KNX-based anti-interference control circuit and device

Abstract

The invention discloses an anti-interference control circuit and device based on KNX. The circuit comprises a protection circuit, a power extraction circuit, a KNX transceiver, a voltage conversion circuit, an MCU control circuit and a relay control circuit. The protection circuit is connected to the KNX bus and protects the KNX transceiver. The power supply extraction circuit obtains a stable first power supply from a bus direct current component obtained after the KNX transceiver performs impedance adjustment on a power supply signal of the KNX bus so as to supply power to the relay control circuit; the voltage conversion circuit filters and compensates a signal output by the KNX transceiver after the first power supply is reduced so as to obtain a second power supply for supplying power to the MCU control circuit; the MCU control circuit controls the relay control circuit and performs data transmission with a KNX bus through the KNX transceiver; the relay control circuit controls on-off of an external load. According to the invention, the interference to the KNX bus can be avoided, and the reliability and stability of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to an anti-interference control circuit and device based on KNX. Background Art

[0002] According to the requirements of the KNX protocol, KNX bus devices need to extract power from the KNX bus power supply to power the KNX transceiver, MCU controller or other control units without an external auxiliary power supply. Since the maximum power current of each KNX node device is only 30mA, the current output of the KNX transceiver, MCU controller or other control units for logic control is often limited. Especially when controlling some relay devices, considering the sudden change of the instantaneous current of the relay device and the harmonic interference of the back electromotive force generated by the internal coil of the relay, the bus data will be interfered with, causing the device nodes to fail to communicate normally. In the case of severe interference, the terminal devices under the entire node cannot work. In order to improve the stability of the system, the method adopted by the prior art is to directly use the DC-DC power management chip to draw power from the KNX bus to power devices such as MCU and relays. Under normal circumstances, the system can maintain relatively stable operation, but there are two fatal defects: 1. Because of the effect of the inductance in the DC-DC power management chip, it will cause greater noise, which will be coupled to the KNX bus, and will cause different degrees of interference to the KNX bus data transmission, reducing the communication reliability of the KNX bus. 2. In order to reduce the power consumption of the system, a low-power magnetic latching relay is used. Once the relay ages and the power consumption is too high, the transient current will be too large when the relay is turned on or off instantly, exceeding the output of the bus current, which will cause the entire system to collapse and the system stability will be poor. Summary of the invention

[0003] The embodiment of the present invention provides a KNX-based anti-interference control circuit and device, aiming to solve the problem of poor reliability and stability of the KNX system in the prior art.

[0004] In the first aspect, an embodiment of the present invention provides an anti-interference control circuit based on KNX, which includes: a protection circuit, a power extraction circuit, a KNX transceiver, a voltage conversion circuit, an MCU control circuit and a relay control circuit; the protection circuit is connected to the power extraction circuit and the KNX transceiver, the power extraction circuit is connected to the KNX transceiver, the voltage conversion circuit and the relay control circuit, the voltage conversion circuit is connected to the KNX transceiver and the MCU control circuit, the MCU control circuit is connected to the KNX transceiver and the relay control circuit; the protection circuit is used to access the KNX bus and protect the KNX transceiver; the power extraction circuit is used to transmit the power signal of the KNX bus to the The KNX transceiver is used to obtain a stable first power supply from the bus DC component obtained after the KNX transceiver performs impedance adjustment on the power supply signal of the KNX bus; wherein the first power supply is used to power the relay control circuit; the voltage conversion circuit is used to transmit the first power supply to the KNX transceiver, and filter and compensate the signal output after the KNX transceiver reduces the first power supply to obtain a second power supply; wherein the second power supply is used to power the MCU control circuit; the MCU control circuit is used to control the relay control circuit and transmit data with the KNX bus through the KNX transceiver; the relay control circuit is used to connect an external load and control the on and off of the external load.

[0005] In a second aspect, an embodiment of the present invention further provides a KNX-based anti-interference control device, which includes the KNX-based anti-interference control circuit described in the first aspect.

[0006] The embodiment of the present invention provides an anti-interference control circuit and device based on KNX, the circuit includes a protection circuit, a power extraction circuit, a KNX transceiver, a voltage conversion circuit, an MCU control circuit and a relay control circuit; the protection circuit is connected to the KNX bus and protects the KNX transceiver; the power extraction circuit obtains a stable first power supply from the bus DC component obtained after the KNX transceiver performs impedance adjustment on the power signal of the KNX bus to power the relay control circuit; the voltage conversion circuit filters and compensates the signal output after the KNX transceiver reduces the first power supply to obtain a second power supply for powering the MCU control circuit; the MCU control circuit controls the relay control circuit and transmits data with the KNX bus through the KNX transceiver; the relay control circuit controls the on-off of the external load. The present invention can avoid interference with the KNX bus and improve the reliability and stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] 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.

