Switching state detection circuit and electric appliance

Abstract

The application discloses a switch state detection circuit and an electric appliance, and relates to the technical field of detection circuits. The switch state detection circuit comprises a control switch, a voltage division circuit and a control chip. The first end of the control switch is connected with a power supply, and the second end of the control switch is connected with a load. The voltage division circuit comprises a first resistor and a second resistor. The first end of the first resistor is connected with the second end of the control switch. The second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is grounded. The second end of the first resistor and the first end of the second resistor are sampling points. The control chip is connected with the sampling points, is used for detecting the voltage of the sampling points, and determines whether the control switch is in an open state or a closed state according to the voltage of the sampling points. The switch state detection circuit and the electric appliance provided by the application can improve the application range of the detection circuit.

Description

Technical Field

[0001] This disclosure relates to the field of detection circuit technology, and in particular to a switch state detection circuit and electrical device. Background Technology

[0002] In applications involving high-risk loads that could potentially cause harm to human health, the load is typically connected in series with a switch. When there is a risk of personnel approaching or operational hazards, the switch forcibly disconnects the circuit, cutting off power to the load and preventing its operation. However, because such switches are usually located in the main power supply circuit and operate independently of the control system logic, the control chip cannot directly determine whether the switch has been triggered. Therefore, to improve system reliability and safety, it is necessary to detect the switch status.

[0003] During testing, a resistor is typically connected in series between the power supply and the switch. The switch status is detected by collecting the voltage across the load through a control chip. When the voltage value falls within the pre-calculated voltage division value of the series circuit load, the load is considered to be energized and working, and the switch is closed; otherwise, the switch is in the open state, and the load device is not working.

[0004] However, the above solution is limited by the input voltage of the control chip. When the load voltage (such as 12V) is high, it will exceed the input voltage range of the control chip (such as 3.3V or 5V), which may damage the control chip, thus limiting the applicability of the solution in high-voltage load scenarios. Utility Model Content

[0005] The purpose of this application is to provide a switch state detection circuit and electrical device, which can improve the applicability of the detection circuit.

[0006] To address the aforementioned technical problems, the embodiments of this application provide the following technical solutions: The first aspect of this application provides a switch state detection circuit, including: The control switch has its first terminal connected to the power supply and its second terminal connected to the load. The voltage divider circuit includes a first resistor and a second resistor. The first end of the first resistor is connected to the second end of the control switch. The second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is grounded. The sampling point is located between the second end of the first resistor and the first end of the second resistor. The control chip is connected to the sampling point and is used to detect the voltage at the sampling point and determine whether the control switch is in an open or closed state based on the voltage at the sampling point.

[0007] In some modified embodiments of the first aspect of this application, the control chip has an input pin connected to a sampling point; When the control switch is open, the sampling point is pulled to ground level, and a low-level signal is input to the input pin. The control chip determines that the control switch is in the open state based on this signal. When the control switch is closed, the power supply provides a high-level signal to the input pin through the voltage divider circuit. The control chip determines that the control switch is in the closed state based on this signal.

[0008] Some modified embodiments of the first aspect of this application also include: The analog-to-digital converter is connected to both the sampling point and the control chip to acquire the voltage at the sampling point. When the analog-to-digital converter (ADC) acquires 0 voltage, the control chip determines that the control switch is in the open state; when the ADC acquires a preset voltage, the control chip determines that the control switch is in the closed state.

[0009] Some modified embodiments of the first aspect of this application also include: The analog-to-digital conversion module, integrated on the control chip, is used to acquire the voltage at the sampling points. When the analog-to-digital converter module acquires 0 voltage, the control chip determines that the control switch is in the open state; when the analog-to-digital converter module acquires the preset voltage, the control chip determines that the control switch is in the closed state.

[0010] In some modified embodiments of the first aspect of this application, the voltage divider circuit is provided in two sets, and the sampling points of the two sets of voltage divider circuits are respectively connected to the control chip. The control chip determines whether the control switch is in an open or closed state based on the voltage of the sampling points of the two sets of voltage divider circuits.

[0011] In some modified embodiments of the first aspect of this application, the first resistor has a first adjustment structure, which is used to adjust the resistance value of the first resistor. And / or, the second resistor has a second adjustment structure for adjusting the resistance value of the second resistor.

[0012] A second aspect of this application provides an electrical device, comprising: The switch state detection circuit described above; The load is connected at one end to the second terminal of the control switch and the first terminal of the first resistor, and the other end of the load is grounded.

[0013] Some modified embodiments of the second aspect of this application also include: The housing has an internal space where the load is disposed. The load includes a UV lamp for emitting UV light into the containment space.

[0014] Some modified embodiments of the second aspect of this application also include: The door is located on one side of the housing and is connected to the control switch via a drive mechanism. When the door is in the open state, the control switch is in the off state; when the door is in the closed state, the control switch is in the closed state, and the ultraviolet lamp emits ultraviolet light within the containment space.

