A microprocessor-controlled current-adjustable charger with multiple protection functions

Abstract

The present invention relates to a microprocessor-controlled charger with adjustable current and multiple protection functions. The designed new charger can automatically charge 6V or 12V batteries. The present invention has two working modes, 6V / 12V, on a control panel. The charger automatically determines and selects the mode, and has corresponding 6V and 12V indicator lights for indication. Indicators for charging voltage, current, and battery power are provided, and can be selected and controlled by a mode selection touch button. Two current selection control touch buttons are provided, with charging currents of 2.5A or 10A respectively. The current cannot be continuously adjusted, and corresponding indicator lights are provided. Indicators for battery charging, full charge, and reverse polarity when the battery is connected, as well as warning indicators for battery disconnection or short circuit are provided. The present invention has small size and volume, light weight, and is easy to carry.

Description

Technical Field

[0001] The present invention relates to an electronically controlled battery charger product, in particular to a charger with adjustable current controlled by a microprocessor and multiple protection functions, belonging to the technical field of battery chargers. Background Art

[0002] At present, competition in the battery charger product market is not only reflected in the advancement of technology, but also depends to a certain extent on the charger's functions, appearance, control circuit and overall structural design, the advancement of production and manufacturing processes, production efficiency, production costs, product consistency and reliability, etc.

[0003] Currently, small battery chargers on the domestic and international markets typically offer output voltages of 6V / 12V, with rated charging currents typically ranging from 1 to 20A. Some chargers can reach charging currents as high as 100 amperes. For reasons of cost and other considerations, battery chargers with low current ratings (such as 2A, 8A, and 10A) are generally the mainstream products. Many of these battery chargers on the market utilize traditional transformer-and-rectifier control circuits and structures. Because these chargers utilize a transformer to convert low-voltage AC power and then rectify it for output control, they are technically advanced and suffer from numerous issues, including large transformer and rectifier size, high heat generation, low energy conversion efficiency, limited control functions, large size and weight, and high raw material consumption and waste. Recent advances in electronic technology have also driven the development of electronically controlled battery chargers. These new electronically controlled battery chargers significantly outperform traditional transformer-and-rectifier chargers in terms of technical performance, energy conservation, and material savings. Advanced technology has significantly reduced the size and weight of new electronically controlled battery chargers, while significantly increasing their control capabilities. These chargers no longer utilize traditional circuitry and structures, but instead employ control circuits based on high-frequency switching power supplies or medium-frequency inverters. The core materials used in their transformers have also undergone fundamental changes. For example, these chargers automatically detect and control the battery charging voltage and current, achieving high current and voltage control accuracy and rapid response. They can include charging status indicators and protection against reverse polarity, disconnection, or short-circuit conditions. They can implement various control modes, including constant voltage, constant current, and floating charge. The output rectifiers of these new electronically controlled chargers are no longer conventional diodes, but instead employ fast-recovery diodes. This significantly reduces the battery charger's inherent heat generation, significantly improving its energy conversion efficiency. They are also highly economical in terms of energy and material conservation. Because the output parameters (voltage and current) of new electronically controlled battery chargers are controlled using switching power supply conversion or inversion, these chargers, featuring switching power supply or inverter control technology, are being hailed as "new, highly efficient, energy-saving charging power supplies," representing the future direction of battery charger power supply development. Because the internal control components of these new electronically controlled battery chargers operate in a high-frequency or medium-frequency switching state, their inherent energy consumption is extremely low. Consequently, their efficiency can exceed 90%, nearly double the efficiency of traditional transformer-rectifier chargers. With the rapid advancement of charger power supply control technology, high-efficiency switching power supply or inverter-controlled chargers are developing towards multifunctionality, miniaturization, high frequency, and high integration, and are finding increasingly widespread application. They are poised to replace traditional chargers in the future.

[0004] The new electronically controlled battery charger mainly relies on the circuit board and the control circuit on it to realize the product's functions and improve the product's performance. Compared with the traditional transformer rectifier charger, their circuit is relatively more complicated; the production process technology is also mainly based on the manufacturing process technology of the circuit board. Of course, under the same output voltage and current levels, different products may have completely different circuit principles and circuit board designs, as well as production methods. These all affect the product's technical performance, reliability, production and manufacturing costs, product market competitiveness, etc. In other words, chargers with different structures and circuit designs have relatively different technical parameters, performance, production efficiency, and even product appearance, reliability, and market competitiveness. Summary of the Invention

[0005] The object of the present invention is to provide a microprocessor-controlled charger with adjustable current and multiple protection functions. The designed new charger can automatically charge 6V or 12V batteries and has two working modes: 6V / 12V. The charger automatically determines and selects the working mode and has corresponding 6V and 12V indicator lights for indication. It is equipped with charging voltage display, current display and battery power display indicator lights, and can be selected and controlled by a mode selection touch button. It is equipped with two current selection control touch buttons, with charging current of 2.5A or 10A respectively. The current cannot be continuously adjusted, and there are 2.5A and 10A current LED indicator lights. It is equipped with battery charging, full charge, reverse polarity prompts when the battery is connected, and warning indicators for battery disconnection or short circuit. The present invention is not only small in size, but also light in weight and easy to carry.

[0006] A microprocessor-controlled current-adjustable charger with multiple protection functions, characterized in that: the main components of the charger include a handle, a housing cover, a power tube radiator (one), a main control board assembly, a cooling fan, a power cord, a fan mesh, a red charging clip, a black charging clip, an output line that cannot be pulled off, a housing base, a housing panel and a control panel assembly; the charger has two circuit board assemblies, one for the main control board assembly and the other for the control panel assembly, which are connected to each other and to the power cord, two battery clips, etc.; a large number of electronic components and parts are arranged on the main control board assembly, including a fine-tuning potentiometer, a control chip, a differential mode capacitor, a rectifier bridge, a drive transformer, an electrolytic capacitor, a three-phase rectifier, and a power supply. The control panel assembly is also provided with many electronic components and parts, including current selection button, digital tube, mode selection button, indicator light, microprocessor controller, and the power cord provides external power supply for the charger circuit board; the main control board assembly includes filter capacitor C9, rectifier bridge BR1, electrolytic capacitors C10 and C11, resistors R29 and R30, NPN transistors Q3 and Q4, inverter transformer T1, fast recovery rectifier diode D1, filter inductor L1, transistor Q7, field effect tube Q8, drive transformer T2, PWM control chip IC1 and many resistors, capacitors, Diodes and transistors; wherein the filter capacitor C9, the rectifier bridge BR1, the electrolytic capacitors C10 and C11, the resistors R29 and R30, the NPN transistors Q3 and Q4, the inverter transformer T1, the fast recovery rectifier diode D1, the filter inductor L1 and their peripheral devices constitute a half-bridge inverter main circuit, the two ends of the filter capacitor C9 of the half-bridge inverter main circuit are connected to the 220-240V power line, the input end of the rectifier bridge BR1 is also connected to the two ends of the power supply, the output end of the rectifier bridge BR1 is connected in series with the electrolytic capacitors C11 and C10, the positive electrode of the electrolytic capacitor C11 is connected to the positive output electrode of the rectifier bridge BR1, the negative electrode of the electrolytic capacitor C10 is grounded, and a resistor is connected in parallel at both ends of each electrolytic capacitor; the rectifier bridge BR1 rectifies After being filtered by electrolytic capacitors C11 and C10, a +310V high voltage is generated. A series circuit of NPN transistors Q3 and Q4 is connected in parallel at both ends of the +310V high voltage to ground. The collector of NPN transistor Q3 is connected to the +310V end, and the emitter of NPN transistor Q3 is connected to the collector of NPN transistor Q4. The emitter of NPN transistor Q4 is grounded, that is, the +310V ground. A diode D11 is connected in parallel between the collector and emitter of NPN transistor Q3, and the anode of diode D11 is connected to the emitter of NPN transistor Q3. A diode D12 is connected in parallel between the collector and emitter of NPN transistor Q4, and the anode of diode D12 is connected to the emitter of NPN transistor Q4.The secondary winding N4 end N1 of the driving transformer T2 is connected to the capacitor C14 and one end of the primary winding N1. The other end of the capacitor C14 is connected to the resistor R36. The other end of the resistor R36 is connected to the other end of the primary winding N1 of the inverter transformer T1. This connection point is connected to one end of the capacitor C18. The other end of the capacitor C18 is connected to the middle connection point of the electrolytic capacitors C11 and C10. The NPN transistors Q3 and Q4 are the switching tubes of the half-bridge inverter main circuit. The electrolytic capacitors C11 and C10 are the commutation capacitors of the half-bridge inverter main circuit. There are 4 secondary windings of the inverter transformer T1, namely the secondary windings N2, N3, N4 and N5. The secondary winding N 2 and N3 are connected in series, indirectly; the other ends of the two secondary windings N2 and N3 are connected to the anode of the fast recovery rectifier diode D1, forming a full-wave output rectifier circuit with a center tap; the secondary windings N4 and N5 of the inverter transformer T1 are also connected in series, indirectly, and the other ends of the two secondary windings N4 and N5 are also connected to the anodes of diodes D19 and D18, and their cathodes are connected to the anode of diode D20, and then the DC voltage is output through the cathode of diode D20, connected to the plug CN4, and connected to the plug CH1 of the control panel circuit part through a connecting line, providing working power for the circuit of the field effect tube Q10 part that realizes 6V or 12V voltage conversion control. voltage; the connection point of the secondary windings N4 and N5 is tapped to ground, and this part of the circuit constitutes a full-wave output rectifier circuit with a center tap; the cathodes of the two fast recovery rectifier diodes D1 are connected to each other, and the anodes of the two fast recovery rectifier diodes D1 are respectively connected to the other ends of the secondary windings N2 and N3 of the inverter transformer T1; capacitors C15 and C16 are respectively connected in parallel at both ends of the two fast recovery rectifier diodes D1, the cathodes of the two fast recovery rectifier diodes D1 are connected to one end of the filter inductor L1, and the other end of the filter inductor L1 is connected to the S pole of the resistors R16, R53 and the S pole of the field effect transistor Q8, and the G gate of the field effect transistor Q8 is connected to the other end of the resistor R53 and the collector of the transistor Q7. The emitter of transistor Q7 is grounded; the D electrode of field-effect transistor Q8 is connected to the output terminal of the charger. A diode is connected in parallel across both ends of field-effect transistor Q8, with the cathode of the diode connected to its S electrode and its anode connected to the D electrode of field-effect transistor Q8. The base of transistor Q7 is connected to one end of resistor R52, the other end of R52 is connected to pin 1 of plug CN5, and pin 2 of plug CN5 is grounded. Pin 1 of plug CN5 is connected to pin 1 of plug CH3 and the control terminal of microprocessor U1. The output terminal of the charger is connected to pins 1 and 3 of plug CN3, and then to plug CN3 via connecting wires, that is, the output of the detected battery voltage is transmitted to microprocessor U1.

