Capacitive step-down ac / dc conversion circuit, packaged module, and apparatus

Abstract

The application relates to the technical field of circuits, and provides an AC / DC conversion circuit with a capacitor voltage reduction, a packaging module and equipment. The circuit comprises a rectifying module, a charging control module and a discharging control module, wherein one end of the rectifying module is connected with a high-voltage alternating current voltage, and the other end outputs a pulsating direct current voltage; the charging control module and the discharging control module realize logical control of charging and discharging of an energy capacitor in a set and controllable voltage range, and finally output a relatively smooth and small-range fluctuating direct current voltage under the premise that the capacitance value of the capacitor is large enough to meet the demand of a subsequent charge. The application controls the charge of an energy storage capacitor, provides a lower input voltage for a subsequent non-isolated voltage reduction, so that the purpose of large-ratio voltage reduction of input and output voltages can be achieved without using a transformer, and meanwhile, the modularization packaging of an AC / DC large-ratio circuit is also possible.

Description

Technical Field

[0001] This invention relates to the field of electronic circuits, and more particularly to a capacitor-based AC / DC converter circuit, its package module, and its device. Background Technology

[0002] AC to DC power conversion circuits are widely used in home appliances, communications, power electronics, and various embedded devices. Currently, there are two main methods for implementing AC-DC step-down conversion: transformer-isolated and non-isolated. In scenarios with a large input-output voltage conversion ratio, a low-frequency transformer is typically used to step down the high-voltage AC to the required range, followed by bridge rectification and capacitor filtering to convert it to DC. Alternatively, when high-precision voltage conversion is required (e.g., 220V AC to 5V DC), rectification and capacitor filtering are typically used to obtain a 310V DC voltage, which is then stepped down using a high-ratio transformer for isolation, and the output voltage is further regulated by a voltage regulator circuit. While these solutions are mature, they suffer from large size, high cost, and complex design. The bulky transformer also presents challenges for modular circuit packaging. In applications requiring low power and low voltage output (e.g., below 3.3VDC), not only is efficiency low, but numerous external components are also required, hindering circuit miniaturization and integration.

[0003] In existing AC / DC conversion schemes, the rectified and filtered DC voltage is approximately √2 times the effective value of the input AC voltage. This necessitates a high switching frequency and an extremely low duty cycle when operating at high voltage input and low voltage output, resulting in complex circuit design, reduced efficiency, limited component selection, and decreased reliability. Therefore, how to achieve a low-power AC-DC conversion circuit with high efficiency and low cost over a wide input voltage range has become an urgent problem to be solved. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide an AC / DC conversion circuit, a packaged module, and a device for capacitor-based voltage reduction. By controlling the charge of the energy storage capacitor, the voltage is safely reduced and the power supply is stabilized. This solves the problems of traditional AC / DC step-down circuits requiring low duty cycles and high switching frequencies, which lead to reduced circuit efficiency and limited component selection. It achieves direct and efficient conversion of high-voltage AC to low-voltage DC, and at the same time makes it possible to modularly package AC-DC high-ratio circuits.

[0005] In a first aspect, embodiments of the present invention provide a capacitor-based AC / DC converter circuit, the circuit comprising a rectifier module, a charging control module, and a discharging control module, wherein... One end of the rectifier module is connected to a high-voltage AC voltage, and the other end outputs a pulsating DC voltage; The charging control module receives a pulsating DC voltage from the rectifier module at one end and is connected to a capacitor at the other end. The charging control module is used to control the circuit to charge the capacitor when the pulsating DC voltage is within a preset voltage range. One end of the discharge control module is connected to the capacitor, and the other end outputs a target low-voltage DC voltage. The discharge control module is used to control the capacitor to discharge when the voltage of the capacitor reaches a preset threshold.

