Power supply detection control circuit and electrical equipment

Abstract

The present invention relates to the field of power electronics technology, and discloses a power supply detection control circuit and electrical equipment. The present invention enables the comparator to operate normally by supplying power to the comparator through the comparator power supply circuit when the mains power access line sequence is correct, and generates a voltage difference at both ends of the first energy storage element, so that the comparator outputs a high level, thereby controlling the control circuit provided between the live wire access end and the power supply end of the power load to be turned on, so that the power load can be powered and operate normally. Conversely, if the live wire and the neutral wire are connected in reverse, the comparator power supply circuit stops supplying power to the comparator, the comparator cannot work, the control circuit is disconnected, and the power load will not be powered. This ensures that the power load will only be connected to the live wire and operate normally when the mains power access line sequence is correct, and cuts off the live wire power supply when the mains power live wire and the neutral wire are connected in reverse, so as to avoid potential power safety hazards to the power load or people, ensure power safety, and enhance the user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to a power supply detection control circuit and electrical equipment. Background Art

[0002] Household appliances are typically powered by mains electricity. If the live and neutral wires of a mains-powered appliance are connected incorrectly, the live wire inside the appliance remains live even when the appliance is turned off. Touching the metal casing of a device (such as an electric water heater or refrigerator) or repairing it can easily create a current loop, leading to electric shock. This can also cause the appliance to malfunction or even damage, posing multiple safety risks to both the appliance and personnel. Therefore, ensuring the safety of the mains power supply and effectively controlling it is a pressing issue. Summary of the Invention

[0003] In view of this, the present invention provides a power supply detection control circuit and electrical equipment to solve the problem in the related art that the mains power supply equipment lacks an effective solution to detect and control whether the live wire and the neutral wire are connected reversely, resulting in potential safety hazards in electricity use.

[0004] In a first aspect, the present invention provides a power supply detection control circuit, comprising: a first energy storage element, a comparator, a comparator power supply circuit, and a control circuit, wherein one end of the first energy storage element is respectively connected to a live wire input terminal and a positive input terminal of the comparator, and the other end is respectively connected to a negative input terminal of the comparator and a ground terminal;

[0005] The output end of the comparator is connected to the control end of the control circuit, and the comparator is used to control the control circuit to be turned on or off;

[0006] The control circuit is arranged between the live wire access terminal and the power supply terminal of the power load;

[0007] The comparator power supply circuit is arranged between the live wire access terminal and the neutral wire access terminal, and the first end of the comparator power supply circuit is connected to the power supply terminal of the comparator. The comparator power supply circuit stores electrical energy to power the comparator when the live wire and the neutral wire are normally connected, and stops powering the comparator when the live wire and the neutral wire are reversed.

[0008] The present invention sets a comparator power supply circuit between the live wire access terminal and the neutral wire access terminal, sets a first energy storage element at the live wire access terminal, connects the two ends of the first energy storage element to the two input terminals of the comparator, and supplies power to the comparator by the comparator power supply circuit when the mains power access line sequence is correct, so that the comparator operates normally. At the same time, due to the energy storage of the first energy storage element, a voltage difference is generated at the two ends of the first energy storage element, so that the comparator outputs a high level, thereby controlling the control circuit set between the live wire access terminal and the power supply terminal of the power load to be turned on, so that the power load is powered and operates normally. Conversely, if the live wire and the neutral wire are connected in reverse, the comparator power supply circuit stops supplying power to the comparator, the comparator cannot work, the control circuit is disconnected, and the power load is not powered. This ensures that the power load will only be connected to the live wire and operate normally when the mains power access line sequence is correct. When the live wire and the neutral wire are connected in reverse, the live wire power supply is cut off to avoid potential power safety hazards to the power load or people, ensure power safety, and enhance the user experience.

[0009] In an optional embodiment, the comparator power supply circuit includes: a second energy storage element, a first power supply branch, and a second power supply branch, wherein the first power supply branch includes: a first diode and a second diode, the forward end of the first diode is connected to the live wire access terminal, and the reverse end is connected to the first end of the second energy storage element, the second end of the second energy storage element is connected to the forward end of the second diode, and the reverse end of the second diode is connected to the neutral wire access terminal;

[0010] The second power supply branch includes: a third diode and a fourth diode, the forward end of the third diode is connected to the neutral line access end, and the reverse end is connected to the first end of the second energy storage element, the second end of the second energy storage element is connected to the forward end of the fourth diode, and the reverse end of the fourth diode is connected to the live line access end.

