Switching power supply circuit for electric energy meter and acquisition terminal

Abstract

The utility model belongs to the technical field of power supply circuits, and relates to a switching power supply circuit for an electric energy meter and an acquisition terminal, which comprises a composite PTC (Positive Temperature Coefficient), an overcurrent and overvoltage protection circuit and a main control circuit, the input end of the composite PTC is used for being connected with a first power supply end; the input end of the overcurrent and overvoltage protection circuit is connected to the output end of the composite PTC; the input end of the master control circuit is connected with the output end of the overcurrent and overvoltage protection circuit, and the output end of the master control circuit is used for being connected with a load circuit. The switching power supply circuit solves the problems of low safety and reliability of a power supply device caused by single protection function of a switching power supply circuit in the prior art.

Description

TECHNICAL FIELD

[0001] The utility model relates to power supply circuit technical field especially relates to a switch power supply circuit for electric energy meter and collection terminal. BACKGROUND

[0002] The switch power supply protection function is an additional function of the electrical performance requirement of the power supply device, but under the influence of uncertain factors such as severe environment, the protection circuit can work according to the predetermined state, and plays a crucial role in the safety and reliability of the power supply device. At present, the common switch power supply circuit only uses the protection circuit inside the switch power supply chip for protection; a few power supplies have the protection of the input end of the switch power supply, but the protection function is single, mainly reflected in the overvoltage protection. Thus, the safety and reliability of the power supply device are easily reduced. SUMMARY

[0003] Therefore, the utility model provides a switch power supply circuit for electric energy meter and collection terminal for solving the single protection function of the switch power supply circuit in the prior art, which leads to the low safety and reliability of the power supply device.

[0004] To achieve one or part or all of the above purposes or other purposes, the utility model provides a switch power supply circuit for electric energy meter and collection terminal, which comprises: a composite PTC, an overcurrent and overvoltage protection circuit and a main control circuit; the input end of the composite PTC is used for connecting a first power supply end; the input end of the overcurrent and overvoltage protection circuit is connected to the output end of the composite PTC; the input end of the main control circuit is connected to the output end of the overcurrent and overvoltage protection circuit, and the output end of the main control circuit is used for connecting a load circuit.

[0005] Further, the overcurrent and overvoltage protection circuit comprises: a high-voltage regulating chip and a peripheral protection circuit; the first connecting end of the high-voltage regulating chip is connected to the output end of the composite PTC, and the second connecting end is connected to the main control circuit; one end of the peripheral protection circuit is connected to the third connecting end of the high-voltage regulating chip, and the other end is connected in parallel between the current loop output end of the composite PTC and the current loop input end of the main control circuit and used for connecting a second power supply end.

[0006] Further, the peripheral protection circuit comprises a first resistor, a first capacitor and a second resistor; one end of the first resistor is connected in parallel between the current loop output end of the composite PTC and the current loop input end of the main control circuit, and is also used for connecting the second power supply end; the other end of the first resistor is connected to the high-voltage regulating chip; two ends of the first capacitor are respectively connected to the other end of the first resistor and the high-voltage regulating chip, and are used for current detection; one end of the second resistor is connected to the high-voltage regulating chip, and the other end of the second resistor is connected to the other end of the second resistor, and is used for voltage detection.

[0007] Further, the high-voltage regulating chip comprises a first pin, a second pin, a third pin and a fourth pin; the first pin is connected to the second resistor, and is used for voltage detection; the second pin is connected to the other end of the first resistor, and is used for connecting the second power supply end; the third pin is connected to the current loop output end of the main control circuit; and the fourth pin is connected to the current loop input end of the composite PTC and the first capacitor, and is used for current detection.

