A power tool battery pack charging circuit

Abstract

The application relates to the technical field of charging rectification, and particularly provides a battery pack charging circuit of an electric tool, which comprises a first filtering module, a rectifier BD, a second filtering module, a voltage transformation module, a discharging module, an output reverse connection protection module, a switching power supply chip U, a grounding protection module and an absorption module. The first filtering module can filter alternating current inputted from an alternating current input end; the rectifier BD can convert the alternating current into direct current; the second filtering module can filter the direct current; the voltage transformation module can transform the voltage of the charging circuit, so that the charging circuit can be adapted to the charging of the electric tool; the discharging module can stabilize voltage and discharge; and the output reverse connection protection module can be used for outputting reverse connection protection of the direct current. The charging output of the charging circuit is reliable, protection can be accurately carried out, hidden dangers can be solved by the product, and the service life of the charger is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of charging rectification, in particular to a battery pack charging circuit of electric tools. BACKGROUND

[0002] The electric tool charger charges the battery pack of electric tools by connecting the power supply.

[0003] The charger circuit in the prior art only has one filtering, which is not conducive to the stable voltage charging output of the charging circuit; and the charging circuit has no reverse connection protection, and the charging safety performance is poor. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a battery pack charging circuit of electric tools, which solves the problems that the charging circuit of the charger in the prior art only has one filtering, which is not conducive to the stable voltage charging output of the charging circuit; and the charging circuit has no reverse connection protection, and the charging safety performance is poor.

[0005] To achieve the above-mentioned purposes and other related purposes, the present application provides a battery pack charging circuit of electric tools, comprising an alternating current input end and a direct current output end arranged at both ends of the charging circuit;

[0006] The charging circuit comprises:

[0007] A first filtering module connected to the alternating current input end for filtering the alternating current inputted by the alternating current input end;

[0008] A rectifier BD connected to the output end of the first filtering module for converting alternating current into direct current;

[0009] A second filtering module connected to the output end of the rectifier BD for filtering the direct current;

[0010] A voltage transformation module connected to the output end of the second filtering module for voltage transformation;

[0011] A discharging module connected to the output end of the voltage transformation module for stable voltage discharging;

[0012] An output reverse connection protection module connected between the discharging module and the direct current output end for direct current output reverse connection protection;

[0013] A switching power supply chip U connected to the second filtering module and the voltage transformation module.

[0014] In an embodiment of the present application, the charging circuit further comprises a common-mode inductor L connected between the first filter module and the rectifier BD for filtering common-mode electromagnetic interference signals.

[0015] In an embodiment of the present application, the first filter module comprises a first variable capacitor C1, a second capacitor C2, a first resistor R1 and a second resistor R2, the first variable capacitor C1 and the second capacitor C2 are connected in parallel between the live wire and the neutral wire of the AC input end, and the first resistor R1 and the second resistor R2 are connected in series and then connected in parallel between the live wire and the neutral wire of the AC input end.

[0016] In an embodiment of the present application, the second filter module comprises a third capacitor C3, a fourth capacitor C4, a third resistor R3 and a fourth resistor R4, the third capacitor C3 and the fourth capacitor C4 are connected in parallel at the output end of the rectifier BD, and the third resistor R3 and the fourth resistor R4 are connected in series and then connected in parallel at the output end of the rectifier BD.

[0017] In an embodiment of the present application, the transformer module comprises a transformer T, a seventh capacitor C7 and a first diode D1, the seventh capacitor C7 and the first diode D1 are connected in series and then connected in parallel at the transformer T.

[0018] In an embodiment of the present application, a grounding protection module is connected to the transformer module for preventing surge voltage, the grounding protection module comprises a fifth resistor R5, a fifth capacitor C5 and a sixth capacitor C6, the fifth resistor R5, the fifth capacitor C5 and the sixth capacitor C6 are connected in series and then connected between the seventh capacitor C7 and the first diode D1 through the fifth resistor R5, and the other end of the sixth capacitor C6 is grounded.

[0019] In an embodiment of the present application, the discharge module comprises a ninth capacitor C9, a tenth capacitor C10 and an eleventh capacitor C11, the ninth capacitor C9, the tenth capacitor C10 and the eleventh capacitor C11 are connected in parallel and then connected to the transformer module through the ninth capacitor C9.

[0020] In an embodiment of the present application, an absorption circuit is arranged between the transformer module and the discharge module for absorbing the spike pulse generated in the circuit, the absorption circuit comprises an eighth capacitor C8 and a sixth resistor R6, the eighth capacitor C8 and the sixth resistor R6 are connected in series and then connected to the transformer module through the eighth capacitor C8 and to the discharge module through the sixth resistor R6.

