A switch control circuit
By combining mechanical and electronic switches in a switch control circuit, and using an impedance unit to control the electronic switch, the mechanical switch is prevented from directly bearing large currents. This solves the overheating problem of mechanical switches in high-current and high-voltage scenarios, thereby extending service life and improving circuit stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGDONG DESHENG ELECTROACOUSTIC CO LTD
- Filing Date
- 2025-06-23
- Publication Date
- 2026-06-30
AI Technical Summary
Mechanical switches are prone to overheating due to the electric arc energy at the contact points or contact plates under high current and high voltage conditions, leading to oxidation and wear, shortening their service life and threatening circuit stability and safety.
By combining mechanical and electronic switches, and using impedance units to control the electronic switches to turn on or off, a low-voltage circuit can control a high-voltage path, and a small-current circuit can control a large-current path, thus avoiding the mechanical switch directly bearing a large current.
It effectively reduces mechanical switch contact losses, extends service life, improves circuit safety and stability, and expands the range of applications.
Smart Images
Figure CN224438966U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of electronic circuit technology, specifically relating to a switch control circuit. Background Technology
[0002] In the field of electronic circuits, mechanical switches, as fundamental and crucial electronic components, are widely used in various electronic and power supply products. Their core function is to control the on / off state of signal or power paths, as well as to flexibly switch between multiple power supplies. With advantages such as intuitive operation, low cost, and simple structure, mechanical switches occupy an important position in numerous scenarios, including consumer electronics, industrial control, and power equipment.
[0003] However, when mechanical switches are used in high-current, high-voltage applications, the instantaneous contact of the contacts generates significant arc energy, causing a rapid increase in temperature and potentially leading to overheating or even arcing. Prolonged operation under these conditions not only accelerates oxidation and wear of the contacts, significantly shortening the lifespan of the mechanical switch, but can also cause faults such as poor contact and short circuits, seriously threatening the stability and safety of the circuit. Utility Model Content
[0004] To address the shortcomings of the prior art, this application provides a switch control circuit that uses a mechanical switch to switch to an electronic switch to achieve low-voltage circuit control of high-voltage path and small-current circuit control of large-current path, effectively reducing mechanical switch contact losses, extending switch lifespan, and improving circuit safety and stability.
[0005] The technical effects to be achieved in this application are realized through the following aspects:
[0006] This application provides a switch control circuit, including:
[0007] A switch control module includes a mechanical switch, an electronic switch, and an impedance unit. The impedance unit is connected between the mechanical switch and the electronic switch. The mechanical switch is used to control the electronic switch to be turned on or off through the impedance unit.
[0008] A low-voltage input module, the output of which is connected to the input of the electronic switch; and
[0009] The boost module has its input terminal connected to the output terminal of the electronic switch.
[0010] In some implementations, the mechanical switch has a common terminal COM, a normally open terminal NO, and a normally closed terminal NC, with the normally closed terminal NC connected to the electronic switch;
[0011] The common terminal COM is connected to the normally closed terminal NC, and is used to turn on the low voltage input module and the boost module through the electronic switch;
[0012] The common terminal COM is connected to the normally open terminal NO, and is used to disconnect the low voltage input module and the boost module through the electronic switch.
[0013] In some implementations, the impedance unit includes resistors R7 and R6 connected in series, the control terminal of the electronic switch is connected between resistors R7 and R6, the other end of resistor R6 is connected to the normally closed terminal NC, and the other end of resistor R7 is connected between the electronic switch and the low voltage input module.
[0014] In some implementations, the electronic switch includes a transistor Q2, the gate of which is connected between resistors R6 and R7, the source of which is connected between the low-voltage input module and resistor R7, and the drain of which is connected to the input of the boost module.
