With the continuous development of mechanical automation, the application fields of fiber laser are becoming more and more extensive, especially the constant temperature control technology of temperature control through NTC thermistor chip. However, at present, most of the constant temperature control circuits will lead to shortcomings such as low working efficiency and difficult development due to complex circuits and algorithms. Based on this, EXSENSE Electronics Technology Co., Ltd. introduced a fiber laser, which constant temperature control circuit improves work efficiency with the assistance of NTC thermistor chip and is suitable for temperature control of low-power multi-mode fiber laser.

The constant temperature control circuit of this fiber laser includes acquisition module, negative feedback control circuit, TEC module drive circuit, and NTC thermistor chip. Among them, NTC thermistor chip is placed on the TEC module to collect the temperature of the TEC module when it is working. NTC thermistor chip is placed on the TEC module, and the temperature of the master computer connected to the first forward voltage input terminal is set to 25℃, and the voltage received by the first forward voltage input and the second forward voltage input is 1.25V. At the beginning of power-up, if the temperature of the controlled object is higher than 25℃, according to the characteristics of the resistance value of NTC thermistor chip decreasing with the increase of temperature, the resistance value will be lower than 10KΩ (10KΩ corresponds to 25℃), so the voltage at the first reverse voltage input of the operational amplifier will be lower than 1.25V, and the operational amplifier output is high. The master computer connected to the second forward voltage input is set to 25℃ and outputs a high level according to the high level of the first operational amplifier. The TEC module drive circuit is electrically connected to the negative feedback control circuit to drive the TEC module to work according to the control voltage signal.

Since the positive input voltage of the negative feedback control circuit is less than the negative input voltage, the control TEC module is carried out in the direction of cooling, the resistance value of NTC thermistor chip will increase, the voltage at the first forward voltage input of the operational amplifier will rise. Due to the integral action of the operational amplifier, the voltage at the co-directional input of the operational amplifier and the output voltage of the operational amplifier will slowly approach, and the TEC module will also stabilize at the set temperature threshold.

The constant temperature control circuit of the fiber laser uses the high-precision NTC thermistor chip to monitor the real-time temperature of the TEC module, control the TEC module drive circuit, effectively improve the working efficiency, ensure the constant temperature of the fiber laser, and avoid failure.