[0008] Figure 1 A schematic block diagram of a KNX-based anti-interference control circuit provided in accordance with an embodiment of the present invention;

[0009] Figure 2 A circuit diagram of a KNX-based anti-interference control circuit provided by an embodiment of the present invention;

[0010] Figure 3 A circuit diagram of a relay control subcircuit provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0011] 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.

[0012] 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, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0013] 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, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0014] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0015] For any resistor or capacitor mentioned in the embodiments of the present invention, if the resistor or capacitor is horizontally arranged in the circuit diagram, then from left to right are the first end of the resistor or capacitor and the second end of the resistor or capacitor; if the resistor or capacitor is arranged vertically to the horizontal direction in the circuit diagram, then from top to bottom are the first end of the resistor or capacitor and the second end of the resistor or capacitor.

[0016] See also Figures 1 to 3 , Figure 1 A schematic block diagram of a KNX-based anti-interference control circuit provided in accordance with an embodiment of the present invention; Figure 2 A circuit diagram of a KNX-based anti-interference control circuit provided by an embodiment of the present invention; Figure 3 A circuit diagram of a relay control subcircuit provided in accordance with an embodiment of the present invention.

[0017] The anti-interference control circuit based on KNX provided in an embodiment of the present invention includes: a protection circuit 1, a power extraction circuit 2, a KNX transceiver U1, a voltage conversion circuit 3, an MCU control circuit 4 and a relay control circuit 5; the protection circuit 1 is connected to the power extraction circuit 2 and the KNX transceiver U1, the power extraction circuit 2 is connected to the KNX transceiver U1, the voltage conversion circuit 3 and the relay control circuit 5, the voltage conversion circuit 3 is connected to the KNX transceiver U1 and the MCU control circuit 4, and the MCU control circuit 4 is connected to the KNX transceiver U1 and the relay control circuit 5; the protection circuit 1 is used to access the KNX bus and protect the KNX transceiver U1; the power extraction circuit 2 is used to transmit the power signal of the KNX bus to the KNX transceiver U1 and obtain a stable first power supply VDDHV from the bus DC component obtained after the KNX transceiver U1 performs impedance adjustment on the power supply signal of the KNX bus; wherein the first power supply VDDHV is used to power the relay control circuit 5; the voltage conversion circuit 3 is used to transmit the first power supply VDDHV to the KNX transceiver U1, and filter and compensate the signal output after the KNX transceiver U1 reduces the first power supply VDDHV to obtain a second power supply VDD; wherein the second power supply VDD is used to power the MCU control circuit 4; the MCU control circuit 4 is used to control the relay control circuit 5, and transmit data with the KNX bus through the KNX transceiver U1; the relay control circuit 5 is used to connect an external load and control the on and off of the external load.

[0018] In this embodiment, see Figure 1 and Figure 2The anti-interference control circuit based on KNX includes a protection circuit 1, a power extraction circuit 2, a KNX transceiver U1, a voltage conversion circuit 3, an MCU control circuit 4 and a relay control circuit 5. Further, the KNX transceiver U1 is internally integrated with an impedance modulator, a voltage reducer, a receiver, a transmitter, a pulse equalizer and a digital logic. Specifically, the protection circuit 1 is connected to the KNX bus, and the protection circuit 1 can play a protective role against overcurrent, overvoltage and reverse connection, thereby preventing the subsequent KNX transceiver U1 from being damaged. The power extraction circuit 2 can control the current change rate of the KNX bus (i.e., the differential relationship dI / dt between current and time), so that the power signal fanned out by the KNX bus flows into the impedance modulator inside the KNX transceiver U1, and the impedance modulator adjusts the impedance of the power signal of the KNX bus to obtain a bus DC component, and the power extraction circuit 2 extracts a stable first power supply VDDHV from the bus DC component, so as to power the relay control circuit 5 through the first power supply VDDHV. The voltage conversion circuit 3 transmits the first power supply VDDHV to the buck inside the KNX transceiver U1, and the first power supply VDDHV is bucked by the buck to reduce the first power supply VDDHV. The voltage conversion circuit 3 filters and compensates the signal output by the buck to obtain the second power supply VDD, and then supplies power to the MCU control circuit 4 through the second power supply VDD. The MCU control circuit 4 controls the relay control circuit 5, and then connects or disconnects the connected external load through the relay control circuit 5, wherein the relay control circuit 5 can control multiple external loads, and can also realize data transmission between the MCU control circuit 4 and the KNX bus through the receiver, transmitter, pulse equalizer and digital logic inside the KNX transceiver U1.