[0015] In some implementations, the boost module includes a boost chip U2, a first filter unit, a second filter unit, a feedback network resistor, a voltage divider resistor, a power conversion unit, and a high-voltage output terminal VOUT1;
[0016] The input voltage terminal VIN of the boost chip U2 is connected to the output terminal of the electronic switch through resistor R5; the first filter unit is connected between resistor R5 and the input voltage terminal VIN of the boost chip U2; the voltage divider resistor is connected between resistor R5 and the enable terminal EN of the boost chip U2; the feedback network resistor is connected to the feedback terminal FB of the boost chip U2; one end of the power conversion unit is connected to the input voltage terminal VIN of the boost chip U2, and the other end of the power conversion unit is connected to the high voltage output terminal VOUT1; the second filter unit is connected between the power conversion unit and the high voltage output terminal VOUT1.
[0017] In some implementations, the first filter unit includes an electrolytic capacitor EC2 and a capacitor C3 connected in parallel, with the other ends of both the electrolytic capacitor EC2 and the capacitor C3 connected to ground.
[0018] The second filter unit includes an electrolytic capacitor EC1 and a capacitor C4 connected in parallel, with the other ends of both the electrolytic capacitor EC1 and the capacitor C4 connected to ground.
[0019] In some implementations, the feedback network resistor includes resistor R2 and resistor R1. One end of each resistor R2 and resistor R1 is connected to the feedback terminal FB of the boost chip U2, the other end of resistor R2 is grounded, and the other end of resistor R1 is connected to the high voltage output terminal VOUT1.
[0020] In some implementations, the voltage divider resistors include resistors R3 and R4 connected in series, one end of resistor R3 is connected to resistor R5, the enable terminal EN of the boost chip U2 is connected between resistors R3 and R4, and one end of resistor R4 is grounded.
[0021] In some implementations, the power conversion unit includes an inductor L1 and a diode D1 connected in series. One end of the inductor L1 is connected to the input voltage terminal VIN of the boost chip U2. The switching terminal SW of the boost chip U2 is connected between the inductor L1 and the diode D1. The output terminal of the diode D1 is connected to the high voltage output terminal VOUT1.
[0022] In some implementations, the low-voltage input module includes a low-voltage input unit and a third filtering unit, wherein the third filtering unit is connected between the low-voltage input unit and the input terminal of the electronic switch.
[0023] In summary, this application has at least the following advantages:
[0024] The switch control circuit provided in this application indirectly controls the mechanical switch and the electronic switch by connecting them through an impedance unit. This avoids large current flowing directly through the mechanical switch contacts, thereby enabling a low-voltage circuit to control a high-voltage path and a small-current circuit to control a large-current path. This reduces the arc energy and contact loss of the mechanical switch, effectively extends the switch's service life, and improves circuit safety and stability. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the switch control circuit in Embodiment 1 of this application.
[0026] Figure 2 This is another schematic diagram of the switch control circuit in Embodiment 1 of this application.
[0027] Figure 3 This is a schematic diagram of the boost module in Embodiment 2 of this application.
[0028] Figure 4 This is a schematic diagram of the low voltage input module in Embodiment 3 of this application.
[0029] Marked in the image:
[0030] 1. Switch control module, SW1, mechanical switch, 11, electronic switch, 12, impedance unit; 2. Low voltage input module, 21, low voltage input unit, 22, third filter unit; 3. Boost module, 31, first filter unit, 32, second filter unit, 33, feedback network resistor, 34, voltage divider resistor, 35, power conversion unit. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of this application, not all embodiments.
[0032] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.
[0033] Example 1:
[0034] Please see the appendix Figure 1-2 The switching control circuit of this application includes a switching control module 1, a low voltage input module 2, and a boost module 3.
[0035] The switch control module 1 includes a mechanical switch SW1, an electronic switch 11, and an impedance unit 12. The impedance unit 12 is connected between the mechanical switch SW1 and the electronic switch 11. The mechanical switch SW1 is used to control the electronic switch 11 to be turned on or off through the impedance unit 12. The low-voltage input module 2 has its output terminal connected to the input terminal of the electronic switch 11. The boost module 3 has its input terminal connected to the output terminal of the electronic switch 11. Preferably, the boost module 3 can be implemented using a boost-type DC-DC converter circuit, which generates a high-voltage output through inductor energy storage and diode rectification.
