Remote-LAB GymKT

Work task and measurement procedure

Work task:

1. Measure the dependence of U_S on the current stream I of two basic types of electrochemical sources (alkaline and zinc- chlorine battery).

2. Add the acquired dependence values to the graphs U_S = U_S(I) , and compare the shapes of the two characteristics with the theory..

3. Specify the basic parameters of the studied sources (electromotive voltage U_e and internal resistance R_i). Compare them to each other and determine how they relate to real resource properties (resource hardness).

4. Specify individual short-circuit currents from the acquired parameters of both sources. Compare them with values obtained by extrapolating linear regressions of the measured characteristics.

Measurement procedure

1. Run the remote experiment ZACHaRIAS – Load characteristic of the source.

2. Choose a type of measured resource. Store the value of the no-load voltage that corresponds to the electromotive voltage of the selected source.

3. Gradually increase the current drawn from the source by using the slider (PC) or the + and — (tablets).

4. Read the value of the clamping voltage for each value of the set current - are deposited into the prepared table.

5. Continually check the measured values in the graph, in the case of larger gaps between the measured dependencies, measure the missing parts.

6. Choose another type of source after measuring the required number of data and repeat the measurement.

7. Reduce the current drawn to zero after measuring the characteristics of all the resources (save all experimental values), leave the remote experiment.

8. Open the experimental data file in the spreadsheet (MS Excel, Oo Calc, Google Tabs, Kingsoft Spreadsheets…).

9. Plot the dependence of the terminal voltage on the drawn electrical current (for the first source) in the graph. Check the shape of the acquired dependence with the assumed shape.

10. You will best determine the equation obtained by the regression line (linear regression). The regression line directive corresponds to the internal resistance of the source - see formula (5), the absolute linear gain obtained corresponds to the electromotive voltage.

11. Determine in a similar way the parameters needed for the second type of source.

12. Determine the magnitude of the short-circuit current of both sources using the electromotive voltage and internal resistance values of the source.

13. Take advantage of the possibility of extending the regression line to higher values than measured maximum currents. This can take (based on the measured values and the assumption of continuous linear relationship) to estimate the value of short circuit current - intercept current (horizontal) axis.

14. Compare the basic parameters of the investigated sources (electromotive voltage, internal resistance and zktrat current) and compare them with the real properties of the sources.