[0008] Further, the main control circuit comprises a main control chip, a first main control protection unit, a main control power supply unit and a second main control protection unit; the current loop input end of the main control chip is connected to the current loop output end of the composite PTC; the first end of the first main control protection unit is connected in parallel between the current loop output end of the composite PTC and the current loop input end of the main control chip to form a first parallel point, and the second end of the first main control protection unit is connected to the main control chip; one end of the main control power supply unit is connected to the main control chip, and the other end of the main control power supply unit is used for connecting a third power supply end; two ends of the second main control protection unit are respectively connected to the current loop output end of the main control chip and the current loop output end of the high-voltage regulating chip; and one end of the first resistor is connected in parallel between the current loop output end of the composite PTC and the first parallel point.

[0009] Further, the first main control protection unit comprises a third resistor, a second capacitor and a diode; one end of the third resistor is connected in parallel between the current loop output end of the composite PTC and the current loop input end of the main control chip; the other end of the third resistor is connected to the main control chip; one end of the second capacitor is connected in parallel between the current loop output end of the composite PTC and the current loop input end of the main control chip; the other end of the second capacitor is connected to the main control chip; and the positive electrode of the diode is connected to the main control chip, and the negative electrode of the diode is connected to the third resistor and the second capacitor.

[0010] Further, the main control circuit further comprises a transformer, wherein the transformer comprises a primary coil and a secondary coil; two ends of the primary coil are connected with the first parallel point and a current loop input end of the main control chip respectively; the secondary coil is coupled with the primary coil, and two ends of the secondary coil are used for connecting the load circuit.

[0011] Further, the switching power supply circuit for the electric energy meter and the collection terminal further comprises a rectifier circuit, which is arranged between the composite PTC and the overcurrent and overvoltage protection circuit.

[0012] Further, the switching power supply circuit for the electric energy meter and the collection terminal further comprises a first filter circuit, which is arranged between the rectifier circuit and the overcurrent and overvoltage protection circuit.

[0013] Further, the switching power supply circuit for the electric energy meter and the collection terminal further comprises a second filter circuit, which is arranged between the overcurrent and overvoltage protection circuit and the main control circuit.

[0014] The embodiment of the utility model has the following beneficial effects:

[0015] The switching power supply circuit for the electric energy meter and the collection terminal provided by the utility model protects the input end of the switching power supply through the composite PTC; then the overcurrent and overvoltage protection circuit is used for monitoring the current and voltage, so that the protection circuit is protected from the damage of overcurrent and overvoltage; and the main control circuit is used for converting the input voltage into a specific voltage value suitable for the load circuit, so that the safe and stable operation of the load circuit is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creating labor.

[0017] Wherein:

[0018] Figure 1 It is a circuit connection schematic diagram of the switching power supply circuit for the electric energy meter and the collection terminal in one embodiment of the utility model;

[0019] Figure 2 It is a circuit connection schematic diagram of the overcurrent and overvoltage protection circuit of the switching power supply circuit for the electric energy meter and the collection terminal in another embodiment of the utility model;

[0020] Figure 3This is a circuit connection diagram of the main control circuit of a switching power supply circuit for an energy meter and a data acquisition terminal, as shown in another embodiment of the present invention.

[0021] Figure label:

[0022] 10. Composite PTC; 20. Overcurrent and overvoltage protection circuit; 21. High voltage regulating chip; 211. First pin; 212. Second pin; 213. Third pin; 214. Fourth pin; 22. Peripheral protection circuit; 221. First resistor; 222. First capacitor; 223. Second resistor; 30. Main control circuit; 31. Main control chip; 32. First main control protection unit; 321. Third resistor; 322. Second capacitor; 323. Diode; 33. Main control power supply unit; 331. Third capacitor; 34. Second main control protection unit; 341. Fourth resistor; 35. Transformer; 40. First parallel connection point; 50. Rectifier circuit; 60. First filter circuit; 70. Second filter circuit. Detailed Implementation

