| 摘要 |
PURPOSE:To obtain a power unit for which bus voltage fluctuation and power loss are minimized by a method wherein a storage battery and a shunt circuit are connected in parallel with a solar battery output, and a charging current is controlled within a permissible range specified beforehand by a storage battery charging voltage detection circuit and charging/discharging current detection element. CONSTITUTION:A shunt circuit consisting of a power transistor 3 shunting a battery current as occasion demands and a power resistor 2 is connected in parallel with a solar battery 1, and further a load 11 and a storage battery 9 having a charging current detecting resistance 10 in series are connected each other, thus consituting a power unit. In this constitution, furthermore, a differential amplifier 4, a reference voltage generator 5, a voltage detecting comparator 7 and a temperature detecting comparator 8 are connected between a base of the transistor 3 and both terminals of the storage battery 9. A temperature of the storage battery 9 suitable for charging is specified and a charging current is controlled within a set point by heat sennsing elements 12 and 13 provided on the comparators 7 and 8 respectively. |
