CN215642442U - Control device and monitoring equipment - Google Patents

Abstract

The utility model relates to the technical field of circuits, and provides a control device and a monitoring device, which comprise a step-down type isolation power circuit, a first step-down type voltage stabilizing circuit, a second step-down type voltage stabilizing circuit, an isolation-to-non-isolation power circuit, an electric energy metering chip and a micro-control chip, wherein the step-down type isolation power circuit is electrically connected with the electric energy metering chip through the first step-down type voltage stabilizing circuit and the isolation-to-non-isolation power circuit in sequence, and is also electrically connected with the micro-control chip through the second step-down type voltage stabilizing circuit so as to simultaneously adapt to the non-isolation power demand of the electric energy metering chip and the isolation power demand of the micro-control chip, under the premise that the step-down type isolation power circuit is used for electrically isolating the power supply and the micro-control chip, the defect that the non-isolation power demand of the step-down type isolation power circuit and the electric energy metering chip is not adapted is overcome, and the power supply application of the step-down type isolation power circuit is expanded, the power supply efficiency and the power supply performance are improved.

Description

Control device and monitoring equipment

Technical Field

The utility model relates to the technical field of circuits, in particular to a control device and monitoring equipment.

Background

Along with the increasing intellectualization of electronic equipment, the intelligent power supply monitoring system is widely applied to various scenes such as intelligent home furnishing, intelligent manufacturing and the like, provides various convenience for life and industrial production of people, and greatly saves labor cost, for example, power supply monitoring equipment such as an intelligent electric meter, an intelligent socket, an intelligent gas meter and the like.

In order to safely use electricity, electronic devices generally need to have good electric shock resistance, and protection means such as using a safe voltage or/and physical isolation or/and electrical isolation can be generally adopted on the electronic devices, for example, an elastic mechanism suitable for shielding a jack is arranged on a smart socket, or an isolated power circuit suitable for electrically isolating commercial power from a load is arranged on a smart meter, so as to prevent a user from getting an electric shock.

However, in some electronic devices, the isolated power supply circuit does not meet the non-isolated power requirements of some electric devices or/and circuits, and the power supply purpose of the isolated power supply circuit is limited.

SUMMERY OF THE UTILITY MODEL

The present invention is directed to solving, at least to some extent, the technical problems in the related art and to providing a control device and a monitoring apparatus.

The utility model provides a control device which comprises a step-down isolation power supply circuit, a first step-down voltage stabilizing circuit, a second step-down voltage stabilizing circuit, an isolation-to-non-isolation power supply circuit, an electric energy metering chip and a micro control chip, wherein a first voltage output end of the step-down isolation power supply circuit is electrically connected with a first voltage input end of the first step-down voltage stabilizing circuit and a second voltage input end of the second step-down voltage stabilizing circuit respectively, a second voltage output end of the first step-down voltage stabilizing circuit is electrically connected with a power pin of the electric energy metering chip through the isolation-to-non-isolation power supply circuit, and a third voltage output end of the second step-down voltage stabilizing circuit is electrically connected with a power pin of the micro control chip.

Optionally, the first buck voltage stabilizing circuit includes a three-terminal regulator tube and a first filter capacitor, a voltage input end of the three-terminal regulator tube is set as the first voltage input end, a voltage output end of the three-terminal regulator tube is set as the second voltage output end grounded through the first filter capacitor, and a ground end of the three-terminal regulator tube is grounded.

Optionally, the second buck-type voltage stabilizing circuit includes a buck-type voltage stabilizing chip, a second filter capacitor, a freewheeling diode, an LC filter sub-circuit, and a current-limiting sub-circuit, a voltage input end of the buck-type voltage stabilizing chip is set as the second voltage input end grounded through the second filter capacitor, a voltage output end of the buck-type voltage stabilizing chip is electrically connected to a cathode of the freewheeling diode, a ground end of the buck-type voltage stabilizing chip is grounded to an anode of the freewheeling diode and the second filter capacitor, the LC filter sub-circuit is electrically connected between the anode and the cathode of the freewheeling diode after being connected in parallel with the current-limiting sub-circuit, and the current-limiting sub-circuit is provided with the third voltage output end.

