A charger is something that every car owner needs. You can buy a ready-made memory in a store, you can assemble it yourself in many ways, or you can use an intermediate option - purchase a construction kit for self-assembly. In this case, you only need a power transformer and a housing. I recently ordered such a charger and now I will share information about it with you, dear visitors of the Radioschemes website.
Technical characteristics of the charger:
Voltmeter…………………………….................................................. ....….. 0 to 29.9 Volts
Ammeter................................................. .................... up to 9.9 Amperes
Charging current stabilizer………...................................…… from 0.5 to 9.9 Ampere
Charge shutdown timer…………………....................….. from 1 to 30 hours
The specified voltage on the battery at which the charge will be turned off…………………….................................... .............................................. 5.1 to 30.0 Volts
Short circuit protection
Reverse polarity protection when connecting battery A
Contents of delivery:
Charger SPARK -3 ……………….............…. 1 PC.
Diode bridge 50 Ampere…......….. 1 pc.
Thyristor 12 Ampere ………….......... 1 pc.
Diode 1N4007……………………….. 2 pcs.
Frame for indicator..…......…… 1 pc.
Instructions…………………..............… 1 pc.
Purpose of the device
The SPARK-3 charger is designed to charge batteries with a voltage of 6, 12, 24 volts with a current from 0.5 to 9.9 amperes to a specified voltage or a specified time. The device includes: Voltmeter, Ammeter, current stabilizer, automatic shutdown when the battery reaches the specified voltage, timer. The kit includes an assembled and debugged board, a diode bridge, a triac, two diodes and a frame for mounting the indicator into the case. Control is carried out using three buttons:
top button - " Top”
middle button - " Menu”
bottom button - " Down”
To turn on charging mode, press " Top” at the same time, the “charging” LED will light up, initiating the active charging mode. Subsequent presses of the “ button Top” will switch the voltage or current display. If the ammeter is turned on, the indicator shows the letter " A" (For example " 0.0A"). To turn off the charging mode, press the button " Down”, the “charging” LED goes out, subsequent presses of this button also alternately show voltage or current on the indicator. To change the charging parameters, use the " button Menu”.
The first time you press and hold it will show the voltmeter symbol " - U” when released, a voltage of 5.1 to 30.0 volts is shown. The last digit flashes. Using the " Top" And " Down” set the required voltage, upon reaching which the charging mode will be turned off.
The second press and hold will show the amp symbol" - A” after release, the charge current setting is shown from 0.5A to 9.9A in amperes using the “Up” and “Down” buttons to set the required charge current.
The third press and hold will show the clock symbol" - h” When released, the sleep timer can be set from 1h to 30h (1 to 30 hours) using the buttons " Top" And " Down” set the required sleep timer value.
When pressed for the fourth time, the indicator will show three dashes " - - - " when released, the device will exit the Menu mode, the last digit will not flash on the indicator.
How to charge the battery
Connect the crocodiles, pressing the “Down” button on the battery terminals, switch the device to voltage indication. The voltmeter will show the voltage on the battery. Press the “Top” button. The “charging” LED will turn on. The current will gradually rise to the set value. Every two minutes, the current is turned off for 4 seconds and when the current is turned off, the voltage is compared with the specified maximum voltage; if the voltage on the battery reaches the specified value, then charging will turn off and the “charging” LED will go out . If the battery voltage does not reach the maximum value, then shutdown will occur after the timer has expired (from 1 to 30 hours).
- To manually turn off charging, press the “Down” button
-
A battery with a voltage less than 5 volts will not charge.
-
When reversing the polarity of the terminals, the charging current will also not be turned on.
-
When the charge is turned off or there is no 220 volt network, the device does not discharge the battery.
Charger assembly
Assembling the charger with MK cog l As per the circuit diagram - click to enlarge the picture:
To assemble the SPARK-3 charger, you will need a transformer with a power of 100 W to 250 W with a voltage on the secondary winding of 18 - 22 Volts, a housing and a radiator (plate measuring 100 * 150 * 3 mm). If you need to assemble a charger for 24 volt batteries, then the transformer must have a voltage on the secondary winding of 30 volts.