[0007] The output part of the half-bridge inverter main circuit is also provided with a cooling fan power supply circuit and a protection control circuit; for the cooling fan power supply circuit, its composition includes: the other end of the resistor R16 is connected to the positive electrode of the electrolytic capacitor C4, the negative electrode of the electrolytic capacitor C4 is grounded, and the two ends of the electrolytic capacitor C4 are connected in parallel with resistors R5 and R44. The two ends of the electrolytic capacitor C4 are connected to the 12V cooling fan FAN through the plug CN2, and are also connected to one end of the resistors R4 and R40 in the low-voltage side drive circuit of the NPN transistors Q3 and Q4 in the half-bridge inverter main circuit. It is the feedback signal Uf end of the charger output voltage. This part of the circuit is called the cooling fan power supply circuit.

[0008] The output part of the half-bridge inverter main circuit is also provided with a protection control circuit; the protection control circuit includes the other end of the output filter inductor L1 connected to the resistor R16, the resistor R53 and the S pole of the field effect tube Q8, the G gate of the field effect tube Q8 is connected to the other end of the resistor R53 and the collector of the transistor Q7, and the emitter of the transistor Q7 is grounded; the D pole of the field effect tube Q8 is connected to the output end of the charger, and a diode is connected in parallel at both ends of the field effect tube Q8, the cathode of the diode is connected to its S pole, and its anode is connected to the D pole of the field effect tube Q8; the base of the transistor Q7 is connected to one end of the resistor R52, the other end of the resistor R52 is connected to pin 1 of the plug CN5, and pin 2 of CN5 is grounded; pin 1 of the plug CN5 is connected to pin 1 of the CH3 plug, which is the microprocessor U1 The control end of the NPN transistors Q3 and Q4 high-voltage side drive circuit includes the secondary windings N3, N4 and N5 of the driving transformer T2, a number of resistors, electrolytic capacitors C12 and C13, and diodes D7~D10. The specific circuit structure is as follows: the base of the NPN transistor Q3 is connected to the resistor R32, the other end of the resistor R32 is connected to the resistor R33, one end of the resistor R37, and the cathode end of the electrolytic capacitor C12 and the diode D8, the other end of the resistor R33 is connected to the +310V end, and the other end of the resistor R37 is connected to the emitter of the NPN transistor Q3 and the same-name terminal of the secondary winding N4 of the driving transformer T2; the anode of the diode D8 is connected to the cathode of the diode D7, the anode of the diode D7 is connected to the anode of the capacitor C12, and also Connected to the same-name terminal of the secondary winding N5 of the driving transformer T2; the secondary winding N5 and the secondary winding N4 are connected in series, and the opposite-name terminal of the secondary winding N5 is connected to the same-name terminal of the secondary winding N4; the opposite-name terminal of the secondary winding N4 is connected to the capacitor C14 and one end of the primary winding N1 of the inverter transformer T1; the base of the NPN transistor Q4 is connected to the resistor R35, the other end of the resistor R35 is connected to the resistor R34, one end of the resistor R38, and the cathode end of the electrolytic capacitor C13 and the diode D10, the other end of the resistor R34 is connected to the emitter of the NPN transistor Q3, and the other end of the resistor R38 is connected to the emitter of the NPN transistor Q4 and the same-name terminal of the secondary winding N3 of the driving transformer T2, which is also the +310V ground terminal. ; The anode of the diode D10 is connected to the cathode of the diode D9, the anode of the diode D9 is connected to the anode of the capacitor C13, and is also connected to the opposite-name end of the secondary winding N3 of the driving transformer T2; the low-voltage side drive circuit of the NPN transistors Q3 and Q4 in the inverter main circuit, the low-voltage side drive circuit includes the primary windings N1 and N2 of the driving transformer T2, the PWM control chip IC1 and their peripheral devices, the primary winding N1 and the primary winding N2 are connected in series, the opposite-name end of the primary winding N2 is connected to the same-name end of the primary winding N1; the opposite-name end of the primary winding N1 is connected to the collector of the transistor Q1 and the cathode of the diode D6, and the emitter of the transistor Q1 is connected to the anodes of the diode D6 and the diode D3, and the emitter of the transistor Q2;The same-name end of the primary winding N2 is connected to the collector of the transistor Q2 and the cathode of the diode D3. The emitter of the transistor Q2 is connected to the anodes of the diodes D3, D4 and D6, the anode of the electrolytic capacitor C7, and the emitter of the transistor Q1. The cathode of the diode D4 is connected to the anode of the diode D5. The cathode of the electrolytic capacitor C7 and the cathode of the diode D5 are grounded. The center taps of the primary winding N1 and the primary winding N2 are connected to the resistor R31. The other end of the resistor R31 is connected to the cathode of the diode D2. The anode of the diode D2 is connected to the cathode of the diode D13, the anode of the electrolytic capacitor C50, and one end of the resistors R21, R24 and R22. The other end of the resistor R21 is connected to 1 of the PWM control chip IC1. Pin 2 is the +VCC operating voltage input terminal of the chip, and an electrolytic capacitor E9 is connected in parallel between this terminal and ground; the other end of resistor R24 is connected to the base of transistor Q1, one end of resistor R20 and pin 8 of PWM control chip IC1, that is, one end of the output PWM pulse width control signal of PWM control chip IC1, and the other end of resistor R20 is grounded. Similarly, resistor R22 is connected to the base of transistor Q2, one end of resistor R23 and pin 11 of PWM control chip IC1, that is, the other end of the output PWM pulse width control signal of IC1, and the other end of resistor R23 is grounded; the anode of diode D13 is connected to the output end of fast recovery diode D1 in the inverter main circuit; Pins 9 and 10 of the PWM control chip IC1 in the PWM control signal generation, output voltage negative feedback, and PI control circuit are grounded, and pin 4 of the PWM control chip IC1 is connected to the cathode of the electrolytic capacitor C8 and one end of the resistor R18. The anode of the electrolytic capacitor C8 is connected to the +5V power supply, and the other end of the resistor R18 is grounded; pin 16 of the PWM control chip IC1 is grounded, and pin 6 of the PWM control chip IC1 is connected to the resistor R19, and the other end of the resistor R19 is grounded; pin 5 of the PWM control chip IC1 is connected to the capacitor C5, and the other end of the capacitor C5 is grounded; through the parameter combination of the resistor R19 and the capacitor C5, the PWM signal frequency output by pins 8 and 11 of the PWM control chip IC1 is 30KHz; pin 7 of the PWM control chip IC1 The pin is grounded, and pin 13 of IC1 is connected to the +5V power supply; pin 1 of the PWM control chip IC1 is connected to one end of resistors R8, R7, R4 and R25, the other ends of resistors R7 and R8 are grounded, and the other end of resistor R4 is connected to the voltage feedback signal output by the charger; the other end of resistor R25 is connected to pin 4 of plug CN1; pin 2 of the PWM control chip IC1 is connected to one end of resistors R3, R17 and capacitor C3, the other end of resistor R3 is connected to the +5V power supply, the other end of resistor R17 is grounded, the other end of capacitor C3 is connected to resistor R10, and the other end of resistor R10 is connected to pin 3 of the PWM control chip IC1, resistors R11 and RJ1, the other end of resistor R11 is connected to capacitor C6, and the other end of capacitor C6 is grounded;The other end of resistor RJ1 is connected to capacitor C2. The other end of capacitor C2 is connected to pin 15 of PWM control chip IC1 and one end of resistors R26, R27, R28, and R39. The other ends of resistors R27 and R28 are connected to a +5V power supply. The other end of resistor R26 is connected to a trimmer potentiometer R2. The other end of resistor R39 is connected to pin 2 of the CN1 connector. One end of resistor R40 is connected to the power supply, and the other end of resistor R40 is connected to pin 3 of CN1.

