Charger circuit and charger

Abstract

This disclosure provides a charger circuit and charger, comprising: an input module adapted to rectify and filter a supply voltage to generate a transformer voltage; the transformer comprising: a primary coil, a secondary coil, and an auxiliary coil, wherein a first end of the primary coil is coupled to the input module, and a third end of the primary coil is coupled to an adjustment module; the secondary coil is coupled to an output module; the first end of the auxiliary coil is coupled to the adjustment module; the adjustment module is adapted to generate a drive signal with an initial duty cycle when receiving the transformer voltage to select a path between the third end of the primary coil and a first ground, and to detect the feedback current on the first end of the auxiliary coil when the path is selected by means of resistor voltage division, and to adjust the duty cycle of the drive signal according to the magnitude between the feedback current and a preset current to change the current at the first end of the auxiliary coil; and an output module. Using the above technical solution, a constant current value can be provided, improving the charging stability of electronic devices.

Description

Technical Field

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

[0002] In recent years, with the rapid development of technology, electronic devices have become indispensable tools in people's daily lives. During use, electronic devices typically require a power source, and chargers are one such tool. Chargers provide a stable power supply to electronic devices by transferring current into them, thus enabling them to be charged.

[0003] In practical applications, situations may arise where the output voltage is high but the output current is low, or vice versa. This can affect the charging stability of electronic devices. Utility Model Content

[0004] In view of this, the present invention provides a charger circuit and a charger that can provide a constant current value and improve the charging stability of electronic devices.

[0005] This utility model provides a charger circuit, including: an input module, a transformer, an adjustment module, and an output module, wherein:

[0006] The input module is coupled to the transformer and the adjustment module respectively, and is suitable for rectifying and filtering the power supply voltage to generate a transformer voltage.

[0007] The transformer includes a primary coil, a secondary coil, and an auxiliary coil. The first end of the primary coil is coupled to the input module, and the third end of the primary coil is coupled to the adjustment module. The secondary coil is coupled to the output module. The first end of the auxiliary coil is coupled to the adjustment module.

[0008] The adjustment module is adapted to generate a drive signal with an initial duty cycle when receiving the transformer voltage, so as to select the path between the third terminal of the primary coil and the first ground, and to detect the feedback current on the first terminal of the auxiliary coil when the path is selected by means of resistor voltage division, and adjust the duty cycle of the drive signal according to the magnitude between the feedback current and the preset current, thereby changing the current at the first terminal of the auxiliary coil.

[0009] The output module is used to rectify and filter the output voltage.

[0010] Optionally, the adjustment module includes: a constant current control chip, a gating transistor, and a voltage divider unit, wherein:

[0011] The voltage divider unit includes: a first voltage divider branch and a second voltage divider branch;

[0012] The power supply pin of the constant current control chip is coupled to the input module, the drive pin is coupled to the control terminal of the gating transistor, the voltage detection pin is coupled to the first terminal of the auxiliary coil through the voltage divider unit, and the current detection pin is coupled to the first terminal of the auxiliary coil through the first voltage divider branch.

[0013] The first terminal of the selection transistor is coupled to the third terminal of the primary coil, and the second terminal of the selection transistor is coupled to the current detection pin through the second voltage divider branch and connected to the first ground.

[0014] When the selector transistor is in the on state, the current detection pin is used to detect the current in the first voltage divider branch and the second voltage divider branch to obtain the feedback current, wherein the equivalent resistance value of the first voltage divider branch and / or the second voltage divider branch is variable.

[0015] Optionally, the first voltage divider branch includes: a first voltage divider resistor, a first diode, and a second voltage divider resistor, wherein the first end of the first voltage divider resistor is coupled to the second voltage divider branch and the current detection pin, and the second end of the first voltage divider resistor is coupled to the first end of the first diode; the second end of the first diode is coupled to the first end of the auxiliary coil through the second voltage divider resistor.

[0016] The second voltage divider branch includes: a third voltage divider resistor, a fourth voltage divider resistor, a fifth voltage divider resistor, a sixth voltage divider resistor, and a seventh voltage divider resistor. The first terminal of the third voltage divider resistor is coupled to the current detection pin and the first voltage divider branch, respectively. The second terminal of the third voltage divider resistor is coupled to the first terminals of the fourth, fifth, sixth, and seventh voltage divider resistors, respectively, and to the second terminal of the selection transistor. The second terminals of the fourth, fifth, sixth, and seventh voltage divider resistors are connected to a first ground.

