17Jul/090
Military applications due to power some of the larger energy-consuming equipment
Military applications due to power some of the larger energy-consuming equipment, and thus commonly used to link up the battery model to avoid excessive current. Serial battery charge and discharge with a single battery charge and discharge is different in different cell battery differences were not taken seriously if it will cause a lower efficiency in the use of batteries and reduce battery life; to consider the application of military equipment environment special requirements not currently on the market to meet these needs a comprehensive charge-discharge control equipment, which can be good here to design a new type of meeting these needs integrated battery charge-discharge control equipment.
1 System Overview
The integrated battery charge-discharge control equipment for the control of a single-chip core MC68HC908SR12 using FPGA-assisted control design. Main power circuit, constant current constant voltage charging control unit, the balance control unit discharge, the central control unit, FPGA auxiliary control unit, temperature detection circuit, such as man-machine interface circuit. Battery charge and discharge control equipment, primarily for military applications power some of the larger energy-consuming equipment is generally adopted in the case of battery-powered tandem design. Focus during the design process to consider the balance of characteristics of the battery to improve battery power supply in series the efficiency of the Group, extending its life. Figure 1 is a block diagram of the system.
2 Hardware Design
The following charge and discharge control of the equipment to carry out an overview of the hardware design process description.
2.1 Power circuit
The use of switching power supply as power supply equipment chargers. Switching Power Supply using Pulse Modulation PWM (Pulse Width Modulation) and the MOSFET, BTS, IGBT, such as the design of electronic devices. Switching power supply of a higher degree of integration with a voltage regulator, current limiting, thermal protection. Compared with the linear power supply wide input voltage range (typically up to the exchange of 85 ~ 265 V), small size, light weight, high efficiency. At the same time, its easy to FPGA-assisted control unit to control.
2.2 Charge Control Unit
Charging control unit of the more mature the current constant current constant voltage charging circuit to design completion. Figure 2 is a circuit schematic diagram. Constant-current constant-voltage circuit MC68HC908SR12 by Motorola's single-chip analog circuit chip-chip modules, and the MOSFET switch, Schottky diodes, filter inductors, filter capacitors and other components devices. Analog circuit module is Motorola's unique single-chip MC68HC908SR12 components, which importation of multi-way switch, two amplifiers can be controlled, on-chip temperature sensor, composed of current detection circuit. Programmable gain amplifier for a total of 1 ~ 256. Choose the input amplifier 2-channel analog input pin (ATD0, ATD1), chip temperature sensor, analog to enter (VSSAM). ATD0 and inter-VSSAM which can be accessed by a current-sense resistors, used to measure the external current, it is connected to the current detection circuit can be greater than a specified value in the current interruption and when the output signal.
In charge before the start of the pre-processing stage, according to detected characteristics of the different batteries, software, select the appropriate charging algorithm, and the charging algorithm from single-chip FPGA realization of supplementary control units. After the beginning of the charge, the software regularly collected on the sense resistor voltage R value, calculated, set the output SR12 single-chip control parameters. At the same time, real-time detection circuit current charge current, in the current laptop battery more than the specified value SR12 when interrupted by the timely turn-off single-chip microcomputer to control the charge current to achieve constant-current constant-voltage charge control.
Equalizing charge is the charge-discharge control equipment, an important feature. In charge of the process, as a result of the quality of the battery is not the same as the capacity of small, poor quality of the battery terminal voltage in the rechargeable battery into the same voltage will appear after the growth of cells and more than another, and if no measures are taken, they will be the voltage difference will increase, as well as a battery which will soon reach the required safety voltage, the charge will be forced to stop the process. At this point the high pressure should stop charging the IBM laptop battery , that is a balanced charge. This is conducive to the restoration of damaged cells within the unit, so that the process of charging a smooth manner.