[0011] The present invention charges and stores energy for the second energy storage element by respectively setting two power supply branches at the live wire access end and the neutral wire access end. Thus, when the mains power access line sequence is correct, in the positive half cycle of the live wire voltage, the current passes through the first power supply branch, and charges the second energy storage element from the live wire through the first diode, and then returns to the neutral wire through the second diode. In the negative half cycle of the live wire voltage, the current passes through the second power supply branch, and charges the second energy storage element from the neutral wire through the third diode, and then returns to the live wire through the fourth diode. This ensures that the second energy storage element is charged regardless of the voltage in the first half cycle or the second half cycle of the mains power, thereby ensuring that the voltage of the second energy storage element can stably maintain the normal operation of the comparator, and further ensuring that the control circuit is continuously turned on, and the electrical load is powered and operates normally and stably. In addition, the positive half cycle and negative half cycle voltages of the mains power are preliminarily rectified by the power supply branch formed by the diode, so that the second energy storage element is charged regardless of the positive half cycle or the negative half cycle, thereby ensuring the stability of the comparator supply voltage.

[0012] In an optional embodiment, the first power supply branch further includes: a first resistor connected in series with the first diode or the second diode;

[0013] The second power supply branch further includes: a second resistor connected in series with the third diode or the fourth diode.

[0014] The present invention can prevent components from being damaged due to excessive current by providing two current-limiting resistors, namely a first resistor and a second limit resistor, thereby ensuring the reliability and stability of the entire power supply detection control circuit.

[0015] In an optional implementation, the second energy storage element is an energy storage capacitor.

[0016] The present invention sets the second energy storage element as an energy storage capacitor. Since the capacitor component is low in cost, the circuit cost is reduced, and the voltage fluctuation after rectification can be buffered to maintain the stability of the comparator supply voltage.

[0017] In an optional implementation, the first energy storage element is an energy storage capacitor.

[0018] The present invention sets the first energy storage element as an energy storage capacitor. Due to the low cost of capacitor components, the circuit cost is reduced, and the voltage fluctuation after rectification can be buffered to maintain the stability of the voltage at the input end of the comparator, thereby ensuring the stability of the output signal at the output end of the comparator.

[0019] In an optional implementation, the power supply detection control circuit further includes: a third resistor, one end of the third resistor is connected to the live wire access end, and the other end of the third resistor is connected to one end of the first energy storage element.

[0020] The present invention limits the instantaneous current during charging and discharging of the first energy storage element by setting a third resistor, thereby avoiding damage to the element due to excessive current. At the same time, the overvoltage energy is dissipated in the form of heat energy through the resistor, and the charging and discharging time of the first energy storage element is extended, making the voltage change more stable, further ensuring the stability of the voltage at the comparator input terminal, and thus improving the stability of the output signal at the comparator output terminal.

[0021] In an optional embodiment, the control circuit includes: a controlled switch, wherein the control end of the controlled switch is connected to the output end of the comparator, the first end is connected to the live wire access end, and the second end is connected to the power supply end of the electrical load.

[0022] The present invention realizes precise power supply control of the power load by controlling the conduction or disconnection between the power load and the live wire access terminal through a controlled switch, reliably ensures that the power load can be powered and work normally when the mains access line sequence is correct, and improves the power safety of the power load.

[0023] In an optional implementation, the controlled switch is a relay.

[0024] The present invention controls the conduction or disconnection between the electrical load and the live wire access terminal by utilizing a relay. Since the relay can switch the circuit at a speed of milliseconds, a rapid response of the power supply to the electrical load is achieved. In addition, the relay has a stable structure and a service life of up to one million operations, thereby improving the reliability of the power supply control of the electrical load. In addition, the relay has a low manufacturing cost, which can reduce the cost of the entire power supply detection control circuit.

[0025] In an optional implementation, the controlled switch is a MOS transistor.

