A charger circuit and a charger

Abstract

The utility model discloses a charger circuit and a charger. The charger circuit comprises an input rectifying and filtering module, a transformer, an output rectifying and filtering module, an output sampling and feedback module, a PWM logic control module and an ESD energy discharge control module. The input end and the output end of the input rectifying and filtering module are respectively connected to the AC input end of a mains power supply and the first end of a primary winding of a transformer. The second end of the primary winding of the transformer is connected to the PWM logic control module through a first switch tube. The secondary winding of the transformer is connected to the DC output end and the output sampling and feedback module after passing through the output rectifying and filtering module. The output sampling and feedback module is connected to the PWM logic control module through a photoelectric coupler. The ESD energy discharge control module comprises an output positive discharge resistor whose two ends are respectively connected to the positive ends of the AC input end and the DC output end of the mains power supply and an output negative discharge resistor whose two ends are respectively connected to the ground ends of the AC input end and the DC output end of the mains power supply.

Description

Technical Field

[0001] The utility model relates to the technical field of chargers, in particular to a charger circuit and a charger. Background Art

[0002] Against the backdrop of the severe global energy and environmental crises, and with the development of electronic application technology, there are more and more types of electronic products on the market. ESD (Electro-Static discharge) phenomenon can be seen everywhere in life, which has a great impact on electronic components and consumer electronic products, causing failures, generating more electronic waste, and causing further adverse effects on the environment.

[0003] In order to eliminate the impact of ESD on the service life of electronic equipment, in addition to the commonly used method of adding ESD protection tubes in the circuit, the main method used in the existing technology is to set up a tip discharge between the primary and secondary grounds in the charger. However, the currently commonly used tip discharge technology sometimes cannot effectively provide an energy discharge channel, and also brings potential safety distance risks. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a charger circuit and a charger to effectively discharge static electricity and improve the ESD protection capability of the charger.

[0005] In a first aspect, the utility model provides a charger circuit, including an input rectifier and filter module, a transformer, an output rectifier and filter module, an output sampling feedback module, a PWM logic control module and an ESD energy discharge control module, wherein the input end of the input rectifier and filter module is connected to the AC input end of the mains power, the output end of the input rectifier and filter module is connected to the first end of the primary winding of the transformer, the second end of the primary winding of the transformer is connected to the PWM logic control module through a first switch tube, the secondary winding of the transformer is connected to the DC output end and the output sampling feedback module after passing through the output rectifier and filter module, the output sampling feedback module is connected to the PWM logic control module through a photoelectric coupler, the ESD energy discharge control module is connected to the AC input end of the mains power and the DC output end, and the ESD energy discharge control module includes an output positive discharge resistor and an output negative discharge resistor, the two ends of the output positive discharge resistor are respectively connected to the positive ends of the AC input end of the mains power and the DC output end, and the two ends of the output negative discharge resistor are respectively connected to the ground ends of the AC input end of the mains power and the DC output end.

[0006] In a second aspect, the utility model further provides a charger, comprising a circuit board, wherein the circuit board comprises the above-mentioned charger circuit.

[0007] The beneficial technical effect of the utility model is that the charger circuit of the utility model is provided with an input rectifier filter module, a transformer, an output rectifier filter module, an output sampling feedback module, a PWM logic control module and an ESD energy discharge control module, and the ESD energy discharge control module is electrically connected between the AC input terminal and the DC output terminal of the mains power, so as to bridge the primary and secondary terminals of the transformer, provide a lower impedance channel for energy discharge and ensure the safety distance requirements of the primary and secondary terminals of the transformer, effectively attenuate ESD energy from the outside, avoid ESD energy coupling into the circuit, discharge large energy as much as possible into the mains network connected to the AC input terminal of the mains power, avoid damage to the charger caused by ESD energy, and prevent failure of the whole machine; and the ESD energy discharge control module includes an output positive The positive discharge resistor and the output negative discharge resistor are used to discharge the ESD energy of the positive terminal and the ground terminal of the DC output terminal to the ground of the mains network connected to the mains AC input terminal through the corresponding discharge resistors, effectively discharge static electricity, improve the ESD protection capability of the charger, effectively reduce the risk of ESD damage, and improve the probability of defective electronic products. The ESD energy is directly connected to the ground of the mains network through the mains AC input terminal, and there is no need to connect it to the primary winding of the rectified transformer, so as to avoid ESD energy from damaging the PWM logic control module connected to the primary winding of the transformer. The static electricity of the positive terminal and the ground terminal of the DC output terminal can be directly released to the mains network connected to the mains AC input terminal, which can effectively reduce the ESD energy discharge to the output sampling feedback module and play a protective role. The charger of the utility model also has the above functions and is highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0009] Figure 1 A schematic diagram of a charger circuit provided by an embodiment of the utility model;