[0036] In this embodiment, the switch control circuit uses a mechanical switch SW1 to send a control signal to an electronic switch 11 via an impedance unit 12 in the low-voltage control circuit. When the mechanical switch SW1 is closed, the impedance unit 12 limits the control current to a safe range, triggering the electronic switch 11 to conduct, allowing the current from the low-voltage input module 2 to flow through the electronic switch 11 into the boost module 3. The boost module 3 then boosts the input voltage to the required high-voltage output via a power conversion unit 35. During this process, the mechanical switch SW1 only handles the small current operation of the control circuit, while the large current of the main circuit is entirely carried by the electronic switch 11. When the mechanical switch SW1 is open, the electronic switch 11 is turned off, cutting off the input power to the boost module 3 and achieving high-voltage output shutdown control.
[0037] Through the above technical solution, electronic switch 11 replaces mechanical switch SW1 in carrying the main circuit current, while mechanical switch SW1 is only used to control the operating state of electronic switch 11. This separation of control paths ensures that the contacts of mechanical switch SW1 only carry a small control current, fundamentally avoiding the conditions for arc generation, significantly reducing the rate of contact oxidation and wear, realizing low-voltage circuit control of high-voltage path, and small-current circuit control of large-current path, effectively extending the service life of the switch and improving operational reliability and circuit safety.
[0038] In addition, the introduction of the boost module 3 in this structure enables the low-voltage control circuit to indirectly manage the high-voltage output circuit, effectively expanding the application range of the mechanical switch SW1.
[0039] In some embodiments, the mechanical switch SW1 has a common terminal COM, a normally open terminal NO, and a normally closed terminal NC. The normally closed terminal NC is connected to the electronic switch 11. The common terminal COM is connected to the normally closed terminal NC and is used to turn on the low voltage input module 2 and the boost module 3 through the electronic switch 11. The common terminal COM is connected to the normally open terminal NO and is used to turn off the low voltage input module 2 and the boost module 3 through the electronic switch 11.
[0040] In this embodiment, when the common terminal COM of the mechanical switch SW1 is connected to the normally closed terminal NC, the control circuit of the electronic switch 11 is activated, creating a current path between the low-voltage input module 2 and the boost module 3. At this time, the boost module 3 is in normal operating condition. When the mechanical switch SW1 is operated, the common terminal COM switches to be connected to the normally open terminal NO, physically disconnecting the control circuit of the electronic switch 11 and cutting off the path between the low-voltage input module 2 and the boost module 3. Through the switching action of the mechanical switch SW1 contacts, only a low-voltage control signal needs to be transmitted, while the high-current switching operation is performed by the electronic switch 11, thereby avoiding the mechanical contacts directly bearing the load current.
[0041] With the above configuration, the mechanical switch SW1 serves only as a switching component for control signals. The current carried by its contacts is limited to the low current range required for the electronic switch 11 to drive, which fundamentally eliminates the root cause of contact oxidation and wear, reduces the oxidation rate of the contact points, and extends the service life of the mechanical switch SW1.
[0042] Meanwhile, the mechanical switch SW1 has the advantages of intuitive operation and simple structure. The physical disconnection mechanism of the normally open terminal NO effectively enhances the reliability of circuit shutdown, and the default conduction design of the normally closed terminal NC ensures that the system maintains a stable working state when not in operation, resulting in high operational safety.
[0043] In some embodiments, the impedance unit 12 includes resistors R7 and R6 connected in series, the control terminal of the electronic switch 11 is connected between resistors R7 and R6, the other end of resistor R6 is connected to the normally closed terminal NC, and the other end of resistor R7 is connected between the electronic switch 11 and the low voltage input module 2.