[0017] Optionally, the constant current control chip further includes:

[0018] A compensation pin is connected to a first ground via a compensation resistor and a compensation capacitor in sequence.

[0019] A grounding pin, wherein the grounding pin is coupled to the first end of the auxiliary coil through the first grounding capacitor and is connected to the first ground;

[0020] The idle pin is coupled to the power supply pin.

[0021] Optionally, the charger circuit further includes at least one or more of the following:

[0022] An absorption module is coupled to the first terminal of the gating transistor and the third terminal of the primary coil, respectively, and is adapted to absorb the spike voltage generated by the gating transistor at the instant the gating transistor is turned off.

[0023] The discharge module includes: a first discharge branch and a second discharge branch. The first discharge branch is disposed between the control terminal of the gating transistor and the drive pin, and the second discharge branch is disposed between the control terminal of the gating transistor and the current detection pin. It is adapted to feed back the junction capacitance voltage to the drive pin and the current detection pin respectively when the gating transistor is turned off.

[0024] The driving module is coupled to the input module and the power supply pin respectively, and is suitable for stepping down the transformer voltage to generate a driving voltage.

[0025] Optionally, the absorption module includes: a second diode, a first absorption capacitor, a first absorption resistor, a second absorption resistor, a third absorption resistor, and a fourth absorption resistor, wherein: the first end of the second diode is coupled to the first end of the selection transistor and the third end of the primary coil, respectively; the second end of the second diode is coupled to the first end of the first absorption capacitor, the second absorption resistor, the third absorption resistor, and the fourth absorption resistor through the first absorption resistor; and the second ends of the first absorption capacitor, the second absorption resistor, the third absorption resistor, and the fourth absorption resistor are coupled to the input module.

[0026] The first bleeder branch includes a third diode and a first bleeder resistor, wherein the first end of the third diode is coupled to the control terminal of the gating transistor, and the second end of the third diode is coupled to the drive pin through the first bleeder resistor;

[0027] The second discharge branch includes: a second discharge resistor;

[0028] The driving module includes a first driving resistor and a second driving resistor, wherein a first end of the first driving resistor is coupled to the input module, and a second end of the first driving resistor is coupled to the power supply pin through the second driving resistor.

[0029] Optionally, the input module includes: a first filtering module, a rectifier module, and a second filtering module, wherein: the first filtering module is coupled to the rectifier module and is adapted to input the power supply voltage; the rectifier module is coupled to the second filtering module and is adapted to convert the type of power supply voltage; the second filtering module is coupled to the first end of the primary coil and the adjustment module, respectively.

[0030] Optionally, the input module satisfies at least one or more of the following:

[0031] The first filtering module includes: a first common-mode inductor, a second common-mode inductor, and a first filtering capacitor, wherein the first and second ends of the first common-mode inductor are adapted to receive the supply voltage, and the third and fourth ends of the first common-mode inductor are respectively coupled to the first and second ends of the second common-mode inductor and the first filtering capacitor;

[0032] The rectifier module includes a full-bridge rectifier circuit and an RC filter circuit, wherein the RC filter circuit is coupled to the full-bridge rectifier circuit and the first filter module, respectively, and the RC filter circuit includes a first filter capacitor, a first filter resistor and a second filter resistor.

[0033] The second filtering module includes: a filtering inductor, a third filtering resistor, a third filtering capacitor, and a fourth filtering capacitor.

[0034] Optionally, the output module includes a rectification branch and a filtering branch, wherein the rectification branch includes a fifth diode, a sixth diode, a first rectifier resistor, a second rectifier resistor, and a rectifier capacitor, wherein: the fifth diode and the sixth diode are connected in parallel, and their first ends are both coupled to the first end of the secondary coil; the first rectifier resistor and the second rectifier resistor are connected in parallel, and their first ends are both coupled to the first end of the secondary coil, and their second ends are coupled to the rectifier capacitor; the second end of the rectifier capacitor is coupled to the second ends of the fifth diode and the sixth diode;

[0035] The filtering branch includes: a fifth filtering capacitor, a sixth filtering capacitor, a seventh filtering capacitor, an eighth filtering capacitor, and a fourth filtering resistor connected in parallel, and a third common-mode inductor coupled to the fifth filtering capacitor.

[0036] Accordingly, the present invention also provides a charger, including: the charger circuit described in any of the foregoing embodiments.

