Circuit with low-voltage alarm indication

Abstract

The utility model relates to a circuit with low-voltage alarm indication, which comprises a low-voltage sampling module, a phase inversion conversion module, a low-voltage alarm indication module, a power supply indication module, an electric leakage protection module, a test electric leakage module and a power supply module. And at the moment, no current flows through the DW2 voltage-regulator tube, so that the triode Q1 is cut off, the voltage at the point B rises, the power indicator light LED1 is extinguished, the triode Q2 is conducted, and the alarm indicator light LED2 flickers, and the circuit has the beneficial effects that under the condition that the power supply voltage is low, correct alarm can be carried out, and a user can be informed of the current unsafe electricity utilization hidden danger in advance.

Description

Technical Field

[0001] This utility model relates to a low-pressure alarm indicator, particularly for use in the leakage protection circuit of electric water heaters or electric water faucets. Background Technology

[0002] In the current use of electric water heaters or faucets, residual current devices (RCDs) are required for safety reasons. However, a common customer complaint arises when the water heater or faucet fails to heat properly. Multiple inspections often reveal that the problem is not a quality issue, but rather due to low power supply voltage. Existing RCDs lack a low-voltage warning function, leading to high customer complaints and inconvenience. Therefore, a circuit with a low-voltage warning is urgently needed to alert customers when the power supply voltage falls below a preset value (factory default), regardless of the cause. This allows customers to easily troubleshoot the problem. Utility Model Content

[0003] The purpose of this invention is to provide a circuit with a low-voltage alarm indicator, which solves the problem that leakage protection circuits do not have a low-voltage alarm indicator.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] This utility model provides a circuit with a low-voltage alarm indicator. The circuit has trip coils installed on the live and neutral wires of its power input terminal. The output of the trip coils is also connected to a rectifier bridge D1. The rectifier bridge is connected to the GND port and a leakage current protection module via its D port. Both the live and neutral wires pass through the zero-sequence current transformer of the leakage current protection module. The circuit also includes a low-voltage sampling module, a phase inversion module, a low-voltage alarm indicator module, a power supply module, and a power indicator module. The low-voltage sampling module includes resistors R9, R13, and R7 connected in series. The two ends of the low-voltage sampling module are connected to the D port. The phase inversion module includes a Zener diode DW2 and a transistor Q1. The cathode of the Zener diode DW2 is connected to point A between resistors R13 and R7, and the anode is connected to the base of the transistor Q1. The low-voltage alarm indicator module includes a transistor Q2. The collector of the transistor Q2 is connected to an alarm indicator LED2, and the base of the transistor Q2 is connected to point B. Point B is located between the collector of the transistor Q1 and the power indicator module. The power indicator module includes a power indicator LED1, and the other end of the power indicator module is connected to a power supply module.

[0006] Furthermore, the low-voltage alarm indicator module is connected between the VCC port and the GND port of the power supply module, and the emitter of the transistor Q2 is grounded.

[0007] Furthermore, the two ends of the power supply module are connected to point C and the GND port respectively, with point C connected to the live wire of the power input terminal.

[0008] Furthermore, the alarm indicator LED2 is a self-flashing light-emitting diode, and the anode and cathode of the self-flashing light-emitting diode are electrically connected to the power supply module and the collector of the transistor Q2, respectively.

[0009] Furthermore, the phase inversion module is also equipped with a filter capacitor C5 and a resistor R10 connected in parallel.

[0010] Furthermore, the power supply module is also equipped with a Zener diode DW1, a filter capacitor C2, and a filter capacitor C3 connected in parallel.