[0015] Some modified embodiments of the second aspect of this application also include: Filter element, used to filter air, is connected to the control switch; When the filter element is in the first position, the control switch is in the off state; when the filter element is in the second position, the control switch is in the closed state, and the ultraviolet lamp emits ultraviolet light in the containment space. The first and second positions are different.

[0016] In some modified embodiments of the second aspect of this application, the housing further includes: Air inlet, the air inlet is located on one side of the housing; The air outlet is located on the other side of the housing, and the filter element is located between the air inlet and the air outlet. A drive fan is installed between the filter element and the air outlet to drive the air to flow between the air inlet and the air outlet.

[0017] Compared to existing technologies, this disclosure connects a voltage divider circuit in parallel with the load by connecting it to the second terminal of the control switch, and connects the control chip between a first resistor and a second resistor connected in series. This allows the control chip to detect 0 voltage when the control switch is open, and detect the voltage drop across the second resistor when the control switch is closed. This voltage drop is the highest voltage that the control chip can detect, and it can be set and adjusted according to the resistance values ​​of the first and second resistors (for example, the resistance value of the first resistor can be set much higher than that of the second resistor to reduce the voltage drop across the second resistor). This avoids exceeding the input voltage range of the control chip and the ADC (if any), thereby improving the applicability of the detection circuit. Attached Figure Description

[0018] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein: Figure 1 A schematic diagram of a detection circuit is shown. Figure 2 A schematic diagram of the internal structure of an electrical device is shown. Figure 3A schematic diagram of the three-dimensional structure of an electrical device is shown. Figure 4 A schematic diagram of another detection circuit is shown. Figure 5 A schematic diagram of yet another detection circuit is shown.

[0019] Explanation of icon numbers: 1. Control switch; 2. Power supply; 3. Voltage divider circuit; 31. First resistor; 32. Second resistor; 4. Load; 5. Control chip; 51. Input pin; 6. Housing; 61. Housing space; 62. Air inlet; 63. Air outlet; 7. Door switch; 8. Filter element; 9. Drive fan; 10. Analog-to-digital converter. Detailed Implementation

[0020] Exemplary embodiments of this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0021] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains.

[0022] In applications involving high-risk loads that may cause harm to human health (such as high-power heating elements, strong light sources, or high-voltage equipment), the load is typically connected in series with a switch. When there is a risk of personnel approaching or operational hazards, the switch forcibly disconnects the circuit, cutting off power to the load and preventing its operation. However, because such switches are usually located in the main power supply circuit and are independent of the control system's logic, the control chip cannot directly determine whether the switch has been triggered. Therefore, to improve system reliability and safety, it is necessary to detect the switch status.

[0023] During testing, a resistor is typically connected in series between the power supply and the switch. The switch status is detected by collecting the voltage across the load through a control chip. When the voltage value falls within the pre-calculated voltage division value of the series circuit load, the load is considered to be energized and working, and the switch is closed; otherwise, the switch is in the open state, and the load device is not working.

[0024] However, the above solution is limited by the input voltage of the control chip. When the load voltage (such as 12V) is high, it will exceed the input voltage range of the control chip (such as 3.3V or 5V), which may damage the control chip, thus limiting the applicability of the solution in high-voltage load scenarios.

[0025] To address the aforementioned technical problems, this application provides a switch state detection circuit and electrical device, which can improve the applicability of the detection circuit.

[0026] like Figure 1 As shown, a switch state detection circuit includes a control switch 1, a voltage divider circuit 3, and a control chip 5. The first end of the control switch 1 is connected to a power supply 2, and the second end of the control switch 1 is connected to a load 4. The voltage divider circuit 3 includes a first resistor 31 and a second resistor 32. The first end of the first resistor 31 is connected to the second end of the control switch 1 and the load 4. The second end of the first resistor 31 is connected to the first end of the second resistor 32, and the second end of the second resistor 32 is grounded. The area between the second end of the first resistor 31 and the first end of the second resistor 32 is a sampling point. The control chip 5 is connected to the sampling point and is used to detect the voltage at the sampling point and determine whether the control switch 1 is in an open or closed state based on the voltage at the sampling point.

[0027] Control switch 1 is an electrical switching element connected in series between power supply 2 (VCC) and load 4 (such as a UV lamp), which can physically disconnect or connect the power supply circuit of load 4. The action of control switch 1 can be linked with the mechanical structure of the equipment (such as the opening and closing of the door, the installation status of filter element 8). When the switch is in the open state, it ensures that load 4 (UV lamp) is completely de-energized, preventing the leakage of dangerous energy (such as ultraviolet light). Its on / off state can be detected by external circuits (such as the sampling points of the voltage divider circuit), realizing real-time monitoring of the safety interlock status by the main control chip. It is not only a power switching device, but also a safety interlock device, which can ensure that users are not exposed to harmful radiation when opening the equipment. Control switch 1 can be a micro switch, which is a mechanical switch that achieves on / off by the pressure or release of the push rod. It has an internal spring mechanism to achieve rapid on / off, avoid electric arc, and has low cost and long life. In some specific embodiments, control switch 1 can be a single-pole mechanical switch or a double-pole mechanical switch.

