The output end of the bright weft switching power supply is connected to the input end of a voltage regulator chip, the output end of the voltage regulator chip is connected to an adjustable resistor, and then the other end of the adjustable resistance is connected to the negative terminal of the bright weft switching power supply, and finally an indicator meter is connected to the adjustable resistance, which can realize the function of changing the bright weft switching power supply to an adjustable power supply. The output voltage can be changed by adjusting the resistance value of the adjustable resistor.