[0019] The KNX-based anti-interference control circuit provided in the embodiment of the present invention extracts a stable first power supply VDDHV from the KNX bus through the power extraction circuit 2 and the KNX transceiver U1 to power the relay control circuit 5, and obtains a second power supply VDD from the first power supply VDDHV through the voltage conversion circuit 3 and the KNX transceiver U1 to power the MCU control circuit 4. There is no need to use a DC-DC power management chip to directly draw power from the KNX bus, which solves the interference of multi-channel control and changes in instantaneous current on the KNX system and improves the reliability and stability of the system.

[0020] In a more specific embodiment, the protection circuit 1 includes a connecting terminal J1, a transient diode TVS, a first magnetic bead FB1, a first diode D1 and a first resistor R1; one end of the transient diode TVS is connected to the anode of the first diode D1 and one end of the connecting terminal J1, the other end of the transient diode TVS and the other end of the connecting terminal J1 are grounded through the first magnetic bead FB1, the anode of the first diode D1 is also connected to the first end of the first resistor R1 and the KNX transceiver U1, the cathode of the first diode D1 is connected to the power extraction circuit 2 and the KNX transceiver U1, and the second end of the first resistor R1 is grounded.

[0021] In this embodiment, see Figure 2 The connecting terminal J1 is used to connect to the KNX bus. The transient diode TVS provides overcurrent and overvoltage protection for the bus to prevent the subsequent KNX transceiver U1 from being burned by surges. The first magnetic bead FB1 plays the role of isolation and filtering. The first diode D1 is an input diode, which plays the role of reverse polarity connection, and the first resistor R1 is a reverse polarity discharge resistor.

[0022] In a more specific embodiment, the power extraction circuit 2 includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6 and a second diode D2; the first end of the first capacitor C1 is connected to the cathode of the first diode D1, and the second end of the first capacitor C1 is connected to the VGATE pin of the KNX transceiver U1; the first end of the second capacitor C2 is grounded, and the second end of the second capacitor C2 is connected to the VREF pin of the KNX transceiver U1; the first end of the third capacitor C3, the first end of the fourth capacitor C4, the first end of the fifth capacitor C5 and the cathode of the second diode D2 are all connected to the VDDHV pin of the KNX transceiver U1, and the fifth capacitor C5 is grounded. The second end of the third capacitor C3, the second end of the fourth capacitor C4 and the second end of the sixth capacitor C6 are all connected to the VFLT pin of the KNX transceiver U1, the second end of the third capacitor C3, the second end of the fourth capacitor C4 and the second end of the sixth capacitor C6 are all grounded, and the anode of the second diode D2 is connected to the VDDHV_PD pin of the KNX transceiver U1; wherein, the node connected with the first end of the third capacitor C3, the first end of the fourth capacitor C4, the first end of the fifth capacitor C5, the cathode of the second diode D2 and the VDDHV pin of the KNX transceiver U1 is used as the first power supply end, the first power supply end is connected to the relay control circuit 5 and the voltage conversion circuit 3, and the first power supply end is used to output the stable first power supply VDDHV.

[0023] In this embodiment, see Figure 2, the first capacitor C1 is used to control the dI / dt of the KNX bus, that is, the size of the first capacitor C1 determines the dI / dt of the KNX bus, and controls the impedance of the bus device during the active pulse and the balanced pulse according to the KNX standard. Since the current drawn from the KNX bus must change very slowly, the sudden load current step from the load applied to the KNX must be absorbed by the large filter capacitor, so the size of the first capacitor C1 should be determined accordingly. The capacitance value of the first capacitor C1 can be set according to the desired current change rate, and then the required first power supply VDDHV is extracted, while ensuring compliance with the KNX impedance specification. Among them, for the current fan-in of the bus load with higher current, it is useful to set a higher current change rate in order to manage wider load changes, thereby minimizing the value of the first power supply VDDHV. Preferably, the capacitance value of the first capacitor C1 in this embodiment can be set to 10uF, which allows the KNX bus to fan out a maximum current of 30mA. The second diode D2 is an output diode. The second diode D2 mainly functions to smooth the DC component of the bus. The fifth capacitor C5 and the sixth capacitor C6 compensate for the impedance change caused by the voltage fluctuation on the bus. The third capacitor C3 and the fourth capacitor C4 play a role of smoothing and filtering. In addition, the third capacitor C3 and the fourth capacitor C4 are used instead of a large capacitor. The reason is that the frequency characteristics of the decoupling can be better, thereby smoothing any load changes applied at the output of the first power supply end, and outputting a stable first power supply VDDHV at the first power supply end, so as to power the relay control circuit 5 through the stable first power supply VDDHV.