[0026] The present invention uses a MOS tube to control the conduction or disconnection between the power load and the live wire access terminal. Since the MOS tube has a simple structure and a long life, the reliability of the power supply control of the power load is improved. In addition, its static power consumption is close to zero and its dynamic power consumption is low, which can reduce losses and save energy.

[0027] In a second aspect, the present invention provides an electrical device, comprising: a power supply detection control circuit as provided in the first aspect or any optional embodiment thereof.

[0028] The electrical equipment of the present invention is provided with a power supply detection control circuit, a comparator power supply circuit is provided between the live wire access terminal and the neutral wire access terminal, and a first energy storage element is provided at the live wire access terminal. By connecting the two ends of the first energy storage element to the two input ends of the comparator, the comparator power supply circuit supplies power to the comparator when the mains power access line sequence is correct, so that the comparator operates normally. At the same time, due to the energy storage of the first energy storage element, a voltage difference is generated at the two ends of the first energy storage element, so that the comparator outputs a high level, thereby controlling the control circuit provided between the live wire access terminal and the power supply terminal of the power load to be turned on, so that the power load is powered and operates normally. Conversely, if the live wire and the neutral wire are connected in reverse, the comparator power supply circuit stops supplying power to the comparator, the comparator cannot work, the control circuit is disconnected, and the power load is not powered. Thus, it is ensured that the power load will only be connected to the live wire and operate normally when the mains power access line sequence is correct. When the live wire and the neutral wire are connected in reverse, the live wire power supply is cut off to avoid potential safety hazards to the power load or people, ensure power safety, thereby ensuring the power safety of the entire electrical equipment and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 is a structural diagram of a power supply detection control circuit according to an embodiment of the present invention;

[0031] Figure 2 2 is a schematic diagram of a charging process during a positive half cycle of a live line voltage according to an embodiment of the present invention;

[0032] Figure 3 2. It is a schematic diagram of the charging process during the negative half cycle of the live line voltage according to an embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of the working logic of the power supply detection control circuit according to an embodiment of the present invention;

[0034] Figure 5 2 is a schematic structural diagram of an electrical device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0036] In related technologies, electrical appliances do not use circuits to prevent reverse connection of the live and neutral wires. Even if there is a circuit to detect the live and neutral wires, it cannot control whether the back-end load is powered, and the mains power will still be connected to the back-end. This still poses a major safety hazard to the back-end load or the human body. The specific hazard scenarios are as follows:

[0037] 1. The metal casing of the appliance is electrified (risk of electric shock).

[0038] Principle: When the live wire is connected reversely, if the device casing is not grounded or grounded poorly, the live wire current may be conducted through the casing.

[0039] For example: Refrigerators / washing machines: If the neutral and live wires are connected incorrectly, the metal casing may become live. Touching it creates a circuit and can cause electric shock. Desktop computers: If the metal chassis becomes live due to reversed connections, plugging or unplugging a USB device can cause an electric shock. For example, if a user touches a refrigerator casing with the neutral and live wires connected incorrectly, they could be burned by a 220V shock.

[0040] 2. The switch is faulty or energized.

[0041] ‌Principle‌: If the switch is installed on the neutral circuit, live wire voltage will still exist inside the device after it is disconnected.

[0042] For example: A switched socket or lamp: Even after turning off the switch, the socket or lamp holder is still live, and touching it can cause an electric shock. An electric water heater: Even after turning off the switch, the heating element still has voltage, which can cause accidents during maintenance.

[0043] 3. The lamp is working abnormally.

[0044] ‌Principle‌: Reverse connection of zero and fire causes the lamp to be disconnected but not disconnected, and residual current occurs after the light is turned off.

[0045] For example, an LED ceiling light may still glow faintly after being turned off (a "ghost fire" phenomenon) because the live wire continues to supply power to the lamp's capacitor. Fluorescent lamps may flicker: The starter switches on and off after the light is turned off, shortening the lamp's lifespan.

[0046] 4. The leakage protector fails.

[0047] Principle: Single-pole (1P+N) leakage protection relies on correct wiring to detect current differences.

[0048] For example: After reverse connection, the leakage protector trips: The device is still energized. For example, after the leakage protector trips, the neutral terminal of the socket is 220V.

