12V / 24V microprocessor control storage battery charger

Abstract

The utility model relates to a 12V / 24V microprocessor control storage battery charger, a control circuit board and an operation and display control panel are arranged in the charger, and a socket J1 of the control circuit board is connected to a socket J1 of the operation and display control panel through a plug and a connecting line thereof; the circuit of the control panel part mainly comprises an input rectification filter circuit, a half-bridge inverter circuit, an output rectification filter circuit, a switching power supply circuit, a drive circuit, a relay contact and a control circuit thereof, a PWM control circuit, an output current and voltage feedback operation control circuit and a power supply circuit. The half-bridge inverter circuit is connected to the driving circuit and is controlled by the driving circuit, and the driving circuit is connected to the PWM control circuit; according to the utility model, a half-bridge inversion and switching power supply technology and a control system constructed by a microprocessor and the like are adopted, so that the problems of high efficiency, energy conservation, material conservation and the like are well solved, and the device has the advantages of reasonable structure, small size, light weight, low cost and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to a 12V / 24V microprocessor control battery charger and belongs to the technical field of battery charger. TECHNICAL BACKGROUND

[0002] At present, the competition in the charger product market not only lies in the advancement of technology, but also depends on the advancement of the circuit function and design, production manufacturing process, production efficiency, production cost, product consistency and reliability and other aspects to a great extent.

[0003] At present, the output voltage of small battery charger on the domestic and foreign market usually has different types such as 6V / 12V / 24V. The charging current is usually 1~50A. The current of a few large chargers can reach the level of hundreds of amperes. Under the condition of considering low cost, the charger product of small current level is usually the mainstream product. However, on the market, many such products adopt the structural form of traditional transformer and rectifier. Such traditional charger, since it adopts the way of changing into low-voltage alternating current through low-frequency (50Hz or 60Hz) transformer and then rectifying, therefore, the product has low technical content, the transformer and rectifier are bulky, consume a lot of materials, have large heat generation, have low work energy efficiency, have large product volume, heavy weight and many other problems. In recent years, the development of electronic control technology also promotes the development of electronic control type battery charger. Such charger, since the control technology way adopted to meet the output requirement is significantly different from the traditional charger, therefore, the technical performance and energy saving, material saving and other indicators are much better than the traditional charger. The advanced technology greatly reduces the transformer of such charger, which is not in the form of ordinary transformer, but adopts the transformer of middle or high frequency switching power supply or inverter power supply (the magnetic core material for making the transformer has fundamentally changed). Not only small in size, but also very light in weight, more convenient to carry and transport. The rectifier is not the rectifier composed of ordinary diode, but the rectifier adopting fast recovery diode. The heat generation is very small, the energy conversion efficiency of the power supply is high, and the energy saving and material saving are very outstanding. Therefore, the charger of switching power supply or inverter power supply is praised as "new type high-efficiency energy-saving power supply", representing the development direction of charger. Since the internal switching device works in high-frequency state, the energy consumption is extremely low. The efficiency of charger can reach more than 90%, which is greatly improved compared with the efficiency of traditional charger. With the rapid development of charger power supply technology, the charger of switching power supply or inverter power supply is developing towards miniaturization, high frequency, integration and digitization, and has been applied more and more widely. The future is definitely the substitute of traditional charger.

[0004] Switching power supply or inverter power supply electronic control type charger, mainly depends on the circuit board and its control circuit on the surface to realize the function, performance of the product. Usually, compared with the traditional charger, their circuit is relatively complex. Production mode is mainly based on the manufacture of circuit board and product assembly. Of course, in the same output voltage and current level, different products, its circuit principle and circuit board design, and production mode may be completely different. These all affect the product's technical performance, reliability, production and manufacturing cost, product market competitiveness, etc. That is, the structure and circuit design of different charger, its technical parameters, performance, production efficiency, even product appearance and reliability and market competitiveness, etc. are quite different.

[0005] Although the types of electronic chargers using switching power supply and inverter control technology, and microprocessor control technology are relatively many, their circuit and structure form are also various. Different circuit and structure design ideas, the specific circuit form used are also different. Not only that, the performance indicators of the charger including output current / voltage, insulation level, temperature rise, manufacturing process level, product reliability, etc. also show some obvious gap. Even in the same product parameter performance index, due to the difference of specific circuit and charger structure design, or the difference of the packaging form of electronic components used, the assembly, welding and detection process level, automation degree of circuit board and components will be significantly different, which will make the convenience of installing the circuit board during production, production efficiency, production cost, product cost, etc. will be significantly different. For example, if a large number of patch components and integrated circuits are used in the charger, due to the small size of these components, the size of the circuit board will be reduced, and the cost of PCB material will be reduced. At the same time, since the welding of these components usually uses advanced, efficient, suitable for mass production and detection equipment, the production efficiency of the circuit board or product can be greatly improved, the production cost can be reduced, and the market competitiveness of the product can be increased.

[0006] The charger of the utility model has two control boards inside, one is control circuit board, the second is operation and display control panel, plus shell, cooling fan, overheat protector, power supply input power line and charger control output line with clamp part composition. In control technology aspect, advanced switching power supply and inverter control technology, and microprocessor control system are adopted, software and hardware are combined, and the technical level of contemporary advanced charger is embodied. Product production mainly solves the processing and debugging problem of circuit board. The assembly of the product is relatively simple.

[0007] The utility model relates to a 12V / 24V microprocessor control battery charger, mainly including control circuit board, operation and display control panel, cooling fan, overheat protector, input and output cable. When selecting charging current, voltage, there is corresponding indication, in addition, there is power, charging, full, alarm indication, there is overheat, polarity reverse protection, and can display voltage, "Err" and "FUL" symbol. When selecting 12V or 24V charging, according to the size of the selected charging current, the control system can realize "constant voltage", "constant current" charging control. And when charging voltage rises to a certain value, charging current will drop, when charging voltage rises to full voltage, charging current reduces to about 1A, enters "float charging" mode. Because adopting half bridge inverter, switching power supply and the control system constructed by microprocessor, therefore, better solve the problems of high efficiency, energy saving, material saving, and the comprehensive performance is significantly better than traditional charger. The utility model charger whole machine circuit and the design of structure are unique, have own characteristic, is the utility model patent protection key and right claim. Utility model content

[0008] The utility model discloses a 12V / 24V microprocessor control battery charger, and the rear panel of the charger is provided with input power cable and cooling fan. Inside the charger, control circuit board, operation and display control panel are arranged, wherein the operation and display control panel is installed on the front panel of the charger. From the outside of the charger, the panel is provided with: 1) 12V / 24V indicator, for indicating whether the user selects to charge 12V battery or 24V battery; 2) power indicator, for indicating whether the charger is working; 3) alarm indicator, for indicating whether the charger has overheat protection phenomenon or abnormal phenomenon such as polarity reverse; 4) a 12V / 24V charging selection button, for selecting to charge 12V battery or 24V battery, when selecting, the corresponding indicator will light up, indicating the charging voltage mode selected by the user; 5) a charging current selection button, for different charging voltage mode, i.e. 12V or 24V mode, the user can select different charging current, for example, in 12V mode, the user can select 5A, 10A, 15A and 20A charging current, while in 24V mode, the user can select 5A, 10A charging current, when selecting current, the corresponding current indicator will light up, indicating the charging current selected by the user; 6) charging indicator, for indicating that the battery is in charging process; 7) full indicator, for indicating that the battery is fully charged; 8) nixie tube display or display table, for displaying voltage and some symbols, such as "Err" error symbol and "FUL" full symbol.

