基于单片机的激光二极管温度控制研究

Research on laser diode temperature control based on single chip microcomputer

激光二极管对温度具有高精度、超调量小等特点,被广泛应用于各领域中,其性能受运行温度影响较为严重,需要保证其工作温度的恒定。因此,深入研究基于单片机的激光二极管温度控制方法,以MSP430F449单片机和半导体制冷片作为主控制器和制冷器,通过温度采集电路采集激光二极管当前温度,用阻值表示,仪表放大器将阻值转化为电压值,同单片机控制器设定的电压值对比,获取温度差值信号;单片机控制器采用PID控制算法处理温度差值信号后,利用定时器生成脉冲宽度调制模式输出电压,电压由驱动电路进入制冷器内产生电流,制冷器按照电流流通方向,对激光二极管进行制冷或加热,完成激光二极管温度控制。实验结果表明,此方法温度控制误差低于0. 03℃,且温度控制响应时间为30 s,优于对比方法。

Laser diode is widely used in various fields because of its high accuracy and small overshoot. Its performance is seriously affected by operating temperature. It is necessary to ensure the constant working temperature.Therefore,the temperature control method of laser diode based on MCU is deeply studied. MSP430F449 MCU and semiconductor chiller are used as main controller and cooler. The current temperature of laser diode is collected by temperature acquisition circuit,which is expressed by resistance value. The instrument amplifier converts resistance value into voltage value,and compares it with voltage value set by MCU controller to obtain temperature difference signal. After processing the temperature difference signal with PID control algorithm,the output voltage of pulse width modulation mode is generated by timer. The voltage is generated by driving circuit into the cooler,and the cooler refrigerates or heats the laser diode according to the direction of current flow to complete the temperature control of the laser diode.The experimental results show that the temperature control error of this method is less than 0.03℃,and the response time of temperature control is 30s,which is better than the contrast method.