[0006] Preferably, the charging control module includes a voltage divider module, a comparison and detection module, a timing module, a logic module, a controlled switch module, a protection module, and a drive module, wherein... The voltage divider module includes a voltage divider resistor. One end of the voltage divider module receives the pulsating DC voltage from the rectifier module, and the other end outputs a low-voltage sampling signal, which is used to divide the high-voltage pulsating DC voltage into a low-voltage sampling signal. The comparison and detection module includes a comparator, whose two input terminals receive low-voltage sampling signals from the voltage divider module, and whose output terminal outputs the original level signal; The timing module includes a JK flip-flop. One end of the timing module receives the transient raw level signal from the comparison and detection module, and the other end outputs the latched level signal. The logic module includes NOR gates and OR gates. The input terminal of the logic module receives the latched level signal from the timing module, and the output terminal outputs a control signal. After receiving a control signal from the logic module, the controlled switch module switches to a closed or open state. The protection module includes a diode to prevent current from flowing back into the capacitor, thus protecting the device. The drive module includes a comparator, a drive circuit, and a main switch, used to control the on / off state of the circuit.

[0007] Preferably, the voltage divider resistors in the voltage divider module are connected in series between the output terminal of the rectifier module and ground, dividing the high-voltage pulsating DC voltage into a low-voltage sampling signal, which is then sent to the input terminal of the comparator in the comparison and detection module.

[0008] Preferably, the comparison and detection module includes a plurality of comparators, wherein, Each comparator receives a low-voltage sampling signal from the voltage divider module at its first input terminal, a reference voltage at its second input terminal, and its output terminal is connected to the JK flip-flop of the timing module. The comparison and detection module is used to provide the original level signal for the logic module to determine the timing of capacitor charging. When the low-voltage sampling signal is higher than the reference voltage, the corresponding comparator outputs a high level, and when the low-voltage sampling signal is lower than the reference voltage, the corresponding comparator outputs a low level.

[0009] Preferably, the controlled switch module includes a voltage control voltage source for receiving control signals from the logic module, wherein, When the control signal is high, the voltage control voltage source is turned on, establishing a capacitor charging path; When the control signal is low, the voltage control voltage source is disconnected, cutting off the capacitor charging path.

[0010] Preferably, the discharge control module includes a voltage sampling and comparison module and a switching module, wherein, The voltage sampling and comparison module includes a comparator for detecting whether the capacitor voltage has reached a set discharge threshold. The switching module includes a voltage control switch, which is used to close or open when a control signal is received from the voltage sampling and comparison module, thereby enabling the capacitor to discharge to the outside.

[0011] Preferably, the voltage sampling and comparison module includes a comparator, wherein, One input terminal of the comparator is connected to a reference voltage source, and the other input terminal is connected to a capacitor. The comparator compares the capacitor output voltage with the reference voltage step by step. When the capacitor output voltage is higher than the reference voltage, the comparator outputs a high level. When the capacitor output voltage is lower than the reference voltage, the comparator outputs a low level. The high or low level output of the comparator serves as a discharge determination signal, and the input voltage controls the voltage source.

[0012] Preferably, the rectifier module is a full-bridge rectifier, including diodes D2, D4, D5, and D6.

[0013] Secondly, embodiments of the present invention provide a packaging module, the packaging module including a packaging shell, the packaging shell encapsulating the capacitor-based AC / DC conversion circuit described in the first aspect. Thirdly, embodiments of the present invention provide an electronic device including the packaging module described in the second aspect.

[0014] In summary, the beneficial effects of the present invention are as follows: The AC / DC conversion circuit with capacitive voltage reduction provided by the embodiments of the present invention controls the charge of the energy storage capacitor to provide a relatively low input voltage for the subsequent non-isolated step-down, so as to achieve the purpose of step-down with a large input-output voltage ratio without using a transformer. At the same time, it makes it possible to modularize and package the AC-DC large ratio circuit. Through internal sampling, comparison, and timing function circuits to control the switch, the logical control of charging and discharging the energy capacitor within a set and controllable voltage range (for example: 70 < VC < 100V) is realized, so as to provide a relatively low input voltage for the subsequent stage, improve the duty cycle of the non-isolated BUCK circuit, fundamentally improve the contradiction between high-voltage input and low-voltage output, make it possible to directly convert high-voltage alternating current into low-voltage direct current, greatly simplify the peripheral circuit, reduce the harsh requirements for the withstand voltage and switching frequency of the switching device, and can easily achieve AC / DC power conversion. Only a step-down charging capacitor and an output filter capacitor are required for the periphery to step down 220VAC to 3.3VDC or even lower DC voltage. The overall efficiency of the circuit is improved, the production and application costs are reduced, the design and implementation are more simplified, and it is suitable for scenarios with low power requirements but high efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly introduced below. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts, and all of these are within the protection scope of the present invention.

