CN218549500U

CN218549500U - High-voltage isolation communication circuit

Info

Publication number: CN218549500U
Application number: CN202222462033.0U
Authority: CN
Inventors: 王东阳
Original assignee: Zhejiang Jinka Power Technology Co ltd
Current assignee: Zhejiang Jinka Power Technology Co ltd
Priority date: 2022-09-16
Filing date: 2022-09-16
Publication date: 2023-02-28
Anticipated expiration: 2032-09-16

Abstract

The utility model discloses a high-voltage isolation communication circuit, including host computer communication module and near-infrared communication module, host computer communication module includes RS232 level switching circuit and power supply circuit, RS232 level switching circuit is used for converting the RS232 signal of host computer into TTL signal; the power supply circuit is connected with the upper computer and used for supplying power to the RS232 level switching circuit and the near infrared communication module; the near-infrared communication module comprises a transmitting circuit and a receiving circuit and is used for realizing isolated communication between the upper computer and the high-voltage controlled circuit. The utility model solves the problem that the pressure resistance intensity of the isolated communication is limited by the isolation device by transmitting data through the optical signal, and improves the high pressure resistance level of the isolated communication; the photoelectric communication power consumption is low, and a communication power supply is provided through an RS232 interface of the upper computer, so that the problem that an isolated communication circuit needs to be independently powered is solved; the circuit has simple structure, low cost and good compatibility.

Description

High-voltage isolation communication circuit

Technical Field

The utility model relates to an keep apart the communication technology field, concretely relates to communication circuit is kept apart to high pressure.

Background

The isolation communication technology has more and more application scenes, the control system and the high-voltage circuit can be electrically isolated through isolation communication, the safety of operators is guaranteed, the influence of the terrain difference and the ground loop of the system can be eliminated, and the communication stability of the system is improved. The existing isolation communication scheme is that isolation communication is carried out through an isolation optocoupler, as shown in fig. 4, an upper computer 7 converts an RS232 signal into an RS485 signal through an RS 232-to-RS 485 communication tool, and an RS485 circuit 8 is interacted with a high-voltage controlled circuit 9 through the optocoupler isolation device. The existing isolation communication mode is mainly limited in the following two aspects, the first is that the withstand voltage strength is limited by an optical coupler device, the withstand voltage of the common optical coupler in the market is generally 5KV, and the cost is very high if a device with customized withstand voltage strength is selected; secondly, the RS485 circuit 8 needs to be powered by an isolation power supply 10, and is easily interfered by the outside, so that the system is unstable in operation. In summary, no low-cost isolated communication scheme which can resist high voltage of dozens of KV exists at present.

For example, chinese patent grant publication no: CN214314543U discloses an anti-interference isolation communication circuit, wherein a signal transmitting end of a singlechip is connected with a DI end of an RS485 chip through an optocoupler U2 and a first secondary level isolation conversion module, and a signal receiving end is connected with an RO end of the RS485 chip through a second secondary level isolation conversion module and an optocoupler U3; a and B ends of the RS485 chip are connected with surge protection modules formed by TSV tubes, and a PTC is connected in series with the A end and used for short-circuit protection. It increases protective device at communication circuit port to send at the singlechip, the receiving port carries out physical isolation through the opto-coupler, can block surge and electrostatic interference better, protection single chip microcomputer system can not receive the damage, has that the interference killing feature is strong, characteristics that protection level is high, but its compressive strength is restricted by the opto-coupler device.