[0044] By setting the impedance unit 12, when the mechanical switch SW1 is in the closed state, the normally closed terminal NC is connected to the common terminal COM, and at this time, resistor R6 and the low-voltage input module 2 form a closed loop. The current flowing through resistor R6 generates a voltage drop across resistor R7, causing the control terminal of electronic switch 11 to receive a voltage lower than the conduction threshold, thereby triggering electronic switch 11 to conduct. When the mechanical switch SW1 switches to the open state, the normally closed terminal NC is disconnected from the common terminal COM, and the loop between resistor R6 and the low-voltage input module 2 is broken. Resistor R7 pulls the potential of the control terminal of electronic switch 11 to a high level equal to that of the low-voltage input module 2, forcing electronic switch 11 to turn off. During this process, resistor R6 absorbs the residual current generated at the moment the mechanical switch SW1 contacts open, while resistor R7 limits the rate of change of the control terminal voltage through voltage division.
[0045] The electronic switch 11 is precisely triggered and controlled by a voltage divider network. At the moment the mechanical switch SW1 is activated, the voltage change between the contacts is converted into a stepped voltage divider of the resistor network. This limits the voltage difference when the contacts are opened to the voltage drop range of resistor R6, avoiding malfunctions caused by sudden voltage changes. This improves the overall reliability of the circuit and the service life of the mechanical switch SW1.
[0046] In some embodiments, the electronic switch 11 includes a transistor Q2, the gate of which is connected between resistors R6 and R7, the source of which is connected between the low-voltage input module 2 and resistor R7, and the drain of which is connected to the input terminal of the boost module 3.
[0047] Specifically, when mechanical switch SW1 is activated, the voltage divider network of impedance unit 12 provides control voltage to the gate of transistor Q2 through resistors R6 and R7. When the common terminal COM is switched to the normally closed terminal NC, the gate voltage drops below 0.5V after being divided by resistor R6, forming a path between the source and drain of transistor Q2. The signal from low-voltage input module 2 is then transmitted to boost module 3 for boosting. When the common terminal COM is switched to the normally open terminal NO, resistor R6 is left floating, and the gate voltage is pulled up to DC 5V by resistor R7. Transistor Q2 is in the off state, and the connection between low-voltage input module 2 and boost module 3 is completely disconnected. By limiting the control signal of mechanical switch SW1 to the small current loop of impedance unit 12, transistor Q2 acts as the main current carrier, avoiding direct exposure of large currents or high voltages to the mechanical contacts, thus eliminating the physical conditions for arc generation.
[0048] By introducing a transistor as the electronic switch 11, the mechanical switch SW1 only needs to control the low-current impedance unit 12 voltage divider network, with the main circuit current carried by the transistor. This design reduces the current load on the mechanical contacts to the milliampere level, fundamentally avoiding the impact of large currents or high voltages on the contacts, isolating the mechanical switch SW1 from the high-voltage, high-current path of the main circuit, reducing the probability of poor contact or short circuits, and improving the stability of circuit operation. At the same time, the fast response characteristics of the transistor enhance the reliability of on / off control.
[0049] In addition, the electronic switch 11 is not limited to P-type MOSFETs or N-type MOSFETs, but can also be a BJT transistor, IGBT or relay. The flexibility of the electronic switch 11 makes it suitable for scenarios with different voltage levels and current requirements, further expanding the application range of the control circuit.
[0050] Example 2:
[0051] The difference between this embodiment and Embodiment 1 is that, please refer to... Figure 2 The boost module 3 in this embodiment includes a boost chip U2, a first filter unit 31, a second filter unit 32, a feedback network resistor 33, a voltage divider resistor 34, a power conversion unit 35, and a high-voltage output terminal VOUT1. The input voltage terminal VIN of the boost chip U2 is connected to the output terminal of the electronic switch 11 through a resistor R5. The first filter unit 31 is connected between the resistor R5 and the input voltage terminal VIN of the boost chip U2. The voltage divider resistor 34 is connected between the resistor R5 and the enable terminal EN of the boost chip U2. The feedback network resistor 33 is connected to the feedback terminal FB of the boost chip U2. One end of the power conversion unit 35 is connected to the input voltage terminal VIN of the boost chip U2, and the other end of the power conversion unit 35 is connected to the high-voltage output terminal VOUT1. The second filter unit 32 is connected between the power conversion unit 35 and the high-voltage output terminal VOUT1.