Attach the rectifier and triac to the radiator. Secure the radiator into the housing through insulators. The buttons on the board serve only to test the device when installed in the case; it is recommended to solder other buttons installed on the front panel.
When you turn it on for the first time, without connecting the battery, press the "Down" button to switch to the Voltmeter. The voltmeter should show "00.0" if the voltmeter shows voltage, it means that the triac is broken, it is unacceptable to connect the battery. Any imported triac with a current of 12-20 amperes is suitable for replacement . Do not connect domestic triacs - they require a large switching current. The price of this set can fluctuate between 12-20 euros - check in online stores. In the future, the device will be assembled, connected to an electronic transformer and placed in a housing. Follow the publications!
Discuss the article CHARGER WITH A MICROCONTROLLER FOR SELF ASSEMBLY
In this article I will tell you how to make a fairly “smart” charger for lead-acid batteries from an AT/ATX computer power supply and a homemade control unit. These include the so-called. “UPS”, automobile and other batteries of wide application.
Description
The device is intended for charging and training (desulfation) lead-acid batteries with a capacity of 7 to 100 Ah, as well as for approximate assessment of their charge level and capacity. The charger has protection against incorrect connection of the battery (reversal of polarity) and against short circuit of accidentally abandoned terminals. It uses microcontroller control, thanks to which safe and optimal charging algorithms are implemented: IUoU or IUIoU, followed by “topping up” to a 100% charging level. Charging parameters can be adjusted to a specific battery (customizable profiles) or you can select those already included in the control program. Structurally, the charger consists of an AT/ATX power supply, which needs to be slightly modified, and a control unit on the ATmega16A MK. The entire device is freely mounted in the housing of the same power supply. The cooling system (standard PSU cooler) turns on/off automatically.
The advantages of this memory are its relative simplicity and the absence of labor-intensive adjustments, which is especially important for beginner radio amateurs.
]1. Charging mode - “Charge” menu. For batteries with capacities from 7Ah to 12Ah, the IUoU algorithm is set by default. This means:
- first stage - charging with a stable current of 0.1C until the voltage reaches 14.6V
- the second stage is charging with a stable voltage of 14.6V until the current drops to 0.02C
- the third stage is maintaining a stable voltage of 13.8V until the current drops to 0.01C. Here C is the battery capacity in Ah.
- fourth stage - “finishing”. At this stage, the voltage on the battery is monitored. If it drops below 12.7V, the charge starts from the very beginning.
For starter batteries (from 45 Ah and above) we use the IUIoU algorithm. Instead of the third stage, the current is stabilized at 0.02C until the battery voltage reaches 16V or after about 2 hours. At the end of this stage, charging stops and “topping up” begins. This is the fourth stage. The charging process is illustrated by graphs in Fig. 1 and Fig. 2.
2. Training mode (desulfation) - “Training” menu. Here is the training cycle:
10 seconds - discharge with a current of 0.01C, 5 seconds - charge with a current of 0.1C. The charge-discharge cycle continues until the battery voltage rises to 14.6V. Next is the usual charge.
3. Battery test mode. Allows you to approximately estimate the degree of battery discharge. The battery is loaded with a current of 0.01C for 15 seconds, then the voltage measurement mode on the battery is turned on.
4. Control-training cycle (CTC). If you first connect an additional load and turn on the “Charge” or “Training” mode, then in this case, the battery will first be discharged to a voltage of 10.8 V, and then the corresponding selected mode will be turned on. In this case, the current and discharge time are measured, thus calculating the approximate capacity of the battery. These parameters are displayed on the display after charging is complete (when the message “Battery charged” appears) when you press the “select” button. As an additional load, you can use a car incandescent lamp. Its power is selected based on the required discharge current. Usually it is set equal to 0.1C - 0.05C (10 or 20 hour discharge current).
Moving through the menu is carried out using the “left”, “right”, “select” buttons. The “reset” button exits any operating mode of the charger to the main menu.
The main parameters of charging algorithms can be configured for a specific battery; for this, there are two customizable profiles in the menu - P1 and P2. The configured parameters are saved in non-volatile memory (EEPROM).
