基于PWM控制H桥驱动半导体制冷片的恒温系统

Thermostat System Based on TEC Driven by PWM Controlling H-bridge

介绍了一种基于PWM控制H桥驱动半导体制冷片的恒温系统。该系统分为两部分,控制电路和驱动电路,两者之间通过光耦隔离。控制电路以SG3525为核心,由NTC进行温度采集,生成占空比从0到1变化的PWM波,控制驱动电路。驱动电路由四个场效应管IRF540N构成全桥,驱动半导体制冷片TEC。该系统适合小型密闭容器,可以长时间稳定运行,精度可以达到0.5℃。

A thermostat system based on TEC driven by PWM controlling H-bridge is introduced in this paper.The system is divided into two parts,control circuit and drive circuit,isolated by optocoupler.The core of control circuit is SG3525,incorporates NTC as temperature collection source,generates the PWM wave of the duty cycle change from 0 to 1,controls the drive circuit.Full-bridge driver circuit consists of four field effect tube,to drive TEC.The system is suitable for small airtight container,stable operating for a long time,up to 0.5℃ accuracy.