[0016] Figure 1 is a schematic diagram of the overall design of an AC / DC conversion circuit with capacitive voltage reduction according to an embodiment of the present invention; Figure 2 is a schematic diagram of the rectification module of an AC / DC conversion circuit with capacitive voltage reduction according to an embodiment of the present invention; Figure 3 is a schematic diagram of the charging control module of an AC / DC conversion circuit with capacitive voltage reduction according to an embodiment of the present invention; Figure 4 is a schematic diagram of the voltage division module, comparison and detection module in the charging control module of an AC / DC conversion circuit with capacitive voltage reduction according to an embodiment of the present invention; Figure 5 is a schematic diagram of the timing module of an AC / DC conversion circuit with capacitive voltage reduction according to an embodiment of the present invention; Figure 6 is a schematic diagram of the logic module of an AC / DC conversion circuit with capacitive voltage reduction according to an embodiment of the present invention; Figure 7This is a schematic diagram of a driving module for a capacitor-based AC / DC converter circuit according to an embodiment of the present invention. Figure 8 This is a schematic diagram of a rectifier module of a capacitor-based AC / DC converter circuit according to an embodiment of the present invention. Figure 9 This is a schematic diagram of the discharge control module of a capacitor-based AC / DC converter circuit according to an embodiment of the present invention. Detailed Implementation

[0017] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the invention.

[0018] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0019] It should be noted that all actions involving the acquisition of signals, information, or data in this invention are carried out in compliance with the relevant data protection laws and regulations of the locality and with authorization from the owner of the relevant device. Example 1

[0020] Please see Figure 1 This invention provides a capacitor-based AC / DC converter circuit, characterized in that the circuit includes a rectifier module, a charging control module, and a discharging control module, wherein... One end of the rectifier module is connected to a high-voltage AC voltage, and the other end outputs a pulsating DC voltage; The charging control module receives a pulsating DC voltage from the rectifier module at one end and is connected to a capacitor at the other end. The charging control module is used to control the circuit to charge the capacitor within a preset voltage range of the pulsating DC voltage. The discharge control module is used to control the capacitor to discharge when the capacitor voltage reaches a set threshold. For details, see Figure 2 The rectifier module employs a typical full-bridge rectifier circuit, including four diodes. High-voltage AC is rectified by the four diodes to produce pulsating DC. The four diodes form a rhombus structure, with only two pairs of diodes conducting at any given time, converting the AC to pulsating DC. During the positive half-cycle of the AC, the two diodes on opposite sides of the rhombus conduct, allowing current to flow from the VAC input through the diodes. During the negative half-cycle, the other pair of diodes conducts, ensuring a constant output voltage direction. The rectifier module receives AC power within the range of 85V to 305V, and its output is connected to the input of the charging control module. Instead of directly connecting a large electrolytic capacitor for smoothing and filtering after rectification, the pulsating DC is directly sent to the charging control module, where logic control selects an appropriate voltage range to charge the capacitor. The pulsating DC output from the rectifier module enters the charging control module. After passing through a voltage divider resistor, it then passes through a comparator and a trigger to obtain a corresponding pulse square wave signal. After level conversion, this signal is converted into a drive control signal, which drives the switch to close. Within a preset voltage range (e.g., 30V~70V), the capacitor is driven for charging and filtering. Through internal sampling, comparison, and timing circuits, the switch control enables logic control of charging and discharging the energy capacitor within a set and controllable voltage range. This provides a relatively low input voltage for subsequent stages and improves the duty cycle of the non-isolated BUCK circuit. This avoids the high-voltage DC problem caused by the large capacitor filtering required after rectification in traditional AC / DC circuits, allowing the circuit to stably output low-voltage DC power under a wide input voltage range.