[0052] In this embodiment, the boost module 3 has its input voltage terminal connected to the output terminal of the electronic switch 11 via resistor R5. This resistor limits the input current and matches the impedance, preventing surge current from impacting the chip. The first filter unit 31 performs high-frequency and low-frequency filtering on the input voltage to ensure the purity of the input power supply. The voltage divider resistor network 34 divides the input voltage and connects it to the enable terminal. When the input voltage is lower than a set threshold, the chip is automatically shut down to avoid abnormal operating conditions. The feedback network resistor 33 collects the high-voltage output voltage in real time and feeds it back to the FB terminal of the chip, forming a closed-loop control to dynamically adjust the boost amplitude. The power conversion unit 35 achieves efficient power conversion through the periodic charging and discharging of the inductor and the unidirectional conduction of the diode. The second filter unit 32 performs secondary filtering on the boosted high-voltage output to eliminate the influence of switching noise on the load circuit.
[0053] Precise control of the chip's operating state is achieved through a 34-voltage divider network, power quality is improved by combining two-stage filtering units, and the output voltage is kept constant by using a feedback network, ultimately achieving efficient and reliable power conversion and ensuring the stability of the multi-stage collaborative system.
[0054] In some embodiments, the first filter unit 31 includes an electrolytic capacitor EC2 and a capacitor C3 connected in parallel, with the other ends of the electrolytic capacitors EC2 and C3 both connected to ground; the second filter unit 32 includes an electrolytic capacitor EC1 and a capacitor C4 connected in parallel, with the other ends of the electrolytic capacitors EC1 and C4 both connected to ground.
[0055] Specifically, at the input of boost module 3, electrolytic capacitor EC2 and capacitor C3 are connected in parallel to form a composite filter network. Electrolytic capacitor EC2 reduces the fluctuation amplitude of the input voltage by absorbing low-frequency ripple current, while capacitor C3 eliminates high-frequency switching noise through rapid charging and discharging. The parallel structure of the two covers the interference spectrum from low frequency to high frequency, thereby improving the voltage stability at the input of the boost chip. At the output of boost module 3, the parallel combination of electrolytic capacitor EC1 and capacitor C4 also forms a wideband filter structure. Electrolytic capacitor EC1 is used to smooth low-frequency fluctuations in the output voltage, while capacitor C4 suppresses high-frequency harmonics generated by power conversion. The common ground design of the two sets of filter units ensures that interference signals are introduced to the ground plane through the shortest path, avoiding the formation of circulating current in the circuit, reducing the current surge during the operation of the boost chip, thereby extending the service life of mechanical switch SW1 and improving the reliability of circuit operation.
[0056] In some embodiments, the feedback network resistor 33 includes resistors R2 and R1. One end of each resistor R2 and R1 is connected to the feedback terminal FB of the boost chip U2, the other end of resistor R2 is grounded, and the other end of resistor R1 is connected to the high-voltage output terminal VOUT1. Specifically, the voltage at the high-voltage output terminal VOUT1 is 1.25*(1+R1 / R2). Substituting the values of resistors R1 and R2 into the formula, the output voltage value is calculated.
[0057] In this embodiment, the feedback network resistor 33 has one end connected to the high-voltage output terminal VOUT1 for real-time acquisition of the actual output voltage value, and the other end connected to the feedback terminal FB, enabling the boost chip to dynamically adjust its operating state based on the deviation between the output voltage and the target value. One end of resistor R2 is grounded, and the other end is connected to the feedback terminal FB. The voltage division coefficient is determined by setting the resistance ratio of R1 and R2, thereby converting the voltage signal from the high-voltage output terminal into a voltage range recognizable by the feedback terminal. When the output voltage deviates due to load changes or input fluctuations, the voltage division signal received by the feedback terminal FB changes accordingly. The boost chip adjusts the conduction time or frequency of its internal switching elements to bring the output voltage back to the preset value. This closed-loop control mechanism effectively suppresses voltage fluctuations, prevents the mechanical switch SW1 from generating arc energy due to abnormal current at the moment of switching on and off, thereby reducing oxidation and wear of the contact pieces, extending the service life of the mechanical switch SW1, and avoiding poor contact or short-circuit faults caused by excessive arc energy.