[0049] 5. Risk of damage to special equipment.

[0050] Meter stall: If a single-phase meter's neutral and live wires are connected reversed (for example, if terminal 1 is connected to the neutral wire), current doesn't flow through the live wire coil, and the meter won't measure. Ground wire overload: If the neutral and ground wires are connected reversed, the ground wire can become overloaded when a high-power appliance (such as an air conditioner) is started, potentially causing a fuse and fire.

[0051] In view of the above problems, a power supply detection control circuit is provided in this embodiment. Figure 1 FIG. 1 is a schematic diagram of a power supply detection control circuit according to an embodiment of the present invention. Figure 1 As shown, the power supply detection control circuit includes:

[0052] A first energy storage element U2, a comparator U3, a comparator power supply circuit 101, and a control circuit 102, wherein one end of the first energy storage element U2 is connected to the live wire input terminal and the positive input terminal of the comparator U3, respectively, and the other end is connected to the negative input terminal of the comparator U3 and the ground terminal, respectively;

[0053] The output terminal of the comparator U3 is connected to the control terminal of the control circuit 102, and the comparator U3 is used to control the control circuit 102 to be turned on or off;

[0054] The control circuit 102 is provided between the live wire input terminal and the power supply terminal of the power load N;

[0055] The comparator power supply circuit 101 is arranged between the live wire access terminal and the neutral wire access terminal. The first end of the comparator power supply circuit 101 is connected to the power supply terminal of the comparator U3. The comparator power supply circuit 101 stores electrical energy to power the comparator U3 when the live wire and the neutral wire are normally connected, and stops powering the comparator U3 when the live wire and the neutral wire are reversed.

[0056] The first energy storage element U2 can be formed by one or more of an inductor, a capacitor, or a battery in combination with corresponding peripheral circuits. For example, the first energy storage element U2 can be an energy storage capacitor. In practical applications, the capacitance of the energy storage capacitor only needs to be a few microfarads to meet circuit requirements.

[0057] Specifically, the comparator U3 can be flexibly selected according to actual needs, as long as it can identify the voltage across the first energy storage element U2 such as a capacitor and drive the control circuit 102 to conduct as required, which will not be elaborated here.

[0058] The embodiment of the present invention provides a comparator power supply circuit between the live wire access terminal and the neutral wire access terminal, provides a first energy storage element at the live wire access terminal, and connects the two ends of the first energy storage element to the two input terminals of the comparator. When the mains power access line sequence is correct, the comparator is powered by the comparator power supply circuit, so that the comparator operates normally. At the same time, due to the energy storage of the first energy storage element, a voltage difference is generated at the two ends of the first energy storage element, so that the comparator outputs a high level, thereby controlling the control circuit provided between the live wire access terminal and the power supply terminal of the load to conduct, so that the load is powered and operates normally. Conversely, if the live wire and the neutral wire are connected in reverse, the comparator power supply circuit stops supplying power to the comparator, the comparator cannot operate, the control circuit is disconnected, and the load is not powered. This ensures that the load is connected to the live wire and operates normally only when the mains power access line sequence is correct. When the live wire and the neutral wire are connected in reverse, the live wire power supply is cut off, thereby avoiding potential safety hazards to the load or people, ensuring power safety, and improving the user experience.

[0059] In some optional embodiments, such as Figure 1 As shown, the comparator power supply circuit 101 includes: a second energy storage element U1, a first power supply branch and a second power supply branch, wherein the first power supply branch includes: a first diode D1 and a second diode D2, the forward end of the first diode D1 is connected to the live wire access terminal, and the reverse end is connected to the first end of the second energy storage element U1, the second end of the second energy storage element U1 is connected to the forward end of the second diode D2, and the reverse end of the second diode D2 is connected to the neutral wire access terminal;

[0060] The second power supply branch includes: a third diode D4 and a fourth diode D3, the forward end of the third diode D4 is connected to the neutral line access end, and the reverse end is connected to the first end of the second energy storage element U1, the second end of the second energy storage element U1 is connected to the forward end of the fourth diode D3, and the reverse end of the fourth diode D3 is connected to the live line access end.

