For power supply of wireless temperature measuring device of high-voltage equipment

a new on-line temperature monitoring system powered by low-voltage LED light was designed. A solar cell was used to convert LED light energy to electric energy for reliable operation of the high-voltage wireless temperature measuring device. A two-stage PWM dimming constant current LED driver was designed to provide constant current for LED and ensure high power factor at input terminal. Temperature signals are collected with thermistor PT1000 and transmitted with ANT wireless communication module in the wireless temperature measuring device

which has the advantages of high precision and low power. Experiments show that the average current consumption of the wireless temperature measuring device is 7.24 m A under 3.3 V voltage

and the output current of the driver is 584 m A with PWM’s full duty cycle. The working condition with 70% of PWM’s duty cycle is the best condition

in which reliable operation of high-voltage circuit and power saving are balanced.