[0058] In some embodiments, the voltage divider resistor 34 includes resistors R3 and R4 connected in series, one end of resistor R3 is connected to resistor R5, the enable terminal EN of the boost chip U2 is connected between resistors R3 and R4, and one end of resistor R4 is connected to ground.
[0059] Specifically, resistors R3 and R4 are connected in series to form a voltage divider branch. One end of resistor R3 receives the voltage signal from resistor R5, and the other end is connected to the enable terminal EN of the boost chip. One end of resistor R4 is grounded to form a reference potential, ensuring a stable voltage division value in the voltage divider branch. By adjusting the resistance ratio of resistors R3 and R4, the divided voltage value is precisely matched to the trigger threshold of the boost chip's enable terminal. When the input voltage fluctuates, the voltage divider network maintains the stability of the enable terminal voltage through the series resistor structure, ensuring that the boost module 3 can still reliably start when the input voltage fluctuates. Simultaneously, the resistance value of voltage divider resistor 34 is adjusted to adapt to the voltage threshold requirements of different boost chip models.
[0060] In some embodiments, the power conversion unit 35 includes an inductor L1 and a diode D1 connected in series. One end of the inductor L1 is connected to the input voltage terminal VIN of the boost chip U2. The switching terminal SW of the boost chip U2 is connected between the inductor L1 and the diode D1. The output terminal of the diode D1 is connected to the high voltage output terminal VOUT1.
[0061] During the conduction period of the boost chip, the input voltage forms a charging circuit through inductor L1, converting electrical energy into magnetic energy stored in the inductor. When turned off, inductor L1 releases the stored energy and transfers it to the high-voltage output terminal through diode D1. The unidirectional conduction characteristic of diode D1 blocks reverse discharge from the inductor, ensuring unidirectional energy transfer to the high-voltage output terminal. By periodically switching between on and off states, the boost chip allows inductor L1 to alternately store and release energy, thereby improving the overall efficiency of the boost module 3 and avoiding stress damage to the device caused by voltage spikes at the switching nodes.
[0062] Example 3:
[0063] The difference between this embodiment and Embodiment 1 is that, please refer to... Figure 4 The low voltage input module 2 in this embodiment includes a low voltage input unit 21 and a third filter unit 22, which is connected between the low voltage input unit 21 and the input terminal of the electronic switch 11.
[0064] Specifically, the third filter unit 22 includes capacitors C1 and C2 connected in parallel, and the other ends of capacitors C1 and C2 connected in parallel are grounded.
[0065] The low-voltage input unit 21 is not limited to a 5V power supply via USB or TYPE-C interface; it can also be a 3.7V lithium battery or other low-voltage source.
[0066] In this embodiment, the low-voltage input module 2 outputs a voltage signal that, after passing through the third filtering unit 22, has its high-frequency noise filtered out and voltage fluctuations suppressed. The third filtering unit 22 is positioned between the low-voltage input unit 21 and the input terminal of the electronic switch 11, ensuring that the filtering process is completed before the power signal enters the electronic switch 11. This design blocks the path of external interference to the electronic switch 11 and prevents noise generated by the electronic switch 11 itself from affecting the stability of the low-voltage input module 2, thereby improving the reliability of the switch control circuit in complex electromagnetic environments.
[0067] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0068] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application 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 on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0069] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0070] In this application, unless otherwise expressly specified and limited, "above or below" a first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" a first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" a first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0071] Although the description of this application has been made in conjunction with the specific embodiments described above, it is obvious to those skilled in the art that many substitutions, modifications, and variations can be made based on the above description. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.