2.3 Discharge Control Unit
Discharge Control Unit 2 main components, first, balance discharge flyback circuit, can achieve the balance of battery discharge. Balance between charge and discharge of the discharge control equipment, an important feature. In the discharge process, the individual differences as a result of the battery, if no measures are taken, the individual cells within the battery pack will become more and more obvious differences, this would reduce the efficiency of battery life reduced. Discharge back to the control unit used in relaxation-firing circuit design, the schematic diagram shown in Figure 3, the circuit itself has a terminal voltage of the inductance characteristics of each check (also called back to the relaxation of the circuit) can be achieved batteries battery discharge the balance of individual discharge. This is conducive to the restoration of damaged batteries IBM ThinkPad T60 , IBM ASM 92P1140 , IBM FRU 92P1137 in the unit, to improve the efficiency and battery life. Second, over-discharge protection circuit, the circuit of the battery pack can be achieved over-discharge protection. Figure 4 is the battery over-discharge protection circuit schematic diagram, when the terminal voltage detection circuit detects a voltage lower than the discharge voltage security settings, the protection circuit can be cut off the discharge circuit to achieve the protection of the battery.
2.4 Temperature detection circuit
In the charging process, Acer battery charge as the temperature increases the capacity, especially in the close to end-of-charge, the rate of temperature change △ T / △ t most, the property is to determine whether the battery is full, one of the main conditions. Therefore, the use of National Semiconductor Corporation produced the number of single-chip temperature sensor LM92 precision temperature detection circuit design. The circuit schematic diagram shown in Figure 5.
2.5 man-machine interface unit
(1) keyboard in response to the circuit
Circuit design of the keyboard to respond, use MC68HC908SR12 single-chip PORT D (PTD6 and PTD7) port of the keyboard interrupt (KBI). According to the actual situation MC68HC908SR12 keyboard MCU Interrupt Enable Register KBIER write the value of people, who write "1" that allow the disruption, write "0" that can not be interrupted. Interrupted to allow the keyboard port, MC68HC908SR12 single chip to its internal 30 kΩ pull-resistance, so that the design of the keyboard in response to the circuit is very simple, it should be noted that applications to increase the jitter elimination Subroutine keyboard to prevent misoperation. (2) the state of display circuit
Status display circuit MC68HC908SR12 single-chip design using PORT A (PTA0 ~ PTA5) port LED driver functions directly. Programming PORT A first set of working conditions, in the LED control register write LEDA corresponding value, write "1" that can directly drive LED, write "0" that as a standard I / O port. In the charge state of each stage shows, such as: the battery is in a state-of-charge, apple batteries temperature is too high to enter the state, such as temperature control.
2.6 Central Control Unit and the FPGA-assisted control unit
Central control unit and auxiliary control unit FPGA main charge and discharge control equipment, conversion of state control. According to the different sensors to obtain the status, write the different commands, different mode of conversion.
3 Software Design
Shell discharge control equipment software design thinking is: the realization of the various functional components of modular programming, software process using interrupted work. Its purpose is to enable the application process clear, readable, and easy to debug as well as the function of the maintenance and upgrade products. Mainly by the software initialization, pre-processing, control algorithms, charge-discharge four parts.
3.1 Initialization
In the initial stage of the procedure should be first initialized MC68HC908SR12 single-chip operation, including A1078 , Apple A1148 , PowerBook G4 15inch battery setting I / O port input / output status, phase-locked loop circuit PLL parameter settings, set the timer parameters, such as TIM.
3.2 Preprocessing
Pre-treatment stage is the integrated charge and discharge control equipment in front of the normal work of the preparatory phase. Initialization procedure, the first single-chip MC68HC908SR12 in accordance with the use of internal temperature sensors detect ambient temperature. When the ambient temperature is too low or too high and can not be carried out on the battery charge and discharge, or they will damage the battery. Then, set the A / D converter channel parameters and to detect the iBook G4 12-inch Series terminal voltage. Will be the experience of testing data with the theoretical value, as well as to determine the type of battery is connected correctly. On low voltage batteries, the use of short pulse of current rechargeable, so the battery will help to activate a chemical reaction within the material, part of the restoration of the damaged cell.
3.3 Charging and Discharging
In accordance with instructions given by the control unit for charging and discharging. Charge-discharge integrated circuit design in hardware devices to take into account the charge balance, the balance discharge protection and over-discharge, therefore, the software design is also given to the appropriate consideration.
3.4 Control Algorithm
Control algorithm to control the main MCU and FPGA-assisted MC68HC908SR12 control unit, write the appropriate command and control integrated equipment charge and discharge co-ordination of the module.
