Self-resetting overvoltage and undervoltage protection circuit

Abstract

The utility model relates to the technical field of power utilization protection, in particular to a self-resetting overvoltage and undervoltage protection circuit, which comprises a power supply, a capacity expansion control circuit, an overload and short circuit detection circuit, an electric leakage detection circuit and a load, the power supply provides required electric signals for the capacity expansion control circuit, the overload and short circuit detection circuit and the electric leakage detection circuit; the overload and short circuit detection circuit detects overload or short circuit signals through a mutual inductor when a load in an alternating current circuit is overloaded or short-circuited. The electric leakage detection circuit is used for detecting residual action current by using a mutual inductor when an electric leakage accident occurs in the circuit or a person is in an electric shock; the load is a device needing power supply.

Description

Technical Field

[0001] This utility model relates to the field of electrical protection technology, and more specifically to a self-resetting over / under voltage protection circuit. Background Technology

[0002] Capacity expansion control refers to controlling and managing the capacity of various parts of a power system to ensure stable operation under increased load. Capacity expansion control typically involves increasing or adjusting the capacity of generating equipment, transformers, transmission lines, etc., to meet growing electricity demand while preventing system overload or failure. This control measure can be implemented through hardware upgrades or optimized use of existing resources to ensure the safety and reliability of the power system.

[0003] Existing circuit structures have low power consumption and poor load capacity, often resulting in damage to the switching control components due to excessively low or high supply voltage. Therefore, there is an urgent need to provide a safe and reliable circuit structure. Utility Model Content

[0004] To address the shortcomings of current circuit structures, a self-resetting over / under voltage protection circuit is provided. This circuit uses a microcomputer chip to identify voltage and current to control the circuit's on / off state, automatically resetting and resuming conduction within a set range.

[0005] To achieve the above objectives, this utility model provides the following technical solution, mainly including:

[0006] A self-resetting over / under voltage protection circuit includes: a power supply, a capacity expansion control circuit, an overload and short circuit detection circuit, a leakage current detection circuit, and a load;

[0007] The power supply provides the necessary electrical signals for the capacity expansion control circuit, overload and short circuit detection circuit, and leakage current detection circuit.

[0008] The overload and short circuit detection circuit detects overload or short circuit signals through a current transformer when the load in the AC circuit is overloaded or short-circuited.

[0009] The leakage current detection circuit uses a current transformer to detect the remaining operating current when a leakage current accident occurs in the circuit or a person is electrocuted.

[0010] The load is a device that requires power.

[0011] Preferably, the expansion control circuit includes a microcomputer controller and an expansion controller.

[0012] Preferably, the overload and short circuit detection circuit includes a first current transformer, a first diode, a third capacitor, a first resistor, a fourth capacitor, a first potentiometer, a second resistor, and a Zener diode;

[0013] The primary side of the first current transformer is connected in series with a 220V AC live wire, and one end of the secondary side is connected to the anode of the first diode, and the other end is connected to the third capacitor, the fourth capacitor, and the second resistor, and grounded.

[0014] The first resistor is connected to the cathode of the first diode and the third capacitor, and the other end is connected to the fourth capacitor and the first potentiometer; one end of the Zener diode is connected to the first potentiometer and the second resistor, and the other end is connected to the base of the first transistor.

[0015] Preferably, the leakage current detection circuit includes a second current transformer, a fifth capacitor, a second diode, a third diode, a sixth capacitor, and a third resistor;

[0016] The primary side of the second current transformer has two coils: a co-current terminal and a reverse-current terminal. One end of the co-current terminal is connected in series with the live wire, and the other end is connected to the primary side of the first current transformer. The other end is connected to the first anode of the thyristor. One end of the reverse-current terminal is connected in series with the neutral wire, and the other end is connected to the normally closed contact of the relay. The secondary side of the second current transformer has the co-current terminal connected to the anode of the fifth capacitor and the second diode, and the other end connected to the anode of the fifth capacitor, the third diode, the sixth capacitor, and the third resistor, and grounded.

[0017] The cathode of the second diode is connected to the anode of the third diode, the sixth capacitor, the third resistor, and the base of the first transistor.

[0018] As can be seen from the above technical solution, compared with the prior art, this utility model consists of a power supply, a capacity expansion control circuit, an overload and short circuit detection circuit, a leakage current detection circuit, an overvoltage and undervoltage circuit, and a load; when the power supply voltage is abnormal and outside the set range, the microcomputer controller is disconnected, the capacity expansion controller loses power and shuts down, protecting the user's electrical equipment; when the power supply voltage is normal, the microcomputer control is turned on, the capacity expansion controller is powered on and works, and the user's electrical equipment continues to work. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of this utility model.

[0021] Figure 2 This is a schematic diagram of the capacity expansion control circuit in this utility model.