Disclosure of Invention

The utility model mainly aims at solving the problems that the compressive strength of the existing isolation communication scheme is limited and the power supply needs to be isolated, and provides a high-voltage isolation communication circuit, which comprises an upper computer communication module and a near-infrared communication module, wherein the upper computer communication module comprises an RS232 level switching circuit and a power circuit, and the RS232 level switching circuit is used for converting RS232 signals of an upper computer into TTL signals; the power supply circuit is connected with the upper computer and used for supplying power to the RS232 level conversion circuit and the near infrared communication module; the near-infrared communication module comprises a transmitting circuit and a receiving circuit and is used for realizing isolated communication between the upper computer and the high-voltage controlled circuit. The utility model solves the problem that the pressure resistance intensity of the isolation communication is limited by the isolation device through the data transmission of the optical signal, and improves the high pressure resistance level of the isolation communication; and the photoelectric communication power consumption is lower, and a communication power supply is provided through an RS232 interface of the upper computer, so that the problem that an isolated communication circuit needs to be independently powered is solved.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a high-voltage isolation communication circuit comprises an upper computer communication module and a near-infrared communication module, wherein the upper computer communication module comprises an RS232 level switching circuit and a power supply circuit, and the RS232 level switching circuit is used for converting RS232 signals of an upper computer into TTL signals; the power supply circuit is connected with the upper computer and used for supplying power to the RS232 level conversion circuit and the near infrared communication module; the near-infrared communication module comprises a transmitting circuit and a receiving circuit and is used for realizing isolated communication between the upper computer and the high-voltage controlled circuit. The RS232 level switching circuit of the utility model is connected with the upper computer, and converts the RS232 signal of the upper computer into the TTL signal; the power circuit gets electricity from the RS232 interface of the upper computer, so that the utility model provides a communication power supply, and solves the problem that the isolated communication circuit needs to be supplied with power independently; the near-infrared communication module realizes optical signal transmission data, avoids using an optical coupler, solves the problem that the withstand voltage strength of isolated communication is limited by an isolating device, can bear 35KV voltage in actual test, and improves the high-voltage-resistant level of isolated communication. The utility model discloses high pressure resistant, low-cost, do not need to keep apart mains operated, simple structure and compatibility are good.

Preferably, the emitting circuit includes a light emitting diode D1, a cathode of the light emitting diode D1 is grounded, an anode of the light emitting diode D1 is connected to one end of a resistor R1, the other end of the resistor R1 is connected to a collector of a PNP type triode Q1, a base of the PNP type triode Q1 is connected to one end of a resistor R2, and the other end of the resistor R2 is a TXD end; and an emitting electrode of the PNP type triode Q1 is connected with a power supply VCC. The light emitting diode D1 (emitter tube) adopts AT205B of available company, and the emission intensity required in IEC62056-21 is turned ON when the optimal action interval should meet the conditions that Ee/T is less than or equal to 5mW/cm2 and more than or equal to 0.5mW/cm2, and is turned OFF when the Ee/T is less than or equal to 0.01mW/cm, and the emission current is estimated to be about 9mA and the AT205 handbook is checked by combining the volt-ampere characteristic curve of the light emitting diode D1 (emitter tube), wherein the radiation intensity is about 5 mW/sr. Normally, the TXD end is at a high level, the PNP type triode Q1 is cut off, and the light emitting diode D1 is not conducted; when data is transmitted, the TXD end is at low level, the PNP type triode Q1 is conducted, and the light emitting diode D1 is conducted.

Preferably, the receiving circuit includes a photodiode D2, the negative electrode of the photodiode D2 is connected to a power source VCC, the positive electrode of the photodiode D2 is connected to one end of a resistor R3, the other end of the resistor R3 is respectively connected to one end of a resistor R4 and the base of an NPN-type triode Q2, the other end of the resistor R4 and the emitter of the NPN-type triode Q2 are all grounded, the collector of the NPN-type triode Q2 is connected to one end of a resistor R5, one end of the resistor R5 is an RXD end, and the other end of the resistor R5 is connected to the power source VCC. The photodiode D2 adopts AT405-PD-01 of available company, the photodiode D2 is used as a receiving device, and is matched with a triode (NPN type triode Q2) to play a role of switching, and the photodiode D2 is in a conducting state when the radiation intensity Ee/R is more than or equal to 0.2mW/cm2 according to the requirement on the sensitivity of a receiver in the standard IEC 62056-21; when Ee/R is less than or equal to 0.02mW/cm < 2 >, the valve is in a closed state. If the reliable cut-off of the triode is ensured, the bright current of the photosensitive diode D2 (receiving diode) is ensured to be larger than 11uA, according to a receiving diode manual, the two tubes are ideally tightly attached, the light power of the light-emitting tube reaches the receiving tube completely, and the bright current of the photosensitive diode D2 under the infrared intensity is about 20 uA. Normally, the photodiode D2 is in a cut-off state, the NPN type triode Q2 is cut off, and the RXD end is in a high level; when light is emitted, the photosensitive diode D2 is conducted, the NPN type triode Q2 is conducted, and the RXD end is at a low level.

