| 摘要 |
PURPOSE:To make use of solar heat effectively by a method wherein the switching between a solar battery power source and an auxiliary power source from a commercial AC power source is performed in a stabilized condition. CONSTITUTION:In case the illumination intensity of the sun is high, the amplified output of an illumination photosensor 12 is larger than a reference voltage E corresponding to the lowest operation output required for driving a pump so that a comparator 15 generates an output to a circuit (a) to turn a switch 9 ON and a motor 4 for driving a pump 5 is operated by a solar battery 6 as a power source. On the other hand, the amplifying output of the photosensor 12 is lower than the refernce voltage E, a switch 10 turns ON by the output of a circuit (b) and the heat collector is operated by the auxiliary power source 7. Further, in order to prevent the hunting of the reference voltage E of the photosensor 12, the comparator 15 is made to have a hysteresis characteristic and no switching is made between the solar battery power source 6 and the auxiliary power source 7 when the variation of the detecting voltage of the photosensor 12 is in the order of E e. In addition, time circuits 16 are provided in the output circuits (a) and (b), respectively, of the comparator so that unless the same output continues to generate longer than a predetermined period of time, no switching operation is performed. |