[0061] Among them, the above-mentioned first diode D1, second diode D2, third diode D4, and fourth diode D3 can be selected according to the requirements of the second energy storage element U1, such as a capacitor, as long as they can charge the capacitor and power the comparator U3 as required. The present invention is not limited to this.

[0062] The embodiment of the present invention charges and stores energy for the second energy storage element by respectively setting two power supply branches at the live wire access end and the neutral wire access end. Therefore, when the mains power access line sequence is correct, in the positive half cycle of the live wire voltage, the current passes through the first power supply branch, and charges the second energy storage element from the live wire through the first diode, and then returns to the neutral wire through the second diode. In the negative half cycle of the live wire voltage, the current passes through the second power supply branch, and charges the second energy storage element from the neutral wire through the third diode, and then returns to the live wire through the fourth diode. This ensures that the second energy storage element is charged regardless of the voltage in the first half cycle or the second half cycle of the mains power, thereby ensuring that the voltage of the second energy storage element can stably maintain the normal operation of the comparator, and further ensures that the control circuit is continuously turned on, and the electrical load is powered and operates normally and stably. In addition, the positive half cycle and negative half cycle voltages of the mains power are preliminarily rectified by the power supply branch formed by the diode, so that the second energy storage element is charged regardless of the positive half cycle or the negative half cycle, thereby ensuring the stability of the comparator supply voltage.

[0063] In some optional embodiments, such as Figure 1 As shown, the first power supply branch further includes: a first resistor R1 connected in series with the first diode D1 or the second diode D2;

[0064] The second power supply branch further includes a second resistor R2 connected in series with the third diode D4 or the fourth diode D3.

[0065] In practical applications, the resistance values ​​of the first resistor R1 and the second resistor R2 can be selected according to actual circuit requirements, as long as they can charge the second energy storage element U1 such as a capacitor and power the comparator U3 as required. No further details will be given here.

[0066] The embodiment of the present invention can prevent damage to components due to excessive current by providing two current-limiting resistors, namely a first resistor and a second limit resistor, thereby ensuring the reliability and stability of the entire power supply detection control circuit.

[0067] For example, assuming that the live wire and the neutral wire of the mains electricity are correctly connected, Figure 2 As shown, the path of the positive half cycle of the live wire voltage is: the current flows from the live wire through D1 and then through R1 to charge U1, and then returns to the neutral wire through D2.

[0068] like Figure 3 As shown in the figure, the path of the negative half-cycle of the live line voltage is: the current goes from the neutral line through D4 and then through R2 to charge U1, and then returns to the live line through D3; therefore, regardless of the voltage in the first half cycle or the second half cycle of the mains power, U1 will be charged, so that the voltage of U1 can be stable to maintain the normal operation of the comparator U3.

[0069] In summary, the control logic after normal access to the mains is: due to normal access to the mains, U1 will be charged to generate voltage: U1 supplies power to the comparator U3 to ensure stable operation of the comparator U3.

[0070] Assuming that the live wire and the neutral wire of the mains are connected in opposite directions, the path principle of the live and neutral wires charging U1 is as follows: Figure 2 and Figure 3 As shown in the figure, U1 will still be charged to ensure that the comparator U3 is in normal working condition.

[0071] In some optional implementations, the second energy storage element U1 is an energy storage capacitor.

[0072] Exemplarily, the capacitance of the energy storage capacitor is in the microfarad level, which can meet the circuit requirements, is low in cost, and can provide power for the comparator to maintain the stability of the power supply of the comparator.

[0073] In the embodiment of the present invention, the second energy storage element is set as an energy storage capacitor. Since the capacitor component is low in cost, the circuit cost is reduced, and the voltage fluctuation after rectification can be buffered to maintain the stability of the comparator supply voltage.

[0074] In some optional implementations, the first energy storage element U2 is an energy storage capacitor.

[0075] For example, the capacitance of the energy storage capacitor is in the microfarad level, which can meet the circuit requirements, is low in cost, and can provide a stable comparison voltage for the comparator, thereby maintaining the stability of the comparator output.

[0076] The embodiment of the present invention sets the first energy storage element as an energy storage capacitor. Due to the low cost of capacitor components, the circuit cost is reduced, and the voltage fluctuation after rectification can be buffered to maintain the stability of the voltage at the input end of the comparator, thereby ensuring the stability of the output signal at the output end of the comparator.

