本文介绍一种0～150℃温控仪,它采用恒流供电,具有电路简单、制作方便、成本低、温控精度为±2℃以内等特点。 工作原理 温控仪电路如图1所示。由A1、A2、基准电压(VD5)及外围元件组成恒流源(电流约0.5mA),向温度传感器R_t(T121)供电,其输出电压V_0就是对应的温度值。要控制的温度由电位器W2的滑臂位置来确定(其滑臂输出的电压相当于0～150℃时的电压)。为保证电位器 This article describes a 0 ~ 150 ℃ temperature controller, which uses constant current power supply, with a simple circuit, easy to manufacture, low cost, temperature control accuracy of ± 2 ℃ or less. Working principle Temperature controller circuit shown in Figure 1. The constant current source (current is about 0.5mA) is composed of A1, A2, reference voltage (VD5) and peripheral components, and the temperature sensor R_t (T121) is powered. The output voltage V_0 is the corresponding temperature value. The temperature to be controlled is determined by the position of the slider of the potentiometer W2 (the voltage at the slider corresponds to the voltage at 0-150 ° C). To ensure that the potentiometer