[0009] The utility model discloses a 12V / 24V microprocessor control battery charger's circuit, its characterized in that: the charger is mainly by control circuit board, operation and display control panel, cooling fan, overheat protector, the input power cable of connecting in the input terminal of control circuit board and connecting in the positive polarity output terminal (Output (+) end, when using, this end connects to the BAT+ end of battery) of control circuit board and connecting in the negative polarity output terminal (Output (-) end, when using, this end connects to the BAT- end of battery) are formed, of course, there will be the shell part of charger. The control line of cooling fan is connected to the CN1 socket of control circuit board through the plug and its connecting line, the socket J1 of control circuit board is connected to the socket J1 of operation and display control panel through the plug and its connecting line, the control line of overheat protector is connected to the socket J3 of operation and display control panel through the plug and its connecting line, and overheat protector is closely attached to the radiator of MOS field effect transistor in control circuit board part half bridge inverter circuit, is used for detecting whether it is overheated, the interface of program burner is J2 socket, is used for the writing of control program to operation and display control panel part microprocessor.

[0010] The utility model discloses a charger's operation and display control panel part (see attached Figure 2 ) circuit is mainly by microprocessor, nixie tube display, 12V / 24V selection button, charging current selection button, photoelectric coupler, diode, capacitor, resistance, +5V power supply, socket J1~J3, 20A, 15A, 10A, 5A pilot lamp, 24V / 12V pilot lamp, power, (is) charging, full, warning pilot lamp composition, socket J1 is connected to the socket J1 of control circuit board through the plug and its connecting line according to its mark (such as +5V, NS1, PWMA, PWMV, SCKZ etc.), the interface of program burner is J2 socket, is used for the writing of control program to microprocessor U1, the plug and its connecting line of positive polarity output Output (+) or BAT+ end are connected to the Output (+) end of control circuit board through the socket J1, when using, this end connects to the positive polarity end of battery, the connection of each component is according to attached Figure 2The identification in the figure corresponds to the connection together, for example, the K1 end of the key KY1 is connected to the 23 pin of U1; the 4 pin of U3 is connected to the 26 pin of U1, and so on, the other connection relationship will not be expanded one by one; the control line of the overheat protector is connected to the socket J3 through the plug and its connecting line, and the overheat protector is close to the radiator of the MOS field effect transistor in the part of the half-bridge inverter circuit of the control circuit board, which is used to detect whether it is overheated; when the overheating phenomenon occurs, the state of the overheat protector will change, that is, the level state of the OT signal will change, and the OT signal is connected to the 5 pin of U1, and the microprocessor U1 can know whether the overheating phenomenon occurs by monitoring the level change of the 5 pin, once the overheating occurs, the corresponding protection control is carried out, for example, the charger output is stopped, or the charging current is reduced to a smaller value, such as 1A, in addition, the warning indicator light can be lit to prompt when overheating, these process controls depend on the programming of the U1 microprocessor control software; the digital tube display or display table is used to display the output voltage and some symbols, for example, the “Err” error symbol and the “FUL” full symbol; the charging current selection key is used for different charging voltage modes, that is, 12V or 24V mode, the user can select different charging currents, for example, when the user selects 12V charging through the key, the 12V indicator light will be lit under the action of the control circuit, and in this 12V charging mode, the user can select 5A, 10A, 15A and 20A charging current, when selecting a certain current, the corresponding current indicator light will be lit accordingly, and if the 24V mode is selected, the 24V indicator light will be lit, and the user can select 5A and 10A charging current, when selecting a certain current, the corresponding current indicator light will be lit accordingly; the change of the NS1 signal can represent the change of the input power voltage, therefore, the change of the ADC2 or Input V signal also represents the change of the input power voltage, the latter is connected to the 8 pin of U1, that is, an A / D analog-digital conversion interface of the microprocessor U1, which can carry out A / D conversion, that is, sampling of the input voltage signal; the change of the Output (+) or BAT+ end signal reflects the change of the charger output voltage, therefore, the change of the ADC1 or Output V signal also represents the change of the output voltage, the latter is connected to the 9 pin of U1, that is, another A / D analog-digital conversion interface of the microprocessor U1, which can carry out A / D conversion, that is, sampling of the output voltage signal, the output voltage obtained by sampling can be displayed through the digital tube display or display table; if the output voltage detected by the U1 microprocessor meets a certain condition or the full voltage value, at this time, under the action of the control circuit, the digital tube display or display table displays the “FUL” full symbol, at the same time, the full indicator light can also be lit to prompt, if the full condition is not met, the (charging) indicator light is lit to prompt, at the same time, the digital tube display or display table displays the detected charging voltage value;The power indicator light is on after the charger is connected to the power supply, indicating that the charger is working with power. Under normal circumstances, the positive output (Output) terminal of the charger is connected to the BAT+ terminal of the battery, and the negative output (Output) terminal is connected to the BAT- terminal of the battery. However, if a connection error occurs, that is, the connection between the charger output line and the battery is abnormal or reversed (also known as reverse polarity), then, Figure 2 In the process, the light-emitting diode in the U3 optocoupler will light up, and then its internal transistor will conduct, which can make the FANJIE signal end low. Since the FANJIE end of U3's 4th pin is reversely connected to U1's 26th pin, the microprocessor U1 can detect whether the polarity is reversed by monitoring the level change of its 26th pin. If this happens, the corresponding protection control will be carried out, for example, stopping the charger output. At the same time, the warning indicator can be lit and the display can show the "Err" symbol as a prompt. In one case, there is a short circuit between the output ends of the charger. At this time, the output voltage detected is 0. At this time, the digital tube display or display meter shows "00", indicating that a short circuit has occurred. At the same time, the microprocessor U1 can issue a control instruction to stop the charger's current output to protect the charger from outputting too much current and being damaged. Of course, when this happens, the warning indicator can also be lit as a prompt and the digital tube display or display meter will show the "Err" error symbol. These process controls depend on the programming of the U1 microprocessor control software.

[0011] The control board of the utility model charger is shown in the attached Figure 3The feature of the part is that the circuit mainly consists of input rectifier filter circuit, half-bridge inverter circuit, output rectifier filter circuit, switching power supply circuit, drive circuit, relay contact and its control circuit, PWM control circuit, output current and voltage feedback operation control circuit, power supply circuit, and J1 and CN1 socket. Input power supply line is connected to input rectifier filter circuit, and input rectifier filter circuit is connected to switching power supply circuit and half-bridge inverter circuit. Input rectifier filter circuit is used to rectify AC input power supply into pulsating DC power supply, and further into stable DC high voltage power supply through electrolytic capacitor filtering. The DC high voltage power supply is used to supply power for switching power supply circuit, and generate +15V DC working power supply through switching power supply circuit, which is used for other circuits (for example, drive circuit, PWM control circuit, output current and voltage feedback operation control circuit). On the other hand, the DC high voltage power supply is used as power supply for the later half-bridge inverter circuit. The half-bridge inverter circuit is used to convert DC high voltage power supply into several tens of kHz high frequency high voltage small current AC power supply (referred to as high frequency high voltage AC power, or high frequency power) under the action of other control circuits. The half-bridge inverter circuit is also connected to drive circuit and controlled by drive circuit, and drive circuit is connected to PWM control circuit. PWM control circuit and output current and voltage feedback operation control circuit are electrically isolated and signal transmission through optocoupler, which guarantees the reliability of charger working. Then, the output current and voltage feedback operation control circuit part is connected to PWMA output current given signal, Uif output current negative feedback signal, and the circuit is used for control operation processing. The generated control signal controls the output signal of optocoupler, and then controls the output PWM pulse width of PWM control circuit. Finally, the output current of charger is controlled through half-bridge inverter circuit and its later circuit. Similarly, the output current and voltage feedback operation control circuit part is connected to PWMV output voltage given signal and +VB output voltage negative feedback signal. The circuit is used for control operation processing, and then controls the output PWM pulse width of PWM control circuit through optocoupler. Finally, the output voltage of charger is controlled through half-bridge inverter circuit and its later circuit. PWMA and PWMV signals are connected to the circuit of operation and display control panel part through 3-pin and 4-pin of socket J1. Uif signal and +VB signal are connected to output rectifier filter circuit. The several tens of kHz high frequency power is changed into low voltage and large current AC through voltage reduction and current conversion of main transformer, and then is changed into DC low voltage power supply through output rectifier filter circuit. Output rectifier filter circuit part generates +VB, Uif, +VA, +VF and NS1 signals. +VB and Uif are transmitted to output current and voltage feedback operation control circuit.The Uif signal end is connected to the negative polarity output end (Output (-) end, in use, the end is connected to the BAT- end of the storage battery) of the control circuit board; +VB and +VF are delivered to the power supply circuit; +VB and NS1 are delivered to the relay contact and its control circuit; the NS1 signal is also connected to the 7th pin of the socket J1, and the signal change thereof represents the change of the input power supply voltage; the output of the output rectifier filter circuit is connected to the normally open contact of a relay, and the other end of the contact is connected to the positive polarity output end (Output (+) end, in use, the end is connected to the BAT+ end of the storage battery), the contact is part of the relay contact and its control circuit, and the relay is controlled by the circuit of the part and the SCKZ control signal; the SCKZ control signal is connected to the 5th pin of the socket J1; the VCC signal is connected to the power supply circuit, which is used to generate VCC, VCC1 and +5V power supply; in addition, +5V and its ground are connected to the 1st pin and the 2nd pin of the socket J1 respectively, and the BAT+ signal is connected to the 6th pin of the socket J1; the socket J1 is connected to the socket J1 of the operation and display control panel through its plug and the connecting line thereof.