[0077] In some optional embodiments, such as Figure 1 As shown, the power supply detection control circuit further includes: a third resistor R3, one end of the third resistor R3 is connected to the live wire access end, and the other end is connected to one end of the first energy storage element U2.

[0078] In practical applications, the resistance value of the third resistor R3 can be selected according to actual circuit requirements, as long as it can charge the first energy storage element such as the capacitor and power the comparator as required, and will not be elaborated here.

[0079] Specifically, assuming that the mains live wire and neutral wire are connected correctly, such as Figure 2As shown in Figure 1, the charging path for U2 during the positive half-cycle of the hot line voltage is as follows: the current charges U2 through R3 and then returns to the ground line. During the negative half-cycle of the hot line voltage, the stored energy in U2 is released across U2 to maintain a voltage difference, ensuring that the voltage at the positive terminal of comparator U3 is greater than the voltage at the negative terminal.

[0080] In summary, after being normally connected to the mains, voltage will be generated at both ends of U2 due to charging. The comparator U3 recognizes that the positive terminal voltage is greater than the negative terminal voltage; therefore, the comparator U3 outputs a voltage to drive the subsequent control circuit 102 to turn on, and the live wire is connected to power the rear-end load.

[0081] Assume that the live wire and the neutral wire of the mains electricity are connected in the opposite direction. Figure 1 R3 in the circuit is connected to the neutral wire, but the potential of the neutral wire to the ground wire is the same. In other words, there is no large voltage difference between the neutral wire and the ground wire. Because the neutral wire and the ground wire are eventually connected to the earth (the ground wire is connected to the earth near the user end, and the neutral wire is connected to the earth near the substation), forming a common reference point, the voltage difference between the neutral wire and the ground wire can be ignored. Therefore, the neutral wire will not charge U2, and no voltage difference will be generated across U2, and the comparator U3 will not output a voltage.

[0082] In summary, when the live and neutral wires are connected reversely, although U1 will be charged, U2 at both ends of the comparator U3 will not be charged, the control circuit 102 will not be driven to turn on, and the rear-end load will not be powered.

[0083] The embodiment of the present invention can limit the instantaneous current during charging and discharging of the first energy storage element by setting a third resistor, thereby avoiding damage to the element due to excessive current. At the same time, the overvoltage energy is dissipated in the form of heat energy through the resistor, and the charging and discharging time of the first energy storage element is extended, making the voltage change more stable, further ensuring the stability of the voltage at the input end of the comparator, and thus improving the stability of the output signal at the output end of the comparator.

[0084] In an optional embodiment, as Figure 1 As shown, the control circuit 102 includes: a controlled switch Q, a control end of the controlled switch Q is connected to the output end of the comparator U3, a first end is connected to the live wire access end, and a second end is connected to the power supply end of the power load N.

[0085] Specifically, the controlled switch Q can be flexibly selected as long as it can control the conduction and disconnection between the power load N and the live wire access terminal based on the output signal of the comparator U3. For example, the controlled switch Q can be a thyristor, a relay, a MOS tube, etc. This is only an example, and the present invention is not limited to this.

[0086] The embodiment of the present invention realizes precise power supply control of the power load by controlling the conduction or disconnection between the power load and the live wire access terminal through a controlled switch, reliably ensures that the power load can be powered and work normally when the mains power access line sequence is correct, and improves the power safety of the power load.

[0087] In some optional implementations, the controlled switch Q is a relay.

[0088] The embodiment of the present invention uses a relay to control the conduction or disconnection between the electrical load and the live wire access terminal. Since the relay can switch the circuit at a speed of milliseconds, a rapid response of the power supply to the electrical load is achieved. In addition, the relay has a stable structure and a service life of up to one million operations, thereby improving the reliability of the power supply control of the electrical load. In addition, the relay has a low manufacturing cost, which can reduce the cost of the entire power supply detection control circuit.

[0089] In some other optional implementations, the controlled switch Q is a MOS transistor.