[0022] Figure 3 This is a combined diagram of the overload and short circuit detection circuit, leakage current detection circuit, and overvoltage and undervoltage circuit diagrams in this utility model. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Example 1

[0025] A self-resetting over / under voltage protection circuit, such as Figure 1 As shown, it includes: power supply, expansion control circuit 1, overload and short circuit detection circuit 2, leakage current detection circuit 3, and load;

[0026] The power supply provides the necessary electrical signals to the expansion control circuit 1, the overload and short circuit detection circuit 2, and the leakage current detection circuit 3.

[0027] When the load in the AC circuit is overloaded or short-circuited, the overload and short-circuit detection circuit 2 detects the overload or short-circuit signal through the current transformer.

[0028] The leakage current detection circuit 3 is used to detect the remaining operating current by a current transformer when a leakage current accident occurs in the circuit or a person is electrocuted.

[0029] The load is a device that requires power.

[0030] Example 2

[0031] To further optimize the above scheme, the overload and short circuit detection circuit 2 also includes a current transformer 21, a diode 22, a capacitor 23, a resistor 24, a capacitor 25, a potentiometer 26, a Zener diode 27, and a resistor 28.

[0032] The primary side of the current transformer 21 is connected in series with the AC 220V live wire, and one end of the secondary side is connected to the anode of the diode 22, and the other end is connected to capacitor 23, capacitor 24 and resistor 28, and grounded.

[0033] The resistor 24 is connected to the cathode of the diode 22 and the capacitor 23, and the other end is connected to the capacitor 25 and the potentiometer 26;

[0034] One end of the Zener diode 27 is connected to potentiometer 26 and resistor 28;

[0035] The leakage current detection circuit 3 includes a current transformer 31, a capacitor 32, a diode 33, a diode 34, a capacitor 35, and a resistor 36.

[0036] The primary side of the current transformer 31 has two coils: a coil with the same name and a coil with the opposite phase. One end of the coil with the same name is connected in series with the live wire, and the other end is connected to the primary side of the current transformer 21. The secondary side of the current transformer 31 has the same name end connected to the anode of capacitor 32 and diode 33, and the other end connected to the anode of capacitor 35 and diode 34, capacitor 35 and resistor 36, and grounded.

[0037] The cathode of diode 33 is connected to the anode of diode 34, capacitor 35, and resistor 36.

[0038] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0039] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A self-resetting over / under voltage protection circuit, characterized by comprising: Includes: power supply, expansion control circuit, overload and short circuit detection circuit, leakage current detection circuit, and load; The power supply provides the necessary electrical signals for the capacity expansion control circuit, overload and short circuit detection circuit, and leakage current detection circuit. The overload and short circuit detection circuit detects overload or short circuit signals through a current transformer when the load in the AC circuit is overloaded or short-circuited. The leakage current detection circuit uses a current transformer to detect the remaining operating current when a leakage current accident occurs in the circuit or a person is electrocuted. The load is a device that requires power.

2. The self-resetting over / under voltage protection circuit of claim 1, wherein, The expansion control circuit includes a microcomputer controller and an expansion controller.

3. The self-resetting over / under voltage protection circuit of claim 1, wherein, The overload and short circuit detection circuit includes a first current transformer, a first diode, a third capacitor, a first resistor, a fourth capacitor, a first potentiometer, a second resistor, and a Zener diode. The primary side of the first current transformer is connected in series with a 220V AC live wire, and one end of the secondary side is connected to the anode of the first diode, and the other end is connected to the third capacitor, the fourth capacitor, and the second resistor, and grounded. The first resistor is connected to the cathode of the first diode and the third capacitor, and the other end is connected to the fourth capacitor and the first potentiometer; one end of the Zener diode is connected to the first potentiometer and the second resistor, and the other end is connected to the base of the first transistor.

4. The self-resetting over / under voltage protection circuit of claim 1, wherein, The leakage current detection circuit includes a second current transformer, a fifth capacitor, a second diode, a third diode, a sixth capacitor, and a third resistor; The primary side of the second current transformer has two coils: a co-current terminal and a reverse-current terminal. One end of the co-current terminal is connected in series with the live wire, and the other end is connected to the primary side of the first current transformer. The other end is connected to the first anode of the thyristor. One end of the reverse-current terminal is connected in series with the neutral wire, and the other end is connected to the normally closed contact of the relay. The secondary side of the second current transformer has the co-current terminal connected to the anode of the fifth capacitor and the second diode, and the other end connected to the anode of the fifth capacitor, the third diode, the sixth capacitor, and the third resistor, and grounded. The cathode of the second diode is connected to the anode of the third diode, the sixth capacitor, the third resistor, and the base of the first transistor.

Images