| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply system which can increase the power efficiency of a solar battery and prevent an overvoltage condition against a load and which can extend the life of the load and can supply power to the load at low cost at night. SOLUTION: This power supply system is constituted of a solar battery 16, a voltage detector 105 which detects the voltage Vc of the solar battery 16 and then outputs the detection result as a voltage detection signal SV, and four FETs(field effect transistor). It also has a main circuit 101 which produces AC voltage Vd which alternates between positive and negative from the voltage Vc and then supplies the AC voltage to a compressor 104 and a controller 102' for controlling the main circuit 101, based on the voltage detection signal SV. The controller 102' controls the main circuit 101 so that the pulse width of the AC voltage Vd may be narrower when the voltage Vc becomes a threshold value or below. |