[0037] Compared with the prior art, the technical solution of this utility model embodiment has the following advantages:

[0038] The charger circuit provided in this utility model embodiment generates a drive signal with an initial duty cycle when the adjustment module receives the transformer voltage, thereby selecting the path between the third terminal of the primary coil and the first ground. When this path is selected, the current in that path gradually increases. The feedback current at the first terminal of the auxiliary coil can then be obtained through resistor voltage division. Since the adjustment module has a preset current, it can adjust the duty cycle of the drive signal according to the difference between the feedback current and the preset current, changing the conduction duration of the path between the third terminal of the primary coil and the first ground, thus changing the current at the first terminal of the auxiliary coil and keeping it constant. Based on the characteristics of the transformer itself, this provides a constant current value, improving the charging stability of the electronic device. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application 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 embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0040] Figure 1 A schematic diagram of a charger circuit according to an embodiment of the present invention is shown;

[0041] Figure 2 A schematic diagram of the specific structure of a charger circuit according to one embodiment of the present invention is shown. Detailed Implementation

[0042] As described in the background section, in practical applications, situations may arise where the output voltage is high but the output current is low, or vice versa. This will affect the charging stability of electronic devices.

[0043] To address the aforementioned technical problems, this invention provides a charger circuit. When the adjustment module receives a transformer voltage, it generates a drive signal with an initial duty cycle to select the path between the third terminal of the primary coil and the first ground. Thus, when this path is selected, the current in that path gradually increases. The feedback current at the first terminal of the auxiliary coil can then be obtained through resistor voltage division. Since the adjustment module has a preset current, it can adjust the duty cycle of the drive signal according to the difference between the feedback current and the preset current, changing the conduction duration of the path between the third terminal of the primary coil and the first ground, thereby changing the current at the first terminal of the auxiliary coil and keeping it constant. Based on the characteristics of the transformer itself, this provides a constant current value, improving the charging stability of the electronic device.

[0044] To enable those skilled in the art to better understand and implement this disclosure, the following detailed description of the specific solutions, principles, advantages, and effects of this disclosure is provided with reference to the accompanying drawings and specific embodiments.

[0045] See Figure 1 , Figure 1 This is a schematic diagram of a charger circuit according to one embodiment of the present invention. Figure 1 As shown, the charger circuit may include: an input module 110, a transformer T, an adjustment module 120, and an output module 130, wherein:

[0046] The input module 110 is coupled to the transformer T and the adjustment module 120 respectively, and is suitable for rectifying and filtering the power supply voltage to generate a transformer voltage.

[0047] In some embodiments, the power supply voltage is 220V AC, and the transformer voltage is 310V DC generated based on the input module 110.

[0048] The transformer T includes a primary coil Wp, a secondary coil Ws, and an auxiliary coil Wc. The first end of the primary coil Wp is coupled to the input module 110, and the third end of the primary coil Wp is coupled to the adjustment module 120. The secondary coil Ws is coupled to the output module 130. The first end of the auxiliary coil Wc is coupled to the adjustment module 120.

[0049] More specifically, a change in the voltage across any one of the primary coil Wp, secondary coil Ws, and auxiliary coil Wc will cause a change in the voltage across the other coils. This voltage change will act on the adjustment module 120, thereby allowing the adjustment module 120 to make adjustments in response to the change.

[0050] In some embodiments, the primary coil Wp and the auxiliary coil Wc are located on the same side, and the third end 1 of the primary coil Wp and the first end 9 of the secondary coil Ws are the same end, and the first end 9 of the secondary coil Ws and the first end 6 of the auxiliary coil Wc are the same end.

[0051] In some embodiments, the number of turns of the primary coil Wp is greater than the number of turns of the secondary coil Ws.

[0052] The adjustment module 120 is adapted to generate a drive signal with an initial duty cycle when receiving the transformer voltage, so as to select the path between the third terminal 1 of the primary coil Wp and the first ground G1, and detect the feedback current on the first terminal of the auxiliary coil when the path is selected by means of resistor voltage division, and adjust the duty cycle of the drive signal according to the magnitude between the feedback current and the preset current, thereby changing the current at the first terminal of the auxiliary coil Wc.

[0053] More specifically, by changing the voltage division ratio of the resistors, the feedback current is made to be the same as the preset current.

[0054] The output module 130 is used to rectify and filter the output voltage.

[0055] Combination Figure 1 Briefly explain the working principle of the charger circuit in this solution:

[0056] Initially, when the transformer voltage is received, the adjustment module 120 starts to work, and the generated drive signal can select the path between the third terminal 1 of the primary coil Wp and the first ground G1.

