Answer :
Answer:
Explanation:A summer circuit, also known as a summing amplifier, is a configuration of an operational amplifier (op-amp) that adds several input voltages together with appropriate weightings. Here's an explanation of its working principle:
1. **Basic Configuration:**
- The summing amplifier typically uses an inverting configuration of the op-amp.
- It has multiple input resistors (R1, R2, R3, ..., Rn) connected to each input voltage (V1, V2, V3, ..., Vn).
- These input resistors are connected to a common node, which in turn connects to the inverting input (-) of the op-amp through a feedback resistor (Rf).
2. **Input Voltage Summation:**
- Each input voltage (V1, V2, V3, ..., Vn) is weighted by its respective input resistor (R1, R2, R3, ..., Rn).
- The currents through these resistors generate corresponding voltages at the common node.
3. **Inverting Amplifier Action:**
- The op-amp inverts the voltage at its input due to its configuration.
- The voltage at the inverting input (-) is the weighted sum of the input voltages, multiplied by the ratio of the feedback resistor (Rf) to the input resistors (R1, R2, R3, ..., Rn).
4. **Output Calculation:**
- The output voltage (V_out) of the summer circuit is given by:
\[ V_{out} = -\left( \frac{Rf}{R1} \cdot V1 + \frac{Rf}{R2} \cdot V2 + \frac{Rf}{R3} \cdot V3 + \ldots + \frac{Rf}{Rn} \cdot Vn \right) \]
- Here, the negative sign indicates the inversion by the op-amp.
5. **Application:**
- Summing amplifiers are used in various applications where multiple signals need to be combined, such as audio mixers, signal processing, instrumentation, etc.
- The ratio of the feedback resistor (Rf) to each input resistor (R1, R2, R3, ..., Rn) determines the weighting of each input signal in the output.
In summary, the summer circuit using an op-amp adds multiple input voltages together with adjustable weightings determined by the ratio of resistors in its configuration. This makes it a versatile tool in electronic circuit design for combining signals accurately and efficiently.