[0090] The embodiment of the present invention uses a MOS tube to control the conduction or disconnection between the power load and the live wire access terminal. Since the MOS tube has a simple structure and a long life, the reliability of the power supply control of the power load is improved. In addition, its static power consumption is close to zero and its dynamic power consumption is low, which can reduce losses and save energy.

[0091] The working principle and working process of the power supply detection control circuit provided by the embodiment of the present invention will be described in detail below with reference to specific application examples.

[0092] For example, the controlled switch Q is a relay, and the first energy storage element U2 and the second energy storage element U1 are both energy storage capacitors. Figure 4 As shown, the core principle of the power supply detection control circuit provided by the embodiment of the present invention is based on the different voltages of the live wire and the neutral wire to the ground of the mains power, and the rectification of the sinusoidal waveform of the live wire: the positive half-cycle and the negative half-cycle pass through different circuits to realize charging of U1 and U2, thereby judging whether the live and neutral wires are connected reversely. If connected reversely, the relay will not work and the back end will not be powered. If connected correctly, the relay will turn on and the back end will be powered and work normally.

[0093] Assuming that the mains live wire and neutral wire are connected correctly, Figure 2 As shown, the path of the positive half cycle of the live wire voltage is: the current goes from the live wire through D1 and then through R1 to charge U1, and then returns to the neutral wire through D2; the synchronous charging path for U2 is: the current charges U2 from R3 and then returns to the ground wire; at this time, both capacitors will be charged.

[0094] like Figure 3As shown in the figure, the path of the negative half-cycle of the live line voltage is: the current goes from the neutral line through D4 and then through R2 to charge U1, and then returns to the live line through D3; therefore, regardless of the voltage in the first half cycle or the second half cycle of the mains power, U1 will be charged, so that the voltage of U1 can be stable to maintain the normal operation of the comparator U3.

[0095] In summary, the control logic after normal access to the mains is: Due to normal access to the mains, U1 and U2 will be charged to generate voltage: U1 supplies power to the comparator U3 to ensure the stable operation of the comparator U3. At the same time, due to the charging of U2, voltage will also be generated at both ends. The comparator U3 recognizes that the positive end voltage is greater than the negative end voltage; therefore, the output voltage of the comparator U3 drives the relay to open, and the live wire is connected to supply power to the back-end load.

[0096] Assume that the live and neutral wires of the mains are connected in opposite directions (the principle of the path for charging U1 by the live and neutral wires remains unchanged, and the following mainly focuses on U2). When the live and neutral wires are connected in opposite directions: Figure 1 R3 in the circuit is connected to the neutral wire, but the potential of the neutral wire to the ground wire is the same. In other words, there is no large voltage difference between the neutral wire and the ground wire. Because the neutral wire and the ground wire are eventually connected to the earth (the ground wire is connected to the earth near the user end, and the neutral wire is connected to the earth near the substation), forming a common reference point, the voltage difference between the neutral wire and the ground wire can be ignored. Therefore, the neutral wire will not charge U2, and no voltage difference will be generated across U2, and the comparator U3 will not output a voltage.

[0097] In summary, when the live and neutral wires are connected reversely, although U1 will be charged, U2 at both ends of the comparator U3 will not be charged, the relay will not be driven to open, and the rear-end load will not be powered.

[0098] Therefore, the power supply detection control circuit provided by the embodiment of the present invention can detect whether the live and neutral wires are connected correctly, that is, it can identify whether the line sequence is correct when the mains power is connected. A comparator is used to control the back-end relay. Only when the line sequence is correct can the back-end be connected to the live wire. That is, when the connection is correct, the relay is automatically turned on synchronously to ensure that the back-end is powered normally; if the connection is incorrect, the back-end will not be powered, ensuring power safety. This prevents the live and neutral wires of the power supply from being reversed, improves circuit safety, and promptly cuts off the live wire power supply when the live and neutral wires are reversed, ensuring power safety.

[0099] The present invention also provides an electrical device, such as Figure 5 As shown, the electrical device includes: a power supply detection control circuit 501 provided by another embodiment of the present invention. The specific content of the power supply detection control circuit 501 is detailed in the related description of another embodiment of the present invention, and will not be repeated here.