4 Conclusion
The integrated PowerBook G4 12 inch battery charge-discharge control equipment designed to take full account of the series when the battery charge and discharge the balance of effect can be applied to series battery charge and discharge control and battery pack in series to improve efficiency and prolong its service life; At the same time taking into account the charge-discharge control equipment integrated with the main power equipment for military use, in its design also takes full account of the military applications of the complexity and uniqueness, so that the battery charge and discharge control of dual-use equipment with a wide application prospect.
1 System Overview
The integrated battery charge-discharge control equipment for the control of a single-chip core MC68HC908SR12 using FPGA-assisted control design. Main power circuit, constant current constant voltage charging control unit, the balance control unit discharge, the central control unit, FPGA auxiliary control unit, temperature detection circuit, such as man-machine interface circuit. Battery charge and discharge control equipment, primarily for military applications power some of the larger energy-consuming equipment is generally adopted in the case of battery-powered tandem design. Focus during the design process to consider the balance of characteristics of the battery to improve battery power supply in series the efficiency of the Group, extending its life. Figure 1 is a block diagram of the system.
2 Hardware Design
The following charge and discharge control of the equipment to carry out an overview of the hardware design process description.
2.1 Power circuit
The use of switching power supply as power supply equipment chargers. Switching Power Supply using Pulse Modulation PWM (Pulse Width Modulation) and the MOSFET, BTS, IGBT, such as the design of electronic devices. Switching power supply of a higher degree of integration with a voltage regulator, current limiting, thermal protection. Compared with the linear power supply wide input voltage range (typically up to the exchange of 85 ~ 265 V), small size, light weight, high efficiency. At the same time, its easy to FPGA-assisted control unit to control.
2.2 Charge Control Unit
Charging control unit of the more mature the current constant current constant voltage charging circuit to design completion. Figure 2 is a circuit schematic diagram. Constant-current constant-voltage circuit MC68HC908SR12 by Motorola's single-chip analog circuit chip-chip modules, and the MOSFET switch, Schottky diodes, filter inductors, filter capacitors and other components devices. Analog circuit module is Motorola's unique single-chip MC68HC908SR12 components, which importation of multi-way switch, two amplifiers can be controlled, on-chip temperature sensor, composed of current detection circuit. Programmable gain amplifier for a total of 1 ~ 256. Choose the input amplifier 2-channel analog input pin (ATD0, ATD1), chip temperature sensor, analog to enter (VSSAM). ATD0 and inter-VSSAM which can be accessed by a current-sense resistors, used to measure the external current, it is connected to the current detection circuit can be greater than a specified value in the current interruption and when the output signal.
In charge before the start of the pre-processing stage, according to detected characteristics of the different batteries, software, select the appropriate charging algorithm, and the charging algorithm from single-chip FPGA realization of supplementary control units. After the beginning of the charge, the software regularly collected on the sense resistor voltage R value, calculated, set the output SR12 single-chip control parameters. At the same time, real-time detection circuit current charge current, in the current laptop battery more than the specified value SR12 when interrupted by the timely turn-off single-chip microcomputer to control the charge current to achieve constant-current constant-voltage charge control.
Equalizing charge is the charge-discharge control equipment, an important feature. In charge of the process, as a result of the quality of the battery is not the same as the capacity of small, poor quality of the battery terminal voltage in the rechargeable battery into the same voltage will appear after the growth of cells and more than another, and if no measures are taken, they will be the voltage difference will increase, as well as a battery which will soon reach the required safety voltage, the charge will be forced to stop the process. At this point the high pressure should stop charging the IBM laptop battery , that is a balanced charge. This is conducive to the restoration of damaged cells within the unit, so that the process of charging a smooth manner.
2.3 Discharge Control Unit
Discharge Control Unit 2 main components, first, balance discharge flyback circuit, can achieve the balance of battery discharge. Balance between charge and discharge of the discharge control equipment, an important feature. In the discharge process, the individual differences as a result of the battery, if no measures are taken, the individual cells within the battery pack will become more and more obvious differences, this would reduce the efficiency of battery life reduced. Discharge back to the control unit used in relaxation-firing circuit design, the schematic diagram shown in Figure 3, the circuit itself has a terminal voltage of the inductance characteristics of each check (also called back to the relaxation of the circuit) can be achieved batteries battery discharge the balance of individual discharge. This is conducive to the restoration of damaged batteries IBM ThinkPad T60 , IBM ASM 92P1140 , IBM FRU 92P1137 in the unit, to improve the efficiency and battery life. Second, over-discharge protection circuit, the circuit of the battery pack can be achieved over-discharge protection. Figure 4 is the battery over-discharge protection circuit schematic diagram, when the terminal voltage detection circuit detects a voltage lower than the discharge voltage security settings, the protection circuit can be cut off the discharge circuit to achieve the protection of the battery.