[0010] Figure 2 A circuit diagram of a charger circuit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0011] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0012] See also Figure 1 to Figure 2 , Figure 1 The schematic diagram of the charger circuit provided by the embodiment of the utility model is a schematic diagram of the framework of the charger circuit, the charger circuit 10 includes an input rectifier filter module 11, a transformer T1A, an output rectifier filter module 13, an output sampling feedback module 14, a PWM logic control module 15 and an ESD energy discharge control module 16, the input end of the input rectifier filter module 11 is connected to the AC input end 101 of the mains, the output end of the input rectifier filter module 11 is connected to the first end of the primary winding of the transformer T1A, the second end of the primary winding of the transformer T1A is connected to the PWM logic control module 15 through the first switch tube Q1, and the secondary winding of the transformer T1A is connected to the DC output end after passing through the output rectifier filter module 13. 102 is connected to the output sampling feedback module 14, the output sampling feedback module 14 is connected to the PWM logic control module 15 through a photoelectric coupler, the ESD energy discharge control module 16 is connected to the mains AC input terminal 101 and the DC output terminal 102, the ESD energy discharge control module 16 includes an output positive discharge resistor NTC2 and an output negative discharge resistor NTC1, the two ends of the output positive discharge resistor NTC2 are respectively connected to the positive terminals Vout+ of the mains AC input terminal 101 and the DC output terminal 102, and the two ends of the output negative discharge resistor NTC1 are respectively connected to the ground terminals of the mains AC input terminal 101 and the DC output terminal 102.

[0013] The charger circuit 10 is provided with an input rectifier filter module 11, a transformer T1A, an output rectifier filter module 13, an output sampling feedback module 14, a PWM logic control module 15 and an ESD energy discharge control module 16, and the ESD energy discharge control module 16 is electrically connected between the AC input terminal 101 and the DC output terminal 102, so as to bridge the primary and secondary terminals of the transformer T1A, provide a lower impedance channel for energy discharge and ensure the safety distance requirements of the primary and secondary terminals of the transformer T1A, effectively attenuate the ESD energy from the outside, avoid the ESD energy from being coupled into the circuit, and discharge the large energy as much as possible to the DC output terminal 102 connected to the AC input terminal 101 of the mains. The mains network is used to avoid damage to the charger caused by ESD energy and prevent failure of the entire device; and the ESD energy discharge control module 16 includes an output positive discharge resistor NTC2 and an output negative discharge resistor NTC1, so as to discharge the ESD energy at the positive terminal Vout+ and the ground terminal of the DC output terminal 102 through the corresponding discharge resistors to the ground of the mains network connected to the mains AC input terminal 101, effectively discharge static electricity, improve the ESD protection capability of the charger, effectively reduce the risk of ESD damage, and improve the probability of defective electronic products. The ESD energy is directly connected to the ground of the mains network through the mains AC input terminal 101, without the need to be connected to the ground of the rectifier transformer T1A. The primary winding is connected to avoid ESD energy from damaging the PWM logic control module 15 connected to the primary winding of the transformer T1A, and the static electricity at the positive terminal Vout+ of the DC output terminal 102 and the ground terminal can be directly released to the mains network connected to the mains AC input terminal 101, which can effectively reduce the ESD energy discharge to the output sampling feedback module 14 and play a protective role; moreover, the mains input from the mains AC input terminal 101 can be converted into a required smoother DC signal through the input rectification and filtering module 11, and the converted DC signal is transmitted to the transformer T1A; the transformer T1A can set different primary currents according to the voltage or current and other electrical information required by the user. The voltage is adjusted by adjusting the turns ratio of the level turns, and the required voltage is transmitted to the output rectifier filter module 13; the output rectifier filter module 13 further rectifies and filters the voltage signal transmitted by the transformer T1A and transmits it to the DC output terminal 102 for the terminal device to connect and power the terminal device; the output sampling feedback module 14 performs real-time sampling according to the high and low changes of the output voltage signal after filtering and rectification, and converts the collected signal into a corresponding level signal and transmits the level signal to the PWM logic control module 15 through the optocoupler; the PWM logic control module 15 adjusts the switch pulse width of the charger according to the received level signal to achieve real-time and accurate control of the output voltage. The input of ESD energy can be as follows Figure 2 Indicated by the arrow.

