Zero-live-line power supply isolation circuit and double-manganese-copper metering device

Abstract

The utility model provides a zero live wire power isolation circuit and double manganese copper measurement equipment relates to power isolation field. This zero live wire power isolation circuit includes current doubling circuit, first rectifier circuit and second rectifier circuit, and current doubling circuit first input end connects GND, second input end connects UN, first output end connects the input end of first rectifier circuit, second output end connects the input end of second rectifier circuit, and current doubling circuit is used for isolating first output end and second output end, the output end of first rectifier circuit connects VBB, the output end of second rectifier circuit connects MHVDD, and first rectifier circuit and second rectifier circuit are used for voltage reduction. The utility model provides zero live wire power isolation circuit design is compact, and simultaneously uses conventional electrical component, and production cost is low.

Description

Technical Field

[0001] This utility model relates to the field of power isolation, and in particular to a neutral and live wire power isolation circuit and a dual manganese copper metering device. Background Technology

[0002] Manganese copper materials possess excellent temperature coefficients and high sensitivity, enabling more accurate current measurements under various operating conditions. Existing metering equipment typically uses current transformers or a combination of single manganese copper transformers and current transformers to achieve power isolation and current measurement. However, the introduction of current transformers leads to a decrease in the accuracy of current measurement.

[0003] Metering equipment using double manganese copper lacks power isolation and requires an additional power isolation circuit. Existing double manganese copper power isolation circuits are expensive and complex to design. This invention aims to provide a miniaturized, integrated, and low-cost power isolation circuit. Utility Model Content

[0004] To address the aforementioned problems, this application provides a live-neutral power isolation circuit, comprising a current multiplier circuit, a first rectifier circuit, and a second rectifier circuit, wherein:

[0005] The current multiplier circuit has its first input terminal connected to GND, its second input terminal connected to UN, its first output terminal connected to the input terminal of the first rectifier circuit, and its second output terminal connected to the input terminal of the second rectifier circuit. The current multiplier circuit is used to isolate the first output terminal and the second output terminal.

[0006] The output terminal of the first rectifier circuit is connected to VBB, and the output terminal of the second rectifier circuit is connected to MHVDD. The first rectifier circuit and the second rectifier circuit are used for voltage reduction.

[0007] In some embodiments of this application, the current multiplier circuit includes diodes DN1, DN2, DN3, and DN4, transistor QN1, resistor RN2, and electrolytic capacitor EN1, wherein:

[0008] The first input terminal of the current multiplier circuit is connected to the positive terminal of diode DN4, and the negative terminal of diode DN4 is connected to the positive terminal of electrolytic capacitor EN1 and the positive terminal of diode DN3;

[0009] The negative terminal of the electrolytic capacitor EN1 is connected to the emitter of the transistor QN1 and the positive terminal of the diode DN2;

[0010] The negative terminal of diode DN3 is connected to the negative terminal of diode DN1, and the negative terminal of diode DN3 is the second output terminal of the current multiplier circuit;

[0011] The negative terminal of diode DN2 is connected to the positive terminal of diode DN1 and the first terminal of resistor RN2, and the negative terminal of diode DN2 is the first output terminal of the current multiplier circuit;

[0012] The second end of the resistor RN2 is connected to the base of the diode QN1, the collector of the diode QN1 is connected to the anode of the diode DN4, and the input end of the diode DN1 is connected to the diode DN2.

[0013] In some embodiments of this application, the first rectifier circuit includes an electrolytic capacitor EN3, a Zener diode DN7, and a diode DN6, wherein:

[0014] The input terminal of the first rectifier circuit is connected to the positive terminal of diode DN6, the negative terminal of diode DN6 is connected to the positive terminal of electrolytic capacitor EN3, and the negative terminal of diode DN6 is connected to VBB;

[0015] The negative terminal of the electrolytic capacitor EN3 is connected to the positive terminal of the Zener diode DN7, and the negative terminal of the Zener diode DN7 is connected to the positive terminal of the diode DN6.

[0016] In some embodiments of this application, the first rectifier circuit further includes a resistor RN1 and a capacitor CN1. The first end of the resistor RN1 is connected to the positive terminal of the diode, and the second end of the resistor RN1 is connected to the first end of the capacitor CN1. The second end of the capacitor CN1 is the input terminal of the first rectifier circuit.