[0021] In an embodiment of the present application, the output reverse connection protection module comprises a PMOS 1, a PMOS 2 and a MOS, the PMOS 1 and the PMOS 2 are connected in series and the source output directions of the PMOS 1 and the PMOS 2 are opposite, the PMOS 1 is connected to the discharge module, the PMOS 2 is connected to the DC output end, and the MOS is connected in parallel between the D pole and the S pole of the PMOS 2.

[0022] In an embodiment of the present application, the ninth resistor R9 and the fourth diode D4 are connected in parallel between the G terminal and the S terminal of the PMOS1; the fifth diode D5 and the eleventh resistor R11 are connected in parallel between the G terminal and the S terminal of the PMOS2; and the twelfth resistor R12 is connected in parallel to the MOS.

[0023] As described above, the electric tool battery pack charging circuit provided by the present application has the following beneficial effects:

[0024] The first filter module can filter the alternating current inputted from the alternating current input terminal, the rectifier BD can convert the alternating current into direct current, the second filter module can filter the direct current, the voltage transformation module can transform the voltage of the charging circuit so that the charging circuit can be adapted to the electric tool charging, the discharging module can stabilize the voltage, and the output reverse connection protection module can be used for the direct current output reverse connection protection; the charging output of the charging circuit is reliable and can be accurately protected, the product can solve the safety hidden trouble, and the service life of the charger is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The circuit principle diagram of the electric tool battery pack charging circuit disclosed by the present application is shown in the figure;

[0026] Figure 2 The circuit principle diagram of the electric tool battery pack charging circuit disclosed by the present application is shown in the figure; Figure 1 The enlarged view of the circuit principle diagram of the middle front section is shown in the figure;

[0027] Figure 3 The enlarged view of the circuit principle diagram of the middle front section is shown in the figure; Figure 1 The enlarged view of the circuit principle diagram of the middle rear section is shown in the figure;

[0028] Figure 4 The enlarged view of the circuit principle diagram of the middle front section is shown in the figure; Figure 1 The enlarged view of the first filter module is shown in the figure;

[0029] Figure 5 The enlarged view of the first filter module is shown in the figure; Figure 1 The enlarged view of the second filter module is shown in the figure;

[0030] Figure 6 The enlarged view of the second filter module is shown in the figure; Figure 1 The enlarged view of the voltage transformation module is shown in the figure;

[0031] Figure 7 The enlarged view of the voltage transformation module is shown in the figure; Figure 1 The enlarged view of the discharging module is shown in the figure;

[0032] Figure 8 The enlarged view of the discharging module is shown in the figure; Figure 1 The enlarged view of the output reverse connection protection module is shown in the figure;

[0033] Figure 9 The enlarged view of the output reverse connection protection module is shown in the figure; Figure 1An enlarged view of the ground protection module;

[0034] Figure 10 is shown as Figure 1 An enlarged view of the absorption circuit;

[0035] Element number explanation

[0036] AC input end 1; DC output end 2; first filter module 3; second filter module 4; voltage conversion module 5; discharge module 6; output reverse connection protection module 7; ground protection module 8; absorption circuit 9; diode packaging structure 10; resistance structure 11. DETAILED DESCRIPTION

[0037] The following describes embodiments of the present application by specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification.

[0038] Please refer to Figures 1 to 10 It should be understood that the structures, proportions, sizes, etc. shown in the drawings attached to the specification are only used to understand and read the content disclosed in the specification by those skilled in the art, and are not used to limit the conditions that the present application can be implemented, and therefore do not have technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present application can produce and the purposes that the present application can achieve, should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" used in the specification are only for the convenience of clear description, and are not used to limit the scope of the present application, and the change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the scope of the present application.

[0039] Please refer to Figures 1-3 The present application provides a power tool battery pack charging circuit, which comprises an AC input end 1 and a DC output end 2 arranged at both ends of the charging circuit;

[0040] The charging circuit comprises a first filter module 3, a rectifier BD, a second filter module 4, a voltage transformation module 5, a discharging module 6, an output reverse connection protection module 7, a switching power supply chip U, and the V end and the D end of the switching power supply chip U are connected in parallel with a thirteenth resistor R13; the first filter module 3 is connected with the AC input end 1 and is used for filtering the AC power input by the AC input end 1; the rectifier BD is connected with the output end of the first filter module 3 and is used for converting the AC power into DC power; the second filter module 4 is connected with the output end of the rectifier BD and is used for filtering the DC power; the voltage transformation module 5 is connected with the output end of the second filter module 4 and is used for voltage transformation; the second filter module 4 and the voltage transformation module 5 are connected with the switching power supply chip U; the discharging module 6 is connected with the output end of the voltage transformation module 5 and is used for voltage stabilization and discharging; the output reverse connection protection module 7 is connected between the discharging module 6 and the DC output end 2 and is used for DC output reverse connection protection; the first filter module 3 can filter the AC power input by the AC input end 1, the rectifier BD can convert the AC power into the DC power, the second filter module 4 can filter the DC power, the voltage transformation module 5 can transform the voltage of the charging circuit so that the charging circuit can be adapted to the electric tool charging, the discharging module 6 can stabilize the voltage and discharge, and the output reverse connection protection module 7 can be used for DC output reverse connection protection; the charging output of the charging circuit is reliable and can be accurately protected, the product solves the safety hidden danger, and the service life of the charger is prolonged.