To get to the settings menu, you need to select any of the profiles, press the “select” button, select “settings”, “profile parameters”, profile P1 or P2. Having selected the desired parameter, press “select”. The left or right arrows will change to up or down arrows, indicating that the parameter is ready to be changed. Select the desired value using the “left” or “right” buttons, confirm with the “select” button. The display will show “Saved”, indicating that the value has been written to the EEPROM.
Setting values:
1. “Charge algorithm.” Select IUoU or IUIoU. See graphs in Fig. 1 and Fig. 2.
2. “Battery capacity”. By setting the value of this parameter, we set the charging current at the first stage I=0.1C, where C is the battery capacity V Ah. (Thus, if you need to set the charge current, for example, 4.5A, you should select a battery capacity of 45Ah).
3. "Voltage U1". This is the voltage at which the first charging stage ends and the second begins. The default value is 14.6V.
4. "Voltage U2". Only used if the IUIoU algorithm is specified. This is the voltage at which the third stage of charging ends. Default is 16V.
5. “2nd stage current I2”. This is the current value at which the second charging stage ends. Stabilization current at the third stage for the IUIoU algorithm. The default value is 0.2C.
6. “End of charge I3.” This is the current value upon reaching which charging is considered complete. The default value is 0.01C.
7. "Discharge current". This is the value of the current that discharges the battery during training with charge-discharge cycles.
Selection and modification of the power supply.
In our design we use a computer power supply. Why? There are several reasons. Firstly, this is an almost ready-made power unit. Secondly, this is also the body of our future device. Thirdly, it has small dimensions and weight. And, fourthly, it can be purchased at almost any radio market, flea market and computer service centers. As they say, cheap and cheerful.
Of all the variety of power supply models, the best fit for us is an ATX format unit with a power of at least 250 W. You just need to consider the following. Only those power supplies that use the TL494 PWM controller or its analogues (MB3759, KA7500, KR1114EU4) are suitable. You can also use an AT format power supply, but you will only have to make a low-power standby power supply (standby) for a voltage of 12V and a current of 150-200mA. The difference between AT and ATX is in the initial startup scheme. The AT starts up independently; power for the PWM controller chip is taken from the 12-volt winding of the transformer. In ATX, a separate 5V source, called the “standby power supply” or “standby”, is used to initially power the chip. You can read more about power supplies, for example, and converting a power supply into a charger is well described
So, there is a power supply. First you need to check it for serviceability. To do this, we disassemble it, remove the fuse and instead solder a 220 volt incandescent lamp with a power of 100-200 W. If there is a mains voltage switch on the back panel of the power supply, it should be set to 220V. We turn on the power supply to the network. The AT power supply starts up immediately; for ATX you need to short-circuit the green and black wires on the large connector. If the light does not light, the cooler is spinning, and all output voltages are normal, then we are lucky and our power supply is working. Otherwise, you will have to start repairing it. Leave the light bulb in place for now.
To convert the power supply into our future charger, we will need to slightly change the “piping” of the PWM controller. Despite the huge variety of power supply circuits, the TL494 switching circuit is standard and can have a couple of variations, depending on how current protection and voltage limits are implemented. The conversion diagram is shown in Fig. 3. 
It shows only one output voltage channel: +12V. The remaining channels: +5V, -5V, +3.3V are not used. They must be turned off by cutting the corresponding tracks or removing elements from their circuits. Which, by the way, may be useful to us for the control unit. More on this a little later. Elements that are installed additionally are indicated in red. Capacitor C2 must have an operating voltage of at least 35V and is installed to replace the existing one in the power supply. After the TL494 “piping” is shown in the diagram in Fig. 3, we connect the power supply to the network. The voltage at the power supply output is determined by the formula: Uout=2.5*(1+R3/R4) and with the ratings indicated on the diagram it should be about 10V. If this is not the case, you will have to check the correct installation. At this point the alteration is completed, you can remove the light bulb and replace the fuse.
Scheme and principle of operation.
The control unit diagram is shown in Fig. 4. 
