Addition circuit

The addition circuit generally adopts the inverting input method, that is,
the inversion addition circuit. It is based on the inverting input operational amplifier circuit, and the signal
voltage to be added is connected to the inverting input terminal of the operational amplifier through a resistor .     The addition circuit is shown in Figure 7-5. This is an inverting addition circuit with three input signals. The input signals 8ii, 2, and 1113 are all input from the inverting input terminal N, the pin is a feedback resistor, and the non-inverting input terminal P is grounded through the balancing resistor R4 . The resistance value of the balancing resistor R4 should be the parallel sum of Ri, R2, R3 and Rr. The output voltage of     the addition circuit is equal to the sum of the input voltages of each branch. This structure can realize the addition of multiple input signals .