[0057] Since the path is directly coupled to the third terminal 1 of the primary coil Wp when it is selected, the current in the path will gradually increase. At this time, the feedback current generated at the first terminal 6 of the auxiliary coil Wc when the path is turned on can be obtained by voltage division of the resistor.

[0058] Since the adjustment module 120 has a preset current, it can adjust the duty cycle of the drive signal according to the magnitude of the feedback current and the preset voltage and current, change the conduction time of the path between the third terminal 1 of the primary coil Wp and the first ground G1, thereby changing the current of the first terminal 6 of the auxiliary coil Wc, so that the current of the first terminal 6 of the auxiliary coil Wc remains constant.

[0059] Based on the inherent characteristics of transformer T, a constant current value can be provided, improving the charging stability of electronic devices.

[0060] In this embodiment, see Figure 1 The adjustment module 120 may include: a constant current control chip 122, a selection transistor Q1, and a voltage divider unit (not shown in the figure), wherein:

[0061] The voltage divider unit includes a first voltage divider branch U1 and a second voltage divider branch U2, wherein the resistance values ​​of the voltage divider resistors of the first voltage divider branch U1 and the second voltage divider branch U2 may be different.

[0062] The power supply pin VIN of the constant current control chip 122 is coupled to the input module 110, the drive pin DRV is coupled to the control terminal of the selection transistor Q1, the voltage detection pin VSEN is coupled to the first terminal 6 of the auxiliary coil Wc through the voltage divider unit, and the current detection pin ISEN is coupled to the first terminal 6 of the auxiliary coil Wc through the first voltage divider branch U1.

[0063] The first terminal of the selection transistor Q1 is coupled to the third terminal 1 of the primary coil Wp. The second terminal of the selection transistor Q1 is coupled to the current detection pin ISEN through the second voltage divider branch U2 and connected to the first ground G1. When the selection transistor is in the on state, the current detection pin is used to detect the current in the first voltage divider branch and the second voltage divider branch to obtain the feedback current.

[0064] More specifically, when the transformer voltage is received, the constant current control chip 122 outputs a drive signal (which can be a PWM signal) through the drive pin DRV and is coupled to the control terminal of the selection transistor Q1, thereby selecting the selection transistor Q1 and the charger circuit works normally.

[0065] When the output current changes, this is reflected at the first terminal 6 of the auxiliary coil Wc. Simultaneously, the current at the first terminal of the auxiliary coil Wc also changes, and as the conduction time of the selection transistor Q1 increases, the current at the first terminal of the auxiliary coil Wc increases. The constant current control chip 122 can adjust the duty cycle of the drive signal based on the preset current and the feedback current. This changes the conduction time of the selection transistor Q1, which in turn, through the first voltage divider branch U1 and the second voltage divider branch U2, causes a change in the current at the current detection pin ISEN.

[0066] Since the current sensing pin ISEN is coupled to the first terminal 6 of the auxiliary coil Wc, the current on the first terminal 6 of the auxiliary coil Wc can be kept constant after adjustment.

[0067] In some embodiments, the equivalent resistance values ​​of the first voltage divider branch and / or the second voltage divider branch are variable, thereby allowing the current at the first end of the auxiliary coil Wc to remain constant while keeping the voltage on the selected branch constant.

[0068] In this embodiment, see [reference] Figure 2 The schematic diagram shown below illustrates the specific structure of a charger circuit in one embodiment of this utility model. Figure 2 As shown, the adjustment module 120 can satisfy at least one or more of the following:

[0069] The first voltage divider branch U1 may include: a first voltage divider resistor R35, a first diode D7, and a second voltage divider resistor R34, wherein the first end of the first voltage divider resistor R35 is coupled to the second voltage divider branch D7 and the current detection pin ISEN, and the second end of the first voltage divider resistor R35 is coupled to the first end of the first diode D7; the second end of the first diode D7 is coupled to the first end 6 of the auxiliary coil Wc through the second voltage divider resistor R34.

[0070] The second voltage divider resistor R34 can be coupled to the first terminal 6 of the auxiliary coil Wc at the feedback node VR.

[0071] In some embodiments, the connection point between the second voltage divider resistor R34 and the first voltage divider resistor R35 is also connected to the first ground G1 through a capacitor C17.