Optionally, the current-limiting sub-circuit includes a first voltage-reducing resistor, a second voltage-reducing resistor, and a shunt resistor, one end of the first voltage-reducing resistor is electrically connected to one end of the shunt resistor and a voltage output end of the LC filter sub-circuit, a common end between the first voltage-reducing resistor and the shunt resistor is set as the third voltage output end, the other end of the first voltage-reducing resistor is electrically connected to one end of the second voltage-reducing resistor and a feedback end of the buck voltage-stabilizing chip, and the other end of the second voltage-reducing resistor is electrically connected to the other end of the shunt resistor and a ground end of the LC filter sub-circuit.

Optionally, the isolated to non-isolated power supply circuit includes an isolated DC-DC converter, a third voltage input end of the isolated DC-DC converter is electrically connected to the second voltage output end, a ground end of the isolated DC-DC converter is grounded to form an isolated voltage input loop with the third voltage input end, a fourth voltage output end of the isolated DC-DC converter is electrically connected to a power pin of the electric energy metering chip, and another ground end of the isolated DC-DC converter is connected to zero to form a non-isolated voltage output loop with the fourth voltage output end.

Optionally, the power supply circuit for converting from isolated to non-isolated further includes a first filter sub-circuit and a second filter sub-circuit, the first filter sub-circuit is electrically connected between the third voltage input terminal and a corresponding one of the ground terminals, and the second filter sub-circuit is electrically connected between the fourth voltage output terminal and another corresponding one of the ground terminals.

Optionally, the control device further includes a first voltage sampling circuit and a second voltage sampling circuit, the first voltage sampling circuit includes a lightning protection sub-circuit, a voltage divider sub-circuit and a third filter sub-circuit, a fifth voltage output end of the lightning protection sub-circuit passes through the voltage divider sub-circuit and is respectively connected with a fifth voltage input end of the third filter sub-circuit and a positive voltage input pin of the electric energy metering chip, a sixth voltage input end of the second voltage sampling circuit is electrically connected with a negative voltage input pin of the electric energy metering chip.

Optionally, the lightning protection sub-circuit includes a connection terminal and a voltage dependent resistor, a live wire end of the connection terminal is electrically connected to one end of the voltage dependent resistor and a fourth voltage input end of the voltage dependent sub-circuit, and a null wire end of the connection terminal and the other end of the voltage dependent resistor are grounded.

Optionally, the control device further includes a current sampling circuit, and a pair of current output terminals of the current sampling circuit is electrically connected to a pair of current input pins of the electric energy metering chip.

A second aspect of the utility model provides a monitoring apparatus comprising the control device of the first aspect.

The control device and the monitoring equipment have the beneficial effects that: the first isolation voltage provided by the buck isolation power supply circuit is converted into a second isolation voltage for supplying power to the isolation-to-non-isolation power supply circuit through the first buck voltage stabilizing circuit, the second isolation voltage is converted into a non-isolation voltage for supplying power to the electric energy metering chip through the isolation-to-non-isolation power supply circuit, the first isolation voltage is converted into a third isolation voltage for supplying power to the micro-control chip through the second buck voltage stabilizing circuit, the non-isolation power demand of the electric energy metering chip and the isolation power demand of the micro-control chip are matched at the same time, under the premise that the power supply and the micro-control chip are electrically isolated through the buck isolation power supply circuit, the defect that the non-isolation power demand of the buck isolation power supply circuit is not matched with that of the electric energy metering chip is overcome, the power supply purpose of the buck isolation power supply circuit is expanded, and the power supply efficiency and the power supply performance are improved.