[0024] In a more specific embodiment, the voltage conversion circuit 3 includes a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12, a second resistor R2, a third resistor R3, a first inductor L1 and a second magnetic bead FB2; the DCDC_IN pin of the KNX transceiver U1 is connected to the first power supply end and the first end of the eighth capacitor C8, and the second end of the eighth capacitor C8 is grounded; the DCDC_LX pin of the KNX transceiver U1 is connected to the first end of the first inductor L1, and the second end of the first inductor L1 is connected to the first end of the ninth capacitor C9, the first end of the tenth capacitor C10, the first end of the eleventh capacitor C11, one end of the second magnetic bead FB2, and the first end of the third resistor R3. The second end of the second magnetic bead FB2 is connected to the second end of the seventh capacitor C7, and the other end of the second magnetic bead FB2 is grounded through the twelfth capacitor C12; the DCDC_GND pin of the KNX transceiver U1, the second end of the ninth capacitor C9, the second end of the tenth capacitor C10 and the second end of the eleventh capacitor C11 are all grounded; the DCDC_FB pin of the KNX transceiver U1 is connected to the first end of the second resistor R2, the first end of the third resistor R3 and the first end of the seventh capacitor C7, and the second end of the second resistor R2 is grounded; wherein, the node where the second magnetic bead FB2 and the twelfth capacitor C12 are connected is used as the second power supply end, the second power supply end is connected to the MCU control circuit 4, and the second power supply end is used to output the second power supply VDD.

[0025] In this embodiment, see Figure 2 , the internal voltage reducer of the KNX transceiver U1 is connected to the first power supply VDDHV and performs voltage reduction processing on the first power supply VDDHV, the eighth capacitor C8 is connected to the input end of the internal voltage reducer of the KNX transceiver U1, and the eighth capacitor C8 mainly plays the role of decoupling and energy storage. The first inductor L1 is the output inductor of the internal voltage reducer of the KNX transceiver U1, which plays the role of smoothing, energy storage and filtering. The first inductor L1 and the ninth capacitor C9, the tenth capacitor C10 and the eleventh capacitor C11 form an LC low-pass filter circuit. Among them, the ninth capacitor C9, the tenth capacitor C10 and the eleventh capacitor C11 take three different values ​​respectively, and better frequency characteristics can be obtained. The second resistor R2 and the third resistor R3 form a negative feedback circuit of the voltage reducer to adjust the output voltage of the voltage reducer, wherein the seventh capacitor C7 is a compensation capacitor, and the seventh capacitor C7 and the third resistor R3 form an RC phase compensation circuit to improve the stability of the entire feedback loop. In addition, the second magnetic bead FB2 and the twelfth capacitor C12 play an efficient filtering role, and the second power supply VDD is output at the node where the second magnetic bead FB2 and the twelfth capacitor C12 are connected, so as to obtain the second power supply VDD for powering the MCU control circuit based on the first power supply VDDHV.

[0026] In a more specific embodiment, the MCU control circuit 4 includes a thirteenth capacitor C13, a fourth resistor R4 and an MCU chip U2; the first end of the thirteenth capacitor C13 is connected to the KNX_TX pin of the KNX transceiver U1, and the second end of the thirteenth capacitor C13 is connected to the MCU chip U2; the first end of the fourth resistor R4 is connected to the KNX_RX pin of the KNX transceiver U1, and the second end of the fourth resistor R4 is connected to the MCU chip U2; the MCU chip U2 is connected to the second power supply end and the relay control circuit 5.

[0027] In this embodiment, see Figure 2 , the MCU chip U2 is connected to the KNX_RX pin and KNX_TX pin of the KNX transceiver U1 through the fourth resistor R4 and the thirteenth capacitor C13 respectively, and the data of the MCU chip U2 is coupled to the KNX bus through the KNX transceiver U1, meeting the requirements of the KNX protocol stack. Among them, the fourth resistor R4 is a short-circuit resistor at the receiving end to prevent signal overshoot. The thirteenth capacitor C13 is the MCU chip U2 transmission data coupling capacitor, which can isolate the direct current and take the data amplitude value to prevent the direct current component from interfering with the KNX transceiver U1.

