Because of the crisis of global energy resources
and global warming, many nations and enterprises are
enthusiastic at developing the integrated scheme about
making good use of renewable energy. In this paper a
power-saving lighting system supplied with solar cell is
proposed. The solar cell is used for electrical energy
supplement and the generated energy is stored in power
storage unit. The power storage unit is charged by pulse-
width modulation (PWM) method. Through the PWM
signal controlled by microcontroller, regulator and
capacitance array, it balances and cushions the voltage
between the solar cell and the power storage unit. It is
helpful to the life-time extension of power storage unit.
The LED array is used in the lighting system. The
lighting system can detect the environmental brightness
and control the brightness of LED array by PWM signal
from the microcontroller. The experimental result is
presented that confirm the power-saving prediction.