Power supply device using a solar cell, electronic device such as communication device provided with the same, and signboard device

摘要

In a power supply using a solar cell module including a plurality of single cells connected in series with one another, irradiation of light to the solar cell module raises the module voltage Vsm, and when the first voltage V1 is reached, the open / close switch is turned on Power is supplied to the load, and from this state, the module voltage Vsm decreases due to the decrease in illuminance at the solar cell module, and when the second voltage V2 (V2 V1) is reached, the open / close switch is turned off and the power to the load By interrupting the supply, deterioration of the single cell can be suppressed, and the performance retention time of the solar cell module can be extended. The second voltage V2 at that time is set in advance to an appropriate value based on the current-voltage characteristics of the solar cell module.