[0072] The second voltage divider branch U2 may include: a third voltage divider resistor R45, a fourth voltage divider resistor R22, a fifth voltage divider resistor R21, a sixth voltage divider resistor R20, and a seventh voltage divider resistor R23. The first terminal of the third voltage divider resistor R45 is coupled to the current detection pin ISEN and the first voltage divider branch U1, respectively. The second terminal of the third voltage divider resistor R45 is coupled to the first terminals of the fourth voltage divider resistor R22, the fifth voltage divider resistor R21, the sixth voltage divider resistor R20, and the seventh voltage divider resistor R23, respectively, and to the second terminal of the selection transistor Q1. The second terminals of the fourth voltage divider resistor R22, the fifth voltage divider resistor R21, the sixth voltage divider resistor R20, and the seventh voltage divider resistor R23 are connected to the first ground G1.

[0073] This solution uses resistors on the first voltage divider branch U1 and the second voltage divider branch U2 to regulate the current on the current detection pin ISEN.

[0074] More specifically, this solution adjusts the resistance values ​​of the third voltage divider resistor R45 and the first voltage divider resistor R35 to make the feedback current the same as the preset current.

[0075] In this embodiment, the system further includes a detection unit 124, which may include a first detection resistor R24, a second detection resistor R18, and a third detection resistor R14. The first end of the first detection resistor R24 ​​is coupled to the voltage detection pin VSEN and the first end of the second detection resistor R18, respectively. The second end of the first detection resistor R14 is connected to the first ground G1. The second end of the second detection resistor R18 is coupled to the first end 6 of the auxiliary coil Wc through the third detection resistor R14.

[0076] In other words, the voltage detected by the detection unit 124 is the voltage drop across the first detection resistor R24.

[0077] In this embodiment, see next. Figure 2 The constant current control chip 122 may further include:

[0078] The compensation pin COMP is connected to the first ground G1 via a compensation resistor R30 and a compensation capacitor C31 in sequence.

[0079] Stable compensation is achieved by setting a compensation resistor R30 and a compensation capacitor C31.

[0080] The grounding pin GND is coupled to the first terminal 6 of the auxiliary coil Wc through the grounding capacitor C32, and connected to the first ground G1.

[0081] The idle pin NC is coupled to the power supply pin VIN.

[0082] In practical applications, as mentioned earlier, the generated DC voltage is 310V. However, the operating voltage of the control chip is generally lower.

[0083] Based on this, see next. Figure 1 The charger circuit may further include a drive module 140, which is coupled to the input module 110 and the power supply pin VIN respectively, and is adapted to step down the transformer voltage to generate a drive voltage.

[0084] In some embodiments, see Figure 2 The driving module 140 may include a first driving resistor R8 and a second driving resistor R10, wherein the first end of the first driving resistor R8 is coupled to the input module 110, and the second end of the first driving resistor R8 is coupled to the power supply pin VIN through the second driving resistor R10.

[0085] By setting the first driving resistor R8 and the second driving resistor R10, a suitable power supply voltage can be provided to the constant current control chip 122, thus ensuring the safe and stable operation of the constant current control chip 122.

[0086] In some embodiments, the second driving resistor R10 is also coupled to the first terminal 6 of the auxiliary coil Wc.

[0087] As can be seen from the foregoing, this scheme achieves constant current output by selecting the on / off state of transistor Q1.

[0088] In practical work, the inventors discovered that at the moment when the turn-on transistor Q1 is turned off, the turn-on transistor Q1 is equivalent to a capacitor, and the spike voltage discharged in the turn-on transistor Q1 will damage the circuit and reduce performance.

[0089] Based on this, see next. Figure 2 The charger circuit may further include: an absorption module 150, which is coupled to the first terminal of the selection transistor Q1 and the third terminal 1 of the primary coil Wp, respectively, and is adapted to absorb the spike voltage generated by the selection transistor Q1 at the instant when the selection transistor Q1 is turned off.

[0090] In one embodiment, see Figure 2 The absorption module 150 may include: a second diode D3, a first absorption capacitor C2, a first absorption resistor R11, a second absorption resistor R3, a third absorption resistor R4, and a fourth absorption resistor R5, wherein: the first end of the second diode D3 is coupled to the first end of the selection transistor Q1 and the third end 1 of the primary coil Wp, respectively; the second end of the second diode D3 is coupled to the first end of the first absorption capacitor C2, the first absorption capacitor C2, the second absorption resistor R3, the third absorption resistor R4, and the fourth absorption resistor R5 through the first absorption resistor R11; and the second ends of the second absorption resistor R3, the third absorption resistor R4, and the fourth absorption resistor R5 are coupled to the input module 110.