[0014] Specifically, in this embodiment, the output positive discharge resistor NTC2 and the output negative discharge resistor NTC1 are both thermistors. The instantaneous large energy makes the thermistor impedance smaller, and the energy can be smoothly released to the ground of the mains network connected to the mains AC input terminal 101 without damaging the components in the charger circuit 10. The resistance values ​​of the output positive discharge resistor NTC2 and the output negative discharge resistor NTC1 can both be 100M ohms, so that the energy discharge will not affect the product leakage current and safety requirements, so that the product anti-static ability can reach more than 30KV.

[0015] Specifically, the AC input terminal 101 of the mains power includes a live wire terminal L and a neutral wire terminal N, and the input rectification and filtering module 11 includes a rectifier bridge D101. The live wire terminal L is connected to the first end of the first coil of the common-mode inductor LF1 and the first end of the bidirectional transient voltage suppression diode TVS1 through a fuse F1. The second end of the bidirectional transient voltage suppression diode TVS1 is connected to the neutral wire terminal N and the first end of the second coil of the common-mode inductor LF1. The second end of the first coil of the common-mode inductor LF1 is connected to the first AC input terminal of the rectifier bridge D101, and the second end of the second coil of the common-mode inductor LF1 is connected to the second AC input terminal of the rectifier bridge D101. The positive DC output terminal of the rectifier bridge D101 is connected to the first end of the primary winding of the transformer T1A, and the negative DC output terminal of the rectifier bridge D101 is grounded. The neutral line terminal N is connected to the first end of the second coil of the common mode inductor LF1 through the third thermistor NTC3, and a first polarity capacitor EC1 is electrically connected between the positive DC output terminal and the negative DC output terminal of the rectifier bridge D101, the positive electrode of the first polarity capacitor EC1 is connected to the positive DC output terminal of the rectifier bridge D101, and the negative electrode of the first polarity capacitor EC1 is grounded. Among them, the rectifier bridge D101 may include four diodes, namely a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4. The anode of the first diode D1 is connected to the cathode of the second diode D2 and serves as the first AC input terminal of the rectifier bridge D101, so as to be connected to the second end of the first coil of the common-mode inductor LF1; the anode of the third diode D3 is connected to the cathode of the fourth diode D4 and serves as the second AC input terminal of the rectifier bridge D101, so as to be connected to the second end of the second coil of the common-mode inductor LF1; the cathode of the first diode D1 is connected to the cathode of the third diode D3 and serves as the positive DC output terminal of the rectifier bridge D101, so as to be connected to the first end of the primary winding of the transformer T1A; the anode of the second diode D2 is connected to the anode of the fourth diode D4 and serves as the negative DC output terminal of the rectifier bridge D101, so as to be connected to the ground.

[0016] Specifically, the first end of the output positive discharge resistor NTC2 and the first end of the output negative discharge resistor NTC1 are connected to the first end of the bidirectional transient voltage suppression diode TVS1, so that the output positive discharge resistor NTC2 and the output negative discharge resistor NTC1 can be connected to the neutral line terminal N of the mains AC input terminal 101 after the bidirectional transient voltage suppression diode TVS1, and the output positive discharge resistor NTC2 and the output negative discharge resistor NTC1 can be connected to the live line terminal L of the mains AC input terminal 101 through the fuse F1, thereby facilitating the discharge of ESD energy to the ground of the mains network electrically connected to the mains AC input terminal 101.

