possibility of load switch failure and power outage. In this way, industrial production can continue, and household electricity consumption is more reliable, providing a stable foundation for social and economic development. Secondly, suppressing surge current is also of great significance for protecting electronic load switches. Suppressing surge current can prevent the switching device from being subjected to excessive current shock, thereby extending the service life of the electronic load switch and improving the reliability and stability of the load switch. Solve the damage of the load switch caused by surge current, such as relay adhesion and switch tube burning.

[0030] See also Figure 1 As shown, the surge suppression circuit includes an NTC resistor and a relay, the input end of the surge suppression circuit is connected to the output end of the surge suppression circuit via the NTC resistor; the relay is connected in parallel at both ends of the NTC circuit.

[0031] In this embodiment, the relay model is HRS3FTH-S-DC12V-A.

[0032] The above settings play the following role: prevent the load switch from being damaged by the surge current caused by the charging of the load capacitor when the load is powered on. The impedance of the power circuit is increased by the NTC resistor, which suppresses the surge current generated at the moment the load is powered on. Bypassing the NTC resistor with a relay is to reduce the time the NTC works in the power circuit and extend the service life of the NTC resistor. If the NTC resistor works in the power circuit for a long time, the service life will be shortened due to excessive temperature rise, which will lead to damage to the NTC resistor. When the NTC resistor is damaged, the surge suppression ability of the circuit will fail.

[0033] See also Figure 2 As shown, when the relay is opened, current passes through the NTC resistor, and when the relay is closed, the NTC resistor is bypassed.

[0034] With the above settings, the relay: A relay is an electrical switch that receives a small input signal (such as current or voltage) and then opens or closes a large load circuit. Usually, a relay consists of a coil and a contact. When the coil is energized, the magnetic field changes, which attracts the contact to close and the circuit is turned on; when the coil is de-energized, the magnetic field disappears, the contact is disconnected, and the circuit is disconnected. NTC resistor: NTC is the abbreviation of negative temperature coefficient, which refers to a resistor whose resistance value decreases as the temperature increases. When the relay is disconnected, current passes through the NTC resistor. In this process, the NTC resistor absorbs electrical energy and converts it into heat energy, causing its own temperature to rise. When the relay is closed, the NTC resistor is bypassed. This means that the current no longer passes through the NTC resistor, but chooses to pass through the contacts of the relay. In this process, the temperature of the NTC resistor drops rapidly because the current no longer passes through it. This process can be repeated, so that the circuit can be turned on or off as needed, while achieving temperature control. The NTC resistor plays a role in surge suppression at the moment of power-on. After the suppression process is completed, the relay is automatically energized and turned on through the control of the Zigbee module. The NTC is bypassed and no longer works in the power circuit. Therefore, the bypass time of the NTC can be accurately controlled to extend the service life of the NTC resistor.

[0035] See also Figure 2 As shown, the NTC resistor is a negative temperature coefficient thermistor.

[0036] In this embodiment, the NTC resistor model is SCK15204.

[0037] NTC is used to suppress surge current, and the resistance of NTC will decrease as the temperature rises, so it will not burn out due to excessive power like ordinary resistors, and it will automatically reduce the impedance to avoid affecting the power supply to the load. The purpose is to reduce the impedance of the NTC resistor as the working time increases, avoid directly burning the NTC resistor and prevent the power circuit from losing the ability to suppress surge current. Avoiding the impact on the power supply to the load is specifically reflected in: when the circuit is working normally, the higher the resistance of the NTC resistor, according to the voltage divider theorem, the higher the voltage divided from the power supply, which reduces the voltage that the load can receive, and there is a hidden danger that the power supply voltage is lower than the normal working voltage. The voltage divider theorem refers to the fact that in a series circuit, the current on each resistor is equal, and the sum of the voltages across each resistor is equal to the total voltage of the circuit. In other words, in a series circuit, the voltage on each resistor is less than the total voltage of the circuit, so series resistors can be used for voltage division. The formula of the voltage divider theorem is R1:R2=U1:U2, where R1 and R2 are series resistors, U1 and U2 are the voltages at their ends, that is, in a series circuit, the voltage divided is proportional to the resistance value. Specifically, in the circuit of this embodiment, the NTC resistor is connected in series with the load circuit, and the voltage that can be divided by the load circuit is proportional to the ratio of the total resistance value of the load circuit to the resistance value of the NTC resistor, that is, U 负载 =U 总 *(R 负载 / R 负载 +R NTC ).

[0038] See also Figure 3 As shown, the surge suppression circuit includes a zero-crossing detection unit, and the zero-crossing detection unit delays the closing of the load switch.

[0039] In this embodiment, the zero-crossing detection unit includes two diodes, three resistors and an optocoupler, the AC live wire is connected to the positive terminal of the first diode D4, the negative terminal of D4 is connected to the first terminal of the first resistor R16, the second terminal of R16 is connected to the first terminal of the second resistor R19, the second terminal of R19 is connected to the first terminal of the third resistor R65, the second terminal of R65 is connected to the first terminal of the phototransistor O1, the second terminal of O1 is connected to the positive terminal of the second diode D23, the negative terminal of D23 is connected to the AC neutral wire, the third terminal of O1 is grounded, the fourth terminal of O1 is connected to the first terminal of the fourth resistor R3 and the ADC sampling IO port of the MCU, and the second terminal of R3 is connected to a 3.3V power supply.

[0040] Through the above settings, the power supply voltage can be monitored in real time and a signal can be generated when the voltage crosses the zero point. This signal can be used as a trigger signal for the power control system to synchronize the operation of the power system. For example, in household appliances, the zero-crossing detection unit can control the precise moment of the power switch to ensure smooth switching of the power supply, reduce the impact on the load switch of the appliance, and increase its service life.

