Fabrication of the electrolytic resistor. The adjustable wire wound resistor can be replaced with an electrolytic resistor. As is known, the resistance of the electrolyte column depends not only on its height, but also on the cross-sectional area and salt concentration in the solution. Therefore, the height of the liquid column and the concentration should be selected experimentally to the diameter of the glass tube. The resistance will decrease as the upper electrode interface moves downward. Because the electrolyte heats up during operation, the top cover cannot be sealed, but it should have a few holes, allow steam to escape. Such a resistor should also be regarded as a makeshift solution.
1 – sliding copper rod; 2 – bakelite cover;
3 – natural cork; 4 – copper plate; 5 – copper sulfate solution; 6 – glass tube; 7 – a rubber stopper tightly seated; 8 – non-sliding copper rod