Drawings

FIG. 1 is a schematic circuit diagram of a control device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a buck-type isolated power supply circuit according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a first buck regulator circuit according to an embodiment of the utility model;

FIG. 4 is a diagram illustrating a second buck regulator circuit according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an isolated to non-isolated power supply circuit according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an electric energy metering chip and its peripheral circuits according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a micro controller chip and its peripheral circuits according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a first voltage sampling circuit according to an embodiment of the present invention;

FIG. 9 is a diagram of a second voltage sampling circuit according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of a current sampling circuit according to an embodiment of the present invention;

fig. 11 is a circuit diagram of a control device according to an embodiment of the utility model.

Detailed Description

In order that the above objects, features and advantages of the present invention will become more apparent, embodiments in accordance with the present invention will be described in detail below with reference to the accompanying drawings, wherein like reference numerals refer to the same or similar elements throughout the different views unless otherwise specified.

It is noted that the terms "aspect," "optionally," and "exemplary" described in the present specification mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or the embodiment is included in at least one embodiment or an exemplary embodiment of the present invention, and embodiments described in the following exemplary embodiments do not represent all embodiments of the present invention, and are merely examples of apparatuses and methods consistent with some aspects disclosed in the present invention as detailed in the claims, and the scope of the present invention is not limited thereto, and features in various embodiments of the present invention may be combined with each other without contradiction.

Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the present invention, "a plurality" means at least two, e.g., two or three, etc., unless specifically limited otherwise.

In some existing control devices, for power utilization safety, a voltage reduction type isolation power supply circuit with a constant reference potential can directly take power from mains supply and convert 220V alternating-current voltage into a plurality of different direct-current voltages so as to simultaneously supply power to an electric energy metering chip and a micro-control chip, and power supply efficiency is improved, for example, 5V direct-current voltage supplies power to a three-phase electric energy metering chip with the model of ADE7758, and 3.3V direct-current voltage supplies power to an MCU chip with the model of STM32F 429.

In some cases, a non-isolated power circuit with a reference potential capable of fluctuating is needed to supply power to an electric energy metering chip with a non-isolated power demand, because the reference potential of a voltage-reducing isolated power circuit is generally constant, that is, the voltage-reducing isolated power circuit is not adaptive to the non-isolated power demand of the electric energy metering chip, which not only limits the power supply application of the voltage-reducing isolated power circuit, but also is harmful to the electric energy monitoring precision, for example, the voltage of commercial power is directly sampled by a resistor and a voltage sampling signal is input into a single-phase electricity larceny prevention metering chip, in order to match with the non-isolated voltage acquisition mode, the non-isolated power circuit with a zero line as the reference potential is used to supply power to the single-phase electricity larceny prevention metering chip, compared with the constant reference potential, the non-isolated power circuit can fluctuate with the zero line to adapt to the non-isolated power demand of the single-phase electricity larceny prevention metering chip, the electric energy monitoring precision is favorably improved, but the non-isolated power supply circuit is not adaptive to the isolated power demand of the MCU chip, and the power supply and the MCU chip cannot be electrically isolated through the non-isolated power supply circuit.

Referring to fig. 1, a control device according to an embodiment of the present invention includes a buck-type isolated power supply circuit, a first buck-type voltage stabilizing circuit, a second buck-type voltage stabilizing circuit, an isolated-to-non-isolated power supply circuit, an electric energy metering chip, and a micro-control chip, where the buck-type isolated power supply circuit has a first voltage output end, the first buck-type voltage stabilizing circuit has a first voltage input end and a second voltage output end, and the second buck-type voltage stabilizing circuit has a second voltage input end and a third voltage output end, where the first voltage output end is electrically connected to the first voltage input end and the second voltage input end, the second voltage output end is electrically connected to a power pin of the electric energy metering chip through the isolated-to-non-isolated power supply circuit, and the third voltage output end is electrically connected to a power pin of the micro-control chip.

For example, the step-down type isolated power supply circuit may adopt an isolated AC-DC switching power supply circuit as shown in fig. 2, wherein a full-bridge rectifier bridge may be electrically connected to a live line and a zero line of a mains supply, 220V AC voltage is directly obtained from the mains supply through the full-bridge rectifier bridge to convert the 220V AC voltage into 12V DC voltage, a common terminal between two diodes and a filter capacitor may be set as a first voltage output terminal adapted to output the 12V DC voltage, and ground is used as a constant zero reference potential.