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this invention are used to distinguish different objects, not to describe a particular order; the cold water mentioned in the specification and claims of this invention includes room temperature water.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0026] Reference Figures 1 to 3The first embodiment of this application proposes a switching power supply circuit for an electricity meter and a data acquisition terminal. The switching power supply circuit for the electricity meter and data acquisition terminal includes: a composite PTC10, an overcurrent and overvoltage protection circuit 20, and a main control circuit 30. The input terminal of the composite PTC10 is used to connect to a first power supply terminal. The input terminal of the overcurrent and overvoltage protection circuit 20 is connected to the output terminal of the composite PTC10. The input terminal of the main control circuit 30 is connected to the output terminal of the overcurrent and overvoltage protection circuit 20, and the output terminal of the main control circuit 30 is used to connect to a load circuit.

[0027] In this embodiment, the current first passes through the composite PTC10, which can monitor the voltage and current in the circuit in real time. Once the detected voltage or current value exceeds a preset threshold, the composite PTC10 reacts quickly based on its own characteristics, its internal structure changes, thereby disconnecting the connection with the circuit behind the composite PTC10 and cutting off the power supply to the circuit behind the composite PTC10; thus preventing excessive voltage or current from causing irreparable damage to other components in the circuit behind the composite PTC10, providing initial safety protection.

[0028] After the initial protection from the composite PTC10, the circuit will immediately enter the overcurrent and overvoltage protection circuit 20. This circuit performs real-time and accurate monitoring of the circuit and current.

[0029] After passing through the overcurrent and overvoltage protection circuit 20, the current enters the main control circuit 30. The main control circuit 30 converts the input voltage into a specific voltage value suitable for use by the circuits downstream of it. Simultaneously, the main control circuit 30 monitors the voltage and current of the circuit; when the detected voltage or current exceeds its normal operating threshold, the main control circuit 30 quickly disconnects the power supply to the circuits downstream of it through its internal control logic. This not only ensures the safe and stable operation of the circuits downstream of the main control circuit 30 but also protects the main control circuit 30 itself from damage caused by excessive voltage or current.

[0030] In summary, the switching power supply circuit used in the electricity meter and data acquisition terminal provides multi-layered protection for the circuit, improving the safety and reliability of the power supply device.

[0031] Specifically, the circuit at the rear end of the main control circuit 30 includes the load circuit.

[0032] Reference Figures 1 to 2The overcurrent and overvoltage protection circuit 20 includes a high-voltage regulating chip 21 and an external protection circuit 22. The first connection terminal of the high-voltage regulating chip 21 is connected to the output terminal of the composite PTC10, and its second connection terminal is connected to the main control circuit 30. One end of the external protection circuit 22 is connected to the third connection terminal of the high-voltage regulating chip 21, and its other end is connected in parallel between the current loop output terminal of the composite PTC10 and the current loop input terminal of the main control circuit 30, and is used to connect to the second power supply terminal.

[0033] In this embodiment, the high voltage regulating chip 21 and the peripheral protection circuit 22 work together to monitor the voltage and current output by the composite PTC10 in real time and accurately. If the voltage and current exceed the threshold, the power supply to the circuit behind the high voltage regulating chip 21 will be disconnected or the power supply to the high voltage regulating chip 21 itself will be disconnected.

[0034] Reference Figures 1 to 2 The peripheral protection circuit 22 includes: a first resistor 221, a first capacitor 222, and a second resistor 223; one end of the first resistor 221 is connected in parallel between the current loop output terminal of the composite PTC10 and the current loop input terminal of the main control circuit 30, and is also used to connect to the second power supply terminal; the other end of the first resistor 221 is connected to the high voltage regulating chip 21; the two ends of the first capacitor 222 are respectively connected to the other end of the first resistor 221 and the high voltage regulating chip 21 for current detection; one end of the second resistor 223 is connected to the high voltage regulating chip 21, and the other end is connected to the other end of the second resistor 223 for voltage detection.