[0009] The control panel assembly includes a control panel circuit, which includes a power selection circuit, a voltage, current, and power display mode conversion circuit, a microprocessor voltage detection and current feedback control circuit and a PWMA current given signal output circuit, a digital tube display circuit, and an LED indicator control circuit; the resistor R301 is connected in series with the selection button S2 and in parallel between the +5V power supply and the ground, and their middle connection point is connected to the PB6 terminal of the microprocessor U1 to form a power circuit and a selection circuit; the resistor R311 is connected in series with the voltage, current, and power display mode conversion button S1 and in parallel between the +5V power supply and the ground, and their middle connection point is connected to the PB7 terminal of the microprocessor U1 to form a Voltage, current and power display mode conversion circuit; resistor R181 and resistor R361 are connected to field effect transistor Q4 and field effect transistor Q10; and the input end of resistor R181 is connected to the PD7 end of the microprocessor U1 to form a 6V or 12V switching control circuit; the microprocessor voltage detection and current feedback control circuit and PWMA current given signal output circuit are composed of microprocessor U1, operational amplifier U2, resistors R11, R21, R31, R41, R51, R61, R251, R261, capacitors C11, C21, C31, C41, C51, C61; the input signal of resistor R31 is the detection signal of the charger output current size; the feedback of operational amplifier U2 A resistor R51 and a capacitor C21 are connected in parallel between the phase input terminal and its output terminal, and its inverting input terminal is connected to the resistor R41 and then grounded; the resistor R31 is the resistor of its non-phase input terminal, and in addition, the non-phase input terminal is also connected in parallel with the anti-interference filter capacitor C61; the output of the operational amplifier U2 is connected to the PB2 terminal of the microprocessor U1 through the resistor R61, and the anti-interference filter capacitor C31 is also connected in parallel between the PB2 terminal and the ground; the output terminal is connected to the resistor R251, and the other end of the resistor R251 is connected to the capacitor C51 and the resistor R261, the other end of the capacitor C51 is grounded, and the other end of the resistor R261 is connected to the 1st pin of the plug CN2, and the 2nd pin of the plug CN2 is grounded; CN2 is connected to the plug through the connecting line The connector CN4 corresponds to the connection point; the output signal of the microprocessor U1 is connected to pin 1 of the connector CH3, which is connected to pin 1 of the connector CN5 via a connecting wire to form a microprocessor voltage detection and current feedback control circuit and a PWMA current given signal output circuit; the digital tube display circuit and the LED indicator light control circuit include a digital tube DPY1, a digital tube DPY2 and a digital tube DPY3; the control circuit of the digital tube DPY1 is composed of the S1 end of the digital tube DPY1 connected to the collector of the NPN transistor Q11, the emitter of the NPN transistor Q11 is grounded, the base of the NPN transistor Q11 is connected to the resistor R71, and the input end of the resistor R71 is connected to the COM1 end of the microprocessor U1;The control circuit of the digital tube DPY2 is composed of the S2 end of the digital tube DPY2 connected to the collector of the NPN transistor Q21, the emitter of the NPN transistor Q21 is grounded, the base of the NPN transistor Q21 is connected to the resistor R81, and the input end of the resistor R81 is connected to the COM2 end of the microprocessor U1; the control circuit of the digital tube DPY3 is composed of the S3 end of the digital tube DPY3 connected to the collector of the NPN transistor Q31, the emitter of the NPN transistor Q31 is grounded, the base of the NPN transistor Q31 is connected to the resistor R91, and the input end of the resistor R91 is connected The PA3 output of microprocessor U1 is connected to resistor R291, and the other end of resistor R291 is connected to NPN transistor Q81. The emitter of NPN transistor Q81 is grounded, and the collector of NPN transistor Q81 is connected to the common cathode of multiple LED indicators.

[0010] The battery is not connected or short-circuited protection indicator light, that is, the LED00 lamp control circuit part, is characterized in that: the cathode of the LED00 lamp is connected to the collector of Q5, the emitter of Q5 is grounded, the base of Q5 is connected to R241, the anode of LED00 is connected to R211 and then connected to the +5V power supply. The input end of R241 is connected to the attached Figure 4 PD4 control terminal of the U1 microprocessor.

[0011] The control panel circuit also includes a battery reverse connection or reverse polarity protection indicator light circuit, which consists of a cathode of a diode LED01 connected to the collector of a field effect transistor Q6, an emitter of the field effect transistor Q6 connected to ground, a base of the field effect transistor Q6 connected to a resistor R231, an anode of the diode LED01 connected to a resistor R221 and then connected to a +5V power supply, and an input end of the resistor R231 connected to the PD5 control terminal of the microprocessor U1.

[0012] The control panel circuit also includes a battery full indicator light circuit, which consists of a cathode of a diode LED5 connected to the collector of a field effect transistor Q91, an emitter of the field effect transistor Q91 connected to ground, a base of the field effect transistor Q91 connected to a resistor R331, an anode of the diode LED5 connected to a resistor R321 and then connected to a +5V power supply, and an input end of the resistor R331 connected to the PD6 control terminal of the microprocessor U1.

[0013] The control panel circuit also includes a battery reverse connection or reverse polarity circuit, which consists of the cathode of the light-emitting diode inside the optocoupler U3 connected to the anode of the diode D22, the cathode of the diode D22 connected to the positive output polarity terminal of the charger, the anode of the light-emitting diode connected to the resistor R191, the other end of the resistor R191 is grounded, the emitter of the output stage transistor inside the optocoupler U3 is grounded, and its collector is connected to the resistor R201 and the PB4 terminal of the microprocessor U1.

[0014] The charger of the present invention uses advanced inverter control technology and has the advantages of good performance, high reliability, small size, light weight, and low cost. By changing the configuration specifications and parameters of different devices or components, a series of products that meet national and international standards can be formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of an exemplary charger product of the present invention;

[0016] Figure 2 It is a schematic diagram of the main control circuit portion of the charger of the present invention;

[0017] Figure 3 This is a circuit diagram of the control panel of the charger of the present invention (1);

[0018] Figure 4 This is the circuit schematic diagram of the control panel of the charger of the present invention (2);

[0019] Figure 5 This is the circuit schematic diagram of the control panel of the charger of the present invention (3);

[0020] The names of the components in the attached figure are as follows: 1. Handle; 2. Upper cover of the casing; 3. Power tube heat sink (1); 4. Main control board; 5. Cooling fan; 6. Power cord; 7. Fan grille; 8. (Positive polarity) red charging clip; 9. (Negative polarity) black charging clip; 10. Output line that cannot be pulled off; 11. Case base; 12. Case panel; 13. Control panel; 14. Trimmer potentiometer; 15. Control chip; 16. Differential mode capacitor; 17. Rectifier bridge; 18. Drive transformer; 19. Electrolytic capacitor; 20. Transistor (1); 21. Transistor (2); 22. Fast recovery diode; 23. Filter inductor; 24. Heat sink (2); 25. Field effect transistor. DETAILED DESCRIPTION

[0021] Attachment Figure 1This is a schematic diagram of an exemplary charger product according to the present invention. The battery charger of the present invention relates to a microprocessor-controlled 6V and 12V current-stepping charger structure and circuit design with multiple protection features. The charger's circuit board is characterized by a power cord providing external power to the charger's power supply. The two battery clamps are red and black. During charging, red represents the positive polarity of the charger output and connects to the battery's positive terminal; black represents the negative polarity of the charger output and connects to the battery's negative terminal. This new charger can automatically charge 6V or 12V batteries. The control panel 13 of the battery charger of the present invention features a yellow charging LED indicator, a green full charge status LED indicator, a red reverse polarity LED indicator when a battery is connected, and an LED warning indicator for battery disconnection or charger output short circuit. These indicators, controlled by the control circuit of the present invention, provide corresponding indications based on different detection states. A microprocessor controller includes a control software programming interface to facilitate the installation of the control program. A digital display tube displays voltage, current, and battery charge data. The specific data displayed depends on whether the green LED indicator for voltage display, current display and battery power display is on. The display of voltage, current and battery power can be selected through mode selection or switch button. There is a selection button for charging current 2.5A or 10A, and there are 2.5A and 10A current LED indicators. In addition, there is an additional Figure 3 , Attachment Figure 4 and attached Figure 5Many electronic components and parts are identified in the circuit schematic. When the voltage indicator light is on, the digital tube displays the actual battery charging voltage; when the current indicator light is on, the digital tube displays the actual battery charging current. When adjusting the charging current, the set current will be displayed through the digital tube, and after 2 seconds, it will automatically return to the original display state. When the power indicator light is on, the digital tube displays the battery fullness. For the 6V indicator light and the 12V indicator light, when the charger of the present invention is connected to a battery and powered on, the charger automatically determines whether the connected battery is a 6V battery or a 12V battery. For example, if the charger is connected to a 6V battery, the charger will automatically determine that it is a 6V battery after power is turned on, and the 6V indicator light will light up. When the warning indicator light is on, it warns that the charger output is not properly connected to the battery or the output clamp is short-circuited. When the reverse connection indicator light is on, it indicates that the positive and negative poles of the output clamp are connected incorrectly. When the full indicator light is on, it indicates that the battery is fully charged. When the charging indicator light is on, it indicates that the battery is charging. In addition to automatically detecting and identifying 6V and 12V batteries, the charger of the present invention also features short-circuit protection, overload protection, and automatic storage. The dimensions of the charger of the present invention are 175 × 200 × 105 mm and a weight of 1.4 kg. Not only is it compact, but it is also lightweight and easy to carry. The charger includes an outer shell and the various components that make up the charger, housed within it, as well as a corresponding operating panel and circuit board design. The main components of the charger of the present invention include: a charger base, a charger cover, a main control (circuit) board assembly, a control panel assembly, a power cord, two battery clips, and a cable (wire) fastener. The charger utilizes an internal structure consisting of two circuit boards, with the two circuit board assemblies, the power cord, and the two battery clips providing the corresponding circuit connections.

[0022] The composition and circuit working principle of the charger of the present invention are described as follows:

[0023] As attached Figure 1As shown, the charger of the present invention primarily utilizes a two-circuit control circuit board structure. The main components of the charger include a handle 1, a housing cover 2, a power tube heat sink (I) 3, a main control board 4, a cooling fan 5, a power cord 6, a fan grille 7, a (positive polarity) red charging clip 8, a (negative polarity) black charging clip 9, a non-detachable output cable 10, a housing base 11, a housing panel 12, and a control panel 13. The main control board 4 also houses numerous electronic components and parts, including a trimmer potentiometer 14, a control chip 15, a differential mode capacitor 16, a rectifier bridge 17, a drive transformer 18, an electrolytic capacitor 19, a transistor (I) 20, a transistor (II) 21, a fast recovery diode 22, a filter inductor 23, a heat sink (II) 24, and a field-effect transistor 25. There are also many electronic components and parts on the control panel 13, such as 2.5A or 10A current selection button, digital tube, mode selection button, indicator light, microprocessor controller and other electronic components and parts. The main control board 4 of the charger of the present invention is equipped with many electronic components and parts, such as the attached Figure 2 Many electronic components and parts are identified in this part of the circuit schematic.