[0012] See the attached Figure 4 The input rectifier filter circuit mainly consists of the fuse FUSE, the rectifier composed of the thermal resistor RM1 and four diodes (D1-D4), the filter electrolytic capacitors EC4 and EC5, and the C1 capacitor; the Input end is the power supply input end, which is connected to the power grid; the function of this part is to convert the alternating current input power supply into pulsating direct current power supply, and further into +310V stable direct current high voltage power supply through the filtering of the electrolytic capacitor, which on one hand supplies the switching power supply circuit to provide power supply, and on the other hand, the +310V direct current high voltage power supply serves as the power supply of the later-stage half-bridge inverter circuit; the ground of the +310V is GND1, which is connected to C1 between another ground GND3.

[0013] See the attached Figure 4 The half-bridge inverter circuit mainly consists of the MOS tubes Q1 and Q2, the parallel-connected commutation capacitors C2 and C3 and C4 and C5, the filter capacitors C6 and C7, the resistors R7-R10, the inductor DK1, the primary N1 winding of the main transformer T2, and the +310V power supply; the G1 and S1 control signal ends of Q1 are connected to the G1 and S1 control signal ends of the driving circuit (see the attached Figure 5 ), and the G2 and S2 control signal ends of Q2 are connected to the G2 and S2 control signal ends of the driving circuit. The half-bridge inverter circuit, under the action of other control circuits, is used to convert the direct current high voltage power supply into several tens of kilohertz high frequency high voltage small current alternating current power supply, and through the voltage and current conversion of the main transformer T2, the output is then sent to the later-stage circuit.

[0014] See the attached Figure 4The output rectifier filter circuit is mainly composed of the secondary N3 and N4 windings with a center tap of the main transformer T2, fast recovery diodes D12-D14, inductor DK2, electrolytic capacitor EC7, capacitor C8, resistors R12-R15, current detection sampling resistors RS1 and RS2; the output of the output rectifier filter circuit is connected to a normally open contact of a relay, and the other end of the contact is connected to a positive polarity output end (Output (+) end, in use, the end is connected to the BAT+ end of a storage battery), the contact is part of the relay contact and its control circuit; the signals detected by RS1 and RS2 are Uif signals, and the signal end is connected to a negative polarity output end (Output (-) end, in use, the end is connected to the BAT- end of the storage battery) of the charger.

[0015] See the attached Figure 4 The relay contact and its control circuit are mainly composed of a relay (JDQ1A is its working line pack; JDQ1B is its normally open contact, used in parallel), NPN type transistors Q5 and Q6, voltage stabilizing tube Z7, diodes D22-D24, capacitors C31 and C32, NS1 signal, SCKZ signal, +VB and VCC power supply, socket CN1; the plug of CN1 and its control line are connected to the cooling fan Fan of the charger; the SCKZ control signal is connected to the 5th pin of the socket J1, that is, connected to the circuit of the operation and display control panel part; under the action of the NS1 signal, Q5 can be turned on, so that the cooling fan Fan can work; under the action of the SCKZ control signal, Q6 can be turned on, so that the relay operates, its contact JDQ1B changes from normally open to normally closed state, so that the charger has output, otherwise, when the relay does not operate, the connection between the positive polarity end of the charger and the output rectifier filter circuit is in an open state, and there will be no output. By controlling the working state of the relay, the normal output and protection control of the charger can be realized, such as overheat, reverse connection and short circuit protection.

[0016] See the attached Figure 5 The switching power supply circuit is mainly composed of a driving chip U1 (XY3018FB), switching power supply transformer T1, diodes D5-D7, electrolytic capacitors EC1-EC3, capacitors C9-C12, resistors R17-R28, +310V power supply; the circuit of this part is used to generate +15V DC power supply for other circuits (for example, driving circuit, PWM control circuit, output current and voltage feedback operation control circuit).

[0017] See the attached Figure 5, driving circuit is mainly composed of two pieces of P and N channel MOS tube driving chip (AO4612) consisting of driving circuit, voltage regulator Z1~Z4, driving transformer T3, diode D15~D16, electrolytic capacitor EC9, capacitor C17~C23, resistor R0~R4 and R32~R40, +15V power supply; the role of this part of the circuit is used to drive Q1 and Q2 tube in half bridge inverter circuit, realize inverter control, and ultimately control the output of the charger. The output drive signal G1 and S1, G2 and S2 of the driving circuit are connected to the corresponding control ends of Q1 and Q2 in the half bridge inverter circuit 120 respectively; the input signal of the driving circuit is connected to the 11 and 14 pins of the PWM chip U4 in the PWM control circuit respectively. Under the action of the control circuit, the PWM square wave pulse signal output by the 11 and 14 pins of U4 (SG3525) chip after the driving circuit controls the working state of MOS tube Q1 and Q2 in the half bridge inverter circuit (attached Figure 4 ), makes two MOS tubes alternate conduction or turn-off, and then makes the half bridge inverter circuit form inverter control. When MOS tube Q1 and Q2 alternate conduction, the primary winding coil of high frequency transformer T2 connected with them will produce alternating intermediate frequency current or voltage. After the secondary winding coil of the transformer is stepped down, it is rectified by fast recovery diode (D12, D13) to change into direct current, and finally controls the output voltage and current of the charger.

[0018] see attached Figure 5The PWM control circuit mainly consists of PWM chip U4 (SG3525), optocoupler U2 (including U2A and U2B, where U2A is in the output current and voltage feedback operation control circuit, and optocoupler U2 is the optocoupler mentioned above), electrolytic capacitor EC8, capacitors C13~C15, resistors R5~R6 and R29~R31, and +15V power supply; PWM chip U4 The 11th and 14th pins output PWM pulse signals, which are respectively connected to the input ends of the drive circuit; the PWM control circuit and the output current and voltage feedback operation control circuit are electrically isolated and signal transmitted through the optocoupler U2. While ensuring the reliability of the charger, the PWMA output current given signal and Uif output current negative feedback signal connected to the output current and voltage feedback operation control circuit are used, and after the control operation is processed by the circuit of this part, the control signal generated is used to control the output signal of the optocoupler U2, and then the output PWM pulse width of the PWM control circuit is controlled. Finally, the output current of the charger is controlled by the half-bridge inverter circuit and its subsequent circuits. Similarly, the PWMV output voltage given signal and +VB output voltage negative feedback signal connected to the output current and voltage feedback operation control circuit are also controlled by the circuit of this part. Then, the output PWM pulse width of the PWM control circuit is controlled through the optocoupler U2, and finally the output voltage of the charger is controlled by the half-bridge inverter circuit and its subsequent circuits.