[0021] In one embodiment, the charging control module includes a voltage divider module, a comparison and detection module, a timing module, a logic module, a controlled switch module, a protection module, and a drive module, wherein... The voltage divider module includes a voltage divider resistor. One end of the voltage divider module receives the pulsating DC voltage from the rectifier module, and the other end outputs a low-voltage sampling signal, which is used to divide the high-voltage pulsating DC voltage into a low-voltage sampling signal. The comparison and detection module includes a comparator, whose two input terminals receive low-voltage sampling signals from the voltage divider module, and whose output terminal outputs the original level signal; The timing module includes a JK flip-flop. One end of the timing module receives the transient raw level signal from the comparison and detection module, and the other end outputs the latched level signal. The logic module includes NOR gates and OR gates. The input terminal of the logic module receives the latched level signal from the timing module, and the output terminal outputs a control signal. After receiving a control signal from the logic module, the controlled switch module switches to a closed or open state. The protection module includes a diode to prevent current from flowing back into the capacitor, thus protecting the device. The drive module includes a comparator, a drive circuit, and a main switch, used to control the on / off state of the circuit.

[0022] Specifically, the pulsating DC power obtained from the AC rectification module enters the capacitor charging control module through the voltage divider module. After passing through the voltage divider module, the pulsating DC power becomes a low-voltage sampling signal. This low-voltage sampling signal enters the comparator in the comparison and detection module, generating a set of original high / low level signals based on the comparison result. The pulsating DC power exhibits significant waveform fluctuations in each half-cycle. Directly driving the switch with a comparator can easily lead to frequent switching due to short pulses. A JK flip-flop is introduced to latch the instantaneous pulses that meet the conditions into a stable signal, thereby avoiding malfunctions caused by glitches. The JK flip-flop receives the transient original high / low level signals from the comparison and detection module and latches them. The stable transient original high / low level signals latched by the JK flip-flop enter the logic control module. The logic control module contains multiple sets of logic gates. Each set of logic gates first processes the two inputs through two NOR gates, then inputs them to an OR gate to obtain the control signal. The logic set controlling the main path outputs not only directly drive the voltage control sources in the controlled switch modules, but also serves as the clock or trigger input for JK, thus combining instantaneous enable with cross-cycle enable. The controlled switch modules include voltage control sources, each with VIN, VOUT, and CNTL terminals. Multiple controlled switch modules are used to enable charging in stages according to voltage segments. When the signal received at the CNTL terminal is high, the voltage control source is effectively closed, and the branch is turned on.

[0023] In one embodiment, the voltage divider resistors in the voltage divider module are connected in series between the output terminal of the rectifier module and ground, thereby dividing the high-voltage pulsating DC voltage into a low-voltage sampling signal. The low-voltage sampling signal is then sent to the input terminal of the comparator in the comparison and detection module.

[0024] Specifically, the pulsating DC current enters the voltage divider module from one end of resistor R14. The voltage divider module includes resistors R14, R15, R16, R18, and R17, which are connected in series between the output of the rectifier module and ground. The voltage divider module converts the rectified high-voltage pulsating DC voltage into a low-voltage sampling signal, thereby ensuring detection accuracy while avoiding the circuit complexity and safety hazards caused by direct high-voltage input, thus improving the reliability and stability of the system.

[0025] In one embodiment, the comparison and detection module includes a plurality of comparators, wherein, Each comparator receives a low-voltage sampling signal from the voltage divider module at its first input terminal, a reference voltage at its second input terminal, and its output terminal is connected to the JK flip-flop of the timing module. The comparison and detection module is used to provide the original level signal for the logic module to determine the timing of capacitor charging. When the low-voltage sampling signal is higher than the reference voltage, the corresponding comparator outputs a high level, and when the low-voltage sampling signal is lower than the reference voltage, the corresponding comparator outputs a low level.

