Tham khảo tài liệu 'understanding automotive electronics 5e episode 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | ELECTRONICS FUNDAMENTALS 3 high input impedance is one of the primary features of the noninverting op amp configuration. A noninverting amplifier is also possible as shown in Figure . The input signal is connected to the noninverting terminal and the output is connected through a series connection of resistors to the inverting - input terminal. The gain A in this case is A Jj-ul 1 R V- 1 R in i Besides adjusting gain negative feedback also can help to correct for the amplifier s nonlinear operation and distortion. Summing Mode Amplifier One of the important op amp applications is summing of voltages. Figure is a schematic drawing of a summing mode op amp circuit. In this circuit a pair of voltages va and vb relative to ground are connected through resistances Rto the inverting input. The output voltage vo is proportional to the sum of the input voltages _ -R K Vb Vo R For example a compatible stereo broadcast system incorporating a right channel and a left channel characterized by voltages Vr and vL respectively transmits the sum Vs of the channel voltages Vs Vr Vl Figure Summing Amplifier UNDERSTANDING AUTOMOTIVE ELECTRONICS 79 3 ELECTRONICS FUNDAMENTALS At the same time the difference voltage VD is transmitted on a subcarrier VD VR - VL The right-channel voltage can be separated from the sum and difference voltages using the circuit of Figure . Replacing voltages V and V by Vs and VD respectively yields an output -Rfí -I- -I- _ t Vo -R Vr VL Vr - VL Analog computers like those used to simulate the performance of automotive systems are constructed with operational amplifiers. Binary circuits can operate in only one of two states on or off . A simple extension of this circuit permits similar separation of the left-channel voltage. Analog Computers The op amp is the basic building block for analog computers. Analog computers are used to simulate the behavior of other systems. Virtually any system that can be described in a block diagram using standard