Preferably, the RS232 level shift circuit includes a level shift chip U1 and a socket P1, where the level shift chip U1 is a UM3232E series chip, a pin 1 of the level shift chip U1 is connected to one end of a capacitor C1, and the other end of the capacitor C1 is connected to a pin 3 of the level shift chip U1; a pin 2 of the level conversion chip U1 is connected with a capacitor C2 and then grounded; a pin 4 of the level conversion chip U1 is connected with one end of a capacitor C3, and the other end of the capacitor C3 is connected with a pin 5 of the level conversion chip U1; a pin 6 of the level conversion chip U1 is connected with a capacitor C4 and then grounded; a pin 9 of the level conversion chip U1 is a TX end; a pin 10 of the level conversion chip U1 is an RX end; pin 11, pin 13 and pin 15 of the level conversion chip U1 are grounded; pin 16 of the level conversion chip U1 is connected to one end of a power supply VCC and one end of a capacitor C5, respectively, and the other end of the capacitor C5 is grounded. The utility model discloses a RS232 changes level circuit, converts the RS232 signal conversion of host computer into the TTL signal. The UM3232E series chip comprises 3 basic circuit modules, including a driver, a receiver and a charge pump, wherein the driver is an inverse transmitter which converts TTL or CMOS logic level into EIA/TIA-232 level opposite to input logic level, and RS232 on an upper computer generally adopts negative logic level, -15 to-3V to represent logic 1; +15 to +3V represents logical 0. The receiver converts the EIA/TIA-232 level to a TTL level. The charge pump needs 4 external capacitors, and a 4-phase voltage conversion technology is applied to keep outputting a symmetrical 5.5V power supply.

Preferably, the type of the socket P1 is DR-9P, and the pin 2 of the socket P1 is connected to the pin 7 of the level conversion chip U1; pin 3 of socket P1 is connected to pin 8 of level shift chip U1; pin 7 of socket P1 is DTR end; pin 4 of socket P1 is RTS end; pin 5 of socket P1 is grounded.

Preferably, the power circuit comprises a rectifier diode D3 and a rectifier diode D4, and an anode of the rectifier diode D3 is a DTR terminal; the positive electrode of the rectifier diode D4 is an RTS end; the cathode of the rectifier diode D3 and the cathode of the rectifier diode D4 are both connected with one end of the capacitor C6 and one end of the capacitor C7, and the other ends of the capacitor C6 and the capacitor C7 are both grounded; the power input end VIN of steady voltage chip U2 is connected to electric capacity C7's one end, and steady voltage chip U2's earthing terminal GND ground connection, and the one end of power VCC and electric capacity C8 is connected respectively to steady voltage chip U2's power output end VOUT, and electric capacity C8's the other end ground connection. The output of DTR and RTS pins of an RS232 interface of the upper computer is +/-12V voltage, the voltage is rectified by two rectifier diodes (a rectifier diode D3 and a rectifier diode D4, the model is TCLL 4148), and the rectified voltage is stabilized by a voltage stabilizing chip U2 (LDO, the model is WL2852K 33-3/TR) to reduce the voltage to 3.3V; the capacitor C6 and the capacitor C7 are used for storing energy and filtering; the capacitor C8 is used for ensuring the stability of the output 3.3V.

Preferably, the socket P1 is used for connecting an upper computer. The RS232 level-switching circuit is connected with the upper computer through a socket P1 and used for receiving RS232 signals from the upper computer.