[0026] Specifically, the comparison and detection module includes comparator X1, comparator X2, comparator X3, and comparator X4. The positive input terminal of comparator X1 is connected between resistors R14 and R15, and the negative input terminal is grounded after passing through resistor R20. The positive input terminal of comparator X2 is connected between resistors R15 and R16, and the negative input terminal is connected to one end of resistor R19. The other end of resistor R19 is grounded after passing through resistor R20. The positive input terminal of comparator X3 is connected between resistors R16 and R18, and the negative input terminal is connected to one end of resistor R19. The other end of resistor R19 is grounded after passing through resistor R20. The positive input terminal of comparator X4 is connected between resistors R18 and R17, and the negative input terminal is connected to one end of resistor R19. The other end of resistor R19 is grounded after passing through resistor R20. The comparator compares the real-time low-voltage sampling signal with different reference voltage sources step by step, which can accurately obtain the current voltage range of the capacitor, thereby realizing the monitoring of the capacitor voltage state. Compared with the single overvoltage / undervoltage determination method, it has higher resolution and flexibility.

[0027] The logic module includes four sets of logic gates. Each set first passes through two NOR gates, and the outputs of the two NOR gates then enter an OR gate: the outputs of NOR gate U10 and NOR gate U9 are connected to the two inputs of OR gate U11, and the output of OR gate U11 is connected to the CNTL pin of voltage control source U24; the outputs of NOR gate U13 and NOR gate U12 are connected to the two inputs of OR gate U14, and the output of OR gate U14 is connected to the CNTL pin of voltage control source U23; the outputs of NOR gate U15 and NOR gate U16 are connected to the OR gate U17, U18, and U19, U19, U10, U11, U11, U12, U13, U14, U15, U16, U17, U18, U19, U19, U19, U10 ... The two inputs of the OR gate U17 are connected together. The output of the OR gate U17 is connected to the CLK pin of the JK flip-flop U18. The Q pin of the JK flip-flop U18 is connected to one input of the NOR gate U19. The QN pin of the JK flip-flop U4 is connected to the other input of the NOR gate U19. The outputs of the NOR gate U20 and the NOR gate U19 are connected to the two inputs of the OR gate U21. The output of the OR gate U21 is connected to the CNTL pin of the voltage control source U22. The output of the voltage control source U22 is connected to the VIN pin of the voltage control source U23 and the VIN pin of the voltage control source U24.

[0028] The NOR gate outputs a high level only when both inputs are low. If either input is high, the output is forced low. The outputs of the two NOR gates are then fed into the two inputs of an OR gate. The output of OR gate U21 is fed to voltage source U22 as a control signal; the output of OR gate U11 is fed to voltage source U24 as a control signal; and the output of OR gate U14 is fed to voltage source U23 as a control signal.

[0029] In one embodiment, the controlled switch module includes a voltage control voltage source for receiving control signals from the logic module, wherein, When the control signal is high, the voltage control voltage source is turned on, establishing a capacitor charging path; When the control signal is low, the voltage control voltage source is disconnected, cutting off the capacitor charging path.

[0030] Specifically, the controlled switch module includes voltage control source U22, voltage control source U23, and voltage control source U24. The VOUT pin of voltage source U23 is connected to the positive terminal of diode D1 in the protection module, and the VOUT pin of voltage control source U24 is connected to the positive terminal of diode D3 in the protection module. Diodes D1 and D3 are used to prevent current from flowing back from the capacitor to the charging control module and rectifier module, thus protecting the components in the circuit.

[0031] In one embodiment, the discharge control module includes a voltage sampling and comparison module and a switching module, wherein, The voltage sampling and comparison module includes a comparator for detecting whether the capacitor voltage has reached a set discharge threshold. The switching module includes a voltage control switch, which is used to close or open when a control signal is received from the voltage sampling and comparison module, thereby enabling the capacitor to discharge to the outside.

[0032] Specifically, the cathodes of diodes D3 and D1 are connected to switch S1. Comparator X5 acts as a detector to determine whether the capacitor is overvoltaged. Using a reference voltage source, if the capacitor voltage is less than the reference supply voltage, it outputs a low level, indicating that the voltage is safe and charging can continue, and S1 is closed. If the capacitor voltage is greater than the reference supply voltage, it outputs a high level, indicating that the capacitor voltage is too high and charging needs to be stopped, and S1 is opened.