For example, the electric energy metering chip may adopt a single-phase anti-electricity-stealing metering chip U1 as shown in fig. 6, the model of the single-phase anti-electricity-stealing metering chip U1 may be RN8209G, the micro-control chip may adopt an embedded microcontroller U2 as shown in fig. 7, and the model of the embedded microcontroller U2 may be STM32F103C8T6, it should be understood that both the single-phase anti-electricity-stealing metering chip U1 and the embedded microcontroller U2 may be implemented by using the prior art, and will not be described herein again.

Optionally, referring to fig. 1, 2 and 3, the first buck-type voltage regulator circuit includes a three-terminal regulator tube U3 and a first filter capacitor C1, a voltage input terminal Vin of the three-terminal regulator tube U3 is set as a first voltage input terminal, a voltage output terminal Vout of the three-terminal regulator tube U3 is set as a second voltage output terminal that is grounded through the first filter capacitor C1, and a ground terminal GND of the three-terminal regulator tube U3 is commonly grounded with the first filter capacitor C1.

Illustratively, the model of the three-terminal regulator tube U3 may be 78M05, a 12V dc voltage as a first isolation voltage may be converted into a 5V dc voltage as a second isolation voltage through the three-terminal regulator tube U3, a ground terminal GND of the three-terminal regulator tube U3 may be connected to the ground, the ground is used as a reference potential, and the first filter capacitor C1 is used for filtering between the first voltage input terminal and the first voltage output terminal, which takes into account reliability and simplicity of the first buck voltage regulator circuit.

Optionally, referring to fig. 1, 2 and 4, the second buck-type voltage stabilizing circuit includes a buck-type voltage stabilizing chip U4, a second filter capacitor C2, a freewheeling diode D, LC filter sub-circuit and a current limiting sub-circuit, a voltage input terminal Vin of the buck-type voltage stabilizing chip U4 is set as a second voltage input terminal grounded through the second filter capacitor C2, a voltage output terminal Vout of the buck-type voltage stabilizing chip U4 is electrically connected to a cathode of the freewheeling diode D, a ground terminal GND of the buck-type voltage stabilizing chip U4 is grounded to an anode of the freewheeling diode D and the second filter capacitor C2, the LC filter sub-circuit is electrically connected between the anode and the cathode of the freewheeling diode D after being connected in parallel to the current limiting sub-circuit, and the current limiting sub-circuit is provided with a third voltage output terminal.

Illustratively, the buck regulator chip U4 may be of a model LM2576SX-ADJ, wherein the control terminal ON/OFF is electrically connected between the ground terminal GND and the anode of the freewheeling diode D, and the 12V dc voltage may be converted into a 3.3V dc voltage as a third isolation voltage by the buck regulator chip U4.

Illustratively, the LC filter sub-circuit may include an inductor L and three third filter capacitors C3 connected in parallel, one end of the inductor L is set as a voltage input end electrically connected to a cathode of the freewheeling diode D, two ends of any third filter capacitor C3 are respectively electrically connected to the other end of the inductor L and an anode of the freewheeling diode D, one end of any third filter capacitor C3 is set as a voltage output end electrically connected to the inductor L, and any third filter capacitor C3 is set as a ground end electrically connected to the anode of the freewheeling diode D.

Optionally, referring to fig. 4, the current limiting sub-circuit includes a first voltage dropping resistor R1, a second voltage dropping resistor R2, and a shunt resistor R3, one end of the first voltage dropping resistor R1 is electrically connected to one end of the shunt resistor R3 and the voltage output end of the LC filter sub-circuit, a common end between the first voltage dropping resistor R1 and the shunt resistor R3 is set as a third voltage output end, the other end of the first voltage dropping resistor R1 is electrically connected to one end of the second voltage dropping resistor R2 and the feedback end FB of the buck-type voltage stabilizing chip U4, and the other end of the second voltage dropping resistor R2 is electrically connected to the other end of the shunt resistor R3 and the ground end of the LC filter sub-circuit, which takes into account reliability and simplicity of the current limiting sub-circuit, for example, the two shunt resistors R3 are connected in parallel.

