Charger

Abstract

The utility model discloses a charger, and relates to the technical field of charging, the charger comprises a charging circuit, the input end of the charging circuit is used for accessing commercial power, and the output end of the charging circuit is used for accessing equipment to be charged; the charging circuit is used for converting the voltage of the mains supply and then outputting charging voltage to equipment to be charged through an output end of the charging circuit; the detection end of the voltage detection circuit is connected with the output end of the charging circuit; the output end of the voltage detection circuit is electrically connected with the PWM control power supply chip; the output end of the switch module is connected with the power supply end of the PWM control power supply chip, and the input end of the switch module is connected to the first power supply end; the main control circuit is electrically connected with the PWM control power supply chip and the controlled end of the switch module; the utility model aims to solve the technical problem that the internal circuit of the existing charging equipment still consumes power continuously under the condition that the accessed to-be-charged equipment is in a standby state.

Description

Technical Field

[0001] This utility model relates to the field of charging technology, and in particular to a charger. Background Technology

[0002] With the widespread adoption and increasing intelligence of electronic devices, the demand for charging equipment such as chargers, car chargers, and power strips is growing daily. Charging devices are widely used in homes, offices, and vehicles, providing convenient charging solutions for smartphones, tablets, laptops, and other smart devices.

[0003] However, current charging devices such as single-port / multi-port chargers, car chargers, and power strips on the market continue to consume power and generate heat even when the connected device is in standby mode (when the charging device is not outputting charging voltage). This unnecessary energy loss not only wastes resources but also accelerates the aging of components and reduces the lifespan of the charging device. Utility Model Content

[0004] The main purpose of this invention is to propose a charger that aims to solve the technical problem that the internal circuit of the charging device continues to consume power when the connected device is in standby mode.

[0005] To achieve the above objectives, this utility model proposes a charger, comprising:

[0006] The charging circuit has an input terminal for connecting to AC power and an output terminal for connecting to the device to be charged. The charging circuit converts the AC voltage and outputs a charging voltage to the device to be charged via its own output terminal.

[0007] A voltage detection circuit is provided, wherein the detection terminal of the voltage detection circuit is connected to the output terminal of the charging circuit, and the voltage detection circuit is used to detect the charging voltage and output a corresponding voltage detection signal.

[0008] A PWM control power supply chip is provided, wherein the output terminal of the voltage detection circuit is electrically connected to the PWM control power supply chip, and the PWM control power supply chip is used to output a first signal when it detects that the charging voltage is less than a preset voltage based on the voltage detection signal.

[0009] A switching module, wherein the output terminal of the switching module is connected to the power supply terminal of the PWM control power chip, and the input terminal of the switching module is connected to the first power supply terminal;

[0010] The main control circuit is electrically connected to the controlled terminals of the PWM control power chip and the switching module respectively. When the main control circuit receives the first signal, it controls the switching module to disconnect the path between the power supply terminal of the PWM control power chip and the first power supply terminal.

[0011] In one embodiment, the voltage detection circuit includes:

[0012] An optocoupler circuit, comprising a light-emitting diode circuit and a phototransistor circuit, wherein the input terminal of the light-emitting diode circuit is connected to the output terminal of the charging circuit, and the output terminal of the light-emitting diode circuit is grounded;

[0013] The phototransistor circuit is electrically connected to the PWM control power supply chip.

[0014] In one embodiment, the light-emitting diode circuit includes:

[0015] The circuit includes a light-emitting diode (LED), a first resistor, and a second resistor. The first end of the first resistor is connected to the output terminal of the charging circuit, and the second end of the first resistor is electrically connected to the anode of the LED. The cathode of the LED is grounded, and the LED and the second resistor are connected in parallel.

[0016] The phototransistor circuit includes:

[0017] The device comprises a phototransistor, a third resistor, and a first capacitor. The input terminal of the phototransistor is connected to the second terminal of the third resistor. The first terminal of the third resistor is connected to the first terminal of the first capacitor and the PWM control power supply chip. The second terminal of the first capacitor and the output terminal of the phototransistor are both grounded.