[0041] The charging circuit further comprises a common-mode inductor L connected between the first filter module 3 and the rectifier BD and used for filtering common-mode electromagnetic interference signals.

[0042] Please refer to Figure 4 The first filter module 3 comprises a first variable capacitor C1, a second capacitor C2, a first resistor R1 and a second resistor R2, the first variable capacitor C1 and the second capacitor C2 are connected in parallel between the live wire and the neutral wire of the AC input end 1, and the first resistor R1 and the second resistor R2 are connected in series and then connected in parallel between the live wire and the neutral wire of the AC input end 1; the unidirectional pulsating DC voltage output by the charging circuit is first filtered by the first variable capacitor C1 to remove most of the AC components, and then further filtered by the filter circuit composed of the second capacitor C2, the first resistor R1 and the second resistor R2 to remove the noise

[0043] Please refer to Figure 5The second filter module 4 includes a third capacitor C3, a fourth capacitor C4, a third resistor R3 and a fourth resistor R4, the third capacitor C3 and the fourth capacitor C4 are connected in parallel at the output end of the rectifier BD, and the third resistor R3 and the fourth resistor R4 are connected in parallel at the output end of the rectifier BD; the other end of the fourth resistor R4 is connected to the V port of the switching power supply chip U; the alternating current voltage output by the rectifier BD is first filtered by the third capacitor C1 to remove most of the alternating current components, and then further filtered by the fourth capacitor C4, the third resistor R3 and the fourth resistor R4 to remove the noise

[0044] Please refer to Figure 6 The transformer module 5 includes a transformer T, a seventh capacitor C7 and a first diode D1, the seventh capacitor C7 and the first diode D1 are connected in series and then connected in parallel to the transformer T, and one end of the first diode D1 connected to the transformer T is connected to the D port of the switching power supply chip U; the main function of the seventh capacitor C7 is to reduce the induced voltage of the primary side to avoid the breakdown of the switching tube, and the first diode D1 is a freewheeling diode, which provides a path for the induced current of the transformer T primary coil due to the inductive reactance when the switching tube is off; a common cathode diode package structure 10 is connected in parallel to the output end of the transformer module 5, including a second diode D2 and a third diode D3 connected in series.

[0045] Please refer to Figure 9 The transformer module 5 is connected with a ground protection module 8 for preventing surge voltage; the ground protection module 8 includes a fifth resistor R5, a fifth capacitor C5 and a sixth capacitor C6, the fifth resistor R5, the fifth capacitor C5 and the sixth capacitor C6 are connected in series, and then the fifth resistor R5 is connected between the seventh capacitor C7 and the first diode D1, and the other end of the sixth capacitor C6 is grounded.

[0046] Please refer to Figure 7 The discharge module 6 includes a ninth capacitor C9, a tenth capacitor C10 and an eleventh capacitor C11, the ninth capacitor C9, the tenth capacitor C10 and the eleventh capacitor C11 are connected in parallel, and then the ninth capacitor C9 is connected to the transformer module 5; a resistor structure 11 including a seventh resistor R7 and an eighth resistor R8 connected in parallel is arranged at the negative output end of the discharge module 6, for reducing the total resistance of the negative output end of the discharge module 6 and increasing the current.

[0047] Please refer to Figure 10 An absorption circuit 9 is arranged between the transformer module 5 and the discharge module 6 for absorbing the sharp pulse generated in the charging circuit; the absorption circuit includes an eighth capacitor C8 and a sixth resistor R6, the eighth capacitor C8 and the sixth resistor R6 are connected in series, the eighth capacitor C8 is connected to the transformer module 5, and the sixth resistor R6 is connected to the discharge module 6.

[0048] Please refer to Figure 8 , the output reverse connection protection module 7 includes PMOS 1, PMOS2 and MOS, PMOS 1 and PMOS2 are connected in series and the source output direction of the two is opposite, PMOS 1 is connected with the discharge module 6, and PMOS2 is connected with the DC output end 2; the MOS is connected in parallel between the D pole and the S pole of PMOS2; the G pole and the S pole of the PMOS1 are connected in parallel with the ninth resistor R9 and the fourth diode D4 in sequence; the G pole and the S pole of PMOS2 are connected in parallel with the fifth diode D5 and the eleventh resistor R11 in sequence, and the MOS is connected in parallel with the twelfth resistor R12; when the charger is not connected with the battery pack, the charging head cannot measure the voltage, so it is called 0V safe no output, in order to consider safety, the output reverse connection protection module 7 can prevent the current from burning the field effect tube element in the circuit and protect the overall circuit.