[0017] Specifically, the first switch tube Q1 is an NMOS tube, the second end of the primary winding of the transformer T1A is connected to the drain of the first switch tube Q1, the source of the first switch tube Q1 is grounded after passing through an inductive resistor, and the gate of the first switch tube Q1 is connected to the PWM logic control module 15, so that the first switch tube Q1 can be controlled to be on and off according to the control of the PWM logic control module 15, so as to adjust the turns ratio of the primary and secondary turns of the transformer T1A, thereby realizing the adjustment of the output voltage of the transformer T1A.

[0018] Specifically, the output rectifier and filter module 13 includes an eleventh diode D11, a third polarity capacitor EC3 and a fourth polarity capacitor EC4, the first end of the secondary winding of the transformer T1A is connected to the anode of the eleventh diode D11, the cathode of the eleventh diode D11 is connected to the positive electrode of the third polarity capacitor EC3, the positive electrode of the fourth polarity capacitor EC4 and the positive terminal Vout+ of the DC output terminal 102, and the negative electrode of the third polarity capacitor EC3, the negative electrode of the fourth polarity capacitor EC4 and the ground terminal of the DC output terminal 102 are all grounded.

[0019] Specifically, the DC output terminal 102 is connected to the interface USB1, so that other devices are connected to the charger circuit 10 through the interface USB1, the positive terminal Vout+ of the DC output terminal 102 is connected to the power supply pin VBUS of the interface USB1, and the ground terminal of the DC output terminal 102 is connected to the ground pin GND of the interface USB1. Preferably, the interface USB1 adopts a USB interface, and the interface USB1 also includes a data positive pin D+ and a data negative pin D-.

[0020] Specifically, the light source U1A of the photoelectric coupler is connected to the output sampling feedback module 14, and the light receiver U1B of the photoelectric coupler is connected to the PWM logic control module 15, so that the level signal obtained by the real-time sampling of the output sampling feedback module 14 according to the high and low changes of the output voltage signal after filtering and rectification is transmitted to the PWM logic control module 15. The output sampling feedback module 14 is connected to the output end of the output filtering and rectifying module 13 through the seventh resistor R7.

[0021] Based on the above design, during operation, when external energy is released from the positive terminal of the DC output terminal to the charger circuit, the instantaneous large energy is directly discharged to the ground of the mains network connected to the mains AC input terminal through the output positive discharge resistor of the ESD energy discharge control module; when external energy is released from the ground terminal of the DC output terminal to the charger circuit, the instantaneous large energy is directly discharged to the ground of the mains network connected to the mains AC input terminal through the output negative discharge resistor of the ESD energy discharge control module.

[0022] Specifically, the charger of the present invention includes a circuit board, and the circuit board includes the above-mentioned charger circuit.

[0023] In summary, the charger circuit of the utility model is provided with an input rectifier filter module, a transformer, an output rectifier filter module, an output sampling feedback module, a PWM logic control module and an ESD energy discharge control module, and the ESD energy discharge control module is electrically connected between the AC input terminal and the DC output terminal of the mains power, so as to bridge the primary and secondary terminals of the transformer, provide a lower impedance channel for energy discharge and ensure the safety distance requirements of the primary and secondary terminals of the transformer, and can effectively attenuate ESD energy from the outside, avoid ESD energy coupling into the circuit, and discharge large energy as much as possible into the mains network connected to the AC input terminal of the mains power, so as to avoid damage to the charger caused by ESD energy and prevent failure of the whole machine; and the ESD energy discharge control module includes an output positive discharge resistor And the output negative electrode discharge resistor, so as to discharge the ESD energy of the positive terminal and the ground terminal of the DC output terminal through the corresponding discharge resistor to the ground of the mains network connected to the mains AC input terminal, effectively discharge static electricity, improve the ESD protection ability of the charger, effectively reduce the risk of ESD damage, improve the probability of defective electronic products, and the ESD energy is directly connected to the ground of the mains network through the mains AC input terminal, without the need to be connected to the primary winding of the rectified transformer, to avoid ESD energy from damaging the PWM logic control module connected to the primary winding of the transformer, and the static electricity of the positive terminal and the ground terminal of the DC output terminal can be directly released to the mains network connected to the mains AC input terminal, which can effectively reduce the ESD energy discharge to the output sampling feedback module, and play a protective role. The charger of the utility model also has the above functions and is highly practical.