[0018] In one embodiment, the voltage detection circuit further includes:

[0019] A Zener diode circuit is provided, wherein the input terminal of the Zener diode circuit is connected to the output terminal of the light-emitting diode circuit, the second terminal of the Zener diode circuit is grounded, and the reference terminal of the Zener diode circuit is connected to the output terminal of the charging circuit; the Zener diode circuit is used to disconnect the path between the light-emitting diode circuit and ground when the charging voltage is less than a preset voltage.

[0020] In one embodiment, the Zener diode circuit includes:

[0021] The circuit comprises a first Zener diode, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second capacitor, a third capacitor, and a fourth capacitor, wherein the first terminal of the fourth resistor is connected to the output terminal of the charging circuit.

[0022] The first terminal of the second capacitor is connected to the output terminal of the light-emitting diode circuit, the first terminal of the fourth capacitor is connected to the first terminal of the second capacitor, and the second terminal of the second capacitor is connected to the second terminal of the fourth resistor.

[0023] The first terminal of the third capacitor is connected to the cathode of the first Zener diode and the first terminal of the second capacitor, respectively; the first terminal of the fifth resistor is connected to the second terminal of the third capacitor, and the second terminal of the fifth resistor is connected to the second terminal of the second capacitor.

[0024] The first end of the sixth resistor and the first end of the seventh resistor are both connected to the reference terminal of the first Zener diode. The first end of the sixth resistor and the first end of the seventh resistor are also connected to the second end of the fifth resistor. The second end of the sixth resistor, the second end of the seventh resistor, and the anode of the first Zener diode are all grounded.

[0025] In one embodiment, the main control circuit has a second power supply terminal, and the PWM control power chip has a first power supply terminal and a second power supply terminal. The first power supply terminal is connected to the output terminal of the switching module, and the second power supply terminal is connected to the second power supply terminal.

[0026] The main control circuit supplies power to the PWM control power chip via the second power supply terminal, so that the PWM control power chip enters a low-power state when the switching module is turned off.

[0027] In one embodiment, the charger further includes:

[0028] A spike absorption circuit is provided, wherein the input terminal of the spike absorption circuit is connected to the first power supply terminal, and the output terminal of the spike absorption circuit is connected to the input terminal of the switching module.

[0029] In one embodiment, the spike absorption circuit includes:

[0030] The system includes an eighth resistor, a fifth capacitor, and a first diode. The anode of the first diode and the second terminal of the fifth capacitor are both connected to a first power supply terminal. The first terminal of the fifth capacitor is connected to the second terminal of the eighth resistor. The first terminal of the eighth resistor and the cathode of the first diode are both connected to the input terminal of the switching module.

[0031] In one embodiment, the charger further includes:

[0032] A power filter circuit, wherein the input terminal of the power filter circuit is connected to the first power supply terminal, and the output terminal of the power filter circuit is connected to the input terminal of the switching module.

[0033] In one embodiment, the power supply filtering circuit includes:

[0034] The sixth capacitor and the seventh capacitor are connected to the input terminal of the switching module, and the second terminals of the sixth capacitor and the seventh capacitor are grounded.

[0035] This invention includes a voltage detection circuit, a PWM control power supply chip, a switching module, and a main control circuit. The voltage detection circuit detects the charging voltage at the output terminal of the charging circuit and outputs a corresponding voltage detection signal. The output terminal of the voltage detection circuit is electrically connected to the PWM control power supply chip. When the PWM control power supply chip detects that the charging voltage is less than a preset voltage based on the voltage detection signal, it outputs a first signal. The output terminal of the switching module is connected to the power supply terminal of the PWM control power supply chip, and the input terminal of the switching module is connected to the power supply terminal. The main control circuit is electrically connected to the controlled terminals of both the PWM control power supply chip and the switching module. When the main control circuit receives the first signal, it controls the switching module to disconnect the power supply terminal of the PWM control power supply chip from the power supply terminal. With this configuration, in practical applications, when the device connected to the charger is in standby mode, this invention cuts off the power supply path to the PWM control power supply chip, causing the PWM control power supply chip to stop working. This avoids the PWM control power supply chip continuously consuming power and generating heat when the device is in standby mode, thus extending the charger's lifespan. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a module according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of a module according to another embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the circuit structure of an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of a module according to another embodiment of the present utility model;

[0041] Figure 5 This is a schematic diagram of the circuit structure of another embodiment of the present invention;

[0042] Figure 6This is a schematic diagram of a module according to another embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of a module according to another embodiment of the present invention;

[0044] Figure 8 This is a schematic diagram of the circuit structure of another embodiment of the present invention;

[0045] Figure 9 This is a schematic diagram of a module according to another embodiment of the present invention;

[0046] Figure 10 This is a schematic diagram of a module according to another embodiment of the present utility model.