[0091] In other words, the absorption module 150 is an RCD absorption circuit. Furthermore, by employing a second diode D3, the flow direction of the peak voltage is ensured to be solely from the second diode D3 to the first absorption resistor R11, which significantly improves the operational stability of the charger circuit.

[0092] Furthermore, at the instant the turn-off transistor Q1 is turned off, the junction capacitance of the turn-off transistor Q1 will also discharge, thus requiring a corresponding discharge circuit.

[0093] Based on this, the charger circuit may further include a discharge module, including a first discharge branch and a second discharge branch. The first discharge branch is disposed between the control terminal of the selector transistor and the drive pin, and the second discharge branch is disposed between the control terminal of the selector transistor and the current detection pin. It is adapted to feed back the junction capacitance voltage to the drive pin and the current detection pin respectively when the selector transistor is turned off.

[0094] In other words, the junction voltage is released to the drive pin through the first bleed branch; and the junction voltage is released to the current detection pin through the second bleed branch.

[0095] In some embodiments, the first discharge branch may include a third diode D6 and a first discharge resistor R16, wherein the first end of the third diode D6 is coupled to the control terminal of the gating transistor Q1, and the second end of the third diode D6 is coupled to the drive pin DRV through the first discharge resistor R16.

[0096] The second bleeder branch includes a second bleeder resistor R17. The control terminal of the select transistor Q1 releases the junction voltage to the current detection pin ISEN through the second bleeder resistor R17.

[0097] In some embodiments, when the selected transistor Q1 is turned off, the voltage drop across the first terminal 6 and the second terminal 4 of the auxiliary coil Wc is positive at the bottom and negative at the top.

[0098] Based on this, the solution also provides a freewheeling module, which is coupled to the first terminal 4 of the auxiliary coil Wc and the ground terminal GND of the constant current control chip 122, respectively, and is suitable for providing a freewheeling path when the selection transistor Q1 is turned off.

[0099] In this embodiment, see Figure 2 The freewheeling module may include: a fourth diode D3, a freewheeling resistor R12, a first freewheeling capacitor C14, and a second freewheeling capacitor CSS. The first end of the freewheeling resistor R12 is coupled to the first end 6 of the auxiliary coil Wc. The second end of the freewheeling resistor R12 is connected to the first ground G1 through the fourth diode D3 and the first freewheeling capacitor C14, and is also connected to the first ground G1 through the fourth diode D3 and the second freewheeling capacitor C32.

[0100] In this embodiment, see Figure 2 The input module 110 may include: a first filtering module, a rectifier module, and a second filtering module, wherein: the first filtering module is coupled to the rectifier module and is adapted to input the power supply voltage; the rectifier module is coupled to the second filtering module and is adapted to convert the type of power supply voltage; the second filtering module is coupled to the first end of the primary coil and the adjustment module, respectively.

[0101] Accordingly, the first filtering module may include: a first common-mode inductor L4, a second common-mode inductor L3, and a first filter capacitor CX2, wherein the first and second terminals of the first common-mode inductor L4 are adapted to receive the supply voltage (e.g., Figure 2 The schematic input ports Nin and Lin are shown. The third and fourth terminals of the first common-mode inductor L4 are coupled to the first and second terminals of the second common-mode inductor L3 and the first filter capacitor CX2, respectively.

[0102] By setting up the first filtering module, noise in the power supply voltage can be filtered out, thus improving the quality of the power supply voltage.

[0103] The rectifier module may include a full-bridge rectifier circuit DB1 and an RC filter circuit, wherein the RC filter circuit is coupled to the full-bridge rectifier circuit DB1 and the first filter module, respectively, and the RC filter circuit includes a first filter capacitor CX1, a first filter resistor R25 and a second filter resistor R16.

[0104] In this embodiment, the full-bridge rectifier circuit DB1 can be composed of 4 diodes.

[0105] The rectifier module can convert AC power into DC power.

[0106] The second filtering module may include: a filter inductor L1, a third filter resistor R7, a third filter capacitor C6, and a fourth filter capacitor C7.

[0107] It should be noted that, see Figure 2 A fuse RV is also installed on the input ports Nin and Lin.

[0108] In this embodiment, the output module 130 may include a rectification branch and a filtering branch. The rectification branch may include a fifth diode D11, a sixth diode D12, a first rectifier resistor R1, a second rectifier resistor R2, and a rectifier capacitor C1. The fifth diode D11 and the sixth diode D12 are connected in parallel, and their first ends are both coupled to the first end 9 of the secondary coil Ws. The first rectifier resistor R1 and the second rectifier resistor R2 are connected in parallel, and their first ends are both coupled to the first end 9 of the secondary coil Ws, and their second ends are coupled to the rectifier capacitor C1. The second end of the rectifier capacitor C1 is coupled to the second ends of the fifth diode D11 and the sixth diode D12.