It is quite simple, since all the main processes are performed by the microcontroller. A control program is written into its memory, which contains all the algorithms. The power supply is controlled using PWM from the PD7 pin of the MK and a simple DAC based on elements R4, C9, R7, C11. The measurement of battery voltage and charging current is carried out using the microcontroller itself - a built-in ADC and a controlled differential amplifier. The battery voltage is supplied to the ADC input from the divider R10R11. The charging and discharging current are measured as follows. The voltage drop from the measuring resistor R8 through dividers R5R6R10R11 is supplied to the amplifier stage, which is located inside the MK and connected to pins PA2, PA3. Its gain is set programmatically, depending on the measured current. For currents less than 1A, the gain factor (GC) is set equal to 200, for currents above 1A GC=10. All information is displayed on the LCD connected to ports PB1-PB7 via a four-wire bus. Protection against polarity reversal is carried out on transistor T1, signaling of incorrect connection is carried out on elements VD1, EP1, R13. When the charger is connected to the network, transistor T1 is closed at a low level from the PC5 port, and the battery is disconnected from the charger. It connects only when you select the battery type and charger operating mode in the menu. This also ensures that there is no sparking when the battery is connected. If you try to connect the battery in the wrong polarity, the buzzer EP1 and the red LED VD1 will sound, signaling a possible accident. During the charging process, the charging current is constantly monitored. If it becomes equal to zero (the terminals have been removed from the battery), the device automatically goes to the main menu, stopping the charge and disconnecting the battery. Transistor T2 and resistor R12 form a discharge circuit, which participates in the charge-discharge cycle of the desulfating charge (training mode) and in the battery test mode. The discharge current of 0.01C is set using PWM from the PD5 port. The cooler automatically turns off when the charging current drops below 1.8A. The cooler is controlled by port PD4 and transistor VT1.
Details and design.
Microcontroller. They are usually found on sale in a DIP-40 or TQFP-44 package and are labeled as follows: ATMega16A-PU or ATMega16A-AU. The letter after the hyphen indicates the type of package: “P” - DIP package, “A” - TQFP package. There are also discontinued microcontrollers ATMega16-16PU, ATMega16-16AU or ATMega16L-8AU. In them, the number after the hyphen indicates the maximum clock frequency of the controller. The manufacturing company ATMEL recommends using ATMega16A controllers (namely with the letter “A”) and in a TQFP package, that is, like this: ATMega16A-AU, although all of the above instances will work in our device, as practice has confirmed. Case types also differ in the number of pins (40 or 44) and their purpose. Figure 4 shows a schematic diagram of the control unit for the MK in a DIP package.
Resistor R8 is ceramic or wire, with a power of at least 10 W, R12 - 7-10 W. All others are 0.125W. Resistors R5, R6, R10 and R11 must be used with a tolerance of 0.1-0.5%. It is very important! The accuracy of measurements and, consequently, the correct operation of the entire device will depend on this.
It is advisable to use transistors T1 and T1 as shown in the diagram. But if you have to select a replacement, then you need to take into account that they must open with a gate voltage of 5V and, of course, must withstand a current of at least 10A. Suitable, for example, are transistors marked 40N03GP, which are sometimes used in the same ATX format power supplies, in a 3.3V stabilization circuit.
Schottky diode D2 can be taken from the same power supply, from the +5V circuit, which we do not use. Elements D2, T1 and T2 are placed on one radiator with an area of 40 square centimeters through insulating gaskets. Buzzer EP1 - with a built-in generator, for a voltage of 8-12 V, the sound volume can be adjusted with resistor R13.
LCD indicator – WH1602 or similar, on the controller HD44780, KS0066 or compatible with them. Unfortunately, these indicators may have different pin locations, so you may have to design a printed circuit board for your instance
Program
The control program is contained in the “Program” folder. The configuration bits (fuses) are set as follows:
Programmed (set to 0):
CKSEL0
CKSEL1
CKSEL3
SPIEN
SUT0
BODEN
BODLEVEL
BOOTSZ0
BOOTSZ1
all others are unprogrammed (set to 1).