[0047] Explanation of icon numbers:

[0048] 10. Charging circuit; 20. Voltage detection circuit; 21. Light-emitting diode circuit; 22. Phototransistor circuit; 23. Zener diode circuit; 30. PWM control power supply chip; 40. Switching module; 50. Main control circuit; 60. Spike absorption circuit; 70. Power supply filtering circuit.

[0049] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0050] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0051] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0052] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0053] With the widespread adoption and increasing intelligence of electronic devices, the demand for charging equipment such as chargers, car chargers, and power strips is growing daily. Charging devices are widely used in homes, offices, and vehicles, providing convenient charging solutions for smartphones, tablets, laptops, and other smart devices.

[0054] However, current charging devices such as single-port / multi-port chargers, car chargers, and power strips on the market continue to consume power and generate heat even when the connected device is in standby mode (when the charging device is not outputting charging voltage). This unnecessary energy loss not only wastes resources but also accelerates the aging of components and reduces the lifespan of the charging device.

[0055] In an exemplary embodiment, existing charging devices include a PWM control power supply chip, which is responsible for adjusting the on and off times (i.e., duty cycle) of the switching transistor to achieve precise control of the output voltage and current. However, when the device to be charged is in standby mode, the charger does not output charging voltage, but the PWM control power supply chip usually continues to work. In this continuous operation, the PWM control power supply chip consumes power and generates heat. This unnecessary energy loss not only wastes resources but also accelerates component aging and reduces the charger's lifespan.

[0056] Therefore, this utility model proposes a charger to solve the technical problem that the internal circuitry of existing charging devices continues to consume power even when the connected device is in standby mode. In one embodiment of this utility model, referring to... Figure 1 The charger includes:

[0057] The power input terminal is connected to AC power.

[0058] The output terminal of the charging circuit 10 is connected to the device to be charged.

[0059] A voltage detection circuit 20 is provided, wherein the detection terminal of the voltage detection circuit 20 is connected to the output terminal of the charging circuit 10, and the voltage detection circuit 20 is used to detect the output voltage of the output terminal of the charging circuit 10 and output a corresponding voltage detection signal.

[0060] The output terminal of the voltage detection circuit 20 is electrically connected to the PWM control power chip 30. When the PWM control power chip 30 detects that the output voltage of the output terminal of the charging circuit 10 is less than a preset voltage according to the voltage detection signal, it outputs a first signal.

[0061] A switching module 40, the output terminal of which is connected to the power supply terminal of the PWM control power chip 30, and the input terminal of which is connected to the power supply terminal;

[0062] The main control circuit 50 is electrically connected to the controlled terminals of the PWM control power chip 30 and the switching module 40 respectively. When the main control circuit 50 receives the first signal, it controls the switching module 40 to disconnect the path between the power supply terminal and the power supply terminal of the PWM control power chip 30.

[0063] In this embodiment, reference Figure 2 Optionally, the voltage detection circuit 20 includes an optocoupler circuit, which includes a light-emitting diode circuit 21 and a phototransistor circuit 22. The input terminal of the light-emitting diode circuit 21 is connected to the output terminal of the charging circuit 10, and the output terminal of the light-emitting diode circuit 21 is grounded. The phototransistor circuit 22 is electrically connected to the PWM control power supply chip 30.

[0064] When the device to be charged is in standby mode, the charging voltage output by the charging circuit is basically zero, so that almost no current flows through the LED circuit 21. The LED circuit 21 cannot emit light or emits weak light when almost no current flows through it. The phototransistor circuit 22 is disconnected when it is not illuminated by the LED circuit 21 or when the illumination is weak. The PWM control power chip 30 includes a pull-up circuit, which is connected to the voltage source and the input terminal of the phototransistor circuit 22 respectively. When the phototransistor circuit 22 is disconnected, the path between the pull-up circuit and ground is broken, so that the PWM control power chip 30 detects the voltage of the voltage source. At this time, the PWM control power chip 30 outputs a first signal. When the main control circuit 50 receives the first signal, it controls the switch module 40 to disconnect the path between the power supply terminal and the power source terminal of the PWM control power chip 30.