[0028] Voltage divider circuit 3 is a simple circuit composed of two or more resistors (or other impedance elements) connected in series. It uses the series resistors to proportionally distribute the voltage of power supply 2, thereby outputting a stable voltage signal lower than the input voltage at the intermediate node (sampling point). Voltage divider circuit 3 includes a first resistor 31 and a second resistor 32, which are connected in series between the output terminal of control switch 1 and ground. The connection node serves as a voltage sampling point, used to provide a voltage signal related to the switch state to control chip 5, thereby realizing the detection of the on / off state of the power supply circuit of high-voltage load 4.

[0029] In some implementations, a filter capacitor (such as a ceramic capacitor) can be connected in parallel at the midpoint of the connection between the two resistors in the voltage divider circuit 3 (i.e., the voltage sampling point). One end of the capacitor is grounded, which is suitable for circuits where the ADC is installed. Since there may be electromagnetic interference, switching noise, power supply fluctuations, etc. on the circuit board of the control chip 5, high-frequency signals will be induced on the sampling line, causing the ADC reading to fluctuate. The filter capacitor presents low impedance to high-frequency signals, short-circuiting them to ground. In addition, the sample-and-hold circuit inside the analog-to-digital converter 10 requires a stable voltage input, and the capacitor can also play a role in local energy storage to prevent voltage surges.

[0030] In some implementations, a voltage clamping element, such as a Zener diode, a TVS diode (transient voltage suppressor diode), or a Schottky diode, can be added to the voltage divider circuit 3. This element is connected in parallel between the sampling point and ground to limit the output voltage within a safe range, thereby protecting sensitive devices (such as the ADC input pin 51 of the control chip 5) from overvoltage breakdown. Even if an abnormally high voltage occurs at the front end, it can be ensured that the sampling point voltage will not exceed the maximum allowable input voltage of the control chip 5. For example, the clamping element can be a TVS diode, which has high resistance under normal conditions; when the voltage exceeds the breakdown voltage (such as 3.6V), it quickly conducts, allowing excess current to flow to ground through the TVS diode, thus clamping the voltage to a safe value.

[0031] In some implementations, two independent voltage divider circuits 3 can be connected to two ADC channels respectively, and the control chip 5 compares the results to prevent misjudgment caused by a single point of failure.

[0032] The first resistor 31 is connected between the output terminal of control switch 1 (i.e., the power supply terminal of load 4) and the sampling point, also known as a pull-up resistor. The second resistor 32 is connected between the sampling point and ground, also known as a pull-down resistor. The first resistor 31 and the second resistor 32 are connected in series to form a resistor voltage divider network, and the connection point between them is the voltage sampling point. By adjusting the resistance ratio of the first resistor and the second resistor, a high voltage (e.g., 12V) can be converted to a low voltage (e.g., 2.1V) acceptable to the control chip 5. The first resistor 31 and the second resistor 32 can be metal film resistors or surface-mount thick film resistors. The resistance values ​​of the first resistor 31 and the second resistor 32 can be fixed or adjustable (e.g., a sliding rheostat).

[0033] Power source 2 refers to the device or interface that provides electrical energy to the circuit or equipment, and is the source of energy for the entire system. In the circuit, power source 2 provides voltage to the front end of control switch 1, which is then supplied to load 4 (such as a UV lamp) for operation. For example, power source 2 can be a DC regulated power supply 2, outputting a stable DC voltage; power source 2 can also include a power source 2 adapter, which can convert 220V AC mains power to low-voltage DC.

[0034] Load 4 refers to the component or device in the circuit that consumes electrical energy. In this scheme, it specifically refers to the electrical equipment controlled by control switch 1, such as UV lamps, incandescent lamps, heating wires, etc. Load 4 is connected between the output terminal of control switch 1 and ground. When the switch is closed, load 4 is energized and works. When the switch is open, load 4 is de-energized and stops working (safety state).