[0049] In summary, the electric tool battery pack charging circuit provided by the present application, the first filter module 3 can filter the alternating current input by the alternating current input end 1, the rectifier BD can convert the alternating current into direct current, the second filter module 4 can filter the direct current, the voltage transformation module 5 can transform the voltage of the charging circuit so that the charging circuit can adapt to the electric tool charging, the discharge module 6 can stabilize and discharge, and the output reverse connection protection module 7 can be used for the direct current output reverse connection protection; the charging output of the charging circuit is reliable, accurate protection can be carried out, the product solves the safety hidden danger, and the service life of the charger is prolonged. Therefore, the present application effectively overcomes the various shortcomings in the prior art and has high industrial utilization value.

[0050] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A charging circuit for a power tool battery pack, comprising an AC input terminal and a DC output terminal disposed at both ends of the charging circuit; Its features are, The charging circuit includes: The first filtering module is connected to the AC input terminal and is used for filtering the AC power input to the AC input terminal. The rectifier BD is connected to the output of the first filter module and is used to convert AC power into DC power. The second filtering module is connected to the output terminal of the rectifier BD and is used for DC filtering. A transformer module, which is connected to the output of the second filter module, is used for voltage transformation; A discharge module, which is connected to the output terminal of the transformer module, is used for regulated discharge. Output reverse connection protection module, which is connected between the discharge module and the DC output terminal, is used for DC output reverse connection protection; The switching power supply chip U is connected to the second filter module and the transformer module. The output reverse connection protection module includes PMOS 1, PMOS 2 and MOS. PMOS 1 and PMOS 2 are connected in series and their source output directions are opposite. PMOS 1 is connected to the discharge module and PMOS 2 is connected to the DC output terminal. MOS is connected in parallel between the drain and source of PMOS 2. The PMOS1 has a ninth resistor R9 and a fourth diode D4 connected in parallel between its gate and source; the PMOS2 has a fifth diode D5 and an eleventh resistor R11 connected in parallel between its gate and source; and a twelfth resistor R12 is connected in parallel on the MOS.

2. The power tool battery pack charging circuit according to claim 1, characterized in that: The charging circuit also includes a common-mode inductor L, which is connected between the first filter module and the rectifier BD to filter common-mode electromagnetic interference signals.

3. The power tool battery pack charging circuit according to claim 2, characterized in that: The first filtering module includes a first variable capacitor C1, a second capacitor C2, a first resistor R1, and a second resistor R2. The first variable capacitor C1 and the second capacitor C2 are connected in parallel between the live wire and the neutral wire of the AC input terminal, respectively. The first resistor R1 and the second resistor R2 are connected in series and also in parallel between the live wire and the neutral wire of the AC input terminal.

4. The power tool battery pack charging circuit according to claim 1, characterized in that: The second filter module includes a third capacitor C3, a fourth capacitor C4, a third resistor R3, and a fourth resistor R4. The third capacitor C3 and the fourth capacitor C4 are connected in parallel to the output terminal of the rectifier BD. The third resistor R3 and the fourth resistor R4 are connected in series and are also connected in parallel to the output terminal of the rectifier BD.

5. The power tool battery pack charging circuit according to claim 1, characterized in that: The transformer module includes a transformer T, a seventh capacitor C7, and a first diode D1. The seventh capacitor C7 and the first diode D1 are connected in series and then in parallel with the transformer T.

6. The power tool battery pack charging circuit according to claim 5, characterized in that: The transformer module is connected to a grounding protection module for surge voltage protection. The grounding protection module includes a fifth resistor R5, a fifth capacitor C5, and a sixth capacitor C6. The fifth resistor R5, the fifth capacitor C5, and the sixth capacitor C6 are connected in series and then connected between the seventh capacitor C7 and the first diode D1 through the fifth resistor R5. The other end of the sixth capacitor C6 is grounded.

7. The power tool battery pack charging circuit according to claim 6, characterized in that: The discharge module includes a ninth capacitor C9, a tenth capacitor C10, and an eleventh capacitor C11. The ninth capacitor C9, the tenth capacitor C10, and the eleventh capacitor C11 are connected in parallel and then connected to the transformer module through the ninth capacitor C9.

8. The power tool battery pack charging circuit according to claim 7, characterized in that: An absorption circuit is provided between the transformer module and the discharge module to absorb the spike pulses generated in the circuit. The absorption circuit includes an eighth capacitor C8 and a sixth resistor R6. The eighth capacitor C8 and the sixth resistor R6 are connected in series and then connected to the transformer module through the eighth capacitor C8 and to the discharge module through the sixth resistor R6.

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