[0065] In one embodiment, reference Figure 3 The light-emitting diode circuit 21 includes:

[0066] The circuit includes a light-emitting diode U2A, a first resistor R1, and a second resistor R2. The first end of the first resistor R1 is connected to the output terminal of the charging circuit 10, and the second end of the first resistor R1 is electrically connected to the anode of the light-emitting diode U2A. The cathode of the light-emitting diode U2A is grounded, and the light-emitting diode U2A and the second resistor R2 are connected in parallel.

[0067] The phototransistor circuit 22 includes:

[0068] The system includes a phototransistor U2B, a third resistor R3, and a first capacitor C1. The input terminal of the phototransistor U2B is connected to the second terminal of the third resistor R3. The first terminal of the third resistor R3 is connected to the first terminal of the first capacitor C1 and the PWM control power supply chip 30. The second terminal of the first capacitor C1 and the output terminal of the phototransistor U2B are both grounded.

[0069] It should be noted that the second resistor R2 is connected in parallel with the light-emitting diode U2A to shunt the current transmitted from the output terminal of the charging circuit 10 to the light-emitting diode U2A, so as to prevent the light-emitting diode U2A from being damaged due to excessive current. The technical effect of the light-emitting diode U2A is the same as that of the light-emitting diode circuit 21 described above, and the technical effect of the phototransistor U2B is the same as that of the phototransistor circuit 22 described above, which will not be described in detail here.

[0070] It is important to consider that when the device to be charged is in standby mode, the charger may output a small voltage and current to the device to put it into standby mode. This small current may be sufficient to illuminate the phototransistor circuit 22, preventing the PWM control power chip 30 from outputting the first signal to the main control circuit 50. Even without receiving the first signal, the main control circuit 50 continues to supply power to the PWM control power chip at its first power supply terminal, meaning the PWM control power chip 30 remains operational and consumes unnecessary power. For further information, refer to... Figure 4 The charger also includes:

[0071] A Zener diode circuit 23 is provided, the input terminal of which is connected to the output terminal of the light-emitting diode circuit 21, the second terminal of which is grounded, and the reference terminal of the Zener diode circuit 21 is connected to the output terminal of the charging circuit 10.

[0072] The Zener diode circuit 23 is used to disconnect the path between the light-emitting diode circuit 21 and ground when the charging voltage is less than the preset voltage.

[0073] With this configuration, when the device to be charged is in standby mode, the charging circuit outputs a small voltage and current to the device. At this time, the charging voltage of the charging circuit 10 is greater than zero, but less than the preset voltage. When the charging voltage is less than the preset voltage, the reference terminal of the Zener diode circuit 23 disconnects the path between the light-emitting diode circuit 21 and ground, so that the current cannot flow through the light-emitting diode circuit 21, that is, the light-emitting diode circuit 21 cannot emit light to illuminate the phototransistor circuit 22, and finally the PWM control power chip 30 stops working. In practical applications, when the charging circuit outputs a small charging current to the device to be charged in standby mode, the charger of this utility model controls the PWM control power chip 30 to stop working, avoiding the PWM control power chip 30 from being in working state and consuming unnecessary power when the charging circuit 10 outputs a small voltage and current, thereby extending the service life of the charger.

[0074] Among them, reference Figure 5 The Zener diode circuit 23 includes:

[0075] The circuit consists of a first Zener diode U1, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4, with the first end of the fourth resistor R4 connected to the output terminal of the charging circuit 10.

[0076] The first terminal of the second capacitor C2 is connected to the output terminal of the light-emitting diode circuit 21, the first terminal of the fourth capacitor C4 is connected to the first terminal of the second capacitor C2, and the second terminal of the second capacitor C2 is connected to the second terminal of the fourth resistor R4.

[0077] The first terminal of the third capacitor C3 is connected to the cathode of the first Zener diode U1 and the first terminal of the second capacitor C2, respectively. The first terminal of the fifth resistor R5 is connected to the second terminal of the second capacitor C2, and the second terminal of the fifth resistor R5 is connected to the second terminal of the third capacitor C3.