[0017] In some embodiments of this application, the second rectifier circuit includes a Zener diode DN5 and an electrolytic capacitor EN2, wherein:

[0018] The negative terminal of the Zener diode DN5 is the input terminal of the second rectifier circuit. The negative terminal of the Zener diode DN5 is connected to the positive terminal of the electrolytic capacitor EN2. The positive terminal of the electrolytic capacitor EN2 is connected to MHVDD. The negative terminal of the electrolytic capacitor EN2 is connected to the positive terminal of the Zener diode DN5 and GND.

[0019] In some embodiments of this application, the second rectifier circuit further includes capacitor CN2 and capacitor CN3, the first ends of capacitor CN2 and capacitor CN3 are connected to the negative terminal of Zener diode DN5, and the second ends of capacitor CN2 and capacitor CN3 are connected to the positive terminal of Zener diode DN5.

[0020] In some embodiments of this application, a resistor RN3 is also connected between GND and UN, and the resistor RN3 is a varistor.

[0021] This application also provides a dual manganese copper metering device that uses the neutral and live wire power isolation circuit described above.

[0022] Compared to existing technologies, the advantages of this application are:

[0023] 1. Power isolation is achieved through a current multiplier circuit, resulting in a compact circuit design that enables miniaturization and integration of the circuit.

[0024] 2. Low production cost due to the use of conventional electrical components;

[0025] 3. It has strong anti-interference ability and environmental adaptability. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a live-neutral power isolation circuit according to an embodiment of this application.

[0027] Figure 2 This is a circuit diagram illustrating the power isolation between the live and neutral wires according to an embodiment of this application.

[0028] Figure 3 This is a circuit diagram of a power chip according to an embodiment of this application.

[0029] Figure 4 This is a schematic diagram of the operation of a dual manganese copper metering device according to an embodiment of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0031] Please see Figure 1 This is a schematic diagram of a live-neutral power isolation circuit according to an embodiment of this application. The circuit includes a current multiplier circuit, a first rectifier circuit, and a second rectifier circuit.

[0032] The first input terminal of the current multiplier circuit is connected to GND, the second input terminal is connected to UN, the first output terminal is connected to the input terminal of the first rectifier circuit, and the second output terminal is connected to the output terminal of the second rectifier circuit.

[0033] The output of the first rectifier circuit is connected to VBB, and the output of the second rectifier circuit is connected to MHVDD.

[0034] The arrows in the diagram indicate the input / output terminals and the direction of the current. Since alternating current is being measured, during operation, the positive and negative values ​​of UN and GND will fluctuate following the sinusoidal voltage wave. The arrows pointing to UN and GND indicate the direction of the current forming a loop when the polarity changes.

[0035] Please see Figure 2 This is a circuit diagram of a live-neutral power isolation circuit according to an embodiment of this application. The current multiplier circuit includes diodes DN1, DN2, DN3, and DN4, transistor QN1, resistor RN2, and electrolytic capacitor EN1. The first input terminal of the current multiplier circuit is connected to the positive terminal of diode DN4. The negative terminal of diode DN4 is connected to the positive terminals of electrolytic capacitor EN1 and diode DN3. The negative terminal of electrolytic capacitor EN1 is connected to the emitter of transistor QN1 and the positive terminal of diode DN2. The negative terminal of diode DN3 is connected to the negative terminal of diode DN1. The negative terminal of diode DN3 is the second output terminal of the current multiplier circuit, which is used to connect to the second rectifier circuit.

[0036] The negative terminal of diode DN2 is connected to the positive terminal of diode DN1 and the first terminal of resistor RN2. The negative terminal of diode DN2 is the first output terminal of the current multiplier circuit, which is used to connect to the first rectifier circuit.

[0037] The isolation between the live and neutral wires can be achieved by using a current multiplier circuit. Normally, the neutral wire is connected to UN and the live wire is connected to GND. When AC power is connected, due to the characteristics of AC power itself, the positive and negative values ​​of UN and GND will fluctuate with the voltage sine wave during operation.

[0038] When GND is positive and UN is negative, the current flows from GND to VBB and UN. Specifically:

[0039] GND, diode DN4, electrolytic capacitor EN1, diode DN2, first rectifier circuit, VBB;

[0040] GND, diode DN4, electrolytic capacitor EN1, diode DN2, UN.

[0041] When GND is negative and UN is positive, the current flow in the circuit is from UN to MHVDD and from the electrolytic capacitor EN1 to MHVDD. Specifically:

[0042] UN, diode DN1, second rectifier circuit, MHVDD;

[0043] Electrolytic capacitor EN1, diode DN3, second rectifier circuit, MHVDD;

[0044] UN, resistor RN2, and base of transistor QN1. At this time, transistor QN1 is turned on, the negative terminal of electrolytic capacitor EN1 is grounded, and the positive terminal is connected to MHVDD. Electrolytic capacitor EN1 discharges, forming a double current.

