In the case of ideal operational amplifier, circuit analysis was simplified by the ideal summing point restraints of zero voltage and zero current at the inverting input.

对于理想的运算放大器而言，通过倒相输入处零电压和零电流的理想求和点限制，可以简化电路分析过程。

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。