[0011] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0012] This invention allows for the pre-setting of resistance values ​​and preset values ​​for each resistor within the low-voltage sampling module. When the power supply voltage is lower than the preset value, due to the resistance values, the voltage at point A will also fall below a certain value. This value is insufficient to activate the Zener diode DW2, resulting in no current flowing through it and causing transistor Q1 to cut off. This causes the voltage at point B to rise, extinguishing the power indicator LED1 and turning on transistor Q2, at which point the alarm indicator LED2 flashes. This indicates that the current power supply voltage is low. (Specific reasons for low voltage include: 1. a thin power supply circuit; 2. poor contact in the plug and socket leading to high circuit resistance; 3. a truly low power supply voltage.) This facilitates troubleshooting for customers. Attached Figure Description

[0013] The following sections will describe some specific embodiments of the present invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0014] Figure 1 This is a circuit diagram of an embodiment of the present invention;

[0015] Figure 2 This is a circuit diagram of the phase inverter module of this utility model;

[0016] Figure 3 This is a circuit diagram of the low-voltage alarm indicator module of this utility model.

[0017] The reference numerals in the attached figures are explained as follows:

[0018] 1. Low-voltage sampling module; 2. Phase inversion module; 3. Low-voltage alarm indicator module; 4. Power supply module; 5. Power indicator module; 6. Leakage protection module; 7. Tripping coil. Detailed Implementation

[0019] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0022] like Figure 1 As shown, it includes a power input terminal, an adjustment module, and a leakage protection module 6.

[0023] A trip coil 7 is installed on the live and neutral wires of the power input terminal of the circuit. The output terminal of the trip coil 7 is also connected to the rectifier bridge D1. The rectifier bridge D1 is connected to the GND port and the leakage protection module 6 through the D port. Both the live and neutral wires pass through the zero-sequence current transformer of the leakage protection module 6, which can effectively prevent leakage. A solid-state relay is used to control the operation of the trip coil 7. The leakage protection module 6 is also connected to the control electrode of the silicon controlled rectifier (SCR) 1. Under normal conditions, the trip coil 7 works normally, and the power supply provides normal power to the load. When leakage occurs, the leakage protection module 6 will quickly feed back to the control electrode of the SCR 1 to make it conduct. The SCR 1 and the rectifier bridge are connected, causing the trip coil 7 to trip and disconnect, so that the power supply no longer supplies power to the load.

[0024] It also includes a low-voltage sampling module 1, a phase inversion module 2, a low-voltage alarm indication module 3, a power supply module 4, and a power indication module 5. The low-voltage sampling module 1 includes resistors R9, R13, and R7 connected in series. A point A is set between resistors R13 and R7. Point A is the sampling point. The resistance values ​​of resistors R9, R13, and R7 need to be set. The voltage value at point A is determined by resistors R9, R13, and R7. Assuming the pre-designed low voltage value is 176V (that is, when the input voltage is not higher than 176V, an alarm will be issued), resistors R9, R13, and R7 are set reasonably so that the voltage at point A is not higher than 5.1V. Then, a suitable Zener diode DW2 is selected so that the voltage of 5.1V is difficult for the Zener diode D2 to conduct, which will trigger a series of events and thus issue a low-voltage alarm indication. One end of resistor R9 is connected to port D, and one end of R7 is connected to port GND.

[0025] The phase inversion module includes a Zener diode DW2 and a transistor Q1. The cathode of the Zener diode DW2 is connected to point A between resistors R13 and R7, and the anode is connected to the base of the transistor Q1. The low-voltage alarm indicator module includes a transistor Q2. The collector of the transistor Q2 is connected to an alarm indicator LED2, and the base of the transistor Q2 is connected to point B. Point B is located between the collector of the transistor Q1 and the power indicator module 5. The power indicator module 5 includes a power indicator LED1, and the other end of the power indicator module 5 is connected to a power supply module 4. Under normal voltage conditions, the voltage at point A is higher than the conduction value of Zener diode DW2. At this time, Zener diode DW2 conducts, and the power indicator LED1 in the power indicator module 5 lights up normally, indicating that the voltage is sufficient. When the voltage is lower than the preset value, the voltage at point A is lower than the conduction value of Zener diode DW2. At this time, no current flows through Zener diode DW2, causing transistor Q1 to be cut off. The voltage at point B increases, the power indicator LED1 goes out, transistor Q2 conducts, and the alarm indicator LED2 flashes, indicating that the voltage is lower than the preset value, reminding personnel to troubleshoot the problem.