[0045] The current multiplier circuit enables power supply from the live wire GND to the chip power supply VBB, and from the neutral wire UN to the chip power supply MHVDD, thereby achieving isolation between the live and neutral wire power supplies.

[0046] Furthermore, the first rectifier circuit includes an electrolytic capacitor EN3, a Zener diode DN7, and a diode DN6. The input terminal of the first rectifier circuit is connected to the positive terminal of the diode DN6, the negative terminal of the diode DN6 is connected to the positive terminal of the electrolytic capacitor EN3, the negative terminal of the diode DN6 is connected to VBB, the negative terminal of the electrolytic capacitor EN3 is connected to the positive terminal of the Zener diode DN7, and the negative terminal of the Zener diode DN7 is connected to the positive terminal of the diode DN6.

[0047] When a Zener diode DN7 is reverse-connected in a circuit, if current flows from the negative terminal of Zener diode DN7 to the positive terminal and the voltage in the circuit exceeds the breakdown threshold, Zener diode DN7 enters the breakdown region and conducts, while stabilizing the voltage in the circuit at a fixed value to prevent damage to other voltage-sensitive components.

[0048] Preferably, the voltage after rectification by the Zener diode DN7 is approximately 12V.

[0049] The DN6 diode is used for half-wave rectification. Specifically, it rectifies the AC power into pulsed DC power, and then the electrolytic capacitor EN3 converts the pulsed DC power rectified by the DN6 diode into smooth DC power.

[0050] Preferably, the first rectifier circuit further includes a resistor RN1 and a capacitor CN1. The first end of the resistor RN1 is connected to the positive terminal of the diode DN6, and the second end of the resistor RN1 is connected to the first end of the capacitor CN1. The second end of the capacitor CN1 is the new input terminal of the first rectifier circuit.

[0051] Resistor RN1 and capacitor CN1 are used for resistive-capacitive voltage reduction. The capacitance of capacitor CN1 is preferably 3.3 × 10⁻⁶. -7 F, it is easy to calculate that the capacitive reactance of capacitor CN1 is 9650Ω.

[0052] Furthermore, the second rectifier circuit includes a Zener diode DN5 and an electrolytic capacitor EN2. The negative terminal of the Zener diode DN5 is the input terminal of the second rectifier circuit. The negative terminal of the Zener diode DN5 is connected to the positive terminal of the electrolytic capacitor EN2. The positive terminal of the electrolytic capacitor EN2 is connected to MHVDD. The negative terminal of the electrolytic capacitor EN2 is connected to the positive terminal of the Zener diode DN5 and GND.

[0053] The function of Zener diode DN5 in the second rectifier circuit is the same as that of Zener diode DN7 in the first rectifier circuit, and will not be elaborated here. Unlike Zener diode DN7, the voltage after rectification by Zener diode DN5 is approximately 24V, which is used to power other detection circuits.

[0054] Preferably, the second rectifier circuit further includes capacitors CN2 and CN3, which are connected in parallel with the Zener diode DN5. Capacitors CN2 and CN3, along with the electrolytic capacitor EN2, are used for filtering and energy storage in the second rectifier circuit.

[0055] The first and second rectifier circuits rectify the 220V high voltage to 12V or 24V respectively, but this is still a relatively high voltage for the metering chip. Please refer to [link / reference needed]. Figure 3 Further voltage reduction is required via power supply chip 100. Specifically, VBB is connected to pin 3 (Vin) of power supply chip 100, pin 2 of power supply chip 100 is grounded, and capacitor C1 is connected between pin 1 (Vout) and pin 2 of power supply chip 100 for circuit filtering. The MHVDD side also needs to be stepped down via power supply chip 100, and its connection method is the same as that of the VBB side, so it will not be described in detail here. Power supply chip 100 can accurately control the voltage flowing into the metering chip, ensuring that the metering chip can operate without being damaged.

[0056] Specifically, the voltage after being stepped down by the power chip 100 is 3.3V, which meets the voltage requirements for the operation of the metering chip and the MCU.

[0057] Please see Figure 4 This is a schematic diagram of the operation of a dual manganese copper metering device according to an embodiment of this application. During operation, the metering device is connected to both the neutral and live wires, and supplied with 220V AC power. A second rectifier circuit generates a neutral voltage at the MHVDD terminal, and a first rectifier circuit generates a live voltage at the VBB terminal. The live voltage is regulated and filtered by resistor RN1 and capacitor CN1. The generated neutral and live voltages are stepped down by an LDO and then used to power the neutral and live metering chips, respectively. The neutral and live voltages are obtained through serial communication with the metering chips. The VBB terminal also powers the MCU, which receives and processes data from the metering chips.