Setup
So, the power supply has been redesigned and produces a voltage of about 10V. When connecting a working control unit with a firmware MK to it, the voltage should drop to 0.8..15V. Resistor R1 sets the contrast of the indicator. Setting up the device involves checking and calibrating the measuring part. We connect a battery or a 12-15V power supply and a voltmeter to the terminals. Go to the “Calibration” menu. We check the voltage readings on the indicator with the readings of the voltmeter, if necessary, correct them using the “<» и «>" Click "Select". Next comes the current calibration at KU=10. With the same buttons "<» и «>“You need to set the current reading to zero. The load (battery) is automatically switched off, so there is no charging current. Ideally, there should be zeros or very close to zero values. If so, this indicates the accuracy of resistors R5, R6, R10, R11, R8 and the good quality of the differential amplifier. Click "Select". Similarly - calibration for KU=200. "Choice". The display will show “Ready” and after 3 seconds. the device will go to the main menu.
Calibration is complete. Correction factors are stored in non-volatile memory. It is worth noting here that if, during the very first calibration, the voltage value on the LCD is very different from the voltmeter readings, and the currents at any KU are very different from zero, you need to use (select) other divider resistors R5, R6, R10, R11, R8, Otherwise, the device may malfunction. With precise resistors (with a tolerance of 0.1-0.5%), the correction factors are zero or minimal. This completes the setup. If the voltage or current of the charger at some stage does not increase to the required level or the device “pops up” in the menu, you need to once again carefully check that the power supply has been modified correctly. Perhaps the protection is triggered.
All material can be downloaded in one archive
Batteries are very common today, but commercially available chargers for them are usually not universal and are too expensive. The proposed device is intended for charging rechargeable batteries and individual batteries (hereinafter the term “battery” is used) with a rated voltage of 1.2...12.6 V and a current of 50 to 950 mA. The input voltage of the device is 7...15 V. Current consumption without load is 20 mA. The accuracy of maintaining the charging current is ±10 mA. The device has an LCD and a convenient interface for setting the charging mode and monitoring its progress.
A combined charging method has been implemented, consisting of two stages. At the first stage, the battery is charged with a constant current. As it charges, the voltage across it increases. As soon as it reaches the set value, the second stage will begin - charging with a constant voltage. At this stage, the charging current is gradually reduced, and the battery maintains the specified voltage. If the voltage for any reason drops below the set value, charging with a constant current will automatically begin again.
The charger circuit is shown in Fig. 1.
Rice. 1. Charger circuit
Its basis is the DD1 microcontroller. It is clocked by an internal RC oscillator at 8 MHz. Two channels of the microcontroller ADC are used. Channel ADC0 measures the voltage at the output of the charger, and channel ADC1 measures the charging current.
Both channels operate in eight-bit mode, the accuracy of which is sufficient for the device being described. The maximum measured voltage is 19.9 V, the maximum current is 995 mA. If these values are exceeded, the inscription “Hi” appears on the HG1 LCD screen.
The ADC operates with a reference voltage of 2.56 V from the microcontroller's internal source. To be able to measure a higher voltage, the resistive voltage divider R9R10 reduces it before applying it to the ADC0 input of the microcontroller.
The charging current sensor is resistor R11. The voltage that drops across it when this current flows is supplied to the input of op-amp DA2.1, which amplifies it approximately 30 times. The gain depends on the ratio of the resistances of resistors R8 and R6. From the output of the op-amp, a voltage proportional to the charging current is supplied through a repeater to the op-amp DA2.2 to the ADC1 input of the microcontroller.
An electronic switch is assembled on transistors VT1-VT4, operating under the control of a microcontroller that generates pulses at the OS2 output, following at a frequency of 32 kHz. The duty cycle of these pulses depends on the required output voltage and charging current. Diode VD1, inductor L1 and capacitors C7, C8 convert pulse voltage into direct voltage, proportional to its duty cycle.
LEDs HL1 and HL2 are charger status indicators. The HL1 LED on means that the output voltage has been limited. The HL2 LED is on when the charging current is increasing, and off when the current does not change or decreases. When charging a healthy discharged battery, the HL2 LED will first turn on. Then the LEDs will flash alternately. The completion of charging can be judged by the glow of only the HL1 LED.
By selecting resistor R7, the optimal contrast of the image on the LCD display is established.