[0035] In this embodiment, the peripheral protection circuit 22 is used to perform real-time and accurate monitoring of the circuit from the composite PTC10 to the main control circuit 30, and also to perform real-time and accurate monitoring of the circuit from the second power supply terminal to the high-voltage regulating chip 21. This not only ensures the safe and stable operation of the circuit downstream of the high-voltage regulating chip 21, but also protects the high-voltage regulating chip 21 itself from damage caused by excessive voltage or current.

[0036] Specifically, the first resistor 221 is formed by connecting multiple resistors in series.

[0037] Reference Figures 1 to 2The high-voltage regulating chip 21 includes: a first pin 211, a second pin 212, a third pin 213, and a fourth pin 214; the first pin 211 is connected to the second resistor 223 for voltage detection; the second pin 212 is connected to the other end of the first resistor 221 for connecting to the second power supply terminal; the third pin 213 is connected to the current loop output terminal of the main control circuit 30; and the fourth pin 214 is connected to the current loop input terminal of the composite PTC 10 and the first capacitor 222 for current detection.

[0038] In this embodiment, the high-voltage regulating chip 21 monitors the voltage between the composite PTC10 and the main control circuit 30 in real time through the first pin 211, the first resistor 221 and the second resistor 223 of the peripheral protection circuit 22; it safely supplies power to the high-voltage regulating chip 21 through the second pin 212 and the first resistor 221 of the peripheral protection circuit 22; it connects to the current loop output terminal of the main control circuit 30 through the third pin 213 and to the current loop output terminal of the composite PTC10 through the fourth pin 214, thus completing the current return connection between the composite PTC10, the overvoltage and overcurrent protection circuit and the main control circuit 30; and it monitors the current between the composite PTC10 and the main control circuit 30 in real time through the fourth pin 214, the first resistor 221 and the first capacitor 222 of the peripheral protection circuit 22.

[0039] Reference Figure 1 and Figure 3 The main control circuit 30 includes: a main control chip 31, a first main control protection unit 32, a main control power supply unit 33, and a second main control protection unit 34; the current loop input terminal of the main control chip 31 is connected to the current loop output terminal of the composite PTC10; the first terminal of the first main control protection unit 32 is connected in parallel between the current loop output terminal of the composite PTC10 and the current loop input terminal of the main control chip 31 to form a first parallel connection point 40, and its second terminal is connected to the main control chip 31; one terminal of the main control power supply unit 33 is connected to the main control chip 31, and its other terminal is used to connect to a third power supply terminal; the two ends of the second main control protection unit 34 are respectively connected to the current loop output terminal of the main control chip 31 and the current loop output terminal of the high voltage regulating chip 21; wherein, one terminal of the first resistor 221 is connected in parallel between the current loop output terminal of the composite PTC10 and the first parallel connection point 40.

[0040] In this embodiment, the main control chip 31, together with the first main control protection unit 32 and the second main control protection unit 34, works to convert the voltage flowing in after passing through the overcurrent and overvoltage protection circuit 20 into a specific voltage value suitable for use by the back-end circuit. Simultaneously, it also has voltage and current monitoring functions. When the voltage or current exceeds the threshold range for the back-end circuit to operate normally, the main control chip 31 will quickly disconnect the power supply connection to the back-end circuit through its internal control logic.

[0041] The main control chip 31 and the main control power supply unit 33 work together to convert the voltage input from the third power supply terminal into a specific voltage value suitable for use by the main control chip 31.

[0042] Reference Figure 1 and Figure 3 The first main control protection unit 32 includes: a third resistor 321, a second capacitor 322, and a diode 323; one end of the third resistor 321 is connected in parallel between the current loop output terminal of the composite PTC10 and the current loop input terminal of the main control chip 31; the other end of the third resistor 321 is connected to the main control chip 31; one end of the second capacitor 322 is connected in parallel between the current loop output terminal of the composite PTC10 and the current loop input terminal of the main control chip 31; the other end of the second capacitor 322 is connected to the main control chip 31; the anode of the diode 323 is connected to the main control chip 31, and its cathode is connected to the third resistor 321 and the second capacitor 322.

