FIELD: measuring equipment.
SUBSTANCE: device for measurement of residual capacitance of a chemical current source relates to measurement equipment and can be used for permanent monitoring of an accumulator battery or a chemical current source (CCS) used in cars, electric vehicles, electric storage cars and other domestic and industrial devices, for which the power source is a CCS, which enables to prevent an unexpected failure of the CCS. Novel in the device for measuring residual capacitance of CCS is separation of the device into two units and simplification of the design, so that the first unit contains a capacitor with a charging switch, which is rigidly fixed as close as possible to the CCS terminals for the smallest length of the leads, and in the second unit there are all the other components of the device with an indicator, on which information upon the CCS residual capacitance will be displayed. Device for measurement of CCS residual capacitance consists of a capacitor with known capacity, electronic controlled switches of charge and discharge, a sampling-storage device, a voltage divider, a microcontroller, a control panel, a low-pass filter, an indicator to display the CCS residual capacity. Device is started manually or automatically. When a command comes from the control panel, a microcontroller supplies a control pulse to the sampling-storage device and saves the value of the CCS electromotive force. From the sampling-storage device output the voltage value is supplied to the microcontroller ADC module input and to the voltage divider (with the division factor of 0.9), from the output of which the voltage is supplied to the microcontroller input corresponding to the first comparator input. From the microcontroller output the control signal is supplied to the electronic switch of charge, then the capacitor starts being charged and a timer starts counting the capacitor charging time. Voltage from the capacitor being charged is supplied to the microcontroller input corresponding to the second comparator input. Second comparator is activated when its input voltage reaches 0.9 of the CCS voltage level and the timer fixes the condenser charging time. Then the microcontroller adds a correction for the capacitor charging time due to the effect of the switch resistance. Corrected value of the charging time is input in the PWM module, which generates a sequence of pulses, duration of which is inversely proportional to the charging time of the capacitor. Pulses passing through the low-pass filter form the reference voltage for the ADC.
EFFECT: program contained in the microcontroller with data processing algorithm when the computations are complete outputs the information on a display,
and the microcontroller supplies a control signal to the electronic switch of discharge, the capacitor is discharged, thus the measurement cycle is completed and the device is ready for a new measurement cycle.
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