[0019] The output voltage and current of the charger power supply are controlled by the control circuit. Output control is performed according to the set parameters. Figure 2 The charging current is determined by the user and the microprocessor and output, and the output current is determined by the attached Figure 4 RS1 and RS2 are connected in parallel to detect and obtain the current feedback signal Uif. The feedback signal of the charger output voltage is +VB. They will eventually affect the surrounding Figure 5 The output of the optocoupler U2 is used to control the output current and voltage of the charger.

[0020] The transistor output of the optocoupler U2 controls the signal at pin 2 of the SG3525, which is the IN+ (non-inverting input) at pin 2 of the SG3525's internal operational amplifier. Pin 2 of the SG3525 (the IN+ of its internal operational amplifier), the inverting input pin 1 (IN- of its internal operational amplifier), and the output pin 9 form an operational amplifier within the SG3525. In the circuit of this utility model, pin 1 and the output pin 9 are connected together. In this way, the internal operational amplifier is a follower. The level of the output pin 9 controls the output pulse width of the SG3525's internal PWM pulse width modulator, ultimately controlling the attached Figure 4The middle field effect transistors Q1 and Q2 are used to change the output size of the charger. For example, when the given value of the charging current is increased, the output pulse width of the internal PWM pulse width regulator of the SG3525 is increased, so that the output current of the charger is increased; on the contrary, the charging output current is decreased. When the given value of the charging current is unchanged and the output current is changed, the control results of the above control circuit will make the charging current output by the charger stable. For example, when the given value of the charging current is unchanged and the output current is increased due to some external factors, the current signal of the feedback is increased, so that the PWM output pulse width of the controller is decreased, so that the output charging current is restored to the given value. That is, the control results of the above control circuit will make the output charging current stable.

[0021] See the attached Figure 5 The output current and voltage feedback operation control circuit mainly consists of the operational amplifier U3 (including U3A and U3B), diodes D18 and D19, capacitors C24-C30, resistors R41-R50, VCC1, +VB, PWMV, U2A of the optocoupler U2, Uif, PWMA, +5V. According to the foregoing, the PWMA and PWMV signals are connected to the circuit of the operation and display control panel part through the 3rd and 4th pins of the socket J1 respectively; the Uif signal and the +VB signal are connected to the output rectification and filtering circuit; the VCC1 and +5V are connected to the power supply circuit; the operational amplifiers U3A and U3B and their peripheral resistors and capacitors constitute proportional integral operation circuits, which realize the feedback operation control of the output voltage and current of the charger respectively; the PWM control circuit and the output current and voltage feedback operation control circuit are electrically isolated and signal transmitted through the optocoupler U2, which can guarantee the working reliability of the charger; the PWMA output current given signal and the Uif output current negative feedback signal are processed by the proportional integral operation circuit of the U3B part, and then the generated control signal controls the output signal of the optocoupler U2, so as to control the output PWM pulse width of the PWM control circuit, and finally the control of the output current of the charger is realized through the half-bridge inverter circuit and its subsequent circuit; similarly, the PWMV output voltage given signal and the +VB output voltage negative feedback signal are processed by the proportional integral operation circuit of the U3A part, and then the output PWM pulse width of the PWM control circuit is controlled through the optocoupler U2, and finally the control of the output voltage of the charger is realized through the half-bridge inverter circuit and its subsequent circuit.

[0022] When the user selects the 12V or 24V charging mode, according to the size of the charging current selected by the user, the control system adopts the output voltage and current feedback control mode to realize the "constant voltage" and "constant current" charging control. Moreover, when the charging voltage slowly rises to a certain value, the charging current slowly decreases; when the charging voltage rises to the full charging voltage, the charging current is reduced to about 1A, entering the so-called "floating charging" mode state.

[0023] See attached Figure 5 The power supply circuit mainly consists of NPN type triodes Q3 and Q4, voltage stabilizing tube Z6, diodes D20 and D21, electrolytic capacitors EC10-EC13, resistors R51 and R52, +VB and +VF power supplies, and integrated voltage stabilizer U4 (7805); which are used to generate VCC, VCC1 and +5V direct current power supplies for the work of other circuits.

[0024] Due to the adoption of half-bridge inverter, switching power supply and other technologies, and the control system constructed by microprocessors, the problems of high efficiency, energy saving, material saving and the like are well solved, and the comprehensive performance is significantly better than that of traditional chargers.

[0025] The good circuit and structure design are the advantages of the utility model, and are also important guarantees for meeting efficient and low-cost production, high reliability and advanced manufacturing technology.

[0026] The utility model not only adopts advanced inverter power supply control technology, but also adopts advanced processing technology and process to produce the circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0027] Attached Figure 1 It is the circuit board composition principle diagram of the charger of the utility model;

[0028] Attached Figure 2 It is the circuit principle diagram of the operation and display control panel part of the charger of the utility model;

[0029] Attached Figure 3 It is the circuit composition principle diagram of the control panel part of the charger of the utility model;

[0030] Attached Figure 4 It is the principle diagram of the input rectification filter circuit, half-bridge inverter circuit, output rectification filter circuit and relay contact and control circuit of the control panel part of the charger of the utility model;

[0031] Attached Figure 5 It is the principle diagram of the switching power supply circuit, drive circuit, PWM control circuit, output current and voltage feedback operation control circuit and power supply circuit of the control panel part of the charger of the utility model. DETAILED DESCRIPTION

[0032] The utility model discloses a 12V / 24V microprocessor control battery charger's circuit, its characterized in that: the rear panel of charger is provided with input power cable and cooling fan, the inside of charger is provided with control circuit board, operation and display control panel, wherein, operation and display control panel are installed on the front panel of charger, from the outside of charger, the panel is provided with: 1) 12V / 24V pilot lamp is used for indicating whether the user of operation has selected 12V battery charging or has selected 24V battery charging, 2) power indicator, is used for indicating whether the charger is live working, 3) alarm pilot lamp is used for indicating whether the charger has appeared overheat protection phenomenon or whether has appeared abnormal phenomenon such as polarity reverse, 4) a 12V / 24V charging selection button is used for selecting 12V or 24V battery charging, selects, and the corresponding pilot lamp will light up, shows the charging voltage mode of user's selection, 5) a charging current selection button is used for different charging voltage mode, that is 12V or 24V mode, and user can select different charging current, for example, in 12V mode, user can select 5A, 10A, 15A and 20A charging current, and in 24V mode, user can select 5A, 10A charging current, selects the current, and the corresponding current pilot lamp will light up, shows the charging current of user's selection, 6) charging pilot lamp is used for indicating that battery is in charging process, 7) fullness pilot lamp is used for indicating that battery has been full of electricity, 8) nixie tube display or display table is used for showing voltage and some symbols, for example, "Err" error symbol, "FUL" fullness symbol.

