数字程控放大器设计与应用

在自动控制系统或智能仪器中 ,如果测量信号的范围比较大 ,为保证必要的测量精度 ,经常采取改变量程的办法。当改变量程时测量放大器的增益也相应地加以改变。这种变化通常是自动进行 ,即不需要人为的改变电路连接 ,而是通过软件实现放大器增益的改变。这样可以实现仪器量程的自动切换。另外 ,通过改变增益的方法使系统功能增强 ,在核测量中 ,稳谱的方法之一就是改变输入信号的放大倍数。这就需要用到数字控制放大器 ,并针对核仪器要解决的具体问题要求放大器的放大倍数在一定范围内变化 ,并且放大倍数调节要求精细。该文提供了这种数控放大的一种设计方案 ,它的放大倍数范围为 9～ 9.999,其倍数的调节步长为 0 .0 0 1倍。

FIGURE DESIGN BY PROGRAMME-CONTROLLED AMPLIFIER

In the automatic control system or the intelligent instrument, if the range which measures the signal is relatively big, in order to guarantee the essential precision of measurement, the method of changing amount is often adopted. When the measure is changed, the gain to measure the amplifier is correspondingly changed, too. This kind of change usually goes on automatically, it does not need artificially changing circuit to be joined, but realizes the change of the amplifier gain through the software. This can realize the automatic change to switch over instrument amount. In addition, the method to change the gain makes the function systematically strenthen, for example, during nuclear measurement, one of the methods of the steady table is to change and input the multiple of enlarging of the signal. This needs to use a figure control amplifier, being directed against the concrete problems that nuclear instrument wants to solve, the special requests to amplifier are proposed: 1. to enlarge multiple change, 2. to enlarge multiple regulated and required meticulously within the specific limit. This text offers a kind of design plan by this kind of numerical control enlargement. The range of multiple enlarged is 9~9.999, and its regulation of multiple is 0.001 times.