The second filter capacitor C2 is used for filtering between the second voltage input end and the first voltage output end, the freewheeling diode D is used for freewheeling between the buck voltage stabilizing chip U4 and the LC filter sub-circuit, reverse voltage protection caused by voltage mutation caused by inductance in the LC filter sub-circuit is eliminated, the LC filter sub-circuit is used for filtering between the buck voltage stabilizing chip U4 and the current limiting sub-circuit, and voltage reduction and current limitation are performed through the current limiting sub-circuit, so that the reliability of the second buck voltage stabilizing circuit is improved.

Optionally, referring to fig. 1, 3 and 5, the isolated to non-isolated power supply circuit includes an isolated DC-DC converter U5, a voltage input terminal Vin of the isolated DC-DC converter U5 is set as a third voltage input terminal electrically connected to the second voltage output terminal, a ground terminal GND1 of the isolated DC-DC converter U5 is grounded to form an isolated voltage input loop with the third voltage input terminal, a voltage output terminal Vout of the isolated DC-DC converter U5 is set as a fourth voltage output terminal electrically connected to the power pin of the power metering chip, and another ground terminal GND2 of the isolated DC-DC converter U5 is connected to zero to form a non-isolated voltage output loop with the fourth voltage output terminal.

Illustratively, the isolated DC-DC converter U5 may be H0505S-1WR2, the isolated DC-DC converter U5 may convert the second isolated voltage into a non-isolated voltage with a constant voltage value, the ground terminal GND1 of the isolated DC-DC converter U5 may be connected to the ground, the other ground terminal GND2 of the isolated DC-DC converter U5 and the power ground AGND of the single-phase anti-electricity-stealing metering chip U1 may both be connected to the zero line of the utility power, and the potentials of the two are the same and may fluctuate together with the zero line to adapt to the non-isolated power demand of the single-phase anti-electricity-stealing metering chip U1, thereby facilitating the isolation to the non-isolated power supply circuit and improving the power monitoring accuracy.

Optionally, referring to fig. 4, the isolated-to-non-isolated power supply circuit further includes a first filter sub-circuit and a second filter sub-circuit, the first filter sub-circuit is electrically connected between the third voltage input terminal and a corresponding one of the grounds GND1, and the second filter sub-circuit is electrically connected between the fourth voltage output terminal and the other ground GND2, which helps to ensure the reliability of the isolated-to-non-isolated power supply circuit.

Illustratively, the first filter sub-circuit may be a capacitor filter circuit formed by connecting two fourth filter capacitors C4 in parallel, and the second filter sub-circuit may be an RC filter circuit formed by connecting two fifth filter capacitors C5 and a shunt resistor R4 in parallel.

The first isolation voltage provided by the buck isolation power supply circuit is converted into a second isolation voltage for supplying power to the isolation-to-non-isolation power supply circuit through the first buck voltage stabilizing circuit, the second isolation voltage is converted into a non-isolation voltage for supplying power to the electric energy metering chip through the isolation-to-non-isolation power supply circuit, the first isolation voltage is converted into a third isolation voltage for supplying power to the micro-control chip through the second buck voltage stabilizing circuit, the non-isolation power demand of the electric energy metering chip and the isolation power demand of the micro-control chip are matched at the same time, under the premise that the power supply and the micro-control chip are electrically isolated through the buck isolation power supply circuit, the defect that the non-isolation power demand of the buck isolation power supply circuit is not matched with that of the electric energy metering chip is overcome, the power supply purpose of the buck isolation power supply circuit is expanded, and the power supply efficiency and the power supply performance are improved.