The R11 current sensor can be made from a piece of high-resistance wire from a heater coil or from a powerful wirewound resistor. The author used a piece of wire with a diameter of 0.5 mm and a length of about 20 mm from the rheostat.
The ATmega8L-8PU microcontroller can be replaced by any of the ATmega8 series with a clock frequency of 8 MHz and higher. The BUZ172 field-effect transistor should be installed on a heat sink with a cooling surface area of at least 4 cm2. This transistor can be replaced with another p-channel transistor with a permissible drain current of more than 1 A and low open-channel resistance.
Instead of transistors KT3102B and KT3107D, another complementary pair of transistors with a current transfer coefficient of at least 200 is suitable. If transistors VT1-VT3 operate correctly, the signal at the transistor gate should be similar to that shown in Fig. 2.
Rice. 2. Gate signal graph
Inductor L1 is removed from the computer power supply (it is wound with a wire with a diameter of 0.6 mm).
The microcontroller configuration must be programmed according to Fig. 3. The codes from the V_A_256_16.hex file should be entered into the microcontroller program memory. The following codes must be written to the EEPROM of the microcontroller: at address 00H - 2CH, at address 01H - 03H, at address 02H - 0BEH, at address 03H -64H.
Rice. 3. Programming the microcontroller
You can start setting up the charger without an LCD and a microcontroller. Disconnect transistor VT4, and connect the connection points of its drain and source with a jumper. Apply a supply voltage of 16 V to the device. Select resistor R10 such that the voltage on it is within 1.9...2 V. You can make this resistor out of two connected in series. If a 16 V voltage source is not found, apply 12 V or 8 V. In these cases, the voltage across resistor R10 should be about 1.5 V or 1 V, respectively.
Instead of a battery, connect an ammeter and a powerful resistor or car lamp in series to the device. By changing the supply voltage (but not lower than 7 V) or selecting the load, set the current through it to 1 A. Select resistor R6 so that the output of op-amp DA2.2 has a voltage of 1.9...2 V. Like resistor R10, It is convenient to make resistor R6 out of two.
Turn off the power, connect the LCD and install the microcontroller. Connect a resistor or a 12 V incandescent lamp with a current of about 0.5 A to the output of the device. When you turn on the device, the LCD will display the voltage at its output U and the charging current I, as well as the limiting voltage Uz and the maximum charging current Iz. Compare the current and voltage values on the LCD with the readings of a standard ammeter and voltmeter. They will probably vary.
Turn off the power, install jumper S1 and turn on the power again. To calibrate the ammeter, press and hold the SB4 button, and use the SB1 and SB2 buttons to set on the LCD the value closest to that shown by the reference ammeter. To calibrate the voltmeter, press and hold the SB3 button, and use the SB1 and SB2 buttons to set the value on the LCD equal to that shown by the reference voltmeter. Without turning off the power, remove jumper S1. Calibration coefficients will be written to the microcontroller EEPROM for voltage at address 02H, and for current at address 03H.
Turn off the power to the charger, replace the VT4 transistor, and connect a 12 V car lamp to the output of the device. Turn on the device and set Uz = 12 V. When Iz changes, the brightness of the lamp should change smoothly. The device is ready for use.
The required charging current and maximum voltage on the battery are set using buttons SB1 "▲", SB2 "▼", SB3 "U", SB4 "I". The charging current change interval is 50...950 mA in 50 mA steps. The voltage change interval is 0.1...16 V in steps of 0.1 V.
To change Uz or Iz, press and hold the SB3 or SB4 button, respectively, and use the SB1 and SB2 buttons to set the required value. 5 s after releasing all buttons, the set value will be written to the EEPROM of the microcontroller (Uz - at address 00H, Iz - at address 01H). It should be borne in mind that holding the SB1 or SB2 button pressed for more than 4 s increases the speed of parameter change by approximately ten times.
The microcontroller program can be downloaded.
Publication date: 25.09.2016
Readers' opinions
- Oleg / 05/19/2018 - 21:49
Please send me the eeprom firmware file by email [email protected] I've been pushing for over a month and the flower doesn't come out!!! - Sasha / 01/19/2018 - 19:10
Folks, has anyone assembled this device! - Yuri / 01/19/2018 - 18:35
Question to the author. The output of microprocessor 1 is hanging in the air. This is not a typo.