Claims
1. A switch control circuit, characterized in that, include: The switch control module (1) includes a mechanical switch, an electronic switch (11) and an impedance unit (12). The impedance unit (12) is connected between the mechanical switch and the electronic switch (11). The mechanical switch is used to control the electronic switch (11) to be turned on or off through the impedance unit (12). The low voltage input module (2) has its output terminal connected to the input terminal of the electronic switch (11); And a boost module (3), whose input terminal is connected to the output terminal of the electronic switch (11).
2. The switch control circuit according to claim 1, characterized in that, The mechanical switch has a common terminal COM, a normally open terminal NO and a normally closed terminal NC, and the normally closed terminal NC is connected to the electronic switch (11); The common terminal COM is connected to the normally closed terminal NC, and is used to turn on the low voltage input module (2) and the boost module (3) through the electronic switch (11). The common terminal COM is connected to the normally open terminal NO, and is used to disconnect the low voltage input module (2) and the boost module (3) through the electronic switch (11).
3. The switch control circuit according to claim 2, characterized in that, The impedance unit (12) includes resistors R7 and R6 connected in series. The control terminal of the electronic switch (11) is connected between resistors R7 and R6. The other end of resistor R6 is connected to the normally closed terminal NC. The other end of resistor R7 is connected between the electronic switch (11) and the low voltage input module (2).
4. The switch control circuit according to claim 3, characterized in that, The electronic switch (11) includes a transistor Q2, the gate of which is connected between the resistor R6 and the resistor R7, the source of which is connected between the low voltage input module (2) and the resistor R7, and the drain of which is connected to the input terminal of the boost module (3).
5. The switch control circuit according to claim 1, characterized in that, The boost module (3) includes a boost chip U2, a first filter unit (31), a second filter unit (32), a feedback network resistor (33), a voltage divider resistor (34), a power conversion unit (35), and a high voltage output terminal VOUT1; The input voltage terminal VIN of the boost chip U2 is connected to the output terminal of the electronic switch (11) through resistor R5; the first filter unit (31) is connected between resistor R5 and the input voltage terminal VIN of the boost chip U2; the voltage divider resistor (34) is connected between resistor R5 and the enable terminal EN of the boost chip U2; the feedback network resistor (33) is connected to the feedback terminal FB of the boost chip U2; one end of the power conversion unit (35) is connected to the input voltage terminal VIN of the boost chip U2, and the other end of the power conversion unit (35) is connected to the high voltage output terminal VOUT1; the second filter unit (32) is connected between the power conversion unit (35) and the high voltage output terminal VOUT1.
6. The switch control circuit according to claim 5, characterized in that, The first filter unit (31) includes an electrolytic capacitor EC2 and a capacitor C3 connected in parallel, and the other ends of the electrolytic capacitor EC2 and the capacitor C3 are both grounded. The second filter unit (32) includes an electrolytic capacitor EC1 and a capacitor C4 connected in parallel, with the other ends of the electrolytic capacitor EC1 and the capacitor C4 both connected to ground.
7. The switch control circuit according to claim 5, characterized in that, The feedback network resistor (33) includes resistor R2 and resistor R1. One end of resistor R2 and resistor R1 are connected to the feedback terminal FB of the boost chip U2. The other end of resistor R2 is connected to ground. The other end of resistor R1 is connected to the high voltage output terminal VOUT1.
8. The switch control circuit according to claim 5, characterized in that, The voltage divider resistor (34) includes resistors R3 and R4 connected in series. One end of resistor R3 is connected to resistor R5. The enable terminal EN of the boost chip U2 is connected between resistors R3 and R4. One end of resistor R4 is connected to ground.
9. The switch control circuit according to claim 5, characterized in that, The power conversion unit (35) includes an inductor L1 and a diode D1 connected in series. One end of the inductor L1 is connected to the input voltage terminal VIN of the boost chip U2. The switching terminal SW of the boost chip U2 is connected between the inductor L1 and the diode D1. The output terminal of the diode D1 is connected to the high voltage output terminal VOUT1.
10. The switch control circuit according to claim 1, characterized in that, The low voltage input module (2) includes a low voltage input unit (21) and a third filter unit (22), the third filter unit (22) being connected between the low voltage input unit (21) and the input terminal of the electronic switch (11).