[0033] In one embodiment, the voltage sampling and comparison module includes a comparator, wherein, One input terminal of the comparator is connected to a reference voltage source, and the other input terminal is connected to a capacitor. The comparator compares the capacitor output voltage with the reference voltage step by step. When the capacitor output voltage is higher than the reference voltage, the comparator outputs a high level. When the capacitor output voltage is lower than the reference voltage, the comparator outputs a low level. The high or low level output of the comparator serves as a discharge determination signal, and the input voltage controls the voltage source.

[0034] Specifically, the voltage sampling and comparison module includes comparators that compare the capacitor output voltage with different reference voltage sources. Based on the comparison result, a high / low level is output. When the capacitor output voltage is higher than the reference voltage, the corresponding comparator outputs a high level; when the capacitor output voltage is lower than the reference voltage, the corresponding comparator outputs a low level. By setting different reference voltages, the capacitor output voltage can be divided into several intervals (e.g., low, charging window, near the upper limit, overvoltage). Each comparator can reflect the interval information of the capacitor output voltage, realizing gradient discharge control.

[0035] In one embodiment, the rectifier module is a full-bridge rectifier, including diodes D2, D4, D5, and D6.

[0036] Specifically, diodes D2 and D4 conduct in half a cycle, and diodes D5 and D6 conduct in the other half cycle to achieve full-bridge rectification. Thus, the input alternating current is effectively converted into a pulsating direct current voltage, providing a stable input voltage for the subsequent circuit modules. Compared with half-wave rectification or other simplified rectification methods, full-bridge rectification can obtain a higher output voltage utilization rate under the same input conditions, while reducing the impact caused by voltage fluctuations at the input end, improving the conversion efficiency and stability of electric energy. This design not only ensures the applicability of the circuit under a wide input voltage range, but also simplifies the pressure of the subsequent capacitor filtering and voltage regulation links, laying a foundation for the efficient operation of the entire AC-DC step-down circuit. Embodiment 2

[0037] An embodiment of the present invention provides a packaging module, which includes a packaging shell, and the AC / DC conversion circuit with capacitive voltage reduction described in Embodiment 1 is packaged inside the packaging shell. Embodiment 3

[0038] An embodiment of the present invention provides an electronic device, and the device includes the packaging module described in Embodiment 2.

[0039] In summary, the beneficial effects of the embodiments of the present invention are as follows: The AC / DC conversion circuit with capacitive voltage reduction provided by the embodiments of the present invention provides a relatively low input voltage for the subsequent non-isolated step-down by controlling the charge of the energy storage capacitor. Thus, without using a transformer, it can also achieve the purpose of step-down with a large input-output voltage ratio. At the same time, it makes it possible to modularize the packaging of the AC-DC large ratio circuit. Through the internal sampling, comparison, and timing function circuits to control the switch, the logical control of charging and discharging the energy capacitor is realized within a set and controllable voltage range (for example: 70 < VC < 100V), so as to provide a relatively low input voltage for the subsequent stage, improve the duty cycle of the non-isolated BUCK circuit, fundamentally improve the contradiction between high-voltage input and low-voltage output, make it possible to directly convert high-voltage alternating current into low-voltage direct current, and greatly simplify the peripheral circuit, reducing the harsh requirements for the withstand voltage and switching frequency of the switching device. It can easily achieve AC / DC power conversion. Only a step-down charging capacitor and an output filtering capacitor are required in the periphery to step down 220VAC to 3.3VDC or even lower direct current voltage. The overall efficiency of the circuit is improved, the production and application costs are reduced, the design implementation is more simplified, and it is suitable for scenarios with low power requirements but high efficiency and low cost.

[0040] The above description is merely a specific embodiment of the present invention. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A capacitor-based AC / DC converter circuit, characterized in that, The circuit includes a rectifier module, a charging control module, and a discharging control module, wherein... One end of the rectifier module is connected to a high-voltage AC voltage, and the other end outputs a pulsating DC voltage; The charging control module receives a pulsating DC voltage from the rectifier module at one end and is connected to a capacitor at the other end. The charging control module is used to control the circuit to charge the capacitor when the pulsating DC voltage is within a preset voltage range. One end of the discharge control module is connected to the capacitor, and the other end outputs a target low-voltage DC voltage. The discharge control module is used to control the capacitor to discharge when the voltage of the capacitor reaches a preset threshold.