Optionally, referring to fig. 6, the control device further includes a peripheral circuit electrically connected to the electric energy metering chip, which may include a first crystal oscillator filtering sub-circuit, a first pull-down resistor, and two fourth filtering sub-circuits, the first crystal oscillator circuit IS electrically connected between the oscillation input pin OSCI and the oscillation output pin OSCO of the electric energy metering chip, the communication interface type selection pin IS of the electric energy metering chip IS grounded through the first pull-down resistor, the reference voltage input output pin REFV of the electric energy metering chip IS grounded through one fourth filtering sub-circuit, and the power supply pin DVDD of the electric energy metering chip IS grounded through the other fourth filtering sub-circuit, which helps to ensure reliability of the crystal oscillator filtering circuit.

Illustratively, the first crystal oscillator filter sub-circuit comprises a crystal oscillator, a tenth filter capacitor and an eleventh filter capacitor, one end of the crystal oscillator is electrically connected with one end of the tenth filter capacitor and the oscillation input pin OSCI of the electric energy metering chip respectively, the other end of the crystal oscillator is electrically connected with one end of the eleventh filter capacitor and the oscillation output pin OSCO of the electric energy metering chip respectively, and the other end of the tenth filter capacitor is grounded with the other end of the eleventh filter capacitor.

Optionally, referring to fig. 7, the control device further includes a peripheral circuit electrically connected to the micro-control chip, the peripheral circuit including a second crystal filter sub-circuit, a second pull-down resistor and two pull-up resistors, the second crystal circuit being electrically connected between the oscillation input pin PD0-OSC _ IN and the oscillation output pin PD1-OSC _ OUT of the micro-control chip, the start pin BOOTO of the micro-control chip being grounded through the second pull-down resistor, the asynchronous reset pin NRST of the micro-control chip being electrically connected to the third voltage output terminal through one pull-up resistor, the power supply pin VDDA of the micro-control chip being electrically connected to the third voltage output terminal through another pull-up resistor, any one of the power supply pin VDD _1, the power supply pin VDD _2 and the power supply pin VDD _3 of the micro-control chip being electrically connected between the two pull-up resistors, it being understood that the second crystal filter sub-circuit may be similar to the first crystal filter sub-circuit, and will not be described in detail herein.

Optionally, referring to fig. 6, 8, 9 and 11, the control device further includes a first voltage sampling circuit and a second voltage sampling circuit, the first voltage sampling circuit includes a lightning protection sub-circuit, a voltage divider sub-circuit and a third filter sub-circuit, a fifth voltage output terminal of the lightning protection sub-circuit is electrically connected to a fifth voltage input terminal of the third filter sub-circuit and a voltage positive input pin of the electric energy metering chip through the voltage divider sub-circuit, a sixth voltage input terminal of the second voltage sampling circuit is electrically connected to a voltage negative input pin of the electric energy metering chip, and signals can be sampled by the first voltage sampling circuit and the second voltage sampling circuit and differentially input the voltage sampled signals to the electric energy metering chip, which is helpful for improving the electric energy monitoring accuracy.

Illustratively, the voltage dividing sub-circuit may be formed by connecting six voltage dividing resistors R5 in series, the third filter sub-circuit may be formed by connecting a voltage stabilizing resistor R6 and a sixth filter capacitor C6 in parallel, one end of the last voltage dividing resistor R5 is electrically connected to the voltage positive input pin V3P of the single-phase anti-theft electricity metering chip U1, one end of the voltage stabilizing resistor R6 may be set as a fifth voltage input end electrically connected between the last voltage dividing resistor R5 and the voltage positive input pin V3P of the single-phase anti-theft electricity metering chip U1, and the other end of the voltage stabilizing resistor R6 may be connected to a zero line, so that the reference potential of the first voltage sampling circuit is the same as the reference potential of the electric energy metering chip.

Illustratively, the second voltage sampling circuit may be formed by connecting a voltage stabilizing resistor R7 and a seventh filter capacitor C7 in parallel, one end of the voltage stabilizing resistor R7 may be set as a sixth voltage input end electrically connected with the voltage negative input pin V3N of the single-phase anti-electricity-stealing metering chip U1, and the other end of the voltage stabilizing resistor R7 may be connected with a zero line, so that the reference potential of the non-isolated second voltage sampling circuit is the same as the reference potential of the electric energy metering chip.