[0035] The control chip 5 refers to an integrated circuit (IC) capable of receiving input signals, performing logical judgments or data processing, and outputting control commands. It is a microcontroller or logic chip used to detect switch states and implement safety interlock control. It can detect the voltage at the sampling point and determine whether the control switch 1 is closed or open based on the voltage value. In some implementations, if the control chip 5 detects a failure to disconnect when it should or abnormal power supply, it can trigger a protection mechanism. The control chip 5 can detect voltage through a built-in ADC module or by connecting to an ADC, or by connecting the input pin 51 to the sampling point. For example, the control chip 5 can set an on / off voltage. When the sampled voltage is greater than the on / off voltage, it determines that the control switch 1 is closed; when the sampled voltage is less than the off voltage, it determines that the control switch 1 is closed; or when the sampled voltage gradually increases over a short period, it determines that the control switch 1 is closed; when the sampled voltage gradually decreases over a short period, it determines that the control switch 1 is closed. Furthermore, when the analog-to-digital converter 10 acquires a voltage of 0, the control chip 5 determines that the control switch 1 is in the open state; when the analog-to-digital converter 10 acquires a preset voltage, the control chip 5 determines that the control switch 1 is in the closed state.

[0036] The voltage V divided by the second resistor 32 H The following formula can be used for calculation: V H = ; Among them, V dd For system power supply 2, R1 represents the resistance of the first resistor 31, and R2 represents the resistance of the second resistor 32. The aforementioned turn-on voltage is less than V. H The shut-off voltage is greater than V. H .

[0037] Compared to existing technologies, this disclosure connects the voltage divider circuit 3 to the second terminal of the control switch 1 to connect the voltage divider circuit 3 in parallel with the load 4, and connects the control chip 5 between the first resistor 31 and the second resistor 32 in series. This allows the control chip 5 to detect 0 voltage when the control switch 1 is in the open state; and when the control switch 1 is in the closed state, the control chip 5 detects the voltage drop across the second resistor 32, which is the highest voltage that the control chip 5 can detect. This voltage can be adjusted according to the resistance values ​​of the first resistor 31 and the second resistor 32 (for example, the resistance value of the first resistor 31 can be set much higher than that of the second resistor 32 to reduce the voltage drop across the second resistor), thereby avoiding exceeding the input voltage range of the control chip 5 and the ADC (if any), thus improving the applicability of the detection circuit.

[0038] In some modified embodiments of this application, the control chip 5 has an input pin 51, which is connected to the sampling point. When the control switch 1 is open, the sampling point is pulled to ground level, and the input pin 51 receives a low-level signal, thereby determining that the control switch 1 is in the open state. When the control switch 1 is closed, the power supply 2 provides a high-level signal to the input pin 51 through the voltage divider circuit 3, thereby determining that the control switch 1 is in the closed state.

[0039] The input pin 51 of the control chip 5 can use a GPIO pin to directly read high and low levels, eliminating the need for software ADC acquisition and embedded software processing, resulting in a simple structure. The input impedance of the GPIO pin is much greater than the resistance values ​​of the first resistor 31 and the second resistor 32 to ensure the stability of the output of the voltage divider circuit 3. For example, the GPIO level received by the status signal receiving IC is 0~V. H That is, the GPIO pin of the control chip 5 will determine 0V as a low level, and will reach V H The voltage is determined to be high. When control switch 1 is not closed, the sampling point is pulled to ground (i.e., the sampling point is connected to ground through R2), and the level acquired by GPIO is low, 0V. That is, the voltage detected by a certain input pin 51 (GPIO) of control chip 5 is 0V, which is identified as logic 0 (low level), indicating that the switch is in the open state. After control switch 1 is closed, the GPIO pin is connected to the connection node of the first resistor 31 and the second resistor 32, and the voltage V is acquired. H V H Satisfying the above formula V H = (V dd R2) / (R1 + R2), thereby providing a high-level signal to input pin 51, based on which control chip 5 determines that control switch 1 is in the closed state. In some embodiments, the high-level input voltage threshold can be configured to be slightly less than the voltage division V of the second resistor 32. HThis ensures that when the control switch is closed, the output voltage is greater than the high-level input voltage threshold and is recognized as a high level.

[0040] like Figure 4 As shown, in some modified embodiments of this application, an analog-to-digital converter 10 is also included. The analog-to-digital converter 10 is connected to the sampling point and the control chip 5 respectively, and is used to collect the voltage of the sampling point. When the analog-to-digital converter 10 collects 0 voltage, the control chip 5 determines that the control switch 1 is in the open state. When the analog-to-digital converter 10 collects a preset voltage, the control chip 5 determines that the control switch 1 is in the closed state.

[0041] The analog-to-digital converter (ADC) 10 is an electronic device that converts continuously varying analog voltage signals (e.g., 0~3.3V) into discrete digital values ​​(e.g., 0~4095) for processing by the digital system of the control chip 5. The preset voltage refers to a voltage pre-set in the control system to determine whether a certain state is valid. When the acquired voltage is equal to (or greater than) the preset voltage, the switch is considered closed. The preset voltage can be the voltage divided by the second resistor 32 mentioned above. H It can also be slightly smaller than V. H The analog-to-digital converter 10 can accurately acquire the voltage at the sampling point and achieve highly reliable detection of the state of the control switch 1 by comparing it with the preset voltage.