These 8-bit Flash microcontrollers S3F9444 are manufactured by Samsung. The S3F9444 controllers are designed for use in applications that require ADC, as indicated by the number 4 (ADC) following the number 9 (8 digits), simple timers/counters and PWM. A special feature of the S3F9444 microcontrollers is the use of the SAM88RCRI CPU core, a junior version of the standard SAM8 core with an architecture typical for 8-bit CPUs from Zilog.
Distinctive features of the architecture:
Register architecture that allows you to use any register as an accumulator and reduces instruction execution time and the required amount of program memory
The software stack provides significantly more depth for subroutine calls and interrupts than the hardware stack
Pipeline fetch and command execution
Reducing the functionality of the SAM88RCRI core, compared to a standard core, led to a reduction in die size, lower consumption, and lower cost of the microcontroller as a whole. Another consequence of the reduction in functionality was the reduction in the number of commands to 41 commands. The F9444 microcontrollers are equipped with 4 KB Flash memory and a register file in which 208 bytes can be used as general purpose registers. The command cycle duration is 400 ns at fOSC = 10 MHz. The operating voltage range extends from 2.0 (set level of operation of the LVR circuit) to 5.5 V. Power-Down and Idle energy saving modes are provided. Typical consumption at a CPU clock frequency of 10 MHz is 5 mA and in Stop mode only 0.1 μA.
The built-in peripherals include:
9-channel 10-bit analog-to-digital converter (ADC)
8-bit pulse width modulator (PWM) with a maximum frequency of 156 kHz (6-bit base + two extension bits)
8-bit basic timer (for watchdog functions) and 8-bit timer/counter with time interval mode
Three I/O ports (up to 18 pins in total) with configuration for each pin. Each pin can drive an LED (typical current 10mA)
Built-in Smart function that determines the starting operating conditions of the device (enable/disable the LVR circuit, used clock signal sources)
As soon as it is finished, the batteries will begin to be charged with a current that is several times less than that of the charger, and you don’t have to worry about the batteries overcharging, overheating, exploding or catching fire, the device itself selects the required current depending on the batteries and their type.
The device also has a battery discharge function, which allows you to discharge them if necessary, and all this is also displayed by LED indicators. The device comes in a box with a power supply (which can also be used for other devices when charging is not used).
It charges even batteries with a large capacity of 2500-2700 mA without problems, and not in a day, as in my old charger, but in 4 hours, I definitely didn’t time it. At the same time, the batteries do not even heat up much.
The article is accompanied by a photo of the charger and its internals, as well as instructions for use with a table of capacities and display modes. Comrade was with you. Vanesex.
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This craft allows you to strobe LED DRLs. The craft is small in size, controlled with just one button, and has wide customization options. The board size is 30 by 19 millimeters. On the reverse side there is a terminal block...
Read completelyWe make and connect the door closer to the alarm system
The number of cars with automatic windows is constantly growing, and even if the car does not have one, many people make it themselves. My goal was to assemble such a device and connect it to...
Read completelyLEDs turn on based on speed
It turned out to be a “by-product”: it was necessary to test the operating mode of the speed sensor for the project of displaying gears on a 5x7 matrix, for this I assembled a small circuit. The circuit can turn on LEDs depending...
Read completelyDigital tachometer on AVR microcontroller (ATtiny2313)
The tachometer measures the rotation speed of parts, mechanisms and other components of the car. The tachometer consists of 2 main parts - a sensor that measures rotation speed and a display where...
Read completelySimple digital speedometer on ATmega8 microcontroller
A speedometer is a measuring device for determining the speed of a car. According to the measurement method, there are several types of speedometers: centrifugal, chronometric, vibration, induction, electromagnetic, electronic, and finally GPS speedometers.
Read completelySmooth ignition of the tidy on the microcontroller
This version has a slightly different layout: a second setting button has been added and the ignition speed potentiometer has been removed. Features: Two separate independent channels. For each channel there are three groups of adjustable parameters: delay time before the start...
