Abstract: A charging and discharge control circuit includes a charging control for detecting a voltage across a storage battery connected with a source of electromotive force and for outputting a first switching signal for a charging circuit of the storage battery, and a discharge control for integrating the amount of voltage discharged from the storage battery and for outputting a second switching signal for a discharge circuit. The second switching signal corresponds to the amount of voltage remaining in the storage battery. The integrated value of the amount of the voltage discharged is reset by an output signal from the charging control which is outputted at the time of completion of the charging of the storage battery.

Abstract: A ZnS thin-film electroluminescent element which exhibits the hysteresis phenomenon within the light emission versus applied voltage characteristics, the electric current versus applied alternating voltage characteristics, or the electric current phase versus applied alternating voltage characteristics. The ZnS element comprises a ZnS EL thin-film including Mn serving as a luminescent center with a concentration of 0.05-5.0 wt. %, and a pair of dielectric layers made of rare earth oxides or oxides groups of III, IV and V of the Periodic Table. The EL thin-film is sandwiched between the pair of the dielectric layers. The ZnS EL thin-film is made by applying the electron-beam heating evaporation technology to a ZnS pellet.