[0024] See attached Figure 2 The main control board 4 components are mainly composed of C9 filter capacitor, BR1 rectifier bridge, electrolytic capacitors C10 and C11, resistors R29 and R30, NPN transistors Q3 and Q4, inverter transformer T1, fast recovery rectifier diode D1, filter inductor L1, transistor Q7, field effect transistor Q8, drive transformer T2, PWM control chip IC1 (TL494), and accessories. Figure 2 It is composed of many resistors, capacitors, diodes, transistors, etc. Its characteristics are:

[0025] 1) The half-bridge inverter main circuit consists of filter capacitor C9, rectifier bridge BR1, electrolytic capacitors C10 and C11, resistors R29 and R30, NPN transistors Q3 and Q4, inverter transformer T1, fast-recovery rectifier diode D1, filter inductor L1, and their peripheral components. Its characteristics are as follows: C9 is connected to the 220-240V power lines L and N, the input of BR1 is also connected to the power supply, and the output of BR1 is connected in parallel with the series-connected electrolytic capacitors C11 and C10. The positive terminal of C11 is connected to the positive terminal of BR1's output, and the negative terminal of C10 is grounded. Resistors, such as R29 and R30, are connected in parallel with each electrolytic capacitor. Since BR1 rectifies and filters C11 and C10, a high voltage of approximately +310V is generated. Therefore, a resistor is connected in parallel across the electrolytic capacitor to release the energy stored in the capacitor when the charger is not operating, thereby preventing harm to circuit maintenance personnel. A series circuit of NPN transistors Q3 and Q4 is connected in parallel across the +310V high voltage to ground. Q3's collector is connected to the +310V terminal, and Q3's emitter is connected to Q4's collector. Q4's emitter is grounded, which is +310V ground. Between Q3's collector and emitter is D11, with its anode connected to Q3's emitter. Similarly, between Q4's collector and emitter is D12, with its anode connected to Q4's emitter. The opposite-name terminal of N4 (the opposite-name terminal refers to the terminal on the T2 transformer winding not marked with a "●" dot. The same applies below and will not be repeated here) is connected to capacitor C14 and one end of the primary winding N1 of inverter transformer T1. The other end of capacitor C14 is connected to resistor R36, the other end of R36 is connected to the other end of the primary winding N1 of inverter transformer T1. This connection point is connected to one end of (DC blocking) capacitor C18, the other end of which is connected to the middle connection point between C11 and C10. NPN transistors Q3 and Q4 are the switching transistors of the half-bridge inverter main circuit. IGBTs and MOSFET field-effect transistors are not used as switching transistors in the main circuit of the charger of the present invention. Electrolytic capacitors C11 and C10 are the commutation capacitors of the half-bridge inverter main circuit. In the charger circuit of the present invention, the secondary windings of the T1 inverter main transformer have four windings: N2, N3, N4, and N5. The N2 and N3 windings of inverter transformer T1 are connected in series, with the center point being SGND. The other ends of the N2 and N3 windings are connected to fast-recovery rectifier output diode D1, forming a center-tapped full-wave output rectifier circuit. N4 and N5 are also connected in series, with the center point being GND, which also serves as the output terminal BAT (-) of the charger. These two "grounds" are different, with a sampling resistor R0 between them.The other ends of the two N4 and N5 windings are also connected to the anodes of fast-recovery rectifier output diodes D19 and D18, with their cathodes connected to the anode of diode D20. This output DC voltage is then connected to the CN4 connector and, via a cable, to the CH1 connector on the control panel circuitry. This provides operating voltage for the FET Q10 circuitry that implements the 6V or 12V conversion control. Because the connection point between the N4 and N5 windings is tapped and connected to GND, this circuitry forms a full-wave output rectifier circuit with a center tap. Fast-recovery rectifier diode D1 is a chip with two fast-recovery diodes. Their cathodes are connected, and their anodes are connected to the other ends of the secondary windings N2 and N3 of inverter transformer T1, respectively. Capacitors C15 and C16 are connected in parallel across the two D1s, respectively. The cathodes of D1 (i.e., their output voltage +VA terminals (this voltage is connected to the anode of D13 in the low-voltage side driver circuits of Q3 and Q4)) are connected to one end of the output filter inductor L1. The other end of L1 is connected to resistors R16 and R53, and the S-terminal terminal of a P-channel FET Q8. The G-terminal terminal of FET Q8 is connected to the other end of R53 and the collector of transistor Q7. The emitter of transistor Q7 is connected to SGND. The D-terminal terminal of FET Q8 is connected to the charger's output terminal BAT (+). A diode (internal to Q8) is connected in parallel across FET Q8, with its cathode connected to its S-terminal terminal and its anode connected to the D-terminal terminal of FET Q8. The base of transistor Q7 is connected to one end of resistor R52. The other end of R52 is connected to pin 1 of connector CN5. Pin 2 of CN5 is connected to SGND. Pin 1 of connector CN5 is connected to the attached. Figure 4 Pin 1 of the CH3 plug is the Figure 4 The PB0 (QD-MOS) control terminal of the U1 microprocessor in the present invention. The function of the half-bridge inverter main circuit of the present invention is to convert +310V DC into AC by alternating conduction of NPN transistors Q3 and Q4 under the action of the driving circuit, and then through the voltage and current conversion of the T1 inverter main transformer and the rectification of the D1 tube, a low-voltage, high-current DC output is obtained at the output of the main circuit. The output BAT (+) and BAT (-) of the charger are connected to the attached Figure 2 Connect the 1st and 3rd pins of the CN3 plug in the Figure 4 The CH3 plug in the output is used to transmit the detected battery voltage to the attached Figure 4 The U1 microprocessor.

[0026] 2) In the output part of the half-bridge inverter main circuit, a cooling fan power supply circuit and a protection control circuit are also provided. For the cooling fan power supply circuit, its composition characteristics are as follows: the other end of the resistor R16 is connected to the positive pole of the electrolytic capacitor C4, the negative pole of C4 is grounded, and R5 and R44 are connected in parallel at both ends of C4. The voltage across C4 is +VB, which is connected to the 12V cooling fan FAN through the plug CN2. At the same time, it is also connected to one end of R4 and R40 in the low-voltage side drive circuit of the NPN transistors Q3 and Q4 in the half-bridge inverter main circuit, which is the feedback signal Uf end of the output voltage of the charger of the present invention. This part of the circuit is called the cooling fan power supply circuit. Its function is to realize the power supply to the cooling fan. For the protection control circuit, its composition characteristics are as follows: the other end of the output filter inductor L1 is connected to the S-pole of the resistors R16, R53 and the P-channel field effect transistor Q8 (such as UTT50P06), the G gate of the field effect transistor Q8 is connected to the other end of R53 and the collector of the Q7 transistor, and the emitter of the transistor Q7 is connected to the SGND ground. The D-pole of the field effect transistor Q8 is connected to the output terminal BAT (+) of the charger. There is a diode (which is built into Q8) connected in parallel at both ends of the field effect transistor Q8, the cathode of the diode is connected to its S-pole, and its anode is connected to the D-pole of the field effect transistor Q8. The base of the transistor Q7 is connected to one end of the resistor R52, the other end of R52 is connected to pin 1 of plug CN5, and pin 2 of CN5 is connected to SGND ground. Pin 1 of plug CN5 is connected to the attached Figure 4 Pin 1 of the CH3 plug is the PB0 (QD-MOS) control terminal of the U1 microprocessor.

[0027] 3) The circuit composed of Q7, Q8, R52 and R53 is called the protection control circuit. Its functions and effects are: Figure 4 The U1 microprocessor control system automatically detects whether the battery connected to the BAT (+) and BAT (-) terminals is a 6V or 12V battery by detecting the voltage and connection status at the charger output terminals. If the battery is not a 6V or 12V battery, Q8 is disabled, implementing battery protection control. If the battery is a 6V or 12V battery, the charging process is controlled according to the corresponding voltage level. If it is detected that the polarity of the external battery connected to the BAT (+) and BAT (-) terminals is reversed, reverse polarity protection control is implemented, and the reverse polarity LED indicator is illuminated to indicate the reverse polarity status. If it is detected that the BAT (+) and BAT (-) terminals are not connected to a battery, or that a short circuit occurs between the terminals, disconnection or short circuit protection control is implemented, and the disconnection or short circuit protection LED indicator is illuminated to indicate the disconnection or short circuit protection status.

[0028] 4) The high-side drive circuit for NPN transistors Q3 and Q4 is characterized by its components: the secondary windings N3, N4, and N5 of the driver transformer T2; resistors R32-R35, R37, and R38; electrolytic capacitors C12 and C13; and diodes D7-D10. Specifically, the base of Q3 is connected to resistor R32. The other end of R32 is connected to one end of resistors R33 and R37, as well as the cathode of electrolytic capacitor C12 and diode D8. The other end of R33 is connected to the +310V terminal, and the other end of R37 is connected to the emitter of NPN transistor Q3 and the same-name terminal of the secondary winding N4 of the driver transformer T2. The anode of D8 is connected to the cathode of diode D7, which is connected to the anode of C12 and also to the same-name terminal of the secondary winding N5 of the driver transformer T2. The N5 and N4 windings are connected in series, with the opposite-name terminal of N5 connected to the same-name terminal of N4. The opposite-name terminal of N4 is connected to capacitor C14 and one end of the primary winding N1 of inverter transformer T1. The base of Q4 is connected to resistor R35. The other end of R35 is connected to one end of resistors R34 and R38, as well as the cathode of electrolytic capacitor C13 and diode D10. The other end of R34 is connected to the emitter of Q3, and the other end of R38 is connected to the emitter of transistor Q4 and the same-name terminal of the secondary winding N3 of driver transformer T2, which also serves as the +310V ground terminal. The anode of D10 is connected to the cathode of diode D9, which is connected to the anode of C13 and also to the opposite-name terminal of the secondary winding N3 of driver transformer T2. As mentioned earlier, the switches Q3 and Q4 in the half-bridge inverter main circuit are transistors, not IGBTs or MOSFETs. The former is a current-type control device, and the latter two are both voltage-type control devices, which are different.