[0041] See also Figure 4 As shown, the Zigbee module includes an MCU, which transmits high and low level signals to the relay drive circuit.

[0042] In this embodiment, the MCU used has 26 interfaces, the first, third, fifteenth and eighteenth interfaces are grounded, the sixteenth and seventeenth interfaces are connected to the VCC power supply terminal, the twenty-fifth interface is connected to the zero signal sampling, and the twenty-sixth interface is connected to the relay drive circuit control terminal.

[0043] Through the above settings, the high and low levels provided by the IO port of the MCU are used to control the transistor to work in the saturation region or the cutoff region, realize the transistor switch function, and drive the relay to close or disconnect. In modern electronic systems, microcontrollers (MCUs) are often used to control various load switches and work processes. Among them, the IO port is an important interface, which can control the switch state of the external circuit by outputting high and low levels. The transistor is a common semiconductor device that has a current amplification function and can control large currents. The relay is a switch load switch that can control high voltage and large current, and is often used for the control and protection of power systems. The high and low levels provided by the IO port of the MCU are used to control the transistor to work in the saturation region or the cutoff region, realize the transistor switch function, and drive the relay to close or disconnect, which is a common application in power electronic control systems. When the IO port of the MCU outputs a high level, the transistor is in a saturated state. At this time, the base and emitter of the transistor are equivalent to a closed switch, and the current can flow through the transistor to the relay coil to close the relay. At this time, the transistor acts as a switch to control the on and off of the current. When the IO port of the MCU outputs a low level, the transistor is in the cut-off state. At this time, the base and emitter of the transistor are equivalent to a switch disconnected, and the current cannot flow through the transistor to the relay coil, so the relay is disconnected. In this way, we can control the switch state of the transistor by changing the output level of the IO port of the MCU, and then control the closing and opening of the relay. This technology is widely used in various power electronic load switches, such as motor control, lighting control, power switch, etc. In practical applications, in order to ensure the stability and reliability of the system, some other factors need to be considered. For example, it is necessary to select appropriate transistor and relay models to meet the current, voltage and frequency requirements of the system; it is also necessary to design reasonable circuit protection measures to prevent abnormal conditions such as overvoltage and overcurrent from damaging the system; at the same time, it is also necessary to optimize the MCU program to achieve precise control and rapid response to the system. In short, it is a very practical technical means to control the relay by controlling the switch state of the transistor through the IO port of the MCU.

[0044] See also Figure 4As shown, the relay drive circuit includes a transistor switch drive circuit, and the transistor switch drive circuit is controlled by the MCU; the control end of the transistor switch drive circuit is connected to the IO port of the MCU that outputs high and low levels.

[0045] In this embodiment, the number of pins of the MCU is 26.

[0046] Through the above settings, the control of the transistor switch is handed over to the MCU, which improves the accuracy and adjustability of the control and achieves accurate and controllable delay.

[0047] See also Figure 5 As shown, the relay control circuit includes two resistors and a transistor, and the transistor model is MMBT9013H.

[0048] In this embodiment, the twenty-sixth pin of the MCU is connected to the first end of the first resistor R111, the second end of R111 is connected to the first end of the second resistor R17 and the base of the transistor Q11, the second end of R17 and the emitter of Q11 are grounded, and the collector of Q11 is connected to the first end of the relay.

[0049] Figure 6 It is a circuit diagram of a solution that can realize the functions of this application.

[0050] The driver connects the IO interface (interface 26) of the MCU through pin 1 of the optocoupler, provides a high level, and then the optocoupler is turned on, and the MOS tube is turned on to the base. The voltage between the gate and the drain is guaranteed to be 5.6V through the voltage regulator diode to avoid breakdown.

Claims

1. A choke type surge suppression circuit based on Zigbee control, characterized in that: It includes a surge suppression circuit and a Zigbee module, wherein a relay driving circuit is provided between the surge suppression circuit and the Zigbee module for connection; It includes a load switch and a load, wherein the output end of the load switch is connected to the input end of the surge suppression circuit, the output end of the surge suppression circuit is connected to the load, the surge suppression circuit includes an NTC resistor and a relay, the input end of the surge suppression circuit is connected to the output end of the surge suppression circuit via the NTC resistor; and the relay is connected in parallel at both ends of the NTC resistor.

2. The choke type surge suppression circuit based on Zigbee control according to claim 1, characterized in that: When the relay is opened, current passes through the NTC resistor, and when the relay is closed, the NTC resistor is bypassed.

3. A choke type surge suppression circuit based on Zigbee control according to claim 1 or 2, characterized in that: The NTC resistor is a negative temperature coefficient thermistor.

4. The choke type surge suppression circuit based on Zigbee control according to claim 1, characterized in that: The surge suppression circuit comprises a zero-crossing detection unit, and the zero-crossing detection unit delays the control of the load switch closing.

5. The choke type surge suppression circuit based on Zigbee control according to claim 1, characterized in that: The Zigbee module includes an MCU, which transmits high and low level signals to the relay drive circuit.

6. The choke type surge suppression circuit based on Zigbee control according to claim 5, characterized in that: The relay drive circuit includes a transistor switch drive circuit, and the transistor switch drive circuit is controlled by the MCU; the control end of the transistor switch drive circuit is connected to the IO port of the MCU outputting high and low levels.

7. A choke type surge suppression circuit based on Zigbee control according to claim 5 or 6, characterized in that: The number of pins of the MCU is 26.

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