For positive inputs, A1 operates as a normal amplifier connected to the A2 summing point through resistor, R5.

输入大于零时，A1起放大作用，输出经电阻R5连到A2的求和节点。

youdao

For positive inputs, A1 operates as a normal amplifier connected to the A2 summing point through resistor, R5.

输入大于零时，A1起放大作用，输出经电阻R5连到A2的求和节点。

youdao