Therefore, the utility model has the advantages that:

(1) The near-infrared communication module is used for realizing data transmission of optical signals, an optocoupler is avoided, the problem that the pressure resistance strength of isolated communication is limited by an isolating device is solved, and the high-voltage resistance level of the isolated communication is improved;

(2) The photoelectric communication power consumption is low, and a communication power supply is provided through an RS232 interface of an upper computer, so that the problem that an isolated communication circuit needs to be independently powered is solved;

(3) The circuit structure is simple and the cost is low;

(4) Most of the common interfaces on the market are compatible, and the communication interfaces can be RJ11, RJ45 and the like according to actual requirements.

Drawings

Fig. 1 is a circuit diagram of a high-voltage isolation communication circuit according to an embodiment of the present invention.

Fig. 2 is a circuit diagram of the near-infrared communication module according to the embodiment of the present invention.

Fig. 3 is a circuit diagram of the upper computer communication module in the embodiment of the present invention.

Fig. 4 is a schematic structural diagram of the existing isolated communication scheme in the background art of the present invention.

1. The device comprises an upper computer communication module 2, a near infrared communication module 3, an RS232 level switching circuit 4, a power supply circuit 5, a transmitting circuit 6, a receiving circuit 7, an upper computer 8, an RS485 circuit 9, a high-voltage controlled circuit 10 and an isolation power supply.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description.

A high-voltage isolation communication circuit is shown in figure 1 and comprises an upper computer communication module 1 and a near-infrared communication module 2, wherein the upper computer communication module 1 comprises an RS232 level switching circuit 3 and a power supply circuit 4, and the RS232 level switching circuit 3 is used for converting an RS232 signal of an upper computer into a TTL signal; the power supply circuit 4 is connected with an upper computer and used for supplying power to the RS232 level conversion circuit 3 and the near infrared communication module 2; the near-infrared communication module 2 comprises a transmitting circuit 5 and a receiving circuit 6, and is used for realizing isolated communication between the upper computer and the high-voltage controlled circuit. The RS232 level conversion circuit 3 of the embodiment is connected with an upper computer, and converts RS232 signals of the upper computer into TTL signals; the power circuit 4 gets electricity from an RS232 interface of the upper computer and provides a communication power supply; the near-infrared communication module 2 realizes data transmission of optical signals, and can bear 35KV voltage in actual test.

As shown in fig. 2, the emitting circuit 5 includes a light emitting diode D1, a cathode of the light emitting diode D1 is grounded, an anode of the light emitting diode D1 is connected to one end of a resistor R1, another end of the resistor R1 is connected to a collector of a PNP type triode Q1, a base of the PNP type triode Q1 is connected to one end of a resistor R2, and another end of the resistor R2 is a TXD end; and an emitting electrode of the PNP type triode Q1 is connected with a power supply VCC. The light emitting diode D1 (emitter tube) adopts AT205B of available company, and the emission intensity required in IEC62056-21 is turned ON when the optimal action interval should meet the conditions that Ee/T is less than or equal to 5mW/cm2 and more than or equal to 0.5mW/cm2, and is turned OFF when the Ee/T is less than or equal to 0.01mW/cm, and the emission current is estimated to be about 9mA and the AT205 handbook is checked by combining the volt-ampere characteristic curve of the light emitting diode D1 (emitter tube), wherein the radiation intensity is about 5 mW/sr. Normally, the TXD end is at a high level, the PNP type triode Q1 is cut off, and the light emitting diode D1 is not conducted; when data is transmitted, the TXD end is at low level, the PNP type triode Q1 is conducted, and the light emitting diode D1 is conducted.