[0042] The analog-to-digital converter 10 can be a relatively independent device connected to the control chip 5. The analog-to-digital converter 10 can use a separate ADC chip (such as ADS1115, ADS7828, etc.). An external independent ADC chip offers high precision, high resolution, and excellent anti-interference capabilities, supporting 16-bit or even 24-bit resolution, significantly improving the accuracy of voltage detection. It features flexible functions such as programmable gain amplification, differential input, and independent reference voltage, making it suitable for precision acquisition in multi-channel, weak signal, or high-noise environments. Furthermore, the independent ADC can communicate with the control chip 5 via interfaces such as I2C (Integrated Circuit Bus) and SPI (Serial Peripheral Interface), facilitating system expansion and isolation design. This makes it suitable for industrial control, sensor monitoring, and high-reliability applications with high requirements for measurement accuracy, stability, and functional expandability.

[0043] In some modified embodiments of this application, an analog-to-digital conversion module is also included. The analog-to-digital conversion module is integrated on the control chip 5 and is used to collect the voltage of the sampling point. When the analog-to-digital conversion module collects 0 voltage, the control chip 5 determines that the control switch 1 is in the open state. When the analog-to-digital conversion module collects a preset voltage, the control chip 5 determines that the control switch 1 is in the closed state.

[0044] An analog-to-digital converter (ADC) module is a hardware unit embedded within the control chip. Its function is similar to that of an analog-to-digital converter (ADC), responsible for sampling and quantizing externally input analog electrical signals (such as voltage signals) according to certain precision, speed, and resolution, converting them into corresponding binary digital values ​​for data processing, control decisions, or communication transmission by the chip's internal processor or logic circuits. Integrating the ADC module onto the control chip 5 offers significant advantages such as low cost, small footprint, and simple design. It achieves analog signal acquisition and conversion without additional components, effectively reducing system material costs and PCB (printed circuit board) layout complexity. It is natively compatible with the control chip 5, requiring no external communication protocols (such as I2C / SPI), simplifying software configuration, and offering fast startup and sampling speeds for more efficient system response. Furthermore, the integrated solution reduces external solder joints and connection lines, improving overall reliability. It is suitable for cost-sensitive, size-constrained, and functionally demanding consumer electronics, home appliances, and embedded control systems, providing a cost-effective solution for switch status detection.

[0045] like Figure 5 As shown, in some modified embodiments of this application, the voltage divider circuit 3 is provided with two sets, and the sampling points of the two sets of voltage divider circuits 3 are respectively connected to the control chip 5. The control chip 5 determines whether the control switch is in an open or closed state based on the voltage of the sampling points of the two sets of voltage divider circuits.

[0046] This dual voltage divider circuit structure can effectively improve the reliability of switch status detection. By comparing the two sampling signals, it can identify single-point faults or abnormal levels, avoiding misjudgments caused by factors such as noise, poor contact or component aging at a single sampling point.

[0047] When the switch is on, the load side (i.e., the second terminal of the switch) is connected to the power supply. Both sampling points of the two voltage groups output a stable high level. The control chip 5 detects that the voltage at both sampling points is higher than the high-level input voltage threshold (or reaches the preset voltage), and determines that the switch is in the closed state. When the switch is off, the load side is either floating or pulled to ground through the load. The upper ends of the two voltage groups lose power, and the sampling point voltage is 0V. The control chip 5 detects that the voltage at both sampling points is lower than the preset threshold, and determines that the switch is in the open state.

[0048] The switch state is confirmed only when both sampling point voltages simultaneously meet the high or low condition. If they are inconsistent (e.g., one high and one low), it is considered abnormal (e.g., line fault, poor contact), which may trigger an alarm or enter a safe mode. If the two voltage-group circuits are designed with different voltage division ratios (e.g., one group is 1:1 and the other is 2:1), the voltages at the two sampling points will have a fixed proportional relationship when closed; when open, they will both be close to 0. The control chip can determine the switch state and circuit integrity by verifying the existence of this proportional relationship.

[0049] In some modified embodiments, the first resistor 31 and / or the second resistor 32 have an adjustment structure for adjusting their resistance value. That is, the first resistor has a first adjustment structure for adjusting the resistance value of the first resistor; and / or, the second resistor has a second adjustment structure for adjusting the resistance value of the second resistor.

[0050] The adjustment structure (first adjustment structure and second adjustment structure) refers to the physical or electronic mechanism set in the circuit to achieve adjustable resistance value, allowing the user or system to adjust the resistance value within a certain range to change the voltage division ratio, voltage output, or system response. The adjustment structure is used to adjust the resistance value of the first resistor 31 or the second resistor 32, thereby ensuring that the output voltage accurately meets the high-level recognition condition of the control chip 5 or does not exceed the applicable range of the analog-to-digital converter 10. The first resistor 31 and / or the second resistor 32 can be adjustable resistors, and the adjustment structure can be an adjuster for the adjustable resistors, changing the effective resistance value by rotating or sliding contacts. The adjustment structure can also consist of multiple parallel resistors and switches, with multiple fixed resistors connected in parallel. The number of fixed resistors in parallel is switched by a DIP switch or relay, thereby changing the effective resistance of the circuit. The adjustment structure can also be a digital potentiometer, controlling the internal resistor network via I2C / SPI to achieve programmable adjustment.

