Patent attributes
A power supply system for a green laser indicating pen, comprises a computer having an USB receptacle which is connected to a current source in the computer; a USB plug being connected to the USB receptacle; a USB transmission line for connecting the USB plug to a transformer; a chargeable battery connected to the transformer for receiving current from the computer so as to charge the chargeable battery; a voltage level detector connected to the chargeable battery for comparing the voltage of the voltage level detector with a reference voltage in the voltage level detector; an indicator light connected to the voltage level detector for displaying the voltage state with different colors; and a power switch being connected between the transformer and the laser source; as the power switch being actuated, the power from the transformer can be directly transferred to the laser source.