[0078] The first end of the sixth resistor R6 and the first end of the seventh resistor R7 are both connected to the reference end of the first Zener diode U1. The first ends of the sixth resistor R6 and the seventh resistor R7 are also connected to the second end of the fifth resistor. The second ends of the sixth resistor R6, the second ends of the seventh resistor R7, and the anode of the first Zener diode U1 are all grounded.

[0079] The fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are used to divide the charging voltage. When the charging voltage is lower than the preset voltage, the voltage at the reference terminal of the first Zener diode U1 is lower than the reference voltage (e.g., 2.5V), causing the first Zener diode U1 to turn off. When the first Zener diode U1 is turned off, the path between the LED circuit 21 and ground is broken, ultimately causing the PWM control power chip 30 to stop working. This prevents the PWM control power chip 30 from remaining in operation and consuming unnecessary power when the charging circuit 10 outputs a small voltage and current, thereby extending the lifespan of the charger.

[0080] In addition, the voltage detection circuit 20 can also be implemented using voltage sensors such as resistive voltage divider voltage sensors, voltage transformers, or Hall effect voltage sensors, without any restrictions.

[0081] In this embodiment, the main control circuit 50 can be implemented using a main controller, such as an MCU (Microcontroller Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or a SOC (System On Chip).

[0082] In this embodiment, the switching module 40 can be implemented using at least one switching transistor, such as a MOSFET, IGBT, thyristor, transistor, power transistor, etc., and / or using at least one switching device, such as a contactor, circuit breaker, and relay.

[0083] In this embodiment, the charging circuit 10 includes a rectifier and filter circuit, a switching circuit, and a transformer. The rectifier and filter circuit rectifies the mains power into DC power and filters the DC power to obtain a relatively stable DC voltage. The switching circuit is used to drive the PWM control power chip 30, thereby realizing precise control of the charging voltage and current of the charging circuit. The transformer is used to realize the step-up or step-down conversion of the DC voltage.

[0084] It should be noted that, optionally, if the charging circuit 10 includes a transformer, the transformer has multiple primary coils, and the first power supply terminal can be the discharge terminal of one of the primary coils. Alternatively, if the charger also includes a battery, the first power supply terminal can be the discharge terminal of the battery; this is not limited in this regard.

[0085] This utility model includes a voltage detection circuit 20, a PWM control power chip 30, a switching module 40, and a main control circuit 50. The voltage detection circuit 20 is used to detect the charging voltage at the output terminal of the charging circuit 10 and output a corresponding voltage detection signal. The output terminal of the voltage detection circuit 20 is electrically connected to the PWM control power chip 30. When the PWM control power chip 30 detects that the charging voltage is less than a preset voltage according to the voltage detection signal, it outputs a first signal. The output terminal of the switching module 40 is connected to the power supply terminal of the PWM control power chip 30, and the input terminal of the switching module 40 is connected to the power supply terminal. The main control circuit 50 is electrically connected to the controlled terminals of the PWM control power chip 30 and the switching module 40 respectively. When the main control circuit 50 receives the first signal, it controls the switching module 40 to disconnect the path between the power supply terminal and the power supply terminal of the PWM control power chip 30. With this configuration, in practical applications, when the device to be charged connected to the charger is in standby mode, the charger of this invention cuts off the power supply path of the PWM control power chip 30, so that the PWM control power chip 30 stops working, avoiding the PWM control power chip 30 from continuously consuming power and generating heat when the device to be charged is in standby mode, thus extending the service life of the charger.

[0086] It is important to consider that waking up the PWM control power chip 30 from its inactive state requires a certain amount of preparation time. When the device to be charged enters the working state, the output of the charging circuit 10 needs to immediately provide a stable voltage. However, since the PWM control power chip 30 is not woken up in time, it cannot quickly adjust the duty cycle to maintain the stability of the charging voltage, thus affecting the normal operation of the device to be charged.

[0087] In one embodiment of this utility model, reference is made to... Figure 6 The main control circuit 50 has a second power supply terminal, and the PWM control power chip 30 has a first power supply terminal and a second power supply terminal. The first power supply terminal is connected to the output terminal of the switching module 40, and the second power supply terminal is connected to the second power supply terminal.

[0088] The main control circuit 50 supplies power to the PWM control power chip 30 via the second power supply terminal, so that the PWM control power chip 30 enters a low power consumption state when the switching module 40 is turned off.