[0033] attached Figure 1 It is the circuit board composition principle diagram of the utility model charger. See attached Figure 1The utility model discloses a 12V / 24V microprocessor control battery charger's circuit, its characterized in that: the charger mainly comprises control circuit board 100, operation and display control panel 200, cooling fan Fan, O.H overheat protector, the input power cable of input end connected to control circuit board 100 and the positive polarity output end (Output (+) end, when using, this end is connected to the BAT+ end of battery) and the negative polarity output end (Output (-) end, when using, this end is connected to the BAT- end of battery) connected to control circuit board 100 are formed, of course, there will be the shell part of charger. The control line of cooling fan Fan is connected to the CN1 socket of control circuit board 100 through plug and its connecting wire, the socket J1 of control circuit board 100 is connected to the socket J1 of operation and display control panel 200 through plug and its connecting wire, and the control line of O.H overheat protector is connected to the socket J3 of operation and display control panel 200 through plug and its connecting wire, and O.H overheat protector is closely attached to the radiator of MOS field effect transistor in control circuit board 100 part half bridge inverter circuit, for detecting whether it is overheated, the interface of program burner is J2 socket, for the writing of control program to the microprocessor of operation and display control panel 200 part.

[0034] Attached Figure 2 It is the circuit schematic diagram of the operation and display control panel 200 part of the utility model charger. See attached Figure 2 The circuit of this part mainly comprises microprocessor U1 (F03F28), nixie tube display DS (CPS5631AG), 12V / 24V selection button KY1, charging current selection button KY2, optocoupler U3, diode D1, capacitor C1~C7, resistance R1~R11, +5V power supply, socket J1~J3, 20A indicating lamp LED1, 15A indicating lamp LED2, 10A indicating lamp LED3, 5A indicating lamp LED4, 24V indicating lamp LED5, 12V indicating lamp LED6, POWER power supply indicating lamp LED7, (is) charging indicating lamp LED8, fullness indicating lamp LED9, warning indicating lamp LED10, socket J1 is connected to the socket J1 of control circuit board 100 through plug and its connecting wire according to its mark (such as +5V, NS1, PWMA, PWMV, SCKZ etc.); the interface of program burner is J2 socket, for the writing of control program to microprocessor U1, the plug of positive polarity output Output (+) or BAT+ end and its connecting wire are connected to the Output (+) end of control circuit board 100, when using, this end is connected to the positive polarity end of battery, attached Figure 2In the figure, the connection of each component is connected according to the mark in the figure, for example, the K1 end of the key KY1 is connected to the 23 pin of U1; the 4 pin of U3 is connected to the 26 pin of U1, and so on, and the other connection relationship will not be expanded one by one; the control line of the O.H. overheat protector is connected to the socket J3 through the plug and its connecting line, and the O.H. overheat protector is close to the heat sink of the MOS field effect tube in the part of the half-bridge inverter circuit of the control circuit board 100, which is used to detect whether it is overheated; when overheating occurs, the state of the overheat protector will change, that is, the level state of the OT signal will change, and the OT signal is connected to the 5 pin of U1, and the microprocessor U1 can know whether the overheating phenomenon occurs by monitoring the level change of the 5 pin, once the overheating occurs, the corresponding protection control is carried out, for example, the charger output is stopped, or the charging current is reduced to a smaller value, such as 1A, in addition, the warning indicator lamp LED10 can be lit to prompt when overheating, and these process controls depend on the programming of the U1 microprocessor control software; the N. tube display or display table is used to display the output voltage and some symbols, for example, "Err" error symbol, "FUL" full symbol; the charging current selection key is used for different charging voltage modes, that is, 12V or 24V mode, the user can select different charging currents, for example, when the user selects 12V charging through the key, the 12V LED6 indicator lamp will be lit under the action of the control circuit, and in this 12V charging mode, the user can select 5A, 10A, 15A and 20A charging current, when selecting a certain current, the corresponding current indicator will be lit accordingly, and if the 24V mode is selected, the 24V LED5 indicator lamp will be lit, and the user can select 5A and 10A charging current, when selecting a certain current, the corresponding current indicator will be lit accordingly; the change of the NS1 signal can represent the change of the input power voltage, therefore, the change of the ADC2 or Input V signal also represents the change of the input power voltage, the latter is connected to the 8 pin of U1, that is, an A / D analog-digital conversion interface of the microprocessor U1, which can carry out A / D conversion, that is, sampling of the input voltage signal; the change of the Output (+) or BAT+ end signal reflects the change of the charger output voltage, therefore, the change of the ADC1 or Output V signal also represents the change of the output voltage, the latter is connected to the 9 pin of U1, that is, another A / D analog-digital conversion interface of the microprocessor U1, which can carry out A / D conversion, that is, sampling of the output voltage signal, and the obtained output voltage can be displayed through the N. tube display or display table.If the output voltage detected by U1 microprocessor meets certain conditions or the value of full voltage, at this time, under the action of control circuit, the digital display or display shows "FUL" full symbol, at the same time, full indicator light LED9 can also be lit to prompt, if the full condition is not met, the charging indicator light LED8 is lit to prompt, at the same time, the digital display or display shows the detected charging voltage value; Power indicator light LED7 is lit after the charger is connected to the power supply, which is used to indicate that the charger is working with electricity; Under normal circumstances, the positive output of the charger Output (+) is connected to the BAT+ end of the battery, and the negative output Output (-) is connected to the BAT- end of the battery, but if the connection error occurs, that is, the output line of the charger is connected to the battery abnormally or reversely connected (also known as polarity reversal), then, attached; Figure 2 In this case, the light emitting diode in U3 optocoupler will emit light, so that the internal triode will be turned on, so that the FANJIE signal end is low level, because the 4 pin of U3 is reversely connected to the FANJIE end of U1 26 pin, the microprocessor U1 can know whether the polarity reversal phenomenon occurs by monitoring the level change of its 26 pin, once this situation occurs, the corresponding protection control is carried out, for example, the charger output is stopped, at the same time, the warning indicator light LED10 can also be lit, and the display can also be displayed "Err" symbol to prompt; There is a situation that the output ends of the charger are short-circuited, at this time, the detected output voltage is 0, at this time, the digital display or display shows "00", indicating that the short circuit phenomenon occurs. At the same time, the microprocessor U1 can issue control command to stop the current output of the charger to protect the charger from being damaged by large current output. Of course, when this phenomenon occurs, the warning indicator light LED10 can also be lit to prompt, and the digital display or display shows "Err" error symbol, these process controls depend on the programming of U1 microprocessor control software.