As shown in fig. 2, the receiving circuit 6 includes a photodiode D2, a negative electrode of the photodiode D2 is connected to a power source VCC, a positive electrode of the photodiode D2 is connected to one end of a resistor R3, the other end of the resistor R3 is respectively connected to one end of a resistor R4 and a base of an NPN-type triode Q2, the other end of the resistor R4 and an emitter of the NPN-type triode Q2 are both grounded, a collector of the NPN-type triode Q2 is connected to one end of a resistor R5, one end of the resistor R5 is an RXD terminal, and the other end of the resistor R5 is connected to the power source VCC. The photodiode D2 adopts AT405-PD-01 of available company, the photodiode D2 is used as a receiving device, and is matched with a triode (NPN type triode Q2) to play a role of switching, and the photodiode D2 is in a conducting state when the radiation intensity Ee/R is more than or equal to 0.2mW/cm2 according to the requirement on the sensitivity of a receiver in the standard IEC 62056-21; and when the Ee/R is less than or equal to 0.02mW/cm < 2 >, the valve is in a closed state. If the triode is required to be reliably cut off, the bright current of the photosensitive diode D2 (receiving diode) is required to be larger than 11uA, according to a receiving diode manual, the two tubes are ideally tightly attached, the optical power of the light-emitting tube reaches the receiving tube completely, and the bright current of the photosensitive diode D2 under the infrared intensity is about 20 uA. Normally, the photodiode D2 is in a cut-off state, the NPN type triode Q2 is cut off, and the RXD end is in a high level; when light is emitted, the photosensitive diode D2 is conducted, the NPN type triode Q2 is conducted, and the RXD end is at a low level.

As shown in fig. 3, the RS232 level shift circuit 3 includes a level shift chip U1 and a socket P1, the level shift chip U1 is a UM3232E series chip, a pin 1 of the level shift chip U1 is connected to one end of a capacitor C1, and the other end of the capacitor C1 is connected to a pin 3 of the level shift chip U1; a pin 2 of the level conversion chip U1 is connected with a capacitor C2 and then grounded; a pin 4 of the level conversion chip U1 is connected with one end of a capacitor C3, and the other end of the capacitor C3 is connected with a pin 5 of the level conversion chip U1; a pin 6 of the level conversion chip U1 is connected with a capacitor C4 and then grounded; a pin 9 of the level conversion chip U1 is a TX end; a pin 10 of the level conversion chip U1 is an RX end; pin 11, pin 13 and pin 15 of the level conversion chip U1 are grounded; pin 16 of the level conversion chip U1 is connected to one end of a power supply VCC and one end of a capacitor C5, respectively, and the other end of the capacitor C5 is grounded. The UM3232E series chip comprises 3 basic circuit modules, including a driver, a receiver and a charge pump, wherein the driver is an inverse transmitter which converts TTL or CMOS logic level into EIA/TIA-232 level opposite to input logic level, and RS232 on an upper computer generally adopts negative logic level, -15 to-3V to represent logic 1; +15 to +3V represents logical 0. The receiver converts the EIA/TIA-232 level to a TTL level. The charge pump needs 4 external capacitors, and a 4-phase voltage conversion technology is applied to keep outputting a symmetrical 5.5V power supply. The type of the socket P1 is DR-9P, and a pin 2 of the socket P1 is connected to a pin 7 of the level conversion chip U1; pin 3 of socket P1 is connected to pin 8 of level shift chip U1; pin 7 of socket P1 is DTR end; pin 4 of socket P1 is RTS end; pin 5 of socket P1 is grounded. The RS232 level-shifting circuit 3 is connected with an upper computer through a socket P1 and is used for receiving RS232 signals from the upper computer.

As shown in fig. 3, the power supply circuit 4 includes a rectifier diode D3 and a rectifier diode D4, and an anode of the rectifier diode D3 is a DTR terminal; the positive electrode of the rectifier diode D4 is an RTS end; the negative electrode of the rectifier diode D3 and the negative electrode of the rectifier diode D4 are both connected with one end of the capacitor C6 and one end of the capacitor C7, and the other end of the capacitor C6 and the other end of the capacitor C7 are both grounded; the power input end VIN of steady voltage chip U2 is connected to electric capacity C7's one end, and steady voltage chip U2's earthing terminal GND ground connection, and the one end of power VCC and electric capacity C8 is connected respectively to steady voltage chip U2's power output end VOUT, and electric capacity C8's the other end ground connection. The output of the DTR and RTS pins of the RS232 interface of the upper computer is +/-12V voltage, the voltage is rectified by two rectifier diodes (a rectifier diode D3 and a rectifier diode D4, the model is TCLL 4148), and the rectified voltage is stabilized by a voltage stabilizing chip U2 (LDO, the model is WL2852K 33-3/TR) to be reduced to 3.3V; the capacitor C6 and the capacitor C7 are used for storing energy and filtering; the capacitor C8 is used for ensuring the stability of the output 3.3V.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A high-voltage isolation communication circuit is characterized by comprising an upper computer communication module and a near-infrared communication module, wherein the upper computer communication module comprises an RS232 level switching circuit and a power circuit, and the RS232 level switching circuit is used for converting RS232 signals of an upper computer into TTL signals; the power supply circuit is connected with the upper computer and used for supplying power to the RS232 level conversion circuit and the near infrared communication module; the near-infrared communication module comprises a transmitting circuit and a receiving circuit and is used for realizing isolated communication between the upper computer and the high-voltage controlled circuit.