[0029] 5) The low-voltage side drive circuit for NPN transistors Q3 and Q4 in the inverter main circuit is characterized by the following: it consists of the primary windings N1 and N2 of the drive transformer T2, the TL494 PWM control chip IC1, and their peripheral components, such as resistors, capacitors, diodes, and NPN transistors Q1 and Q2. N1 is connected in series with the primary winding N2, with the opposite-signal terminal of N2 connected to the same-signal terminal of N1. The opposite-signal terminal of N1 is connected to the collector of Q1 and the cathode of diode D6. The emitter of Q1 is connected to the anodes of D6 and D3, and the emitter of Q2. The same-signal terminal of N2 is connected to the collector of Q2 and the cathode of diode D3. The emitter of Q2 is connected to the anodes of D3, D4, and D6, the anode of electrolytic capacitor C7, and the emitter of Q1. The cathode of D4 is connected to the anode of D5. The cathodes of C7 and D5 are grounded. The center taps of N1 and the primary winding N2 are connected to R31. The other end of R31 is connected to the cathode of D2. The anode of D2 is connected to the cathode of D13, the anode of the C50 electrolytic capacitor, R21, R24, and one end of R22. The other end of R21 is connected to pin 12 of IC1, the chip's +VCC operating voltage input. An E9 electrolytic capacitor is connected in parallel between this pin and ground. The other end of R24 is connected to the base of Q1, one end of R20, and pin 8 of IC1 (the output terminal of IC1's PWM pulse-width control signal). The other end of R20 is grounded. Similarly, R22 is connected to the base of Q2, one end of R23, and pin 11 of IC1 (the output terminal of IC1's PWM pulse-width control signal). The other end of R23 is grounded. The anode of D13 is connected to +VA (the output terminal of the fast-recovery rectifier diode D1 in the inverter main circuit). Under the action of the PWM control circuit, pins 8 and 11 of IC1 generate two alternating PWM pulse-width control signals. The signal frequency is fixed at 30 kHz. However, the pulse width of the PWM signal is affected by the output current setpoint signal, the output voltage setpoint signal, and the magnitude of the current and voltage feedback signals. A change in any of these factors will result in a different pulse width for the resulting PWM signal. This determines the output voltage and current of the charger of this invention.

[0030] 6) The PWM control signal generation, output voltage negative feedback, and PI (proportional-integral) control circuitry are characterized by the following: Pins 9 and 10 of IC1 are grounded. Pin 4 of IC1 is connected to the cathode of electrolytic capacitor C8 and one end of resistor R18. The anode of C8 is connected to the +5V power supply, and the other end of R18 is grounded. Pin 16 of IC1 is grounded. Pin 6 (RT) of IC1 is connected to R19, the other end of R19 is grounded. Pin 5 (CT) of IC1 is connected to C5, the other end of C5 is grounded. The parameters of R19 and C5 are combined to ensure that the PWM signal frequency output by pins 8 and 11 of IC1 is 30 kHz. Pin 7 of IC1 is grounded. Pin 13 of IC1 is connected to the +5V power supply. Pin 1 of IC1 (the non-inverting input IN+ of the operational amplifier within IC1) is connected to one end of R8, R7, R4, and R25. The other ends of R7 and R8 are grounded. The other end of R4 is connected to the voltage feedback signal +VB or Uf output by the charger. The other end of R25 is connected to the 3rd pin of the CN4 plug and also to the attached Figure 3 Pin 3 of CH1 (SW1 end) is the 6V or 12V switching control end of the charger of the present invention. Pin 2 of IC1 (the inverting input end IN- of the operational amplifier inside IC1) is connected to resistors R3, R17 and one end of capacitor C3. The other end of R3 is connected to the +5V power supply. The other end of R17 is grounded. The other end of C3 is connected to resistor R10. The other end of R10 is connected to pin 3 of IC1, R11 and RJ1. The other end of R11 is connected to C6. The other end of C6 is grounded. The other end of RJ1 is connected to capacitor C2. The other end of C2 is connected to pin 15 of IC1, one end of R26, R27, R28 and R39. The other ends of R27 and R28 are connected to the +5V power supply. The other end of R26 is connected to a fine-tuning potentiometer R2. The other end of R39 is connected to pin 2 of the CN1 plug, which is the PWMA signal control end, and is also the current given Ig input signal end. This signal end is connected to the panel control board (the circuit schematic diagram of the board is shown in the attached Figure 3 and attached Figure 4 Pin 1 of the CN2 connector (as shown) is the signal output from pin 15 of the U1 microprocessor after passing through R251 and R261. Figure 2 One end of R40 is connected to +VB power supply, and the other end of R40 is connected to the 4th pin of CN4, which is also connected to the attached Figure 3 The 4th pin of CH1 (SW2 terminal) in IC1. The internal operational amplifier of IC1 and its peripheral resistors, capacitors and corresponding circuit connections constitute the PI control circuit. Figure 2As can be seen in the figure, IC1 contains two operational amplifiers, with their non-inverting input terminals labeled IN+ and their inverting input terminals labeled IN-. The specific internal structure and operating principle of IC1 (TL494) are already well documented, so I will not reiterate them here. As previously mentioned, pins 8 and 11 of IC1, under the control of the PWM control circuit, generate two alternating PWM pulse-width control signals. The signal frequency is fixed at 30 kHz. However, the pulse width of the PWM signal is affected by the output current setpoint signal, the output voltage setpoint signal, and the current and voltage feedback signals. A change in any of these factors will result in a different pulse width for the generated PWM signal. This determines the output voltage and current of the charger. For example, if the signal at pin 2 of CN4, i.e., the PWMA signal (current reference signal) at the input terminal of R39, changes, the signal will cause the PWM pulse width signals output from pins 8 and 11 of IC1 to change through the PI control circuit, ultimately changing the output current of the charger of the present invention. If the signal at pin 3 of CN4, i.e., the 6V or 12V control signal, changes, the output voltage reference signal of the charger will change. Similarly, through the PI control circuit, the PWM pulse width signals output from pins 8 and 11 of IC1 will change, ultimately changing the output voltage of the charger of the present invention.

[0031] The control panel of the charger of the present invention is also provided with many electronic components and parts, such as the attached Figure 3 , Attachment Figure 4 , Attachment Figure 5 Many electronic components and parts are identified in the schematic diagram of this part of the circuit.

[0032] The control panel circuit mainly consists of field effect transistors Q4 and Q10, NPN transistor Q7, 5V integrated voltage regulator U7, 2.5A or 10A selection button S2, voltage (U), current (I) and power (Q) display mode conversion button S1, U1 microprocessor, U2 operational amplifier, DPY1~DPY3 display digital tubes, attached Figure 5 It consists of NPN transistors Q11~Q31, Q51~Q61, Q81~Q91, light-emitting diodes LED00, LED01, LED1~LED11, and some peripheral electronic components. Its characteristics are:

[0033] 1) +5V power supply circuit. Figure 3 As shown in Figure 1, this part of the circuit consists of diode D21, electrolytic capacitors E1~E4, capacitors C81, C91, C101, C131 and C151, voltage regulator Z1, NPN transistor Q7, resistors R271 and R281, and +5V output U7 integrated voltage regulator. The input voltage of the circuit is VCC, which is connected to the attached Figure 2 The +VCC voltage is connected to pin 12 of IC1. Its output is a +5V power supply, which is used to operate other circuits. This part of the circuit is relatively simple and will not be explained in detail.

[0034] 2) 2.5A or 10A selection button S2 circuit. Figure 3 As shown in Figure 1, this part of the circuit consists of the selection button S2 and the resistor R30. R301 is connected in series with S2 and in parallel between the +5V power supply and its ground. Their middle connection point PB6 is connected to the attached Figure 4 The U1 microprocessor in the control unit connects to the PB6 pin. The U1 microprocessor detects the level on PB6 to determine whether the S2 button is pressed, thereby determining whether the user has selected a 2.5A or 10A output current. The control system also indicates this through the 2.5A and 10A current LED indicators.

[0035] 3) Voltage (U), current (I) and power (Q) display mode conversion button S1 circuit. Figure 3 As shown in Figure 1, this part of the circuit consists of a touch button S1 and a resistor R311. R311 is connected in series with S1 and in parallel between the +5V power supply and its ground. Their middle connection point PB7 is connected to the attached Figure 4 The PB7 terminal of the U1 microprocessor in the device. The U1 microprocessor determines whether the S1 button is pressed by detecting the high and low levels of the PB7 electrical level to determine whether the user has selected the voltage (U) display, the current (I) display, or the power (Q) display. Of course, according to the operation of the button, the corresponding control signal will be sent through the U1 microprocessor control system to light up the corresponding LED indicator. For example, if the voltage (U) display is selected, the LED1 indicator will be lit. At the same time, if the battery is charging, the digital tube will also display the corresponding voltage; if the current (I) display is selected, the LED2 indicator will be lit. At the same time, if the battery is charging, the digital tube will also display the corresponding current; if the power (Q) display is selected, the LED3 indicator will be lit. At the same time, if the battery is charging, the digital tube will also display the corresponding power level;

[0036] 4) 6V or 12V switching control circuit. Figure 3 As shown in the figure, this part of the circuit consists of resistors R181, R361, field effect transistors Q4 and Q10. The input end of R181 is connected to the attached Figure 4 The PD7 terminal of the U1 microprocessor system is the 6V or 12V control conversion instruction issued by the microprocessor. According to the voltage detection signal at both ends of the battery connected to the charger output terminal of the present invention, the microprocessor control system can automatically identify whether it is a 6V battery or a 12V battery, and at the same time, according to the detected signal, it will issue corresponding control instructions through PD7 to control the attached Figure 3The on and off of the field effect tubes Q4 and Q10 ultimately determine the Figure 3 Is the state between SW1 and SW2 closed or open? Figure 2 Is the connection between pin 3 and pin 4 of CN4 on the lower left of the image closed or disconnected? Figure 2 The PWM control circuit in the battery changes the pulse width of the PWM signal, ultimately enabling charging in 6V mode or 12V mode.