[0028] In a more specific embodiment, the relay control circuit 5 includes at least one relay control sub-circuit, each relay control sub-circuit includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first transistor Q1, a second transistor Q2, a double-coil magnetic latching relay LS1, a third diode D3, a fourth diode D4, a fourteenth capacitor C14 and a third magnetic bead FB3; the first end of the fifth resistor R5 and the first end of the seventh resistor R7 are respectively connected to an IO pin of the MCU chip U2; the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6 and the base of the first transistor Q1, the second end of the sixth resistor R6 and the emitter of the first transistor Q1 are both grounded, and the collector of the first transistor Q1 is connected to the first pin of the double-coil magnetic latching relay LS1 and the The anode of the fourth diode D4 is connected; the second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8 and the base of the second transistor Q2, the second end of the eighth resistor R8 and the emitter of the second transistor Q2 are both grounded, and the collector of the second transistor Q2 is connected to the second pin of the double-coil magnetic latching relay LS1 and the anode of the third diode D3; the cathode of the third diode D3, the cathode of the fourth diode D4, the first end of the fourteenth capacitor C14 and the first end of the ninth resistor R9 are all connected to the fifth pin of the double-coil magnetic latching relay LS1, the second end of the fourteenth capacitor C14 is grounded, and the second end of the ninth resistor R9 is connected to the first power supply end through the third magnetic bead FB3; the third pin and the fourth pin of the double-coil magnetic latching relay LS1 are used to connect the external load.

[0029] In this embodiment, see Figure 3, the fifth resistor R5 and the seventh resistor R7 are respectively connected in series to an IO pin of the MCU chip U2, and the resistance values ​​of the fifth resistor R5 and the seventh resistor R7 respectively control the current size when the first transistor Q1 and the second transistor Q2 are turned on. The sixth resistor R6 and the eighth resistor R8 are pull-down resistors, which discharge the residual voltage and residual current of the base of the first transistor Q1 and the second transistor Q2 respectively. The collector of the first transistor Q1 and the collector of the second transistor Q2 are respectively connected to the first pin and the second pin of the double-coil magnetic latching relay LS1 (i.e., the coil end inside the double-coil magnetic latching relay LS1), wherein the coil inside the double-coil magnetic latching relay LS1 adopts a high-voltage design and can directly withstand a 36V DC voltage. The third diode D3 and the fourth diode D4 are freewheeling diodes, and form a loop with the coil of the double-coil magnetic latching relay LS1. The function of this loop is that when the first transistor Q1 or the second transistor Q2 is turned on, current flows through the coil of the double-coil magnetic latching relay LS1, the coil generates magnetic attraction, and the spring inside the double-coil magnetic latching relay LS1 (i.e., the third pin and the fourth pin of the double-coil magnetic latching relay LS1) is closed or disconnected; when the first transistor Q1 or the second transistor Q2 is turned off, the coil generates a back electromotive force, and the back electromotive force current flows through the third diode D3 or the fourth diode D4 to the fourteenth capacitor C14 to prevent the current spike from impacting the double-coil magnetic latching relay LS1, thereby preventing damage to the relay. The switch state of the double-coil magnetic latching relay LS1 (i.e., the closing or disconnection of the third pin and the fourth pin of the double-coil magnetic latching relay LS1) is not maintained by continuous current, but is maintained by the magnetic force generated by the permanent magnet. The switch state of the double-coil magnetic latching relay LS1 can be completed by simply exciting the coil with positive and negative pulse signals.

[0030] Specifically, the third pin and the fourth pin of the dual-coil magnetic latching relay LS1 are connected to the external load, wherein the third pin and the fourth pin of the dual-coil magnetic latching relay LS1 serve as a signal output pin and a signal input pin, respectively. When the MCU chip U2 controls the first transistor Q1 to send a 50ms high-level pulse signal, the dual-coil magnetic latching relay LS1 is closed, that is, the third pin and the fourth pin of the dual-coil magnetic latching relay LS1 are closed, thereby connecting the connected external load; when the MCU chip U2 controls the second transistor Q2 to send a 50ms high-level pulse signal, the dual-coil magnetic latching relay LS1 is opened, that is, the third pin and the fourth pin of the dual-coil magnetic latching relay LS1 are disconnected, thereby cutting off the connected external load. At the same time, the third magnetic bead FB3 plays the role of isolation and filtering, and considering that the double-coil magnetic holding relay LS1 will cause instantaneous fluctuations in current when it is opened or closed, it is necessary to add an RC filtering network, which is composed of a ninth resistor R9 and a fourteenth capacitor C14. The ninth resistor R9 and the fourteenth capacitor C14 are also an integrating circuit for the power-on of the double-coil magnetic holding relay LS1, which can slowly increase the current of the double-coil magnetic holding relay LS1 to avoid interference with the bus data.