Optionally, referring to fig. 8, the lightning protection sub-circuit includes a connection terminal JP and a voltage dependent resistor VR, a live wire end of the connection terminal JP is electrically connected to one end of the voltage dependent resistor VR and a fourth voltage input end of the voltage dependent sub-circuit respectively, and a zero wire end of the connection terminal JP is grounded to the other end of the voltage dependent resistor VR, which helps to take both lightning protection and simplicity into consideration.

Illustratively, the common terminal between the connection terminal JP and the varistor VR is set as a fifth voltage output terminal electrically connected to the fourth voltage input terminal, one terminal of the first voltage dividing resistor R5 is set as the fourth voltage input terminal, and one terminal of the last voltage dividing resistor R5 is set as a sixth voltage output terminal electrically connected to the fifth voltage input terminal.

Optionally, referring to fig. 6, 10 and 11, the control device further includes a current sampling circuit, a pair of current output terminals of the current sampling circuit is electrically connected to a pair of current input pins of the electric energy metering chip, and the current sampling circuit samples signals and inputs the current sampling signals to the electric energy metering chip in a differential manner, which is helpful for improving the electric energy monitoring accuracy.

Illustratively, the current sampling circuit includes a current transformer CT, a first sampling resistor R8, a second sampling resistor R9, a first current limiting resistor R10, an eighth filter capacitor C8, a second current limiting resistor R11 and a ninth filter capacitor C9, a current positive output pin 3 and a current negative output pin 6 of the current transformer CT are adapted to output current in a differential manner, wherein the current positive output pin 3 is electrically connected to one end of the first sampling resistor R8 and one end of the first current limiting resistor R10, the current negative output pin 6 is electrically connected to one end of the second sampling resistor R9 and one end of the second current limiting resistor R11, the other end of the first sampling resistor R8 and the other end of the second sampling resistor R9 can both be connected to the neutral line, the other end of the first current limiting resistor R10 is grounded or connected to zero through the eighth filter capacitor C8, and a common end between the first current limiting resistor R10 and the eighth filter capacitor C8 can be set to be electrically connected to the current-stealing-preventing metering U581V 2 of the single-phase current metering chip The other end of the second current-limiting resistor R11 is grounded or connected to zero through the ninth filter capacitor C9, and the common end between the second current-limiting resistor R11 and the ninth filter capacitor C9 can be set as another current output end electrically connected to the current negative input pin V1N of the single-phase anti-electricity-stealing metering chip U1, which is helpful to ensure the reliability of the current sampling circuit.

A monitoring device according to another embodiment of the present invention includes the above-mentioned control device, has similar advantages to the above-mentioned control device, and may refer to the description of the above-mentioned control device, which is not described herein again.

It should be noted that the embodiment provided by the present invention only relates to the improvement of the shape and the structure of the product, and does not relate to the improvement of the software program, so that a person skilled in the art can simply adopt the software program in the prior art to implement the circuit with the electric energy monitoring capability, and details are not described here.

Although embodiments of the present invention have been shown and described, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the spirit and scope of the present disclosure, and that such changes will fall within the scope of the present invention.

Claims (10)

1. A control device is characterized by comprising a step-down isolation power supply circuit, a first step-down voltage stabilizing circuit, a second step-down voltage stabilizing circuit, an isolation-to-non-isolation power supply circuit, an electric energy metering chip and a micro control chip, wherein a first voltage output end of the step-down isolation power supply circuit is electrically connected with a first voltage input end of the first step-down voltage stabilizing circuit and a second voltage input end of the second step-down voltage stabilizing circuit respectively, a second voltage output end of the first step-down voltage stabilizing circuit is electrically connected with a power pin of the electric energy metering chip through the isolation-to-non-isolation power supply circuit, and a third voltage output end of the second step-down voltage stabilizing circuit is electrically connected with a power pin of the micro control chip.