2. The capacitor-based AC / DC converter circuit according to claim 1, characterized in that, The charging control module includes a voltage divider module, a comparison and detection module, a timing module, a logic module, a controlled switch module, a protection module, and a drive module, wherein... The voltage divider module includes a voltage divider resistor. One end of the voltage divider module receives the pulsating DC voltage from the rectifier module, and the other end outputs a low-voltage sampling signal, which is used to divide the high-voltage pulsating DC voltage into a low-voltage sampling signal. The comparison and detection module includes a comparator, whose two input terminals receive low-voltage sampling signals from the voltage divider module, and whose output terminal outputs the original level signal; The timing module includes a JK flip-flop. One end of the timing module receives the transient raw level signal from the comparison and detection module, and the other end outputs the latched level signal. The logic module includes NOR gates and OR gates. The input terminal of the logic module receives the latched level signal from the timing module, and the output terminal outputs a control signal. After receiving a control signal from the logic module, the controlled switch module switches to a closed or open state. The protection module includes a diode to prevent current from flowing back into the capacitor, thus protecting the device. The drive module includes a comparator, a drive circuit, and a main switch, used to control the on / off state of the circuit.

3. The capacitor-based AC / DC converter circuit according to claim 2, characterized in that, The voltage divider resistors in the voltage divider module are connected in series between the output terminal of the rectifier module and ground, dividing the high-voltage pulsating DC voltage into a low-voltage sampling signal. The low-voltage sampling signal is then sent to the input terminal of the comparator in the comparison and detection module.

4. The capacitor-based AC / DC converter circuit according to claim 2, characterized in that, The comparison and detection module includes several comparators, wherein, Each comparator receives a low-voltage sampling signal from the voltage divider module at its first input terminal, a reference voltage at its second input terminal, and its output terminal is connected to the JK flip-flop of the timing module. The comparison and detection module is used to provide the original level signal for the logic module to determine the timing of capacitor charging. When the low-voltage sampling signal is higher than the reference voltage, the corresponding comparator outputs a high level, and when the low-voltage sampling signal is lower than the reference voltage, the corresponding comparator outputs a low level.

5. The capacitor-based AC / DC converter circuit according to claim 2, characterized in that, The controlled switch module includes a voltage control voltage source for receiving control signals from the logic module, wherein... When the control signal is high, the voltage control voltage source is turned on, establishing a capacitor charging path; When the control signal is low, the voltage control voltage source is disconnected, cutting off the capacitor charging path.

6. The AC / DC converter circuit with capacitor voltage reduction according to claim 1, characterized in that, The discharge control module includes a voltage sampling and comparison module and a switching module, wherein, The voltage sampling and comparison module includes a comparator for detecting whether the capacitor voltage has reached a set discharge threshold. The switching module includes a voltage control switch, which is used to close or open when a control signal is received from the voltage sampling and comparison module, thereby enabling the capacitor to discharge to the outside.

7. The capacitor-based AC / DC converter circuit according to claim 6, characterized in that, The voltage sampling and comparison module includes a comparator, wherein, One input terminal of the comparator is connected to a reference voltage source, and the other input terminal is connected to a capacitor. The comparator compares the capacitor output voltage with the reference voltage step by step. When the capacitor output voltage is higher than the reference voltage, the comparator outputs a high level. When the capacitor output voltage is lower than the reference voltage, the comparator outputs a low level. The high or low level output of the comparator serves as a discharge determination signal, and the input voltage controls the voltage source.

8. The capacitor-based AC / DC converter circuit according to claim 1, characterized in that, The rectifier module is a full-bridge rectifier, including diodes D2, D4, D5, and D6.

9. A packaging module, characterized in that, The encapsulation module includes an encapsulation shell, and the encapsulation shell encapsulates the AC / DC conversion circuit with capacitor step-down as described in any one of claims 1-8.

10. An electronic device, characterized in that, Includes the encapsulation module as described in claim 9.

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