[0051] like Figure 2 and Figure 3 As shown, an electrical device includes the aforementioned switch state detection circuit and a load 4. One end of the load 4 is connected to the second end of the control switch 1 and the first end of the first resistor 31, and the other end of the load 4 is grounded.

[0052] The electrical equipment is the main product integrated into this switch status detection circuit. Based on the circuit design described above (used to detect the open / closed status of the door / cover and control the on / off state of the load), it is applicable to enclosed equipment with safety interlocking mechanisms. The electrical equipment can be household appliances, such as air purifiers, disinfection cabinets, dishwashers, microwave ovens, washing machines, dryers, and water purifiers. These devices often have doors or covers, requiring detection of whether they are closed before activating the UV lamp or heating. The electrical equipment can also be medical and health-related structures, such as ultraviolet sterilizers, toothbrush sterilizers, endoscope sterilization cabinets, and biosafety cabinets, which have extremely high safety requirements and must ensure the door is closed before activating the UV lamp. The electrical equipment can also be smart home devices, such as smart trash cans, smart shoe cabinets, pet sterilization boxes, and smart wardrobes, integrating UV sterilization functions and requiring safety testing.

[0053] Load 4 is an electrical component controlled by its switch status; it is only permitted to operate when the hatch is closed (switch closed). Load 4 can be an ultraviolet lamp used for air, water, and object surface disinfection, and exposure must be prevented. Load 4 can also be a heating element, such as a heating wire or ceramic heating plate, used for drying, disinfection, and heat preservation, and overheating or accidental contact must be prevented. Load 4 can also be a high-voltage discharge module, such as a plasma generator or ozone generator, which can produce a strong electric field or reactive gas, posing a high risk and requiring interlocking control. Load 4 can also be a low-power laser module, which can be used in industrial or medical equipment, and laser leakage must be prevented.

[0054] Compared to existing technologies, this disclosure connects the voltage divider circuit 3 of the electrical equipment switch status detection circuit to the second terminal of the control switch 1 to connect the voltage divider circuit 3 in parallel with the load 4, and connects the control chip 5 between the first resistor 31 and the second resistor 32 in series. This allows the control chip 5 to detect 0 voltage when the control switch 1 is in the open state; when the control switch 1 is in the closed state, the control chip 5 detects the voltage division of the second resistor 32, which is the highest voltage of the control chip 5. This voltage can be adjusted according to the resistance values ​​of the first resistor 31 and the second resistor 32 (for example, the resistance value of the first resistor 31 can be set much higher than that of the second resistor 32), thereby avoiding exceeding the input voltage range of the control chip 5 and the ADC (if any), thus improving the applicability of the detection circuit. This makes it easier for users to replace different types of loads 4, thereby improving the applicability of the electrical equipment and the user experience.

[0055] like Figure 2 As shown, in some modified embodiments of this application, a housing 6 is also included, which has a receiving space 61, and a load 4 is disposed in the receiving space 61; the load 4 includes an ultraviolet lamp for emitting ultraviolet light into the receiving space 61.

[0056] The accommodating space 61 is a space formed inside the housing 6 to accommodate items to be processed. The load 4 is an ultraviolet lamp, located within the accommodating space 61, used to emit ultraviolet light into this space for sterilization and disinfection. The control switch 1 is linked to the openable door of the housing 6. When the door is closed, the switch is on, and after the switch status detection circuit determines this, the control chip 5 allows the ultraviolet lamp to operate. When the door is opened, the switch is off, and the control chip 5 immediately cuts off the power supply to the ultraviolet lamp to prevent ultraviolet leakage and ensure operator safety. This design elevates the original switch status detection circuit from a general-purpose electronic module into a safety control system tailored to specific application scenarios, suitable for electrical appliances such as ultraviolet disinfection cabinets, air purifiers, smart shoe cabinets, and toothbrush sterilizers.

[0057] The housing 6 refers to a structural enclosure used to house, protect, and support internal components of electrical equipment (such as circuit boards, loads 4, sensors, etc.). It may have one or more openable doors or covers, forming an internal space 61 for placing items to be processed. The housing 6 provides physical protection and can also create a closed disinfection environment. A control switch 1 can be integrated into the housing 6 to implement a safety interlock mechanism for door opening and closing. The housing 6 can be a single-door structure, opening and closing on one side, suitable for small devices such as toothbrush sterilizers and shoe cabinets. The housing 6 can also be a double-door structure, facilitating the placement of large items, suitable for large disinfection cabinets and biosafety cabinets. The housing 6 can also be a fully enclosed structure with an openable top cover, suitable for laboratory equipment and UV curing machines.