[0109] The filtering branch includes: a fifth filter capacitor C3, a sixth filter capacitor C4, a seventh filter capacitor C5, an eighth filter capacitor C9 and a fourth filter resistor connected in parallel, and a third common-mode inductor L2.

[0110] Specifically, the first electrolytic capacitor C9 and the second electrolytic capacitor C10 connected to the secondary coil Ws can rectify and filter the transformer voltage, thereby improving the quality of the transformer voltage.

[0111] It should be noted that, firstly, in this embodiment, a mica capacitor CY is provided between the first ground G1 and the second ground G2; secondly, Figure 2 The output port pads Led1 and Led2 are also shown.

[0112] It is understood that the above description provides multiple embodiment solutions, and the optional methods described in each embodiment solution can be combined with each other and cross-referenced without conflict, thereby extending to a variety of possible embodiment solutions, all of which can be considered as the embodiment solutions disclosed in this disclosure.

[0113] This disclosure also provides a charger, including: a transformer, the transformer including: a primary coil, a secondary coil, and an auxiliary coil; and a charger circuit as described in any of the foregoing examples, wherein the charger circuit is coupled to the transformer.

[0114] For details regarding the structure and working principle of the charger circuit, please refer to the aforementioned example.

[0115] While the embodiments disclosed herein are as described above, this utility model is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of this utility model; therefore, the scope of protection of this utility model should be determined by the scope defined in the claims.

Claims

1. A charger circuit, characterized in that, include: The system includes an input module, a transformer, an adjustment module, and an output module, among which: The input module is coupled to the transformer and the adjustment module respectively, and is suitable for rectifying and filtering the power supply voltage to generate a transformer voltage. The transformer includes a primary coil, a secondary coil, and an auxiliary coil. The first end of the primary coil is coupled to the input module, and the third end of the primary coil is coupled to the adjustment module. The secondary coil is coupled to the output module. The first end of the auxiliary coil is coupled to the adjustment module. The adjustment module is adapted to generate a drive signal with an initial duty cycle when receiving the transformer voltage, so as to select the path between the third terminal of the primary coil and the first ground, and to detect the feedback current on the first terminal of the auxiliary coil when the path is selected by means of resistor voltage division, and adjust the duty cycle of the drive signal according to the magnitude between the feedback current and the preset current, thereby changing the current at the first terminal of the auxiliary coil. The output module is used to rectify and filter the output voltage.

2. The charger circuit according to claim 1, characterized in that, The adjustment module includes: a constant current control chip, a gating transistor, and a voltage divider unit, wherein: The voltage divider unit includes: a first voltage divider branch and a second voltage divider branch; The power supply pin of the constant current control chip is coupled to the input module, the drive pin is coupled to the control terminal of the gating transistor, the voltage detection pin is coupled to the first end of the auxiliary coil through the voltage divider unit, and the current detection pin is coupled to the first end of the auxiliary coil through the first voltage divider branch. The first terminal of the selection transistor is coupled to the third terminal of the primary coil, and the second terminal of the selection transistor is coupled to the current detection pin through the second voltage divider branch and connected to the first ground. When the selector transistor is in the on state, the current detection pin is used to detect the current in the first voltage divider branch and the second voltage divider branch to obtain the feedback current, wherein the equivalent resistance value of the first voltage divider branch and / or the second voltage divider branch is variable.

3. The charger circuit according to claim 2, characterized in that, The adjustment module satisfies at least one or more of the following: The first voltage divider branch includes: a first voltage divider resistor, a first diode, and a second voltage divider resistor, wherein the first end of the first voltage divider resistor is coupled to the second voltage divider branch and the current detection pin, and the second end of the first voltage divider resistor is coupled to the first end of the first diode; the second end of the first diode is coupled to the first end of the auxiliary coil through the second voltage divider resistor. The second voltage divider branch includes: a third voltage divider resistor, a fourth voltage divider resistor, a fifth voltage divider resistor, a sixth voltage divider resistor, and a seventh voltage divider resistor. The first terminal of the third voltage divider resistor is coupled to the current detection pin and the first voltage divider branch, respectively. The second terminal of the third voltage divider resistor is coupled to the first terminals of the fourth, fifth, sixth, and seventh voltage divider resistors, respectively, and to the second terminal of the selection transistor. The second terminals of the fourth, fifth, sixth, and seventh voltage divider resistors are connected to a first ground.

