Self-discharge logger RSR-01 records the voltage drop curve U(t) during self-discharge of supercapacitors and supercapacitor batteries.
- General information about the self discharge logger PCR-01
- Basic parameters of PCR-01 self discharge logger
- Measurement result files
- Ordering loggers of self discharge RSR-01
General information about the self discharge logger PCR-01
The devices record the voltage drop curve across the tested supercapacitor over time.
As a result of the recorder operation, the User receives the dependence of the voltage at the terminals of the supercapacitor under test vs the time U(t). The device returns voltage versus time dependence in tabular and graphical form.
Self-discharge logger RSR-01 has the following key advantages:
- high input impedance, which has little effect on the investigated supercapacitor
- as well as a built-in battery capable of supporting the operation of the device for at least 1 day.
Block diagram of the recorders PCR-01
Self-discharge recorders RCR-01 have the following block diagram:
The self-discharge logger RCR-01 includes:
- power supply unit PS
- uninterruptible power supply circuit UPS with lithium-ion battery BT
- microcontroller including analog-to-digital converter ADC
- block for selecting voltage subranges BSVS
- transistor switch S for connecting the ADC input to the device terminals
- memory for measurement results FLASH
- as well as a number of other auxiliary components.
Voltage measurement circuit
The operation of the self-discharge logger RCR-01 is based on periodic measurement of the voltage at the terminals of the device “+” and “-“. Voltage measurement is performed by the analog-to-digital converter ADC, which is part of the microcontroller.
The device contains a transistor switch S, which connects the terminals of the device to the ADC input. The connection takes place only at the moment of performing the voltage measurement. When the switch S is on, the input resistance of the logger is at least 280 kOhm. The measurement usually takes 2 to 10 s, depending on the stability and repeatability of the measurement results. After the end of the measurement, the switch S opens. The input resistance of the device with an open switch S is more than 1 GΩ.
A special algorithm automatically adjusts the period between voltage measurements. The algorithm adjusts measurement period depending on the rate of drop of the measured voltage.
The faster the voltage drops at the terminals of the supercapacitor, the shorter the period between adjacent measurements will be. The minimum value for the period between measurements is 10 s. Conversely, if the rate of voltage drop across the supercapacitor is not significant, the voltage measurement period is automatically increased. The maximum value of the period between measurements is 12 hours (2 measurements per day).
Thus, the effective input impedance of the RCR-01 logger is from 1 to 1000 MΩ.
To expand the range of measured voltages, the device contains a block for selecting the measurement ranges BSVS. This unit has 4 hardware voltage measurement subranges, from 0…3 to 0…370 V.
Integrated uninterruptible power supply
Self-discharge tests often have considerable duration, up to several months or more. Over such a long period, there is the possibility of a temporary line power interruption. For such case, the RCR-01 self-discharge logger has an uninterruptible power supply circuit (UPS). This circuit provides power to the microcontroller from a backup lithium-ion battery BT. This allows the device to continue to operate when the line power is disconnected for up to 1 day.
Device memory and autonomous operation
The self-discharge logger RCR-01 operates under control from the User’s personal computer. A computer helps to setup and run a test of supercapacitor, as well as receive the measurement results. However, after starting the test, User may turn off the computer. In this case, the device will continue to work in autonomous mode.
In autonomous mode logger saves a measurement results into the built-in memory FLASH. When the User turn on the coputer again, device transmin saved data to the computer. Computesr saves the data to a measurement result files. After that, the memory of the device is cleared and becomes ready for the next period of autonomous operation.
Basic parameters of PCR-01 self discharge logger
|Working range of voltage measurement, V||from 0.1 to 370|
|Voltage measurement subranges, V||0…3; 0…15; 0…75; 0…370|
|Resolution (scale division) of voltage measurement, mV||2; 10; 40; 200|
|Maximum voltage measurement error||no more than 0.5% of the maximum of the selected subrange|
|Effective input impedance of the voltage meter, MOhm||from 1 to 1000, depending on the rate of voltage drop across the tested supercapacitor|
|Interface for connecting the device to a computer||Ethernet|
|Overall dimensions, mm|
height x width x length
|140 х 110 х 35|
RCR-01 self discharge logger software
The RCR-01 self-discharge recorder operates under the control of a personal computer. Пользователь должен установить на свой компьютер специальное программное обеспечение YsD1. YsD1 software is supplied with the device.
The YsD1 application contains several pages, and allows:
- setup the required supercapacitor testing program
- select a file to save measurement results
- run the prepared testing program for execution
- monitor in real time the operation of the device
- display measurement results in text and graphic form
- save the plotting area as a picture
- and also interrupt the test at any time.
allows to setup the supercapacitor testing program, as well as to select a file for saving measurement results.
In addition, the Control page allows you to start and stop a test. Also, on the Control page, you can observe the formation of the measurement results file.
ДTo start testing a supercapacitor for self-discharge on the “Control” page, you should:
- select a suitable voltage measurement subrange
- set the end voltage for the test
- set the end time of the test
- select a file to save measurement results
- and also start the test with the Start button.
U Chart page
allows to display the dependence of the voltage on the tested supercapacitor vs time in a convenient graphical form.
The page allows you to monitor the progress of the testing process in real time.
allowes to setup the connection of the RCR-01 self-discharge recorder to the computer, as well as for viewing the state of the internal systems of the device.
In addition, the “Settings” page allows you to calibrate the device if necessary.
Measurement result files
The most important result of the operation of the RCR-01 self-discharge recorder is the text files of the measurement results. The structure of the measurement results files is as follows:
Measurement data files consist of a header line and two measured value columns.
Each line of the file contains an instantaneous voltage value (second column). In addition, each row contains a point in time (first column) when this voltage was recorded. The voltage units is Volts, the time units is days (1 day = 24 hours = 86400 s).
Space separates columns in a table.
The device logs falling voltages. A new line is entered into the result files at the moment of recording a voltage lower than during the previous measurement. This principle allows you to minimize the size of the measurement results files.
The maximum number of data lines stored in the file corresponds to the ADC resolution and does not exceed 2048.
In fact, the measurement files for different tested supercapacitors has the same set of voltage values. The difference is in values of time at which the voltage data were recorded (at the same voltage sub-range).
User may open measurement results files in various programs for further processing, for example, in Microsoft Excel. In this case, for the Time column you should select the column format: “Time”. Then the time values will be displayed in a human-friendly form.
In additions, User may build self-discharge graphs of the tested supercapacitors based on data from the measurement results files.
Ordering loggers of self discharge RSR-01
To order loggers of self discharge RSR-01, call us by phone
or send a request to the email address Yarstst@gmail.com
We supply self discharge logger RSR-01 under a supply contract.
The cost, as well as the delivery time, depends on the required number of devices.