[0031] Furthermore, the number of relay control subcircuits is not specifically limited here and can be limited according to specific application requirements. For example, the number of relay control subcircuits can be increased to 12, and because there are more relay control subcircuits, the IO control of the MCU chip U2 needs to be time-sharing controlled to achieve multi-channel control.

[0032] In a more specific embodiment, the KNX-based anti-interference control circuit also includes a fifteenth capacitor C15 and a fifth diode D5; the first end of the fifteenth capacitor C15 is connected to the cathode of the first diode D1, the second end of the fifteenth capacitor C15 is connected to the cathode of the fifth diode D5 and the KNX_AC pin of the KNX transceiver U1, and the anode of the fifth diode D5 is grounded.

[0033] In this embodiment, see Figure 2, the fifteenth capacitor C15 is a bus AC coupling capacitor, and the fifth diode D5 is an embedded diode after the bus AC coupling, which can improve the noise introduced from the outside. The fifteenth capacitor C15 and the fifth diode D5 are connected to the KNX_AC pin of the KNX transceiver U1, that is, the fifteenth capacitor C15 and the fifth diode D5 are connected to the receiver inside the KNX transceiver U1. The receiver inside the KNX transceiver U1 detects the start and end of the valid pulse on the KNX bus, and provides a logic level output on the KNX_RX pin of the KNX transceiver U1, so that the MCU chip U2 receives the data. Among them, the logic level of the KNX_RX pin of the KNX transceiver U1 is high during the valid pulse and low during the balancing stage and the idle state.

[0034] In a more specific embodiment, the KNX-based anti-interference control circuit further includes a tenth resistor R10; a first end of the tenth resistor R10 is connected to the cathode of the first diode D1, and a second end of the tenth resistor R10 is connected to the RTX pin of the KNX transceiver U1.

[0035] In this embodiment, see Figure 2 , the tenth resistor R10 is connected to the RTX pin of the KNX transceiver U1, that is, the tenth resistor R10 is connected to the transmitter inside the KNX transceiver U1. The tenth resistor R10 is a buffer resistor at the KNX data transmitter, and its power is greater than 1W. The value of the tenth resistor R10 is between 40Ω-100Ω. Its function is to superimpose a valid pulse on the bus voltage, and absorb the overshoot current through the tenth resistor R10, thereby avoiding damage to the KNX transceiver U1. Among them, the transmitter inside the KNX transceiver U1 converts the logic level signal received by the KNX_TX pin of the KNX transceiver U1 into an analog signal on the KNX bus, and transmits it to the KNX bus through the RTX pin of the KNX transceiver U1, thereby coupling the data of the MCU chip U2 to the KNX bus. Specifically, to transmit a logic 1 signal, the MCU chip U2 controls the KNX_TX pin of the KNX transceiver U1 to maintain a low level for 104μs; to transmit a logic 0 signal, the MCU chip U2 must force the KNX_TX of the KNX transceiver U1 to be a high level for 35μs first and then a low level for 69μs.

[0036] In a more specific embodiment, the KNX-based anti-interference control circuit also includes a sixteenth capacitor C16, a seventeenth capacitor C17, an eleventh resistor R11 and a twelfth resistor R12; the first end of the sixteenth capacitor C16 is connected to the anode of the first diode D1, and the second end of the sixteenth capacitor C16 is connected to the CP_H pin of the KNX transceiver U1 through the eleventh resistor R11; the first end of the seventeenth capacitor C17 is connected to the CP_L pin of the KNX transceiver U1 through the twelfth resistor R12, and the second end of the seventeenth capacitor C17 is grounded.

[0037] In this embodiment, see Figure 2 The sixteenth capacitor C16 and the eleventh resistor R11 form the positive phase input terminal of the pulse equalizer inside the KNX transceiver U1, wherein the sixteenth capacitor C16 is a separation capacitor and the eleventh resistor R11 is an input impedance. The seventeenth capacitor C17 and the twelfth resistor R12 form the negative phase input terminal of the pulse equalizer, and the values ​​of the seventeenth capacitor C17 and the twelfth resistor R12 are respectively consistent with the values ​​of the sixteenth capacitor C16 and the eleventh resistor R11, and the negative phase input terminal is grounded to maintain impedance balance with the positive phase input terminal.