[0058] An ultraviolet (UV) lamp is a light source that emits electromagnetic waves with wavelengths ranging from 100 nm to 400 nm, and is particularly used for sterilization, disinfection, curing, and purification. In this invention, the UV lamp can serve as a load 4, housed within the receiving space 61 of the housing 6, for UV irradiation treatment of internal items. The UV lamp can be fixed to the inner wall, top, or side wall of the housing 6.

[0059] like Figure 2 and Figure 3 As shown, in some modified embodiments of this application, a switch door 7 is also included. The switch door 7 is disposed on one side of the housing 6 and is connected to the control switch 1 in a driving manner. When the switch door 7 is in the open state, the control switch 1 is in the open state; when the switch door 7 is in the closed state, the control switch 1 is in the closed state, and the ultraviolet lamp emits ultraviolet light in the accommodating space 61.

[0060] The switch door 7 refers to an openable component installed on the electrical equipment housing 6, used to close or open the internal accommodating space 61 of the equipment. Its opening and closing action is linked to the control switch 1. When the door is closed, the switch is triggered to close, allowing the load 4 (such as an ultraviolet lamp) to operate; when the door is opened, the switch is opened, forcibly cutting off the power supply to the load 4, thus achieving electrical safety interlocking. The switch door 7 can provide physical enclosure to prevent users from contacting dangerous areas (such as UV radiation, high temperature). Through mechanical linkage, the control switch 1 is triggered to realize the safety logic of power cut-off when the door is opened. This clearly links the originally abstract control switch 1 with physical operation (opening / closing the door), constructing a complete safety interlocking mechanical and electrical system.

[0061] In some embodiments, a magnet or protrusion may be provided on the inner side of the door 7. When the door is closed, the magnet attracts the reed switch, or the protrusion presses the micro switch to achieve automatic triggering. A sensor may also be provided inside the housing 6 to detect whether the door 7 is fully closed, avoiding false close judgments.

[0062] like Figure 2As shown, in some modified embodiments of this application, a filter element 8 is also included. The filter element 8 is used to filter air and is connected to the control switch 1. When the filter element 8 is in the first position, the control switch 1 is in the off state. When the filter element 8 is in the second position, the control switch 1 is in the closed state, and the ultraviolet lamp emits ultraviolet light in the accommodating space 61. The first position and the second position are different.

[0063] Filter element 8 refers to a functional component used to remove pollutants from the air. It is detachably installed in the airflow channel or housing space 61 of the electrical equipment. It is equipped with a filter medium and can physically intercept, adsorb, or chemically decompose the flowing air to achieve air purification, dust removal, sterilization, and odor removal. Filter element 8 is not only a purification component but also mechanically linked to the control switch 1 through its installation status to determine whether the equipment meets safe operating conditions (e.g., whether filter element 8 is correctly installed), thereby deciding whether to allow the load 4, such as the ultraviolet lamp, to operate. Filter element 8 can have a cylindrical structure, with the ultraviolet lamp located in the hollow part of the cylindrical structure to prevent ultraviolet leakage and improve the sterilization effect. In some embodiments, filter element 8 can have a plate-like structure, with the ultraviolet lamp positioned between filter element 8 and the fan.

[0064] The first position refers to the position where filter element 8 is fully inserted into the filter element compartment and reaches the predetermined installation depth. At this time, the triggering structure on filter element 8 (such as a protrusion or magnet) can reliably trigger control switch 1 to close, indicating that filter element 8 has been correctly installed and the equipment is ready to operate. The second position refers to the state where filter element 8 is not installed, partially inserted, installed in reverse, or misaligned. At this time, control switch 1 cannot be triggered, and the switch remains open, indicating that filter element 8 is missing or improperly installed, and the equipment is prohibited from operation.

[0065] like Figure 2 and Figure 3 As shown, in some modified embodiments of this application, the housing 6 further includes an air inlet 62 and an air outlet 63. The air inlet 62 is disposed on one side of the housing 6, and the air outlet 63 is disposed on the other side of the housing 6. The filter element 8 is disposed between the air inlet 62 and the air outlet 63. A drive fan 9 is also disposed between the filter element 8 and the air outlet 63 to drive air to flow between the air inlet 62 and the air outlet 63.

[0066] The air inlet 62 allows outside air to enter the housing 6; the air outlet 63 exhausts the purified air, forming a circulation. A UV lamp can also be positioned between the air inlet 62 and the air outlet 63, driving the fan 9 to provide airflow power, ensuring efficient airflow through the filter 8 and UV lamp, thus achieving air filtration and sterilization, suitable for air purifiers. For example, the UV lamp can be positioned between the filter 8 and the driving fan 9, or surrounding the air duct, to maximize irradiation time and uniformity. The driving fan 9 can be a centrifugal fan, axial fan, or crossflow fan, selected according to the equipment structure. Multiple control switches 1 can be connected in series, simultaneously detecting the filter 8 installation status and the door 7 opening / closing status; only when both conditions are met is the fan and UV lamp allowed to start.