[0035] Attached Figure 3 It is the circuit composition principle diagram of the charger control board 100 part of the utility model. See attached Figure 3As shown, the utility model charger control panel 100 part, its characterized in be that the circuit of this part mainly comprises input rectifier filter circuit 110, half bridge inverter circuit 120, output rectifier filter circuit 130, switching power supply circuit 140, drive circuit 150, relay contact and its control circuit 160, PWM control circuit 170, output current and voltage feedback operation control circuit 180, power supply circuit 190 and J1 and CN1 socket are connected;Input power supply line is connected to input rectifier filter circuit 110, and input rectifier filter circuit 110 is connected with switching power supply circuit 140, half bridge inverter circuit 120, and input rectifier filter circuit 110 is used to rectify and change AC input power supply into pulsating DC power supply, and after the filtering of electrolytic capacitor, it is further changed into smooth DC high voltage power supply, which is used to supply switching power supply circuit 140, provide power supply, and generate +15V DC working power supply through switching power supply circuit 140, supply other circuits (for example, drive circuit 150, PWM control circuit 170, output current and voltage feedback operation control circuit 180) for use, on the other hand, the DC high voltage power supply is used as the power supply of the later-stage half bridge inverter circuit 120, and the half bridge inverter circuit 120 is used to change the DC high voltage power supply into tens of kilohertz high-frequency high-voltage small-current AC power supply (referred to as high-frequency high-voltage AC or high-frequency power supply) under the action of other control circuits;Half bridge inverter circuit 120 is also connected to drive circuit 150 and controlled by drive circuit 150, and drive circuit 150 is connected to PWM control circuit 170;PWM control circuit 170 and output current and voltage feedback operation control circuit 180 are electrically isolated and signal transmission through optocoupler, while ensuring the reliability of the charger, and then the output current given signal PWMA of output current and voltage feedback operation control circuit 180 part, the output current negative feedback signal Uif, after the control operation processing of the circuit of this part, the control signal generated is used to control the output signal of optocoupler, and then the output PWM pulse width of PWM control circuit 170 is controlled, and finally the output current of the charger is controlled through half bridge inverter circuit 120 and its later-stage circuit, in addition, similarly, the output voltage given signal PWMV of output current and voltage feedback operation control circuit 180 part, the output voltage negative feedback signal +VB, after the control operation processing of the circuit of this part, the output PWM pulse width of PWM control circuit 170 is controlled through optocoupler, and finally the output voltage of the charger is controlled through half bridge inverter circuit 120 and its later-stage circuit;PWMA and PWMV signals are connected to the circuit of operation and display control panel 200 part through the 3rd pin and the 4th pin of socket J1 respectively;Uif signal and +VB signal are connected to output rectifier filter circuit 130.The high-frequency power supply of tens of kilohertz is converted into low-voltage, high-current AC power through the voltage reduction and current conversion of the main transformer, and then converted into a DC low-voltage power supply through the output rectifier and filter circuit 130; the output rectifier and filter circuit 130 generates +VB, Uif, +VA, +VF and NS1 signals, among which +VB and Uif are transmitted to the output current and voltage feedback operation control circuit 180; the Uif signal terminal is connected to the negative polarity output terminal (Output (-) terminal) of the control circuit board 100, which is connected to the BAT- terminal of the battery when in use; +VB and +VF are transmitted to the power circuit 190; +VB and NS1 are transmitted to the relay contact and its control circuit 160; the NS1 signal is also connected to pin 7 of the socket J1, and its signal change represents the input power voltage. The output of the output rectifier and filter circuit 130 is connected to the normally open contact of a relay, while the other end of the contact is connected to the positive polarity output terminal (Output (+) terminal, which, when in use, is connected to the BAT+ terminal of the battery). This contact is part of the relay contact and its control circuit 160, and the relay is controlled by this circuit and its SCKZ control signal. The SCKZ control signal is connected to pin 5 of socket J1. The VCC signal is connected to the power supply circuit 190, which is used to generate VCC, VCC1, and +5V power supplies. In addition, +5V and ground are connected to pins 1 and 2 of socket J1, respectively, and the BAT+ signal is connected to pin 6 of socket J1. Socket J1 is connected to socket J1 of the operation and display control panel 200 via its plug and connecting wires.

[0036] Attachment Figure 4 It is a schematic diagram of the input rectifier filter circuit 110, the half-bridge inverter circuit 120, the output rectifier filter circuit 130, and the relay contacts and their control circuit 160 of the charger control board of the present invention.

[0037] See attached Figure 4 As shown, the input rectifier and filter circuit 110 primarily consists of a fuse (FUSE), a thermistor (RM1), a rectifier consisting of four diodes (D1-D4), filter electrolytic capacitors (EC4 and EC5), and capacitor C1. The input terminal is the power supply input terminal and is connected to the power grid. This component rectifies the AC input power into a pulsating DC power supply, which is then filtered by the electrolytic capacitors and further converted into a stable +310V DC high-voltage power supply. This DC high-voltage power supply not only supplies power to the switching power supply circuit 140 but also serves as the power supply for the subsequent half-bridge inverter circuit 120. The +310V ground is GND1, which is connected to another ground (GND3) via C1. Since this part of the circuit is relatively common, it will not be further explained here.

[0038] See attached Figure 4As shown, the half-bridge inverter circuit 120 is mainly composed of MOS transistors Q1 and Q2, parallel commutation capacitors C2 and C3 and C4 and C5, filter capacitors C6 and C7, resistors R7-R10, inductor DK1, the primary N1 winding of the main transformer T2, and the +310V power supply; the G1 and S1 control signal terminals of Q1 are connected to the G1 and S1 control signal terminals of the driving circuit 150 (see attached Figure 5 ), and the G2 and S2 control signal terminals of Q2 are connected to the G2 and S2 control signal terminals of the driving circuit 150. The half-bridge inverter circuit 120, under the action of other control circuits, is used to convert the direct-current high-voltage power supply into a high-frequency high-voltage small-current alternating-current power supply of tens of kilohertz, and then perform voltage and current conversion through the main transformer T2, and then output to the subsequent circuit. Since the circuit in this part is relatively common, it will not be described in detail here.

[0039] See attached Figure 4 As shown, the output rectification and filtering circuit 130 is mainly composed of the secondary N3 and N4 windings with center taps of the main transformer T2, fast recovery diodes D12-D14, inductor DK2, electrolytic capacitor EC7, capacitor C8, resistors R12-R15, current detection sampling resistors RS1 and RS2; the output of the output rectification and filtering circuit 130 is connected to the normally open contact of a relay, and the other end of the contact is connected to the positive polarity output end (Output (+) end, which is connected to the BAT+ end of the storage battery when in use), and the contact is part of the relay contact and its control circuit 160; the signals detected by RS1 and RS2 are Uif signals, and the signal end is connected to the negative polarity output end (Output (-) end, which is connected to the BAT- end of the storage battery when in use) of the charger; in addition, this part of the circuit also generates +VA, +VB, +VF and NS1 signals, and the circuits connected to these signals have been described above and will not be repeated here. Since the circuit in this part is relatively common, it will not be described in detail here.

[0040] See attached Figure 4As shown, the relay contact and its control circuit 160 is mainly composed of a relay (JDQ1A is its working line package; JDQ1B is its normally open contact, used in parallel), NPN type triode Q5 and Q6, voltage stabilizing tube Z7, diode D22~D24, capacitor C31 and C32, NS1 signal, SCKZ signal, +VB and VCC power supply, socket CN1; the plug of CN1 and its control line connect the cooling fan Fan of the charger; the SCKZ control signal is connected to the 5th pin of socket J1, that is, connected to the circuit of the operation and display control panel 200 part; the relevant signal and power supply connected circuit have been described before, which will not be repeated here. Under the action of NS1 signal, Q5 can be turned on, so that the cooling fan Fan can work; under the action of SCKZ control signal, Q6 can be turned on, so that the relay operates, its contact JDQ1B changes from normally open to normally closed state, so that the charger has output, otherwise, when the relay does not operate, the connection between the positive polarity end of the charger and the output rectifier filter circuit 130 is in an open state, and there will be no output. By controlling the working state of the relay, the normal output and protection control of the charger can be realized, such as overheat, reverse connection and short circuit protection. Since the circuit of this part is relatively common, it will not be described here.

[0041] The Figure 5 It is the schematic diagram of the switching power supply circuit 140, the drive circuit 150, the PWM control circuit 170, the output current and voltage feedback operation control circuit 180 and the power supply circuit 190 of the charger control panel part of the utility model.

[0042] The Figure 5 As shown, the switching power supply circuit 140 is mainly composed of a drive chip U1 (XY3018FB), a switching power supply transformer T1, diodes D5~D7, electrolytic capacitors EC1~EC3, capacitors C9~C12, resistors R17~R28 and +310V power supply; the circuit of this part is used to generate +15V DC power supply for other circuits (for example, the drive circuit 150, the PWM control circuit 170, the output current and voltage feedback operation control circuit 180). The working principle of this part of the circuit will not be described here.