[0089] In this embodiment, the main control circuit 50 outputs an extremely low current to the second power supply terminal of the PWM control power chip 30 via the second power supply terminal. This allows the PWM control power chip 30 to enter a low-power state when the switching module 40 disconnects the first power supply terminal and the power supply terminal, with power consumption of less than 5mW, approaching the theoretical "zero power consumption". The PWM control power chip 30 maintains its basic functions in the low-power state, ensuring it can quickly wake up and resume normal operation, avoiding startup delays or abnormalities caused by prolonged complete power outages. Through the above settings, in practical applications, the charger equipped with this invention not only avoids unnecessary energy consumption when the device is in standby mode, but also immediately provides a stable voltage when the device enters the working state, preventing the inability to quickly adjust the duty cycle to maintain a stable charging voltage and thus affecting the normal operation of the device.

[0090] In one embodiment of this utility model, reference is made to Figure 7 The charger also includes:

[0091] A spike absorption circuit 60 is provided, the input terminal of which is connected to the first power supply terminal, and the output terminal of which is connected to the input terminal of the switching module 40.

[0092] In this embodiment, the spike absorption circuit 60 is used to absorb and suppress voltage spikes or transient interference signals at the first power supply terminal, thereby protecting subsequent circuits (such as the switching module 40 and the PWM control power chip 30) from high-voltage surges or noise interference. The spike absorption circuit 60 can be implemented using a circuit composed of capacitors and resistors, for example, refer to... Figure 8 The spike absorption circuit 60 includes:

[0093] The eighth resistor R8, the fifth capacitor C5, and the first diode D1 are connected to the first power supply terminal. The anode of the first diode D1 and the second terminal of the fifth capacitor C5 are both connected to the first power supply terminal. The first terminal of the fifth capacitor C5 is connected to the second terminal of the eighth resistor R8. The first terminal of the eighth resistor R8 and the cathode of the first diode D1 are both connected to the input terminal of the switch module 40.

[0094] Among them, the fifth capacitor C5 is used to absorb the high-frequency noise and transient energy present in the output voltage of the first power supply terminal, and the eighth resistor R8 consumes the electrical energy stored in the fifth capacitor C5 to prevent the fifth capacitor C5 from being overcharged.

[0095] In one embodiment of this utility model, reference is made to Figure 9 The charger also includes:

[0096] A power filter circuit 70 is provided, the input terminal of which is connected to the first power supply terminal, and the output terminal of which is connected to the input terminal of the switch module 40.

[0097] In this embodiment, the power supply filter circuit 70 is used to filter out high-frequency noise in the output voltage of the first power supply terminal and smooth the waveform of the output voltage, thereby providing a stable DC voltage for the PWM power control chip and ensuring that the PWM power control chip can generate accurate switching signals normally.

[0098] The power supply filter circuit 70 can be implemented using at least one capacitor, for example, reference... Figure 10 The power supply filtering circuit 70 includes:

[0099] The sixth capacitor C6 and the seventh capacitor C7 are connected to the input terminal of the switch module 40, and the second terminals of the sixth capacitor C6 and the seventh capacitor C7 are grounded.

[0100] The sixth capacitor C6 and the seventh capacitor C7 are both used to filter out high-frequency noise in the output voltage of the first power supply terminal and smooth the waveform of the output voltage, thereby providing a stable DC voltage for the PWM power control chip.

[0101] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A charger characterized by comprising: The application relates to a charging circuit, which comprises: a charging circuit, an input end of which is used for accessing commercial power, and an output end of which is used for accessing a device to be charged; the charging circuit is used for outputting a charging voltage to the device to be charged after voltage conversion of the commercial power; a voltage detection circuit, a detection end of which is connected with the output end of the charging circuit, the voltage detection circuit is used for detecting the charging voltage and outputting a corresponding voltage detection signal; a PWM control power supply chip, an output end of the voltage detection circuit is electrically connected with the PWM control power supply chip, the PWM control power supply chip is used for outputting a first signal when the voltage detection signal detects that the charging voltage is less than a preset voltage; a switch module, an output end of the switch module is connected with a power supply end of the PWM control power supply chip, and an input end of the switch module is connected with a first power supply end; a main control circuit, the main control circuit is electrically connected with the PWM control power supply chip and the switch module, respectively, and the main control circuit controls the switch module to disconnect a path between the power supply end of the PWM control power supply chip and the first power supply end when the first signal is received.

