Sem I UNIT 5 (MTR)

Unit 5 SIGNAL CONDITIONING and DAQ SYSTEMS 

 1. Explain briefly Signal Conditioning. 
Analog signals need to be correctly "prepared" before they can be converted into digital form for further processing. 
Signal conditioning is an electronic circuit that manipulates a signal in a way that prepares it for the next stage of processing. 
Many data acquisition (DAQ) applications involve environmental or mechanical measurements from sensors, such as temperature and vibration. 
These sensors require signal conditioning before a data acquisition device can effectively and accurately measure the signal.
For example, thermocouple signals have very small voltage levels that must be amplified before they can be digitized



2. What is Amplification? explain its types.
A signal amplifier is a circuit that uses electrical power to increase the amplitude of an incoming signal voltage or current signal, and output this higher amplitude version at its output terminals. The ideal signal amplifier creates an exact replica of the original signal that is larger but identical in every other way.
In data acquisition (DAQ) systems, signal amplifiers are needed to increase the amplitudes from sensors that output small signals, up to the level where they can be sent to an A/D converter (ADC) for digitization.
Types:
Operational amp-An operational amplifier is an integrated circuit that can amplify weak electric signals. An operational amplifier has two input pins and one output pin. Its basic role is to amplify and output the voltage difference between the two input pins.
Inverting op amp- An inverting op amp is an operational amplifier circuit with an output voltage that changes in the opposite direction as the input voltage.



3. What is Filtering? explain its types. Filtering is one of the most basic and important signal-processing techniques. It is used to see the true signal by suppressing “noise” and other unwanted interferences. Filtering is used for applications from adjusting the bass and treble response of your music player to adjusting the channel frequency of a radio, and improving sound quality on telephone lines.
Types:
Notch filter - a filter that rejects only a specific frequency
Comb filter - a filter that has multiple regularly spaced narrow pass-bands.
All-pass filter - a filter that passes all frequencies, but the phase of the output is modified.

4. Explain the principle of the Sample and hold circuit.

The Sample and Hold circuit is an electronic circuit which creates the samples of voltage given to it as input, and after that, it holds these samples for the definite time. 

A sample and hold circuit is used extensively in analog-to-digital conversion where a signal value must be stabilized while it is converted to a digital presentation.

The sample and hold circuit consists of a voltage-holding capacitor and a voltage follower.

When the switch is opened, the capacitor C holds the input voltage corresponding to the last sampled value, because negligible current is drawn by the follower.

5. Explain the principle of Analog to digital conversion

The main purpose of the A/D converters within a data acquisition system is to convert conditioned analog signals into a stream of digital data so that the data acquisition system can process them for display, storage, and analysis.

Analogue-to-Digital Converters, (ADCs) allow micro-processor controlled circuits, Arduinos, Raspberry Pi, and other such digital logic circuits to communicate with the real world.

In the real world, analogue signals have continuously changing values which come from various sources and sensors which can measure sound, light, temperature or movement, and many digital systems interact with their environment by measuring the analogue signals from such transducers.

6. Explain briefly the Data Acquisition system. 

A data acquisition system is a system that includes measurement devices, sensors, a computer, and data acquisition software.

A data acquisition system is used for acquiring, storing, visualizing, and processing data. This involves collecting the information required to understand electrical or physical phenomena.

7. Explain the Single Channel Data Acquisition System.

The single channel data acquisition system has

only one input signal.

It consists of a transducer, signal conditioner, an analog to digital converter and a buffer circuitry

8. Explain the Multi-Channel Data Acquisition System.

There are multiple input signals

The output of transducers is processed with signal conditioning circuits

A multiplexer is used to select the processed input signal

It is then converted in to digital signal with the help of ADC

9. What is a Data logging system? 

Data logging is the process of collecting and storing data over a period of time in different systems or environments. It involves tracking a variety of events. it is collecting data about a specific, measurable topic or topics

10. Enlist the data logging applications in automobiles.

● Reliability/Life Cycle Testing

● Component Testing

● Environmental Chamber Monitoring

● Quality Test and Inspection

● Laboratory Instrumentation

● In-Vehicle Drive Testing

● Stress/Strain Measurement

● Vibration Analysis

● Environmental Testing

● Life Cycle Stress Testing

● Mechanical/Production Testing

● Engine/Emission Testing

● Aerodynamic and Wind Tunnel Testing

● Discontinuity Testing

● ATE Alternative Logging

● Integrated Systems Testing

● Thermal Performance Checks

● Durability Testing

● Battery Cell Monitoring

11. Enlist the data logging applications in Aerospace. 

● Environmental Testing

● Flight Test Recorder

● Component Level Testing

● Fatigue Testing

● Motor Development Tests

● Material Testing

● Data Acquisition

● Vibration and multi-signal Inputs

● Production Life Cycle Stress Tests

● Portable Structural Testing

● Weapons Testing

● Discontinuity Testing