Question

Describe with block diagram; working of signal generator and state at least two applications of signal generator.

Answer 1

### Signal Generator: Working and Applications

A signal generator is an electronic device used to create electrical signals, typically in the form of oscillating waveforms (like sine, square, or triangular waves), at a variety of frequencies. Signal generators are widely used in testing, calibration, and development of electronic systems.

Block Diagram of a Signal Generator

Here is a basic block diagram of a signal generator:

`
+-------------------+
|  Oscillator      |---->  Output Signal
|  (Frequency      |
|   Control)       |
+-------------------+
         |
         v
+-------------------+
|  Amplifier       |
+-------------------+
         |
         v
+-------------------+
|  Attenuator      |
+-------------------+
         |
         v
+-------------------+
|  Output Stage    |
+-------------------+
`

Explanation of the blocks:

1. Oscillator (Frequency Control):
   

   - The core part of the signal generator is the oscillator, which creates a periodic waveform (like sine, square, etc.). The frequency of this waveform can be adjusted based on user settings.

1. Amplifier:
   

   - After the oscillator generates the signal, it may not have enough power to be used effectively. The amplifier boosts the signal to a level that can be used by other devices or equipment.

1. Attenuator:
   

   - The attenuator is used to reduce the amplitude of the signal if needed. It allows for controlling the strength of the output signal.

1. Output Stage:
   

   - This is where the final signal is delivered to the device under test (DUT) or circuit that needs it.

Working of a Signal Generator:

1. Signal Generation:
   

   The signal generator starts by using the oscillator to generate a waveform of a specific frequency. The waveform can be of different shapes, like sine, square, triangular, or pulse waves. The frequency and waveform type are usually controlled by the user.

1. Amplification:
   

   The generated signal is typically weak in amplitude. The amplifier boosts the signal so it can drive a load or be used by other instruments effectively.

1. Amplitude Control (Attenuation):
   

   After amplification, if the signal is too strong, the attenuator reduces its amplitude to the desired level.

1. Output:
   

   The signal is finally delivered to the device under test (DUT) or used in other applications as per the user's requirement.

---

Applications of Signal Generators:

1. Testing and Calibration of Audio Equipment:
   

   Signal generators are widely used in testing audio systems, such as amplifiers and speakers. For example, a signal generator can generate sine waves of various frequencies to test the frequency response of audio equipment.

1. Communication System Testing:
   

   Signal generators are essential in testing communication systems, including radio and television transmitters. They are used to generate different modulated signals (AM, FM) to simulate actual transmission signals during testing.

These are just two common applications, but signal generators are used in various other fields, such as radar systems, signal analysis, and in the development of new electronic products.