Sterol derivative compounds, structurally related to natural compounds which can be extracted from bull testes and from human follicular fluid, useful for regulating meiosis in oocytes and in male germ cells. The photovoltaic cells produce a varying electric output that is transmitted to the stationary contact by the rotary connector. The protective coating comprises at least one polymer resulting from a monomeric anaerobic chemical mixture having been cured in a vacuum in the absence of oxygen.