[0043] The Figure 5 As shown, the drive circuit 150 is mainly composed of a drive chip (AO4612) composed of two P and N channel MOS tubes, voltage stabilizing tubes Z1~Z4, drive transformer T3, diodes D15~D16, electrolytic capacitor EC9, capacitors C17~C23, resistors R0~R4 and R32~R40, and +15V power supply; the function of this part of the circuit is to drive Q1 and Q2 tubes in the half-bridge inverter circuit 120, realize inverter control, and finally control the output of the charger.Figure 5 The output drive signals G1 and S1, G2 and S2 of the drive circuit 150 are connected to the corresponding control terminals of Q1 and Q2 in the half-bridge inverter circuit 120, respectively; the input signals of the drive circuit 150 are connected to the 11 and 14 pins of the PWM chip U4 in the PWM control circuit 170, respectively. Under the action of the control circuit, the PWM square wave pulse signals output from the 11 and 14 pins of the U4 (SG3525) chip are transmitted through the drive circuit 150 to control the working states of the MOS transistors Q1 and Q2 in the half-bridge inverter circuit 120 (see the attached schematic diagram), so that the two MOS transistors are alternately turned on and off, and the half-bridge inverter circuit is formed. When the MOS transistors Q1 and Q2 are alternately turned on, the primary winding coil of the high-frequency transformer T2 connected thereto will generate an alternating intermediate-frequency current or voltage. After being stepped down by the secondary winding coil of the transformer, the current is rectified by the fast-recovery rectifier diodes (D12, D13) to become a direct current, and finally the output voltage and current of the charger are controlled. Figure 4

[0044] As shown in the attached schematic diagram, the PWM control circuit 170 mainly consists of a PWM chip U4 (SG3525), an optocoupler U2 (containing U2A and U2B, wherein U2A is in the output current and voltage feedback operation control circuit 180, and the optocoupler U2 is the optocoupler mentioned above), an electrolytic capacitor EC8, capacitors C13-C15, resistors R5-R6 and R29-R31, and a +15V power supply; the PWM chip U4 outputs PWM pulse signals from the 11 and 14 pins, which are connected to the input terminals of the drive circuit 150, respectively. The PWM control circuit 170 and the output current and voltage feedback operation control circuit 180 are electrically isolated and signal-transmitted through the optocoupler U2, which not only ensures the reliability of the charger, but also generates control signals by applying the circuit connected to the output current and voltage feedback operation control circuit 180 to control the output signals of the optocoupler U2, and then controls the output PWM pulse width of the PWM control circuit 170, so as to finally control the output current of the charger through the half-bridge inverter circuit 120 and its subsequent circuits. Similarly, the output voltage given signal PWMV and the output voltage negative feedback signal +VB connected to the output current and voltage feedback operation control circuit 180 will also be applied to the circuit for control operation processing, and then the output PWM pulse width of the PWM control circuit 170 will be controlled through the optocoupler U2, so as to finally control the output voltage of the charger through the half-bridge inverter circuit 120 and its subsequent circuits. Figure 5

[0045] The output voltage and current of the charger power supply are controlled by the control circuit. The output control is performed according to the set parameters. In the attached schematic diagram, the output voltage and current of the charger are controlled by the control circuit. Figure 2 ​​The size of the charging current is determined by the user and the microprocessor and outputted, and the size of the output current is determined by the feedback of the output voltage of the charger and outputted. Figure 4 The feedback signal of the output voltage of the charger is +VB. They finally affect the output current of the charger. Figure 5 The output of the optocoupler U2 controls the output current and voltage of the charger.

[0046] The triode output of the optocoupler U2 controls the pin 2 signal of the SG3525, i.e. the pin 2 IN+ (same-phase input end) of the internal operational amplifier of the SG3525. The pin 2 (the same-phase input end IN+ of the internal operational amplifier), the pin 1 (the opposite-phase input end IN- of the internal operational amplifier) and the pin 9 (the output end) of the SG3525 are an operational amplifier in the internal SG3525. In the circuit of the utility model, the pin 1 and the pin 9 are connected together. In this way, the internal operational amplifier is a follower. The level of the pin 9 can control the output pulse width of the internal PWM pulse width regulator of the SG3525, and finally control the output current of the charger. Figure 4 The field effect tubes Q1 and Q2 change the output size of the charger. For example, when the given value of the charging current increases, the output pulse width of the internal PWM pulse width regulator of the SG3525 increases, and the output current of the charger increases; on the contrary, the output current of the charger decreases. When the given value of the charging current is unchanged and the output current changes, the control results of the above-mentioned control circuit will make the charging current of the charger stable. For example, when the given value of the charging current is unchanged and the output current increases due to some external factors, the PWM output pulse width of the controller decreases, and the output charging current returns to the given value. That is to say, the control results of the above-mentioned control circuit will make the output charging current stable.

[0047] The working principle of the PWM chip U4 (SG3525) can be consulted in the data, and here it will not be described too much.

[0048] See the attached Figure 5As shown, the output current and voltage feedback operation control circuit 180 is mainly composed of an operational amplifier U3 (including U3A, U3B), diodes D18 and D19, capacitors C24~C30, resistors R41~R50, VCC1, +VB, PWMV, U2A, Uif, PWMA, and +5V of the optocoupler U2; according to the above, the PWMA and PWMV signals are connected to the circuit of the operation and display control panel 200 through pins 3 and 4 of the socket J1 respectively; the Uif signal and the +VB signal are connected to the output rectifier filter circuit 130; VCC1 and +5V are connected to the power supply circuit 190; the operational amplifiers U3A, U3B and their peripheral resistors and capacitors constitute a proportional integral operation circuit, which respectively realizes the feedback operation control of the charger output voltage and current; the PWM control circuit 170 and the output current and voltage feedback operation control The circuits 180 are electrically isolated and signal transmitted through the optocoupler U2, which can ensure the reliability of the charger. The PWMA output current setting signal and the Uif output current negative feedback signal are processed by the proportional-integral operation circuit of the U3B part, and the generated control signal is used to control the output signal of the optocoupler U2, thereby controlling the output PWM pulse width of the PWM control circuit 170. Finally, the output current of the charger is controlled by the half-bridge inverter circuit 120 and its subsequent circuits. Similarly, the PWMV output voltage setting signal and the +VB output voltage negative feedback signal are processed by the proportional-integral operation circuit of the U3A part, and then controlled by the optocoupler U2. Finally, the output PWM pulse width of the PWM control circuit 170 is controlled by the half-bridge inverter circuit 120 and its subsequent circuits. Finally, the output voltage of the charger is controlled by the half-bridge inverter circuit 120 and its subsequent circuits.

[0049] When the user selects 12V or 24V charging mode, the control system uses output voltage and current feedback control to achieve "constant voltage" and "constant current" charging control based on the user's selected charging current. Furthermore, as the charging voltage gradually increases to a certain value, the charging current gradually decreases. When the charging voltage reaches the full charge voltage, the charging current decreases to approximately 1A, entering the so-called "float charge" mode.

[0050] Further explanation of the working principle of the output current and voltage feedback operation control circuit 180 will not be described in detail here.

[0051] See attached Figure 5 As shown, power supply circuit 190 primarily consists of NPN transistors Q3 and Q4, voltage regulator diode Z6, diodes D20 and D21, electrolytic capacitors EC10-EC13, resistors R51 and R52, +VB and +VF power supplies, and integrated voltage regulator U4 (7805). It generates VCC, VCC1, and +5V DC power for other circuits. This circuit is not described in detail here.

[0052] It can be seen that good circuit and structure design is the advantage of the utility model, and is also an important guarantee for high efficiency and low cost production, high reliability and advanced technology. The content of the utility model patent application is to protect the circuit and structure design of the charger.

[0053] The utility model not only adopts advanced inverter power control technology, but also adopts advanced processing technology and process to produce circuit board. The charger has the advantages of reasonable structure, small size, light weight, low cost, high production efficiency, advanced manufacturing technology and the like.