4. The charger circuit according to claim 2, characterized in that, The constant current control chip also includes: A compensation pin is connected to a first ground via a compensation resistor and a compensation capacitor in sequence. A grounding pin is coupled to the first end of the auxiliary coil through the first ground capacitor and connected to the first ground. The idle pin is coupled to the power supply pin.

5. The charger circuit according to claim 2, characterized in that, The charger circuit also includes at least one or more of the following: An absorption module is coupled to the first terminal of the gating transistor and the third terminal of the primary coil, respectively, and is adapted to absorb the spike voltage generated by the gating transistor at the instant the gating transistor is turned off. The discharge module includes: a first discharge branch and a second discharge branch. The first discharge branch is disposed between the control terminal of the gating transistor and the drive pin, and the second discharge branch is disposed between the control terminal of the gating transistor and the current detection pin. It is adapted to feed back the junction capacitance voltage to the drive pin and the current detection pin respectively when the gating transistor is turned off. The driving module is coupled to the input module and the power supply pin respectively, and is suitable for stepping down the transformer voltage to generate a driving voltage.

6. The charger circuit according to claim 5, characterized in that, The absorption module includes: a second diode, a first absorption capacitor, a first absorption resistor, a second absorption resistor, a third absorption resistor, and a fourth absorption resistor, wherein: the first end of the second diode is coupled to the first end of the selection transistor and the third end of the primary coil, respectively; the second end of the second diode is coupled to the first end of the first absorption capacitor, the second absorption resistor, the third absorption resistor, and the fourth absorption resistor through the first absorption resistor; and the second ends of the first absorption capacitor, the second absorption resistor, the third absorption resistor, and the fourth absorption resistor are coupled to the input module. The first bleeder branch includes a third diode and a first bleeder resistor, wherein the first end of the third diode is coupled to the control terminal of the gating transistor, and the second end of the third diode is coupled to the drive pin through the first bleeder resistor; The second discharge branch includes: a second discharge resistor; The driving module includes a first driving resistor and a second driving resistor, wherein a first end of the first driving resistor is coupled to the input module, and a second end of the first driving resistor is coupled to the power supply pin through the second driving resistor.

7. The charger circuit according to claim 1, characterized in that, The input module includes: a first filtering module, a rectifier module, and a second filtering module, wherein: the first filtering module is coupled to the rectifier module and is adapted to input the power supply voltage; the rectifier module is coupled to the second filtering module and is adapted to convert the type of power supply voltage; the second filtering module is coupled to the first end of the primary coil and the adjustment module, respectively.

8. The charger circuit according to claim 7, characterized in that, The input module satisfies at least one or more of the following: The first filtering module includes: a first common-mode inductor, a second common-mode inductor, and a first filtering capacitor, wherein the first and second ends of the first common-mode inductor are adapted to receive the supply voltage, and the third and fourth ends of the first common-mode inductor are respectively coupled to the first and second ends of the second common-mode inductor and the first filtering capacitor; The rectifier module includes a full-bridge rectifier circuit and an RC filter circuit, wherein the RC filter circuit is coupled to the full-bridge rectifier circuit and the first filter module, respectively, and the RC filter circuit includes a first filter capacitor, a first filter resistor and a second filter resistor. The second filtering module includes: a filtering inductor, a third filtering resistor, a third filtering capacitor, and a fourth filtering capacitor.

9. The charger circuit according to claim 1, characterized in that, The output module includes a rectification branch and a filtering branch. The rectification branch includes a fifth diode, a sixth diode, a first rectifier resistor, a second rectifier resistor, and a rectifier capacitor. The fifth diode and the sixth diode are connected in parallel, and their first terminals are both coupled to the first terminal of the secondary coil. The first rectifier resistor and the second rectifier resistor are connected in parallel, and their first terminals are both coupled to the first terminal of the secondary coil, while their second terminals are coupled to the rectifier capacitor. The second terminal of the rectifier capacitor is coupled to the second terminals of the fifth diode and the sixth diode. The filtering branch includes: a fifth filtering capacitor, a sixth filtering capacitor, a seventh filtering capacitor, an eighth filtering capacitor, and a fourth filtering resistor connected in parallel, and a third common-mode inductor coupled to the fifth filtering capacitor.

10. A charger, characterized in that, include: The charger circuit as described in any one of claims 1 to 9.

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