[0100] It should be noted that the power load corresponding to the power detection control circuit 501 is the power load in the electrical device. For example, the electrical device can be a fan, electric heater, humidifier, or other electrical device powered by mains electricity. This is only an example, and the present invention is not limited to this.

[0101] The electrical equipment of the embodiment of the present invention is provided with a power supply detection control circuit, a comparator power supply circuit is provided between the live wire access terminal and the neutral wire access terminal, and a first energy storage element is provided at the live wire access terminal. By connecting the two ends of the first energy storage element to the two input ends of the comparator, the comparator power supply circuit supplies power to the comparator when the mains power access line sequence is correct, so that the comparator operates normally. At the same time, due to the energy storage of the first energy storage element, a voltage difference is generated at the two ends of the first energy storage element, so that the comparator outputs a high level, thereby controlling the control circuit provided between the live wire access terminal and the power supply terminal of the power load to conduct, so that the power load is powered and operates normally. Conversely, if the live wire and the neutral wire are connected in reverse, the comparator power supply circuit stops supplying power to the comparator, the comparator cannot operate, the control circuit is disconnected, and the power load is not powered. This ensures that the power load will only be connected to the live wire and operate normally when the mains power access line sequence is correct. When the live wire and the neutral wire are connected in reverse, the live wire power supply is cut off, thereby avoiding potential power safety hazards to the power load or people, ensuring power safety, and thus ensuring the power safety of the entire electrical equipment and improving the user experience.

[0102] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A power supply detection control circuit, characterized in that: include: A first energy storage element, a comparator, a comparator power supply circuit and a control circuit, wherein: One end of the first energy storage element is connected to the live wire input terminal and the positive input terminal of the comparator respectively, and the other end is connected to the negative input terminal of the comparator and the ground terminal respectively; The output end of the comparator is connected to the control end of the control circuit, and the comparator is used to control the control circuit to be turned on or off; The control circuit is arranged between the live wire access terminal and the power supply terminal of the power load; The comparator power supply circuit is arranged between the live wire access terminal and the neutral wire access terminal, the first terminal of the comparator power supply circuit is connected to the power supply terminal of the comparator, the comparator power supply circuit stores electrical energy to power the comparator when the live wire and the neutral wire are normally connected, and stops powering the comparator when the live wire and the neutral wire are reversed; The comparator power supply circuit includes: a second energy storage element, a first power supply branch and a second power supply branch, wherein: The first power supply branch includes: a first diode and a second diode, wherein the forward end of the first diode is connected to the live wire access terminal, the reverse end is connected to the first end of the second energy storage element, the second end of the second energy storage element is connected to the forward end of the second diode, and the reverse end of the second diode is connected to the neutral wire access terminal; The second power supply branch includes: a third diode and a fourth diode, the forward end of the third diode is connected to the neutral line access end, and the reverse end is connected to the first end of the second energy storage element, the second end of the second energy storage element is connected to the forward end of the fourth diode, and the reverse end of the fourth diode is connected to the live line access end.

2. The power supply detection control circuit according to claim 1, characterized in that: The first power supply branch further includes: a first resistor connected in series with the first diode or the second diode; The second power supply branch further includes: a second resistor connected in series with the third diode or the fourth diode.

3. The power supply detection control circuit according to claim 1, characterized in that: The second energy storage element is an energy storage capacitor.

4. The power supply detection control circuit according to claim 1, characterized in that: The first energy storage element is an energy storage capacitor.

5. The power supply detection control circuit according to claim 4, characterized in that: Also includes: a third resistor, one end of the third resistor being connected to the live wire access end, and the other end of the third resistor being connected to one end of the first energy storage element.

6. The power supply detection control circuit according to any one of claims 1 to 5, characterized in that: The control circuit includes a controlled switch, wherein a control end of the controlled switch is connected to the output end of the comparator, a first end of the controlled switch is connected to the live wire access end, and a second end of the controlled switch is connected to the power supply end of the power load.

7. The power supply detection control circuit according to claim 6, characterized in that: The controlled switch is a relay.

8. The power supply detection control circuit according to claim 6, characterized in that: The controlled switch is a MOS tube.

9. An electrical device, characterized in that: The electrical device includes: a power supply detection control circuit according to any one of claims 1 to 8.

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