[0038] In one embodiment, the PCB board of the KNX-based anti-interference control circuit adopts a two-layer board layout, wherein the top layer basically maintains the integrity of a GND, and the bottom layer mainly places the KNX transceiver U1, the MCU chip U2, the double-coil magnetic latching relay LS1 and its passive components, and the routing of the bottom layer control port corresponds to the top layer, thereby achieving a better EMC design effect.

[0039] An embodiment of the present invention further provides a KNX-based anti-interference control device, which includes the KNX-based anti-interference control circuit described in the above embodiment.

[0040] In this embodiment, the KNX-based anti-interference control device can be applied to KNX bus device terminal products, such as KNX actuators, KNX intelligent gateways, KNX thermostats, KNX control panels, etc. The KNX-based anti-interference control device has a KNX-based anti-interference control circuit as described in any of the above embodiments, so it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0041] The embodiment of the present invention provides a KNX-based anti-interference control circuit and device, the circuit includes a protection circuit, a power extraction circuit, a KNX transceiver, a voltage conversion circuit, an MCU control circuit and a relay control circuit; the protection circuit is connected to the KNX bus and protects the KNX transceiver; the power extraction circuit obtains a stable first power supply from the bus DC component obtained after the KNX transceiver performs impedance adjustment on the power signal of the KNX bus to power the relay control circuit; the voltage conversion circuit filters and compensates the signal output after the KNX transceiver reduces the first power supply to obtain a second power supply for powering the MCU control circuit; the MCU control circuit controls the relay control circuit and transmits data with the KNX bus through the KNX transceiver; the relay control circuit controls the on-off of the external load. The present invention can avoid interference with the KNX bus and improve the reliability and stability of the system.

[0042] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions 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 KNX-based anti-interference control circuit, characterized in that: include: Protection circuit, power extraction circuit, KNX transceiver, voltage conversion circuit, MCU control circuit and relay control circuit; The protection circuit is connected to the power extraction circuit and the KNX transceiver, the power extraction circuit is connected to the KNX transceiver, the voltage conversion circuit and the relay control circuit, the voltage conversion circuit is connected to the KNX transceiver and the MCU control circuit, and the MCU control circuit is connected to the KNX transceiver and the relay control circuit; The protection circuit is used to access the KNX bus and protect the KNX transceiver; The power extraction circuit is used to transmit the power signal of the KNX bus to the KNX transceiver, and obtain a stable first power supply from the bus DC component obtained after the KNX transceiver performs impedance adjustment on the power signal of the KNX bus; wherein the first power supply is used to power the relay control circuit; The voltage conversion circuit is used to transmit the first power supply to the KNX transceiver, and filter and compensate the signal output by the KNX transceiver after reducing the first power supply to obtain a second power supply; wherein the second power supply is used to power the MCU control circuit; The MCU control circuit is used to control the relay control circuit and perform data transmission with the KNX bus through the KNX transceiver; The relay control circuit is used to connect an external load and control the on and off of the external load.

2. The KNX-based anti-interference control circuit according to claim 1 is characterized in that: The protection circuit includes a connecting terminal, a transient diode, a first magnetic bead, a first diode and a first resistor; One end of the transient diode is connected to the anode of the first diode and one end of the connecting terminal, the other end of the transient diode and the other end of the connecting terminal are grounded through the first magnetic bead, the anode of the first diode is also connected to the first end of the first resistor and the KNX transceiver, the cathode of the first diode is connected to the power extraction circuit and the KNX transceiver, and the second end of the first resistor is grounded.

3. The KNX-based anti-interference control circuit according to claim 2 is characterized in that: The power extraction circuit includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor and a second diode; The first end of the first capacitor is connected to the cathode of the first diode, and the second end of the first capacitor is connected to the VGATE pin of the KNX transceiver; the first end of the second capacitor is grounded, and the second end of the second capacitor is connected to the VREF pin of the KNX transceiver; the first end of the third capacitor, the first end of the fourth capacitor, the first end of the fifth capacitor and the cathode of the second diode are all connected to the VDDHV pin of the KNX transceiver, the second end of the fifth capacitor and the first end of the sixth capacitor are all connected to the VFLT pin of the KNX transceiver, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the sixth capacitor are all grounded, and the anode of the second diode is connected to the VDDHV_PD pin of the KNX transceiver; Among them, the node connected by the first end of the third capacitor, the first end of the fourth capacitor, the first end of the fifth capacitor, the cathode of the second diode and the VDDHV pin of the KNX transceiver is used as the first power supply end, the first power supply end is connected to the relay control circuit and the voltage conversion circuit, and the first power supply end is used to output the stable first power supply.