[0026] The low-voltage alarm indicator module 3 is connected between the VCC port and the GND port of the power supply module 4. At the same time, the low-voltage alarm indicator module 3 is controlled by point B during normal operation. The voltage at point B determines the action of the low-voltage alarm indicator module 3, and the voltage at point B is determined by the phase inversion module 2.

[0027] The power supply module 4 includes parallel filter capacitors C2 and C5 and diode DW1, as well as three resistors R3, R4 and R5 connected in series. The two ends of the resistors are connected to point C and the GND port, respectively. Point C is connected to the live wire of the power input terminal. The power supply module 4 uses half-wave rectification to reduce the temperature rise of resistors R3, R4 and R5, improve the service life of components, reduce size and reduce cost.

[0028] The leakage current protection module 6 is connected between the D port and the GND port, meaning it is powered by full-wave rectification, which can control the leakage current protection actuation time to within 20ms.

[0029] The alarm indicator LED2 is a self-flashing light-emitting diode. The anode and cathode of the self-flashing light-emitting diode LED2 are electrically connected to the power supply module 4 and the collector of the transistor Q2, respectively. Therefore, the operation of the alarm indicator LED2 is controlled by the transistor Q2. Once it is turned on, the alarm indicator will activate quickly.

[0030] The phase inverter module 2 is also equipped with a filter capacitor C5 and a resistor R10 connected in parallel for filtering within the phase inverter module 2.

[0031] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this invention and implement it accordingly. They should not be used to limit the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this invention should be covered within the scope of protection of this utility model.

Claims

1. A circuit with a low-voltage alarm indication, wherein a trip coil is provided on the live wire and neutral wire of the power input terminal of the circuit, the output terminal of the trip coil is also connected to a rectifier bridge D1, the rectifier bridge D1 is connected to the GND port and the leakage current protection module through the D port respectively, and the live wire and neutral wire both pass through the zero-sequence current transformer of the leakage current protection module, characterized in that, It also includes a low-voltage sampling module, a phase inversion module, a low-voltage alarm indicator module, a power supply module, and a power indicator module. The low-voltage sampling module includes resistors R9, R13, and R7 connected in series, with its two ends connected to port D and port GND. The phase inversion module includes a Zener diode DW2 and a transistor Q1. The cathode of the Zener diode DW2 is connected to point A between resistors R13 and R7, and its anode is connected to the base of transistor Q1. The low-voltage alarm indicator module includes transistor Q2, with an alarm indicator LED2 connected to the collector of transistor Q2. The base of transistor Q2 is connected to point B, which is located between the collector of transistor Q1 and the power indicator module. The power indicator module includes a power indicator LED1, and its other end is connected to the power supply module.

2. The circuit with a low-voltage alarm indicator according to claim 1, wherein, The low-voltage alarm indicator module is connected between the VCC port and the GND port of the power supply module, and the emitter of the transistor Q2 is grounded.

3. The circuit with a low-voltage alarm indicator according to claim 1, wherein, The two ends of the power supply module are connected to point C and the GND port, respectively, with point C connected to the live wire of the power input terminal.

4. A circuit with a low-voltage alarm indicator according to claim 1, wherein, The alarm indicator LED2 is a self-flashing light-emitting diode, and the anode and cathode of the self-flashing light-emitting diode are electrically connected to the power supply module and the collector of the transistor Q2, respectively.

5. A circuit with a low-voltage alarm indicator according to claim 1, wherein, The phase inversion module also includes a filter capacitor C5 and a resistor R10 connected in parallel.

6. A circuit with a low-voltage alarm indicator according to claim 1, wherein, The power supply module also includes a Zener diode DW1, a filter capacitor C2, and a filter capacitor C3 connected in parallel.

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