2. The control device according to claim 1, wherein the first buck-type voltage regulator circuit includes a three-terminal regulator tube and a first filter capacitor, a voltage input terminal of the three-terminal regulator tube is provided as the first voltage input terminal, a voltage output terminal of the three-terminal regulator tube is provided as the second voltage output terminal which is grounded through the first filter capacitor, and a ground terminal of the three-terminal regulator tube is grounded.

3. The control device according to claim 1, wherein the second buck-type voltage regulator circuit comprises a buck-type voltage regulator chip, a second filter capacitor, a freewheeling diode, an LC filter sub-circuit and a current-limiting sub-circuit, a voltage input terminal of the buck-type voltage regulator chip is set as the second voltage input terminal grounded through the second filter capacitor, a voltage output terminal of the buck-type voltage regulator chip is electrically connected with a cathode of the freewheeling diode, a ground terminal of the buck-type voltage regulator chip is grounded with an anode of the freewheeling diode and the second filter capacitor, the LC filter sub-circuit is electrically connected between the anode and the cathode of the freewheeling diode after being connected in parallel with the current-limiting sub-circuit, and the current-limiting sub-circuit is provided with the third voltage output terminal.

4. The control device according to claim 3, wherein the current limiting sub-circuit includes a first step-down resistor, a second step-down resistor, and a shunt resistor, one end of the first step-down resistor is electrically connected to one end of the shunt resistor and the voltage output terminal of the LC filter sub-circuit, respectively, a common terminal between the first step-down resistor and the shunt resistor is set as the third voltage output terminal, the other end of the first step-down resistor is electrically connected to one end of the second step-down resistor and the feedback terminal of the step-down voltage stabilization chip, respectively, and the other end of the second step-down resistor is electrically connected to the other end of the shunt resistor and the ground terminal of the LC filter sub-circuit, respectively.

5. The control device according to claim 1, wherein the isolated-to-non-isolated power supply circuit includes an isolated DC-DC converter, a third voltage input terminal of the isolated DC-DC converter is electrically connected to the second voltage output terminal, a ground terminal of the isolated DC-DC converter is grounded to form an isolated voltage input loop with the third voltage input terminal, a fourth voltage output terminal of the isolated DC-DC converter is electrically connected to the power supply pin of the electric energy metering chip, and another ground terminal of the isolated DC-DC converter is connected to zero to form a non-isolated voltage output loop with the fourth voltage output terminal.

6. The control apparatus of claim 5, wherein the isolated to non-isolated power supply circuit further comprises a first filter sub-circuit electrically connected between the third voltage input terminal and a corresponding one of the grounds and a second filter sub-circuit electrically connected between the fourth voltage output terminal and a corresponding other of the grounds.

7. The control device according to claim 1, wherein the control device further comprises a first voltage sampling circuit and a second voltage sampling circuit, the first voltage sampling circuit comprises a lightning protection sub-circuit, a voltage divider sub-circuit and a third filter sub-circuit, a fifth voltage output terminal of the lightning protection sub-circuit is electrically connected to a fifth voltage input terminal of the third filter sub-circuit and a positive voltage input terminal of the power metering chip through the voltage divider sub-circuit, respectively, and a sixth voltage input terminal of the second voltage sampling circuit is electrically connected to a negative voltage input terminal of the power metering chip.

8. The control device of claim 7, wherein the lightning protection sub-circuit comprises a connection terminal and a voltage dependent resistor, a live wire end of the connection terminal is electrically connected with one end of the voltage dependent resistor and a fourth voltage input end of the voltage dependent sub-circuit respectively, and a neutral wire end of the connection terminal is grounded with the other end of the voltage dependent resistor.

9. The control device according to any one of claims 1 to 8, wherein the control device further comprises a current sampling circuit, and a pair of current output terminals of the current sampling circuit are electrically connected with a pair of current input pins of the electric energy metering chip.

10. A monitoring device, characterized in that it comprises a control device according to any one of claims 1-9.

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