[0043] In this embodiment, the current and voltage input to the main control chip 31 are monitored using the third resistor 321, the second capacitor 322, and the diode 323.

[0044] Reference Figure 1 and Figure 3 The main control power supply unit 33 includes a third capacitor 331, and the two ends of the third capacitor 331 are respectively connected to the main control chip 31 and the third power supply terminal.

[0045] Reference Figure 1 and Figure 3 The second main control protection unit 34 includes a fourth resistor 341, the two ends of which are respectively connected to the current loop output terminals of the main control chip 31 and the high voltage regulation chip 21.

[0046] Specifically, the fourth resistor 341 is formed by connecting multiple resistors in parallel.

[0047] In some embodiments, the overcurrent voltage range of the composite PTC10 is 200-400V, the overcurrent voltage range of the high voltage regulating chip 21 is 800-1100V, and the overcurrent voltage range of the main control chip 31 is 300-500V.

[0048] In this embodiment, the protection value ranges of the composite PTC10, high voltage regulating chip 21, and main control chip 31 are used to adapt to the voltage of circuit components in different circuit segments.

[0049] Specifically, the composite PTC10 has an overcurrent voltage of 310V and an overcurrent current of 120mA; the high-voltage regulating chip 21 has an overcurrent voltage of 1000V and an overcurrent current of 100mA; and the main control chip 31 has an overcurrent voltage of 430V and an overcurrent current of 50mA. This improves the range of voltages that the circuit can protect against.

[0050] Reference Figure 1 and Figure 3 The main control circuit 30 further includes a transformer 35; the transformer 35 includes a primary coil and a secondary coil; the two ends of the primary coil are respectively connected to the first parallel point 40 and the current loop input terminal of the main control chip 31; the secondary coil is coupled to the primary coil, and the two ends of the secondary coil are used to connect to the load circuit.

[0051] In this embodiment, transformer 35 is used to connect the load circuit.

[0052] Reference Figure 1 The switching power supply circuit for the electricity meter and data acquisition terminal further includes a rectifier circuit 50, which is located between the composite PTC 10 and the overcurrent and overvoltage protection circuit 20.

[0053] In this embodiment, the circuit at the back end of the composite PTC10 is rectified.

[0054] Reference Figure 1 The switching power supply circuit for the electricity meter and data acquisition terminal further includes a first filter circuit 60, which is located between the rectifier circuit 50 and the overcurrent and overvoltage protection circuit 20.

[0055] In this embodiment, the circuitry at the back end of the composite PTC10 is filtered.

[0056] Reference Figure 1 Figure 1 The switching power supply circuit for the electricity meter and data acquisition terminal further includes a second filter circuit 70, which is located between the overcurrent and overvoltage protection circuit 20 and the main control circuit 30.

[0057] In this embodiment, the circuit at the back end of the overcurrent and overvoltage protection circuit 20 is filtered.

[0058] Obviously, the embodiments described above are only some embodiments of this utility model, not all embodiments. The accompanying drawings show preferred embodiments of this utility model, but do not limit the patent scope of this utility model. This utility model can be implemented in many different forms; conversely, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this utility model.

Claims

1. A switching power supply circuit for an electricity meter and a data acquisition terminal, characterized in that, include: A composite PTC, wherein the input terminal of the composite PTC is used to connect to the first power supply terminal; An overcurrent and overvoltage protection circuit, wherein the input terminal of the overcurrent and overvoltage protection circuit is connected to the output terminal of the composite PTC; The main control circuit has its input terminal connected to the output terminal of the overcurrent and overvoltage protection circuit, and its output terminal is used to connect to the load circuit.