4. The KNX-based anti-interference control circuit according to claim 3 is characterized in that: The voltage conversion circuit includes a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a second resistor, a third resistor, a first inductor and a second magnetic bead; The DCDC_IN pin of the KNX transceiver is connected to the first power supply end and the first end of the eighth capacitor, and the second end of the eighth capacitor is grounded; the DCDC_LX pin of the KNX transceiver is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the ninth capacitor, the first end of the tenth capacitor, the first end of the eleventh capacitor, one end of the second magnetic bead, the second end of the third resistor and the second end of the seventh capacitor, and the other end of the second magnetic bead is grounded through the twelfth capacitor; the DCDC_GND pin of the KNX transceiver, the second end of the ninth capacitor, the second end of the tenth capacitor and the second end of the eleventh capacitor are all grounded; the DCDC_FB pin of the KNX transceiver is connected to the first end of the second resistor, the first end of the third resistor and the first end of the seventh capacitor, and the second end of the second resistor is grounded; Among them, the node where the second magnetic bead and the twelfth capacitor are connected is used as the second power supply end, the second power supply end is connected to the MCU control circuit, and the second power supply end is used to output the second power supply.

5. The KNX-based anti-interference control circuit according to claim 4 is characterized in that: The MCU control circuit includes a thirteenth capacitor, a fourth resistor and an MCU chip; The first end of the thirteenth capacitor is connected to the KNX_TX pin of the KNX transceiver, and the second end of the thirteenth capacitor is connected to the MCU chip; the first end of the fourth resistor is connected to the KNX_RX pin of the KNX transceiver, and the second end of the fourth resistor is connected to the MCU chip; the MCU chip is connected to the second power supply end and the relay control circuit.

6. The KNX-based anti-interference control circuit according to claim 5, characterized in that: The relay control circuit includes at least one relay control sub-circuit, and each relay control sub-circuit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first transistor, a second transistor, a double-coil magnetic latching relay, a third diode, a fourth diode, a fourteenth capacitor and a third magnetic bead; The first end of the fifth resistor and the first end of the seventh resistor are respectively connected to an IO pin of the MCU chip; the second end of the fifth resistor is connected to the first end of the sixth resistor and the base of the first transistor, the second end of the sixth resistor and the emitter of the first transistor are both grounded, and the collector of the first transistor is connected to the first pin of the double-coil magnetic latching relay and the anode of the fourth diode; the second end of the seventh resistor is connected to the first end of the eighth resistor and the base of the second transistor, the second end of the eighth resistor and the emitter of the second transistor are both grounded, and the collector of the second transistor is connected to the second pin of the double-coil magnetic latching relay and the anode of the third diode; the cathode of the third diode, the cathode of the fourth diode, the first end of the fourteenth capacitor and the first end of the ninth resistor are all connected to the fifth pin of the double-coil magnetic latching relay, the second end of the fourteenth capacitor is grounded, and the second end of the ninth resistor is connected to the first power supply end through the third magnetic bead; the third pin and the fourth pin of the double-coil magnetic latching relay are used to connect the external load.

7. The KNX-based anti-interference control circuit according to claim 6 is characterized in that: It also includes a fifteenth capacitor and a fifth diode; the first end of the fifteenth capacitor is connected to the cathode of the first diode, the second end of the fifteenth capacitor is connected to the cathode of the fifth diode and the KNX_AC pin of the KNX transceiver, and the anode of the fifth diode is grounded.

8. The KNX-based anti-interference control circuit according to claim 7, characterized in that: It also includes a tenth resistor; a first end of the tenth resistor is connected to the cathode of the first diode, and a second end of the tenth resistor is connected to the RTX pin of the KNX transceiver.

9. The KNX-based anti-interference control circuit according to claim 8, characterized in that: It also includes a sixteenth capacitor, a seventeenth capacitor, an eleventh resistor and a twelfth resistor; the first end of the sixteenth capacitor is connected to the anode of the first diode, and the second end of the sixteenth capacitor is connected to the CP_H pin of the KNX transceiver through the eleventh resistor; the first end of the seventeenth capacitor is connected to the CP_L pin of the KNX transceiver through the twelfth resistor, and the second end of the seventeenth capacitor is grounded.

10. A KNX-based anti-interference control device, characterized in that: It comprises a KNX-based anti-interference control circuit as described in any one of claims 1 to 9.

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