[0037] 5) U1 microprocessor circuit, voltage detection and current feedback control circuit, PWMA current given signal output circuit. Figure 4 As shown, this part of the circuit consists of the U1 microprocessor, operational amplifier U2 (LM358), resistors R11, R21, R31, R41, R51, R61, R251, R261, and capacitors C11 to C51. The output voltage detection signal of the charger comes from the BAT (+) terminal, which is the Uf voltage feedback signal. This signal passes through the voltage divider circuit composed of R11 and R21, and is output from the two ends of the rear stage R21 to the PB3 input terminal of the U1 microprocessor. C11 plays a filtering role. As mentioned earlier, the ground marked with SGND is not the same as the ground marked with a triangle. There is a current sampling resistor R0 between the two. See the attached Figure 2 Therefore, in the attached Figure 4 In the figure, the input signal of the resistor R31 is the detection signal If of the output current of the charger of the present invention. U2A is an amplifier in the U2 multi-operational amplifier integrated chip. R5 and C2 are connected in parallel between the inverting input and the output of U2, and its inverting input is connected to R41 and then grounded. R31 is the resistor of its non-inverting input. In addition, the non-inverting input is also connected in parallel with an anti-interference filter capacitor C61. The output of the operational amplifier is connected to PB2 of the U1 microprocessor through R16, and an anti-interference filter capacitor C3 is also connected in parallel between PB2 and ground. The U1 microprocessor samples the output current signal of the charger through the PB2 port, amplifies the sampled signal, and finally inputs it into the microprocessor for A / D (analog / digital) conversion. The output end of PB1 is connected to resistor R251, the other end of R251 is connected to C51 and R261, the other end of C51 is grounded, the other end of R261 (PWMA or Ig signal) is connected to pin 1 of CN2, and pin 2 of CN2 is grounded. CN2 is connected to the attached via a connecting line. Figure 2 CN4 in the figure corresponds to the connection point. Under the control of the microprocessor software, the current feedback signal will be compared with the set current given signal, and the current negative feedback control will be performed. Finally, the PB1 output terminal of the U1 microprocessor will output the PWMA signal (Ig) to control the attached Figure 2In addition, U1's PB0 outputs a QD-MOS signal, which is connected to the attached Figure 4 Connect the CH3 pin 1 to the attached Figure 2 The 1st pin of CN5 in the control Figure 2 The on and off of Q7 and field effect transistor Q8 are used to implement protection control such as reverse battery connection or reverse polarity according to the detection results.

[0038] 6) Digital tube display circuit and LED indicator light control circuit. Figure 5 As shown in the figure, this part of the circuit consists of DPY1~DPY3 digital tubes (CPS05631AR), NPN transistors Q11~Q31, Q51~Q61, Q81~Q91, light-emitting diodes LED00, LED01, LED1~LED11, etc., as well as some peripheral resistor components, diode D22, and optocoupler U3 (EL817). The S1 terminal of DPY1 is connected to the collector of Q11, the emitter of Q11 is grounded, the base of Q11 is connected to R71, and the input terminal of R71 is connected to the attached Figure 4 When the COM1 terminal is high, the transistor Q11 is turned on, which can make the common terminal of the DPY1 digital tube grounded, and the display data of DPY1 is from the attached Figure 4The eight-segment display control signals (A, B, C, D, E, F, and G) are determined by the microprocessor data. The control circuit for the DPY2 and DPY3 digital tubes is similar to that of DPY1, except that the control signals for the common selection of S2 and S3 come from COM2 and COM3 of U1. DP is the control signal for the decimal point of the displayed data. The output terminal of PA3 of the U1 microprocessor is connected to R291, and the other end of R291 is connected to transistor Q81. The emitter of Q81 is grounded, and the collector of Q81 is connected to the common cathode of many LED indicators. Which of these LED indicators illuminates depends on the voltage level at the anode end of each LED, the charger's control status, and whether Q81 is turned on. For example, if the charger of the present invention detects that the connected battery is 12V, the control system will cause the anode of LED9 to output a high level. Simultaneously, PA3 outputs a high level, turning on Q81. This illuminates LED9, indicating that the 12V battery is charging. Similarly, if the charger of the present invention detects that the connected battery is 6V, the control system will cause the anode of LED8 to output a high level, and at the same time, PA3 outputs a high level to turn on Q81, so that the indicator light LED8 lights up, indicating that the 6V battery is being charged; if the charger of the present invention is charging the connected battery, the control system will cause the anode of LED4 to output a high level, and at the same time, PA3 outputs a high level to turn on Q81, so that the indicator light LED4 lights up, indicating that the battery is being charged; if the charger of the present invention detects that the connected battery is being charged with a current of 2.5A, the control system will cause the anode of LED10 to output a high level, and at the same time, PA3 outputs a high level to turn on Q81, so that the indicator light LED10 lights up, indicating that the battery is being charged with a current of 2.5A. If the charger of the present invention detects that the connected battery is charged with a current of 10A, the control system will cause the anode of LED11 to output a high level. At the same time, PA3 outputs a high level to turn on Q81. In this way, the LED11 indicator light will light up, indicating that the battery is being charged with a current of 10A. The control of the battery's charging current, voltage, and power indicator light is also similar and will not be described in detail here.

[0039] Regarding the output polarity reverse control of the charger of the present invention, when the charger circuit is working normally, when the polarity of the two clip lines output by the charger and the battery are connected correctly, the attached Figure 2 When transistor Q7 and field effect switch Q8 are turned on, the battery can be charged. Conversely, if the polarity of the charger output wires and the battery is incorrect or reversed, transistor Q7 is stopped and switch Q8 will not turn on. In this case, the charger will not charge the battery.

[0040] In the attached Figure 5In the figure, LED00 (red indicator) is the battery disconnected or short-circuited protection indicator. Its cathode is connected to the collector of Q51, the emitter of Q51 is grounded, the base of Q51 is connected to R241, and the anode of LED00 is connected to R21 and then to the +5V power supply. The input end of R241 is connected to the attached Figure 4 The PD4 control terminal of the U1 microprocessor. When the control system of this charger detects that the two level charging clips are not connected to the battery or the connection is short-circuited, the PD4 control terminal of U1 will output a high level, turning on Q51 and the LED00 indicator light, indicating that the battery is not connected or short-circuited. The user will take appropriate measures after seeing this.

[0041] In the attached Figure 5 In the figure, LED01 (red indicator) is the battery reverse connection or reverse polarity protection indicator. Its cathode is connected to the collector of Q61, the emitter of Q61 is grounded, the base of Q61 is connected to R231, and the anode of LED01 is connected to R221 and then to the +5V power supply. The input end of R231 is connected to the attached Figure 4 PD5 control terminal of the U1 microprocessor. When the control system of this charger detects that the battery is reversely connected or the polarity is reversed, the PD5 control terminal of U1 will output a high level, turning on Q61 and lighting up the LED01 indicator, indicating that the battery is reversely connected or the polarity is reversed. The user will take appropriate measures after seeing this.

[0042] In the attached Figure 5 In the figure, U3 is an optocoupler, the cathode of the light-emitting diode inside it is connected to the anode of D22, the cathode of D22 is connected to BAT (+), that is, the positive output terminal of the charger of the present invention, the anode of the light-emitting diode is connected to R191, the other end of R191 is grounded, the emitter of the output stage transistor inside the U3 optocoupler is grounded, and its collector is connected to R201 and the attached Figure 4 PB4 terminal of the U1 microprocessor. When the control system of this charger detects that the battery is reversely connected or the polarity is reversed, the light-emitting diode in the U3 optocoupler will be turned on and emit light, so the transistor in its output stage will be turned on, and the output signal of PB4 will be low level; when the control system of this charger detects that the connection polarity of the battery is normal, the light-emitting diode in the U3 optocoupler will not be turned on and emit light, so the transistor in its output stage will be cut off, and the output signal of PB4 will be high level. Therefore, the attached Figure 4 The U1 microprocessor control system can detect whether the charger connection is normal and whether there is reverse connection or reverse polarity by detecting the level of PB4.

[0043] In the attached Figure 5In the diagram, LED5 is the battery full indicator. Its cathode is connected to the collector of Q91, the emitter of Q91 is grounded, the base of Q91 is connected to R331, and the anode of LED5 is connected to R321 and then to the +5V power supply. The input of R331 is connected to the attached Figure 4 PD6 control terminal of the U1 microprocessor. When the control system of this charger detects that the battery is fully charged, the PD6 control terminal of U1 will output a high level, turning on Q91 and lighting up the LED5 indicator, indicating that the battery is fully charged. The user will take appropriate measures after seeing this.

[0044] In the circuit of the present invention, IC1 (TL494) is a highly integrated, low-power PWM (pulse width modulation) control chip. It has 16 pins. Pin 14 REF is the reference voltage +5V terminal. It has two operational amplifiers inside. The output of the two operational amplifiers (that is, the output of pin 3 of the chip) determines the width of the drive pulse of the inverter switch tube. The chip determines the width of the drive pulse by connecting the resistor R19 and electrolytic capacitor C5 to pins 6 and 5 respectively. Figure 2 The operating frequency of the NPN transistors Q3 and Q4 in the middle switch. Pin 8 (C1) and pin 11 (C2) output two sets of square wave drive pulses. The interval between the two drive pulses, i.e. the dead time, is determined by the parameters of the external device connected to pin 4 (DTC). By determining the appropriate parameters, a sufficient and appropriate dead time can be obtained to ensure the safety of the attached Figure 2 The normal alternating conduction of the NPN transistors Q3 and Q4 in the middle switch. If the dead time is too short, it is easy to cause the Figure 2 The NPN transistors Q3 and Q4 in the middle switch are "shoot-through" or turned on at the same time, which will cause the inverter control to fail and cause the switches Q3 and Q4 to explode. The circuit cannot work properly.

[0045] The square wave signal output alternately from pin 8 (C1) and pin 11 (C2) of IC1 chip is Figure 2 The circuit composed of transistors Q1 and Q2 and their peripheral devices, and then drives the transformer T2 and its driving circuit to control the attached Figure 2 The operation of the middle switch NPN transistors Q3 and Q4 can enable the switch tubes Q3 and Q4 to achieve inverter output control according to the set operating frequency and the PWM pulse width determined by circuits such as IC1, thereby obtaining different charger output voltages and currents.

[0046] In the charger of the present invention, in 6V voltage output mode, the voltage across the 6V battery gradually increases as charging progresses. When the output charging voltage is less than 7V, the circuitry of the charger of the present invention enables constant current charging at a set current. Simultaneously, the "Charging" indicator LED 4 illuminates, indicating that the battery is charging. When the output charging voltage exceeds 7.3V, the charging current of the charger of the present invention decreases. When the current decreases to less than 1.2A, the control system illuminates the "Full" LED 5, indicating that the 6V battery is fully charged.