[0058] LDO is an LDO voltage regulator chip, namely the power chip 100 mentioned above.

[0059] In this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0060] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0061] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations fall within the scope of the claims of this application and their equivalents, the intent of this application also includes these modifications and variations.

Claims

1. A neutral-live wire power isolation circuit, characterized in that, include: The circuit consists of a current multiplier circuit, a first rectifier circuit, and a second rectifier circuit, wherein: The current multiplier circuit has its first input terminal connected to GND, its second input terminal connected to UN, its first output terminal connected to the input terminal of the first rectifier circuit, and its second output terminal connected to the input terminal of the second rectifier circuit. The current multiplier circuit is used to isolate the first output terminal and the second output terminal. The output terminal of the first rectifier circuit is connected to VBB, and the output terminal of the second rectifier circuit is connected to MHVDD. The first rectifier circuit and the second rectifier circuit are used for voltage reduction.

2. The neutral-live wire power isolation circuit as described in claim 1, characterized in that, The current multiplier circuit includes diodes DN1, DN2, DN3, and DN4, transistor QN1, resistor RN2, and electrolytic capacitor EN1, wherein: The first input terminal of the current multiplier circuit is connected to the positive terminal of diode DN4, and the negative terminal of diode DN4 is connected to the positive terminal of electrolytic capacitor EN1 and the positive terminal of diode DN3; The negative terminal of the electrolytic capacitor EN1 is connected to the emitter of the transistor QN1 and the positive terminal of the diode DN2; The negative terminal of diode DN3 is connected to the negative terminal of diode DN1, and the negative terminal of diode DN3 is the second output terminal of the current multiplier circuit; The negative terminal of diode DN2 is connected to the positive terminal of diode DN1 and the first terminal of resistor RN2, and the negative terminal of diode DN2 is the first output terminal of the current multiplier circuit; The second end of the resistor RN2 is connected to the base of the diode QN1, the collector of the diode QN1 is connected to the anode of the diode DN4, and the input end of the diode DN1 is connected to the diode DN2.

3. The neutral-live wire power isolation circuit as described in claim 1, characterized in that, The first rectifier circuit includes an electrolytic capacitor EN3, a Zener diode DN7, and a diode DN6, wherein: The input terminal of the first rectifier circuit is connected to the positive terminal of diode DN6, the negative terminal of diode DN6 is connected to the positive terminal of electrolytic capacitor EN3, and the negative terminal of diode DN6 is connected to VBB; The negative terminal of the electrolytic capacitor EN3 is connected to the positive terminal of the Zener diode DN7, and the negative terminal of the Zener diode DN7 is connected to the positive terminal of the diode DN6.

4. The neutral-live wire power isolation circuit as described in claim 3, characterized in that, The first rectifier circuit further includes a resistor RN1 and a capacitor CN1. The first end of the resistor RN1 is connected to the positive terminal of the diode DN6, and the second end of the resistor RN1 is connected to the first end of the capacitor CN1. The second end of the capacitor CN1 is the input terminal of the first rectifier circuit.

5. A neutral-live wire power isolation circuit as described in claim 1, characterized in that, The second rectifier circuit includes a Zener diode DN5 and an electrolytic capacitor EN2, wherein: The negative terminal of the Zener diode DN5 is the input terminal of the second rectifier circuit. The negative terminal of the Zener diode DN5 is connected to the positive terminal of the electrolytic capacitor EN2. The positive terminal of the electrolytic capacitor EN2 is connected to MHVDD. The negative terminal of the electrolytic capacitor EN2 is connected to the positive terminal of the Zener diode DN5 and GND.

6. The neutral-live wire power isolation circuit as described in claim 5, characterized in that, The second rectifier circuit further includes capacitors CN2 and CN3. The first terminals of capacitors CN2 and CN3 are connected to the negative terminal of Zener diode DN5, and the second terminals of capacitors CN2 and CN3 are connected to the positive terminal of Zener diode DN5.

7. A neutral-live wire power isolation circuit as described in claim 1, characterized in that, A resistor RN3 is also connected between GND and UN, and the resistor RN3 is a varistor.

8. A dual manganese copper metering device, characterized in that, Use the live and neutral power isolation circuit as described in any one of claims 1 to 7.

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