[0067] An air purifier can be composed of a housing, filter, UV lamp (load), and drive fan. Integrating the aforementioned detection circuit into the air purifier allows for real-time and reliable monitoring of the power supply switch status of critical loads such as the UV lamp, ensuring the device operates as expected. For example, when the door is closed and the filter is in the first position, if the control chip detects that the control switch corresponding to the UV lamp is in the off state, it can determine that the UV lamp is not working properly and issue a fault warning via indicator light, display screen, or wireless communication module, reminding the user to check or replace the component. If an abnormal switch closure is detected (such as still conducting in standby mode), the power supply can be cut off in time to prevent safety hazards caused by accidental start-up.

[0068] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A switch state detection circuit, characterized in that, include: A control switch (1) is provided, the first end of which is connected to a power supply (2), and the second end of which is connected to a load (4). Voltage divider circuit (3), the voltage divider circuit (3) includes a first resistor (31) and a second resistor (32), the first end of the first resistor (31) is connected to the second end of the control switch (1); the second end of the first resistor (31) is connected to the first end of the second resistor (32), and the second end of the second resistor (32) is grounded; the second end of the first resistor (31) and the first end of the second resistor (32) are sampling points; The control chip (5) is connected to the sampling point and is used to detect the voltage of the sampling point and determine whether the control switch (1) is in an open or closed state based on the voltage of the sampling point.

2. The switch state detection circuit according to claim 1, characterized in that, The control chip (5) has an input pin (51), which is connected to the sampling point; When the control switch (1) is open, the sampling point is pulled to ground level, and the input pin (51) receives a low-level signal. The control chip (5) determines that the control switch (1) is in the open state. When the control switch (1) is closed, the power supply (2) provides a high-level signal to the input pin (51) through the voltage divider circuit (3). The control chip (5) determines that the control switch (1) is in the closed state.

3. The switch state detection circuit according to claim 1, characterized in that, Also includes: An analog-to-digital converter (10) is connected to the sampling point and the control chip (5) respectively, and is used to collect the voltage of the sampling point; When the analog-to-digital converter (10) acquires 0 voltage, the control chip (5) determines that the control switch (1) is in the open state; when the analog-to-digital converter (10) acquires a preset voltage, the control chip (5) determines that the control switch (1) is in the closed state.

4. The switch state detection circuit according to claim 1, characterized in that, Also includes: An analog-to-digital converter module, which is integrated on the control chip (5), is used to collect the voltage of the sampling point; When the analog-to-digital converter module acquires 0 voltage, the control chip (5) determines that the control switch (1) is in the open state; when the analog-to-digital converter module acquires a preset voltage, the control chip (5) determines that the control switch (1) is in the closed state.

5. The switch state detection circuit according to claim 1, characterized in that, The voltage divider circuit (3) is provided in two sets. The sampling points of the two sets of voltage divider circuits (3) are respectively connected to the control chip (5). The control chip (5) determines whether the control switch (1) is in the open or closed state based on the voltage of the sampling points of the two sets of voltage divider circuits (3).

6. The switch state detection circuit according to any one of claims 1-5, characterized in that, The first resistor (31) has a first adjustment structure, which is used to adjust the resistance value of the first resistor (31); And / or, the second resistor (32) has a second adjustment structure for adjusting the resistance value of the second resistor (32).

7. An electrical appliance, characterized in that, include: The switch state detection circuit as described in any one of claims 1-6; The load (4) is connected at one end to the second end of the control switch (1) and the first end of the first resistor (31), and the other end of the load (4) is grounded.

8. The electrical equipment according to claim 7, characterized in that, Also includes: The housing (6) has a receiving space (61) inside, and the load (4) is disposed in the receiving space (61); The load (4) includes an ultraviolet lamp for emitting ultraviolet light into the containment space (61).

9. The electrical equipment according to claim 8, characterized in that, Also includes: A switch door (7) is provided on one side of the housing (6) and is connected to the control switch (1) in a transmission manner; When the switch door (7) is in the open state, the control switch (1) is in the open state; when the switch door (7) is in the closed state, the control switch (1) is in the closed state, and the ultraviolet lamp emits ultraviolet light in the accommodating space (61).

10. The electrical equipment according to claim 8, characterized in that, Also includes: Filter element (8), the filter element (8) is used to filter air, and the filter element (8) is connected to the control switch (1); When the filter element (8) is in the first position, the control switch (1) is in the off state; when the filter element (8) is in the second position, the control switch (1) is in the closed state, and the ultraviolet lamp emits ultraviolet light in the accommodating space (61); the first position and the second position are different.

Images