[0047] In 12V output mode, the voltage across the 12V battery gradually increases as charging progresses. When the output charging voltage is less than 13V, the charger circuitry of the present invention enables constant-current charging at a set current. Simultaneously, the "Charging" indicator LED 4 illuminates, indicating that the 12V battery is charging. When the output charging voltage exceeds 14.6V, the charging current of the charger of the present invention decreases. When the current decreases to less than 1.2A, the control system illuminates the "Full" LED 5, indicating that the 12V battery is fully charged.

[0048] Since the present invention adopts a medium frequency inverter conversion control of tens of kHz, it can greatly reduce the size and weight of the transformer compared with the traditional transformer rectifier output control charger, thereby achieving the goals of saving materials and energy.

[0049] In summary, the output voltage and current of the charger are both controlled by the circuit. These controls are an important prerequisite for ensuring the stable operation of the charger.

[0050] It can be seen that the good circuit and structural design are the advantages of the present invention and are also an important guarantee for meeting the requirements of high efficiency, high reliability and advanced manufacturing technology. The content of the patent application of this invention is to protect the circuit and structural design of this charger.

[0051] The above description is a detailed explanation of the present invention in conjunction with the specific charger structure, circuit board, and control functions. The specific implementation of the present invention should not be construed as being limited to this description. Those skilled in the art of the present invention may make simple deductions and substitutions without departing from the scope of the present invention, and these should be considered within the scope of protection of the present invention.

Claims

1. A microprocessor-controlled current-adjustable charger with multiple protection functions, characterized by: The charger's components include a handle, an upper shell cover, a power tube radiator (1), a main control panel assembly, a cooling fan, a power cord, a fan screen, a red charging clip, a black charging clip, a non-detachable output cable, a chassis base, a chassis panel, and a control panel assembly. The charger has two circuit board assemblies, one for the main control panel assembly and the other for the control panel assembly, which are connected to each other and to the power cord, the red charging clip, and the black charging clip. The main control panel assembly is equipped with electronic components and parts, including a trimmer potentiometer, a control chip, a differential mode capacitor, a rectifier bridge, a drive transformer, an electrolytic capacitor, a transistor (1), a transistor (2), a fast recovery diode, and a power supply. Tube, filter inductor, radiator (II), field effect tube; electronic components and parts are arranged on the control panel assembly, including current selection button, digital tube, mode selection button, indicator light, microprocessor controller, and the power cord provides external power supply for the charger circuit board; the main control board assembly includes filter capacitor C9, rectifier bridge BR1, electrolytic capacitors C10 and C11, resistors R29 and R30, NPN transistors Q3 and Q4, inverter transformer T1, fast recovery rectifier diode D1, filter inductor L1, transistor Q7, field effect tube Q8, drive transformer T2, PWM control chip IC1; wherein filter capacitor C9, rectifier bridge BR1, electrolytic capacitor C10 and C11, resistors R29 and R30, NPN transistors Q3 and Q4, inverter transformer T1, fast recovery rectifier diode D1, filter inductor L1 and their peripheral devices constitute a half-bridge inverter main circuit. The two ends of the filter capacitor C9 of the half-bridge inverter main circuit are connected to the 220-240V power line, and the input end of the rectifier bridge BR1 is also connected to the two ends of the power supply. The output end of the rectifier bridge BR1 is connected in series with electrolytic capacitors C11 and C10. The positive electrode of the electrolytic capacitor C11 is connected to the positive output electrode of the rectifier bridge BR1, and the negative electrode of the electrolytic capacitor C10 is grounded. Resistors are connected in parallel at both ends of each electrolytic capacitor; the rectifier bridge BR1 rectifies and filters the electrolytic capacitors C11 and C10. After the wave, a high voltage of +310V is generated. A series circuit of NPN transistors Q3 and Q4 is connected in parallel at both ends of the +310V high voltage to the ground. The collector of NPN transistor Q3 is connected to the +310V end, and the emitter of NPN transistor Q3 is connected to the collector of NPN transistor Q4. The emitter of NPN transistor Q4 is grounded, that is, the +310V ground. A diode D11 is connected in parallel between the collector and emitter of NPN transistor Q3, and the anode of diode D11 is connected to the emitter of NPN transistor Q3. A diode D12 is connected in parallel between the collector and emitter of NPN transistor Q4, and the anode of diode D12 is connected to the emitter of NPN transistor Q4.The secondary winding N4 end of the driving transformer T2 is connected to the capacitor C14 and one end of the primary winding N1 of the inverter transformer T1. The other end of the capacitor C14 is connected to the resistor R36. The other end of the resistor R36 is connected to the other end of the primary winding N1 of the inverter transformer T1. This connection point is connected to one end of the capacitor C18. The other end of the capacitor C18 is connected to the middle connection point of the electrolytic capacitors C11 and C10. The NPN transistors Q3 and Q4 are the switching tubes of the half-bridge inverter main circuit; the electrolytic capacitors C11 and C10 are the commutation capacitors of the half-bridge inverter main circuit; the inverter transformer T1 has 4 secondary windings, namely the secondary windings N2, N 3. N4 and N5, the secondary windings N2 and N3 are connected in series, indirectly; the other ends of the two secondary windings N2 and N3 are connected to the anode of the fast recovery rectifier diode D1, forming a full-wave output rectifier circuit with a center tap; the secondary windings N4 and N5 are also connected in series, indirectly, the other ends of the two secondary windings N4 and N5 are also connected to the anodes of diodes D19 and D18, and their cathodes are connected to the anode of diode D20, and then the DC voltage is output through the cathode of diode D20 and connected to the plug CN4. The plug CN4 is connected to the plug CH1 of the control panel circuit part through a connecting wire to achieve 6V or 12 The circuit of the field effect transistor Q10 part of the V voltage conversion control provides the operating voltage; the connection point of the secondary windings N4 and N5 is tapped to ground, and this part of the circuit constitutes a full-wave output rectifier circuit with a center tap; the cathodes of the two fast recovery rectifier diodes D1 are connected to each other, and the anodes of the two fast recovery rectifier diodes D1 are respectively connected to the other ends of the secondary windings N2 and N3 of the inverter transformer T1; capacitors C15 and C16 are respectively connected in parallel at both ends of the two fast recovery rectifier diodes D1, and the cathodes of the two fast recovery rectifier diodes D1 are connected to one end of the filter inductor L1, and the other end of the filter inductor L1 is connected to resistors R16 and R5. 3 and the S pole of the field effect transistor Q8, the G gate of the field effect transistor Q8 is connected to the other end of the resistor R53 and the collector of the transistor Q7, and the emitter of the transistor Q7 is grounded; the D pole of the field effect transistor Q8 is connected to the output end of the charger, and a diode is connected in parallel at both ends of the field effect transistor Q8, the cathode of the diode is connected to its S pole, and its anode is connected to the D pole of the field effect transistor Q8; the base of the transistor Q7 is connected to one end of the resistor R52, and the other end of R52 is connected to pin 1 of plug CN5, and pin 2 of plug CN5 is grounded; pin 1 of plug CN5 is connected to pin 1 of plug CH3, and pin 1 of plug CH3 is connected to the control end of the microprocessor U1; The output end of the charger is connected to pins 1 and 3 of the CN3 plug through connecting wires. The output part of the half-bridge inverter main circuit is also equipped with a cooling fan power supply circuit; The cooling fan power supply circuit is composed of the following components: the other end of resistor R16 is connected to the positive electrode of electrolytic capacitor C4, the negative electrode of electrolytic capacitor C4 is grounded, resistors R5 and R44 are connected in parallel at both ends of electrolytic capacitor C4, both ends of electrolytic capacitor C4 are connected to the 12V cooling fan FAN through plug CN2, and the anode of electrolytic capacitor C4 is connected to one end of resistors R4 and R40 in the low-voltage side drive circuit of NPN transistors Q3 and Q4 in the half-bridge inverter main circuit, that is, the feedback signal Uf end of the charger output voltage. This part of the circuit is called the cooling fan power supply circuit; The control panel assembly includes a control panel circuit, which includes a power selection circuit, a voltage and current display mode conversion circuit, a microprocessor voltage detection and current feedback control circuit and a PWMA current given signal output circuit, a digital tube display circuit and an LED indicator light control circuit; Resistor R301 is connected in series with the selection button S2 and in parallel between the +5V power supply and the ground. The middle connection point between them is connected to the PB6 terminal of the microprocessor U1 to form a power selection circuit; The resistor R311 is connected in series with the voltage, current and power display mode conversion button S1, and is connected in parallel between the +5V power supply and the ground. The middle connection point between them is connected to the PB7 terminal of the microprocessor U1 to form a voltage, current and power display mode conversion circuit; Resistor R181 and resistor R361 are connected to field effect transistor Q4 and field effect transistor Q10; and the input end of resistor R181 is connected to the PD7 end of microprocessor U1 to form a 6V or 12V switching control circuit; The microprocessor voltage detection and current feedback control circuit and the PWMA current given signal output circuit are composed of a microprocessor U1, an operational amplifier U2, resistors R11, R21, R31, R41, R51, R61, R251, R261, and capacitors C11, C21, C31, C41, C51, and C61; the input signal of resistor R31 is a detection signal of the charger output current; a resistor R51 and a capacitor C21 are connected in parallel between the inverting input terminal and the output terminal of the operational amplifier U2, and its inverting input terminal is connected to the resistor R41 and then grounded; the resistor R31 is the resistor of its non-inverting input terminal, and in addition, the non-inverting input terminal is also connected in parallel with an anti-interference filter capacitor C61; the output of the operational amplifier U2 is connected to the PB2 terminal of the microprocessor U1 through the resistor R61. An anti-interference filter capacitor C31 is also connected in parallel between the PB2 terminal and ground; the output terminal of the microprocessor voltage detection and current feedback control circuit and the PWMA current given signal output circuit is connected to resistor R251, the other end of resistor R251 is connected to capacitor C51 and resistor R261, the other end of capacitor C51 is grounded, and the other end of resistor R261 is connected to pin 1 of plug CN2, and pin 2 of plug CN2 is grounded; CN2 is connected to the corresponding connection point of plug CN4 via a connecting wire; The output signal of the microprocessor U1 is connected to pin 1 of the CH3 plug, and is connected to pin 1 of the CN5 plug through a connecting wire to form the microprocessor voltage detection and current feedback control circuit and the PWMA current given signal output circuit; The digital tube display circuit and the LED indicator light control circuit include a digital tube DPY1, a digital tube DPY2 and a digital tube DPY3; the control circuit of the digital tube DPY1 is composed of the S1 end of the digital tube DPY1 connected to the collector of the NPN transistor Q11, the emitter of the NPN transistor Q11 is grounded, the base of the NPN transistor Q11 is connected to the resistor R71, and the input end of the resistor R71 is connected to the COM1 end of the microprocessor U1; the control circuit of the digital tube DPY2 is composed of the S2 end of the digital tube DPY2 connected to the collector of the NPN transistor Q21, the emitter of the NPN transistor Q21 is grounded, the base of the NPN transistor Q21 is connected to the resistor R81, and the input end of the resistor R81 is connected to the COM2 end of the microprocessor U1; the control circuit of the digital tube DPY3 is composed of the digital tube DPY1 The S3 end of the tube DPY3 is connected to the collector of the NPN transistor Q31, the emitter of the NPN transistor Q31 is grounded, the base of the NPN transistor Q31 is connected to the resistor R91, and the input end of the resistor R91 is connected to the COM3 end of the microprocessor U1. The display data of the digital tube is determined by the data display control signal from the microprocessor U1; the data display control signal of the digital tube display circuit and the LED indicator control circuit is selected from COM1, COM2 and COM3 of the microprocessor U1 through the selection button; the PA3 output end of the microprocessor U1 is connected to the resistor R291, and the other end of the resistor R291 is connected to the NPN transistor Q81, the emitter of the NPN transistor Q81 is grounded, and the collector of the NPN transistor Q81 is connected to the common cathode point of multiple LED indicators.