2. The charger of claim 1, wherein The voltage detection circuit comprises: an optoelectronic coupler circuit, which comprises a light emitting diode circuit and a photosensitive transistor circuit, an input end of the light emitting diode circuit is connected with the output end of the charging circuit, and an output end of the light emitting diode circuit is grounded; the photosensitive transistor circuit is electrically connected with the PWM control power supply chip.

3. The charger of claim 2, wherein The light emitting diode circuit comprises: a light emitting diode, a first resistor and a second resistor, a first end of the first resistor is connected with the output end of the charging circuit, a second end of the first resistor is electrically connected with an anode of the light emitting diode, a cathode of the light emitting diode is grounded, and the light emitting diode is connected in parallel with the second resistor; the photosensitive transistor circuit comprises: a photosensitive transistor, a third resistor and a first capacitor, an input end of the photosensitive transistor is connected with a second end of the third resistor, a first end of the third resistor is connected with a first end of the first capacitor and the PWM control power supply chip, respectively, and a second end of the first capacitor and an output end of the photosensitive transistor are grounded.

4. The charger of claim 2, wherein The voltage detection circuit further comprises: a voltage stabilizing diode circuit, an input end of the voltage stabilizing diode circuit is connected with an output end of the light emitting diode circuit, a second end of the voltage stabilizing diode circuit is grounded, and a reference end of the voltage stabilizing diode circuit is connected with the output end of the charging circuit; the voltage stabilizing diode circuit is used for disconnecting a path between the light emitting diode circuit and the ground when the charging voltage is less than the preset voltage.

5. The charger of claim 4, wherein, The voltage stabilizing diode circuit comprises: a first voltage stabilizing diode, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second capacitor, a third capacitor and a fourth capacitor, a first end of the fourth resistor is connected with the output end of the charging circuit; The first end of the second capacitor is connected with the output end of the light emitting diode circuit, the first end of the fourth capacitor is connected with the first end of the second capacitor, and the second end of the second capacitor is connected with the second end of the fourth resistor; The first end of the third capacitor is connected with the cathode of the first voltage stabilizing diode and the first end of the second capacitor respectively, the first end of the fifth resistor is connected with the second end of the third capacitor, and the second end of the fifth resistor is connected with the second end of the second capacitor; The first end of the sixth resistor and the first end of the seventh resistor are connected with the reference end of the first voltage stabilizing diode, the first end of the sixth resistor and the first end of the seventh resistor are also connected with the second end of the fifth resistor, and the second end of the sixth resistor, the second end of the seventh resistor and the anode of the first voltage stabilizing diode are grounded.

6. The charger of any one of claims 1 to 5, wherein, The main control circuit has a second power supply end, the PWM control power supply chip has a first power supply end and a second power supply end, the first power supply end is connected with the output end of the switch module, and the second power supply end is connected with the second power supply end. The main control circuit supplies power to the PWM control power supply chip through the second power supply end, so that the PWM control power supply chip enters a low-power consumption state when the switch module is disconnected.

7. The charger of any one of claims 1 to 5, wherein The charger further comprises: A spike absorption circuit, an input end of the spike absorption circuit is connected with the first power supply end, and an output end of the spike absorption circuit is connected with the input end of the switch module.

8. The charger of claim 7, wherein, The spike absorption circuit comprises: An eighth resistor, a fifth capacitor and a first diode, the anode of the first diode and the second end of the fifth capacitor are connected with the first power supply end, the first end of the fifth capacitor is connected with the second end of the eighth resistor, and the first end of the eighth resistor and the cathode of the first diode are connected with the input end of the switch module.

9. The charger of any one of claims 1 to 5, wherein, The charger further comprises: A power supply filtering circuit, an input end of the power supply filtering circuit is connected with the first power supply end, and an output end of the power supply filtering circuit is connected with the input end of the switch module.

10. The charger of claim 9, wherein, The power supply filtering circuit comprises: A sixth capacitor and a seventh capacitor, the first end of the sixth capacitor and the first end of the seventh capacitor are connected with the input end of the switch module, and the second end of the sixth capacitor and the second end of the seventh capacitor are grounded.

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