[0054] The above content is a detailed description of the utility model in combination with specific charger circuit, structure and control function, and cannot be determined that the specific implementation of the utility model is limited to these descriptions. For other technical personnel in the technical field described in the utility model, without departing from the circuit and structure concept of the utility model, a number of simple deductions and substitutions can also be made, which should be considered as belonging to the scope of protection of the utility model.

Claims

1. A 12V / 24V microprocessor controlled battery charger characterized by: The charger is internally provided with a control circuit board and an operation and display control panel, which is installed on the front panel of the charger; the front panel is provided with: 1) a 12V / 24V indicator; 2) a power indicator; 3) an alarm indicator; 4) a 12V / 24V charging selection button; 5) a charging current selection button; 6) a charging indicator; 7) a full charging indicator; 8) a digital tube display or display table; the socket J1 of the control circuit board is connected to the socket J1 of the operation and display control panel through a plug and its connecting wire; the control wire of the overheat protector is connected to the socket J3 of the operation and display control panel through a plug and its connecting wire, and the overheat protector is installed close to the radiator of the MOS field effect tube in the half-bridge inverter circuit of the control circuit board part; The circuit of the control board part mainly includes an input rectification and filtering circuit, a half-bridge inverter circuit, an output rectification and filtering circuit, a switching power supply circuit, a driving circuit, a relay contact and its control circuit, a PWM control circuit, an output current and voltage feedback operation control circuit, a power supply circuit, and the socket J1 and the socket CN1; the input power supply wire is connected to the input rectification and filtering circuit, and the input rectification and filtering circuit is connected to the switching power supply circuit and the half-bridge inverter circuit; the half-bridge inverter circuit is connected to the driving circuit and is controlled by the driving circuit, and the driving circuit is connected to the PWM control circuit; the PWM control circuit and the output current and voltage feedback operation control circuit are electrically isolated and signal-transmitted through an optical coupler; the PWMA and PWMV signals of the PWM control circuit are connected to the circuit of the operation and display control panel part through the socket J1; the output rectification and filtering circuit generates the +VB, Uif, +VA, +VF and NS1 signals, wherein the +VB and Uif are delivered to the output current and voltage feedback operation control circuit; the Uif signal end is connected to the negative polarity output end of the control circuit board; the +VB and +VF are delivered to the power supply circuit; the +VB and NS1 are delivered to the relay contact and its control circuit; the NS1 signal is also connected to the 7th pin of the socket J1; the output of the output rectification and filtering circuit is connected to the normally open contact of a relay, and the other end of the contact is connected to the positive polarity output end, and the relay is controlled by the control signal of the circuit of the control board part; ​ The operation and display control panel part circuit mainly comprises a microprocessor U1, a digital tube display DS, a 12V / 24V selection button KY1, a charging current selection button KY2, an optical coupler U3, diodes D1, capacitors C1-C7, resistors R1-R11, a +5V power supply, sockets J1-J3, indicator lamps LED1-LED10, and a power supply indicator lamp LED7.

2. A 12V / 24V microprocessor controlled battery charger as claimed in claim 1, wherein: The relay contact and its control circuit comprise a relay, NPN type triodes Q5 and Q6, a voltage stabilizing tube Z7, diodes D22-D24, capacitors C31 and C32, an NS1 signal, an SCKZ signal, +VB and VCC power supplies, and a socket CN1.

3. A 12V / 24V microprocessor controlled battery charger as claimed in claim 1, wherein: The input rectification filter circuit mainly comprises a fuse FUSE, a thermal resistor RM1, a rectifier, filter electrolytic capacitors EC4 and EC5, and a capacitor C1. The input rectification filter circuit converts the alternating current input power supply into pulsating direct current power supply, and further into +310V stable direct current high voltage power supply through the filtering of electrolytic capacitors. The direct current high voltage power supply is used as the power supply of the later-stage half-bridge inverter circuit, and the ground of the +310V direct current high voltage power supply is connected to the capacitor C1 between GND1 and another ground GND3.

4. A 12V / 24V microprocessor controlled battery charger as claimed in claim 3, wherein: The half-bridge inverter circuit mainly comprises MOS tubes Q1 and Q2, parallel commutation capacitors C2 and C3 and C4 and C5, filter capacitors C6 and C7, resistors R7-R10, inductor DK1, the primary N1 winding of the main transformer T2, a +310V power supply; the G1 and S1 control signal ends of the MOS tube Q1 are connected to the G1 and S1 control signal ends of the driving circuit, and the G2 and S2 control signal ends of the MOS tube Q2 are connected to the G2 and S2 control signal ends of the driving circuit; the half-bridge inverter circuit is used for converting a direct-current high-voltage power supply into a high-frequency high-voltage small-current alternating current power supply of tens of kilohertz, and then outputting to a subsequent circuit after voltage and current conversion through the main transformer T2.

5. A 12V / 24V microprocessor controlled battery charger as claimed in claim 4, characterized in that: The driving circuit mainly comprises a driving chip composed of two P and N channel MOS tubes, voltage stabilizing tubes Z1-Z4, a driving transformer T3, diodes D15-D16, an electrolytic capacitor EC9, capacitors C17-C23, resistors R0-R4 and R32-R40; the driving circuit is used for driving the Q1 and Q2 tubes in the half-bridge inverter circuit 120, realizing inverter control, and finally controlling the output of the charger. In Fig. 5, the output driving signals G1 and S1 and G2 and S2 of the driving circuit are respectively connected to the corresponding control ends of the Q1 and Q2 in the half-bridge inverter circuit; the input signals of the driving circuit are respectively connected to the 11 and 14 pins of the PWM chip U4 in the PWM control circuit, the PWM square wave pulse signals output by the 11 and 14 pins of the PWM chip U4 control the working states of the MOS tubes Q1 and Q2 in the half-bridge inverter circuit 120 through the driving circuit, so that the two MOS tubes are alternately turned on or turned off, and then the half-bridge inverter circuit realizes inverter control.

6. A 12V / 24V microprocessor controlled battery charger as claimed in claim 3, wherein: The PWM control circuit mainly comprises a PWM chip U4, a photo-coupler U2, electrolytic capacitors EC8, capacitors C13-C15, resistors R5-R6 and R29-R31; the photo-coupler U2 comprises U2A and U2B, wherein U2A is in the output current and voltage feedback operation control circuit, the photo-coupler U2 is the photo-coupler mentioned above, the 11th and 14th pins of the PWM chip U4 output PWM pulse signals, which are connected to the input ends of the driving circuit respectively; the PWM control circuit and the output current and voltage feedback operation control circuit are electrically isolated and signal-transmitted through the photo-coupler U2, while ensuring the reliability of the charger, the output current given signal of the output current and voltage feedback operation control circuit part, the output current negative feedback signal Uif, and the control signal generated after the control operation processing of the circuit part are applied to control the output signal of the photo-coupler U2, and then the output PWM pulse width of the PWM control circuit is controlled, finally the control of the output current of the charger is realized through the half-bridge inverter circuit and the subsequent circuit; the output voltage given signal of the output current and voltage feedback operation control circuit part, the output voltage negative feedback signal +VB, and the control signal generated after the control operation processing of the circuit part are also applied to control the output PWM pulse width of the PWM control circuit through the photo-coupler U2, finally the control of the output voltage of the charger is realized through the half-bridge inverter circuit 120 and the subsequent circuit.

7. A 12V / 24V microprocessor controlled battery charger as claimed in claim 3, characterized in that: The switching power supply circuit mainly comprises a driving chip U1, a switching power supply transformer T1, diodes D5-D7, electrolytic capacitors EC1-EC3, capacitors C9-C12, resistors R17-R28, and a +310V power supply; the switching power supply circuit is used to generate +15V DC power supply for the driving circuit, the PWM control circuit, and the output current and voltage feedback operation control circuit.

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