2. The switching power supply circuit for an electricity meter and data acquisition terminal according to claim 1, characterized in that, The overcurrent and overvoltage protection circuit includes: A high-voltage regulating chip, wherein the first connection terminal of the high-voltage regulating chip is connected to the output terminal of the composite PTC, and the second connection terminal is connected to the main control circuit; An external protection circuit is provided, one end of which is connected to the third connection terminal of the high voltage regulating chip, and the other end is connected in parallel between the current loop output terminal of the composite PTC and the current loop input terminal of the main control circuit, and is used to connect to the second power supply terminal.

3. The switching power supply circuit for an electricity meter and data acquisition terminal according to claim 2, characterized in that, The peripheral protection circuit includes: The first resistor has one end connected in parallel between the current loop output terminal of the composite PTC and the current loop input terminal of the main control circuit, and is also used to connect the second power supply terminal. The other end of the first resistor is connected to the high voltage regulation chip. A first capacitor, the two ends of which are respectively connected to the other end of the first resistor and the high voltage regulation chip, for current detection; A second resistor, one end of which is connected to the high-voltage regulating chip, and the other end of which is connected to the other end of the second resistor, is used for voltage detection.

4. The switching power supply circuit for an electricity meter and data acquisition terminal according to claim 3, characterized in that, The high-voltage regulating chip includes: The first pin is connected to the second resistor for voltage detection; The second pin is connected to the other end of the first resistor to be used to connect to the second power supply terminal; The third pin is connected to the current loop output terminal of the main control circuit; The fourth pin is connected to the current loop input terminal of the composite PTC and the first capacitor for current detection.

5. The switching power supply circuit for an electricity meter and data acquisition terminal according to claim 3, characterized in that, The main control circuit includes: The main control chip has its current loop input terminal connected to the current loop output terminal of the composite PTC. The first main control protection unit has its first end connected in parallel between the current loop output terminal of the composite PTC and the current loop input terminal of the main control chip to form a first parallel point, and its second end is connected to the main control chip. A main control power supply unit, one end of which is connected to the main control chip, and the other end of which is used to connect to a third power supply terminal; The second main control protection unit has its two ends connected to the current loop output terminal of the main control chip and the current loop output terminal of the high voltage regulation chip, respectively. Wherein, one end of the first resistor is connected in parallel between the current loop output terminal of the composite PTC and the first parallel connection point.

6. The switching power supply circuit for an electricity meter and data acquisition terminal according to claim 5, characterized in that, The first main control protection unit includes: The third resistor has one end connected in parallel between the current loop output terminal of the composite PTC and the current loop input terminal of the main control chip; the other end of the third resistor is connected to the main control chip. The second capacitor has one end connected in parallel between the current loop output terminal of the composite PTC and the current loop input terminal of the main control chip; the other end of the second capacitor is connected to the main control chip. A diode, the positive terminal of which is connected to the main control chip, and the negative terminal of which is connected to the third resistor and the second capacitor.

7. The switching power supply circuit for an electricity meter and data acquisition terminal according to claim 5, characterized in that, The main control circuit also includes: a transformer; the transformer includes: The primary coil has its two ends connected to the first parallel point and the current loop input terminal of the main control chip, respectively. The secondary coil is coupled to the primary coil, and its two ends are used to connect to the load circuit.

8. The switching power supply circuit for an electricity meter and data acquisition terminal according to claim 1, characterized in that, The switching power supply circuit for the electricity meter and data acquisition terminal also includes a rectifier circuit, which is located between the composite PTC and the overcurrent and overvoltage protection circuit.

9. The switching power supply circuit for an electricity meter and data acquisition terminal according to claim 8, characterized in that, The switching power supply circuit for the electricity meter and data acquisition terminal further includes a first filter circuit, which is located between the rectifier circuit and the overcurrent and overvoltage protection circuit.

10. The switching power supply circuit for an electricity meter and data acquisition terminal according to claim 1, characterized in that, The switching power supply circuit for the electricity meter and data acquisition terminal further includes a second filter circuit, which is located between the overcurrent and overvoltage protection circuit and the main control circuit.

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