2. The isolated high-voltage communication circuit according to claim 1, wherein the transmitting circuit comprises a light emitting diode D1, a cathode of the light emitting diode D1 is grounded, an anode of the light emitting diode D1 is connected to one end of a resistor R1, the other end of the resistor R1 is connected to a collector of a PNP transistor Q1, a base of the PNP transistor Q1 is connected to one end of a resistor R2, and the other end of the resistor R2 is a TXD end; and an emitting electrode of the PNP type triode Q1 is connected with a power supply VCC.

3. The high-voltage isolation communication circuit according to claim 1, wherein the receiving circuit comprises a photodiode D2, the negative electrode of the photodiode D2 is connected to a power source VCC, the positive electrode of the photodiode D2 is connected to one end of a resistor R3, the other end of the resistor R3 is respectively connected to one end of a resistor R4 and the base of an NPN-type triode Q2, the other end of the resistor R4 and the emitter of the NPN-type triode Q2 are both grounded, the collector of the NPN-type triode Q2 is connected to one end of a resistor R5, one end of the resistor R5 is an RXD end, and the other end of the resistor R5 is connected to the power source VCC.

4. The isolated communication circuit of claim 1, wherein the RS232 level shifting circuit comprises a level shifting chip U1 and a socket P1, the level shifting chip U1 is a UM3232E series chip, a pin 1 of the level shifting chip U1 is connected to one end of a capacitor C1, and the other end of the capacitor C1 is connected to a pin 3 of the level shifting chip U1; a pin 2 of the level conversion chip U1 is connected with a capacitor C2 and then grounded; a pin 4 of the level conversion chip U1 is connected with one end of a capacitor C3, and the other end of the capacitor C3 is connected with a pin 5 of the level conversion chip U1; a pin 6 of the level conversion chip U1 is connected with a capacitor C4 and then grounded; a pin 9 of the level conversion chip U1 is a TX end; a pin 10 of the level conversion chip U1 is an RX end; pin 11, pin 13 and pin 15 of the level conversion chip U1 are grounded; pin 16 of level shift chip U1 is connected to one end of power VCC and electric capacity C5 respectively, and the other end of electric capacity C5 is ground.

5. The isolated communication circuit of claim 4, wherein the socket P1 is of type DR-9P, and pin 2 of the socket P1 is connected to pin 7 of the level shifter chip U1; pin 3 of socket P1 is connected to pin 8 of level shift chip U1; a pin 7 of the socket P1 is a DTR end; pin 4 of socket P1 is RTS end; pin 5 of socket P1 is grounded.

6. The high-voltage isolation communication circuit according to claim 1, wherein the power circuit comprises a rectifier diode D3 and a rectifier diode D4, the positive electrode of the rectifier diode D3 is a DTR terminal; the positive electrode of the rectifier diode D4 is an RTS end; the cathode of the rectifier diode D3 and the cathode of the rectifier diode D4 are both connected with one end of the capacitor C6 and one end of the capacitor C7, and the other ends of the capacitor C6 and the capacitor C7 are both grounded; the power input end VIN of steady voltage chip U2 is connected to electric capacity C7's one end, and steady voltage chip U2's earthing terminal GND ground connection, and power VCC and electric capacity C8's one end, electric capacity C8's other end ground connection are connected respectively to steady voltage chip U2's power output end VOUT.

7. The isolated high voltage communication circuit according to claim 4 or 5, wherein the socket P1 is used for connecting an upper computer.