2. A microprocessor-controlled current-adjustable charger with multiple protection functions as claimed in claim 1, characterized in that: The high-voltage side drive circuit of the NPN transistors Q3 and Q4 includes the secondary windings N3, N4 and N5 of the driving transformer T2, several resistors, electrolytic capacitors C12 and C13, and diodes D7~D10. The specific circuit structure is as follows: the base of the NPN transistor Q3 is connected to the resistor R32, the other end of the resistor R32 is connected to the resistor R33, one end of the resistor R37, and the cathode end of the electrolytic capacitor C12 and the diode D8, the other end of the resistor R33 is connected to the +310V terminal, and the other end of the resistor R37 is connected to the emitter of the NPN transistor Q3 and the same-name terminal of the secondary winding N4 of the driving transformer T2; the anode of the diode D8 is connected to the diode The cathode of the tube D7 and the anode of the diode D7 are connected to the anode of the capacitor C12, and are also connected to the same-name terminal of the secondary winding N5 of the driving transformer T2; the secondary winding N5 and the secondary winding N4 are connected in series, and the opposite-name terminal of the secondary winding N5 is connected to the same-name terminal of the secondary winding N4; the opposite-name terminal of the secondary winding N4 is connected to the capacitor C14 and one end of the primary winding N1 of the inverter transformer T1; the base of the NPN transistor Q4 is connected to the resistor R35, the other end of the resistor R35 is connected to the resistor R34, one end of the resistor R38, and the cathode end of the electrolytic capacitor C13 and the diode D10, and the other end of the resistor R34 is connected to the NPN transistor Q4. The emitter of transistor Q3 and the other end of resistor R38 are connected to the emitter of NPN transistor Q4 and the same-name terminal of secondary winding N3 of driving transformer T2, which is also the +310V ground terminal; the anode of diode D10 is connected to the cathode of diode D9, the anode of diode D9 is connected to the anode of capacitor C13, and is also connected to the opposite-name terminal of secondary winding N3 of driving transformer T2; the low-voltage side drive circuit of NPN transistors Q3 and Q4 in the half-bridge inverter main circuit, the low-voltage side drive circuit includes the primary windings N1 and N2 of driving transformer T2, PWM control chip IC1 and their peripheral devices, the primary winding N1 and the primary winding N2 is connected in series, and the opposite-name end of the primary winding N2 is connected to the same-name end of the primary winding N1; the opposite-name end of the primary winding N1 is connected to the collector of the transistor Q1 and the cathode of the diode D6, and the emitter of the transistor Q1 is connected to the anodes of the diode D6 and the diode D3, and the emitter of the transistor Q2; the same-name end of the primary winding N2 is connected to the collector of the transistor Q2 and the cathode of the diode D3, and the emitter of the transistor Q2 is connected to the anodes of the diodes D3, D4, and D6, the anode of the electrolytic capacitor C7, and the emitter of the transistor Q1, the cathode of the diode D4 is connected to the anode of the diode D5, and the cathode of the electrolytic capacitor C7 and the cathode of the diode D5 are grounded;The center taps of the primary winding N1 and the primary winding N2 are connected to resistor R31. The other end of resistor R31 is connected to the cathode of diode D2. The anode of diode D2 is connected to the cathode of diode D13, the anode of electrolytic capacitor C50, resistors R21, R24, and one end of R22. The other end of resistor R21 is connected to pin 12 of PWM control chip IC1, which is the +VCC working voltage input terminal of the chip. Electrolytic capacitor E9 is connected in parallel between this end and ground. The other end of resistor R24 is connected to the base of transistor Q1, one end of resistor R20, and pin 8 of PWM control chip IC1, which is the output PWM pulse of PWM control chip IC1. One end of the width control signal is connected, the other end of the resistor R20 is grounded, the resistor R22 is connected to the base of the transistor Q2, one end of the resistor R23 and the 11th pin of the PWM control chip IC1, that is, the other end of the output PWM pulse width control signal of IC1 is connected, and the other end of the resistor R23 is grounded; the anode of the diode D13 is connected to the output end of the fast recovery rectifier diode D1 in the half-bridge inverter main circuit; the 9th and 10th pins of the PWM control chip IC1 for the PWM control signal generation, output voltage negative feedback, and PI control circuit are grounded, and the 4th pin of the PWM control chip IC1 is connected to the cathode of the electrolytic capacitor C8 and one end of the resistor R18 , the anode of electrolytic capacitor C8 is connected to the +5V power supply, and the other end of resistor R18 is grounded; pin 16 of PWM control chip IC1 is grounded, pin 6 of PWM control chip IC1 is connected to resistor R19, and the other end of resistor R19 is grounded; pin 5 of PWM control chip IC1 is connected to capacitor C5, and the other end of capacitor C5 is grounded; through the parameter combination of resistor R19 and capacitor C5, the PWM signal frequency output by pins 8 and 11 of PWM control chip IC1 is 30KHz; pin 7 of PWM control chip IC1 is grounded, and pin 13 of IC1 is connected to the +5V power supply; pin 1 of PWM control chip IC1 is connected to resistor R8 and resistor R7, resistor R4, and one end of resistor R25, the other ends of resistor R7 and resistor R8 are grounded, and the other end of resistor R4 is connected to the voltage feedback signal output by the charger; the other end of resistor R25 is connected to pin 4 of plug CN1; pin 2 of PWM control chip IC1 is connected to resistor R3, resistor R17, and one end of capacitor C3, the other end of resistor R3 is connected to the +5V power supply, the other end of resistor R17 is grounded, the other end of capacitor C3 is connected to resistor R10, and the other end of resistor R10 is connected to pin 3 of PWM control chip IC1, resistor R11, and RJ1. The other end of resistor R11 is connected to capacitor C6, and the other end of capacitor C6 is grounded;The other end of resistor RJ1 is connected to capacitor C2. The other end of capacitor C2 is connected to pin 15 of PWM control chip IC1 and one end of resistors R26, R27, R28, and R39. The other ends of resistors R27 and R28 are connected to a +5V power supply. The other end of resistor R26 is connected to a trimmer potentiometer R2. The other end of resistor R39 is connected to pin 2 of the CN1 connector. One end of resistor R40 is connected to the power supply, and the other end of resistor R40 is connected to pin 3 of CN1.

3. The microprocessor-controlled current-adjustable charger with multiple protection functions as claimed in claim 1, characterized in that: The control panel circuit also includes an LED lamp control circuit part. The cathode of the LED lamp in the LED lamp control circuit part is connected to the collector of the transistor Q51, the emitter of the transistor Q51 is grounded, the base of the transistor Q51 is connected to the resistor R241, the anode of the LED lamp is connected to the resistor R211 and then connected to the +5V power supply, and the input end of the resistor R241 is connected to the PD4 control end of the microprocessor U1.

4. A microprocessor-controlled current-adjustable charger with multiple protection functions as claimed in claim 1, characterized in that: The control panel circuit also includes a battery reverse connection or reverse polarity protection indicator light circuit, which consists of a cathode of a diode LED01 connected to the collector of a field effect transistor Q61, an emitter of the field effect transistor Q61 connected to ground, a base of the field effect transistor Q61 connected to a resistor R231, an anode of the diode LED01 connected to a resistor R221 and then connected to a +5V power supply, and an input end of the resistor R231 connected to the PD5 control terminal of the microprocessor U1.

5. The microprocessor-controlled current-adjustable charger with multiple protection functions as claimed in claim 1, characterized in that: The control panel circuit also includes a battery full indicator light circuit, which consists of a cathode of a diode LED5 connected to the collector of a field effect transistor Q91, an emitter of the field effect transistor Q91 connected to ground, a base of the field effect transistor Q91 connected to a resistor R331, an anode of the diode LED5 connected to a resistor R321 and then connected to a +5V power supply, and an input end of the resistor R331 connected to the PD6 control terminal of the microprocessor U1.

6. A microprocessor-controlled current-adjustable charger with multiple protection functions as claimed in claim 1, characterized in that: The control panel circuit also includes a battery reverse connection or reverse polarity circuit, which consists of the cathode of the light-emitting diode inside the optocoupler U3 connected to the anode of the diode D22, the cathode of the diode D22 connected to the positive output polarity terminal of the charger, the anode of the light-emitting diode connected to the resistor R191, the other end of the resistor R191 is grounded, the emitter of the output stage transistor inside the optocoupler U3 is grounded, and its collector is connected to the resistor R201 and the PB4 terminal of the microprocessor U1.

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