2.4 Temperature detection circuit
In the charging process, Acer battery charge as the temperature increases the capacity, especially in the close to end-of-charge, the rate of temperature change △ T / △ t most, the property is to determine whether the battery is full, one of the main conditions. Therefore, the use of National Semiconductor Corporation produced the number of single-chip temperature sensor LM92 precision temperature detection circuit design. The circuit schematic diagram shown in Figure 5.
2.5 man-machine interface unit
(1) keyboard in response to the circuit
Circuit design of the keyboard to respond, use MC68HC908SR12 single-chip PORT D (PTD6 and PTD7) port of the keyboard interrupt (KBI). According to the actual situation MC68HC908SR12 keyboard MCU Interrupt Enable Register KBIER write the value of people, who write "1" that allow the disruption, write "0" that can not be interrupted. Interrupted to allow the keyboard port, MC68HC908SR12 single chip to its internal 30 kΩ pull-resistance, so that the design of the keyboard in response to the circuit is very simple, it should be noted that applications to increase the jitter elimination Subroutine keyboard to prevent misoperation. (2) the state of display circuit
Status display circuit MC68HC908SR12 single-chip design using PORT A (PTA0 ~ PTA5) port LED driver functions directly. Programming PORT A first set of working conditions, in the LED control register write LEDA corresponding value, write "1" that can directly drive LED, write "0" that as a standard I / O port. In the charge state of each stage shows, such as: the battery is in a state-of-charge, apple batteries temperature is too high to enter the state, such as temperature control.
2.6 Central Control Unit and the FPGA-assisted control unit
Central control unit and auxiliary control unit FPGA main charge and discharge control equipment, conversion of state control. According to the different sensors to obtain the status, write the different commands, different mode of conversion.
3 Software Design
Shell discharge control equipment software design thinking is: the realization of the various functional components of modular programming, software process using interrupted work. Its purpose is to enable the application process clear, readable, and easy to debug as well as the function of the maintenance and upgrade products. Mainly by the software initialization, pre-processing, control algorithms, charge-discharge four parts.
3.1 Initialization
In the initial stage of the procedure should be first initialized MC68HC908SR12 single-chip operation, including A1078 , Apple A1148 , PowerBook G4 15inch battery setting I / O port input / output status, phase-locked loop circuit PLL parameter settings, set the timer parameters, such as TIM.
3.2 Preprocessing
Pre-treatment stage is the integrated charge and discharge control equipment in front of the normal work of the preparatory phase. Initialization procedure, the first single-chip MC68HC908SR12 in accordance with the use of internal temperature sensors detect ambient temperature. When the ambient temperature is too low or too high and can not be carried out on the battery charge and discharge, or they will damage the battery. Then, set the A / D converter channel parameters and to detect the iBook G4 12-inch Series terminal voltage. Will be the experience of testing data with the theoretical value, as well as to determine the type of battery is connected correctly. On low voltage batteries, the use of short pulse of current rechargeable, so the battery will help to activate a chemical reaction within the material, part of the restoration of the damaged cell.
3.3 Charging and Discharging
In accordance with instructions given by the control unit for charging and discharging. Charge-discharge integrated circuit design in hardware devices to take into account the charge balance, the balance discharge protection and over-discharge, therefore, the software design is also given to the appropriate consideration.
3.4 Control Algorithm
Control algorithm to control the main MCU and FPGA-assisted MC68HC908SR12 control unit, write the appropriate command and control integrated equipment charge and discharge co-ordination of the module.
4 Conclusion
The integrated PowerBook G4 12 inch battery charge-discharge control equipment designed to take full account of the series when the battery charge and discharge the balance of effect can be applied to series battery charge and discharge control and battery pack in series to improve efficiency and prolong its service life; At the same time taking into account the charge-discharge control equipment integrated with the main power equipment for military use, in its design also takes full account of the military applications of the complexity and uniqueness, so that the battery charge and discharge control of dual-use equipment with a wide application prospect.