[0024] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the utility model, and these modifications or replacements should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A charger circuit, characterized in that: The invention comprises an input rectifying and filtering module, a transformer, an output rectifying and filtering module, an output sampling and feedback module, a PWM logic control module and an ESD energy discharge control module, wherein the input end of the input rectifying and filtering module is connected to the AC input end of the mains power, the output end of the input rectifying and filtering module is connected to the first end of the primary winding of the transformer, the second end of the primary winding of the transformer is connected to the PWM logic control module through a first switch tube, the secondary winding of the transformer is connected to the DC output end and the output sampling and feedback module after passing through the output rectifying and filtering module, the output sampling and feedback module is connected to the PWM logic control module through a photoelectric coupler, the ESD energy discharge control module is connected to the AC input end of the mains power and the DC output end, the ESD energy discharge control module comprises an output positive discharge resistor and an output negative discharge resistor, the two ends of the output positive discharge resistor are respectively connected to the positive ends of the AC input end of the mains power and the DC output end, and the two ends of the output negative discharge resistor are respectively connected to the ground ends of the AC input end of the mains power and the DC output end.

2. The charger circuit according to claim 1, characterized in that: The output positive electrode discharge resistor and the output negative electrode discharge resistor are both thermistors.

3. The charger circuit according to claim 1, characterized in that: The AC input end of the mains power includes a live wire end and a neutral wire end, the input rectification and filtering module includes a rectifier bridge, the live wire end is connected to the first end of the first coil of the common mode inductor and the first end of the bidirectional transient voltage suppression diode after passing through a fuse, the second end of the bidirectional transient voltage suppression diode is connected to the neutral wire end and the first end of the second coil of the common mode inductor, the second end of the first coil of the common mode inductor is connected to the first AC input end of the rectifier bridge, the second end of the second coil of the common mode inductor is connected to the second AC input end of the rectifier bridge, the positive DC output end of the rectifier bridge is connected to the first end of the primary winding of the transformer, and the negative DC output end of the rectifier bridge is grounded.

4. The charger circuit according to claim 3, characterized in that: The first end of the output positive electrode discharge resistor and the first end of the output negative electrode discharge resistor are connected to the first end of the bidirectional transient voltage suppression diode.

5. The charger circuit according to claim 3, characterized in that: The first switch tube is an NMOS tube, the second end of the primary winding of the transformer is connected to the drain of the first switch tube, the source of the first switch tube is grounded after passing through an inductive resistor, and the gate of the first switch tube is connected to the PWM logic control module.

6. The charger circuit according to claim 1, characterized in that: The output rectification and filtering module includes an eleventh diode, a third polarity capacitor and a fourth polarity capacitor. The first end of the secondary winding of the transformer is connected to the anode of the eleventh diode, the cathode of the eleventh diode is connected to the positive electrode of the third polarity capacitor, the positive electrode of the fourth polarity capacitor and the positive terminal of the DC output end, and the negative electrode of the third polarity capacitor, the negative electrode of the fourth polarity capacitor and the ground terminal of the DC output end are all grounded.

7. The charger circuit according to claim 1, characterized in that: The DC output terminal is connected to the interface, the positive terminal of the DC output terminal is connected to the power supply pin of the interface, and the ground terminal of the DC output terminal is connected to the ground pin of the interface.

8. The charger circuit according to claim 7, characterized in that: The interface is a USB interface.

9. The charger circuit according to claim 1, characterized in that: The light source of the photoelectric coupler is connected to the output sampling feedback module, and the light receiver of the photoelectric coupler is connected to the PWM logic control module.

10. A charger, characterized in that: It comprises a circuit board, wherein the circuit board comprises the charger circuit according to any one of claims 1 to 9.

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