摘要
为了实现对微小数值的电阻进行准确和高精度的测量,本文设计了以STC12C5A60S2单片机为核心,利用直流电压源和运算放大器组成一个多值恒流源,实现多量程电阻精确测量。利用单片机内部集成的A/D转换器对被测电阻两端的电压进行采样,通过数值比对,自动控制各个电阻档位继电器的开关,实现量程自动切换功能。用键盘输入筛选电阻阻值及误差值,通过单片机对步进电机的控制来实现电位器阻值的变化,由LCD12864显示测量数据和变化的曲线,符合筛选条件时,系统发出声音提示,实现准确、快速筛选电阻。
In order to realize measurement of resistors with toothful numerical value, this paper introduces a kind of simple test instrument for resistor based on STC12C5A60S2MCU. The design took STC12C5A60S2 single-chip microcomputer as the core, the DC voltage source and an operational amplifier were used to form a multivalve constant- current source, it can realize wide-range resistance measurement. The MCU internal integrated A/D converter was used to sample the voltage across the resistor. Through numerical comparing, the MCU automatically control various grades of resistor relay switch, so that automatic range switching function is realized.The keyboard was used to input the screening resistor value and the error value; through the control of MCU for stepper motor, a potentiometer resistance change was achieved. The measurement data and the changes curve were displayd by the LCD12864. When meetting the screening conditions, system sounds an alarm, and achieves an accurate, rapid screening of resistor.
出处
《现代科学仪器》
2012年第3期30-33,共4页
Modern Scientific Instruments
