Lecture 5 Flashcards
What is a AC source?
Provide current in a periodically.
What is active power, Reactive power & apparent power?
active power: powers the equipment and performs useful work
reactive power: the power that a magnetic equipment needs to produce the magnetizing flux.
apparent power: the vector summation of active and reactive power/
What is an ADC?
device that converts continuous analog signals to discrete digital values (voltage).
How does an ADC convert a analog to a digital signal?
Samples the analog signal at a regular interval and quantifies the measured values into a finite set of digital codes.
What are the key parameters of ADC’s (3)
- resolution
- sampling rate (how frequently the analog signal is measured)
- input range ( min and max voltages the ADC can measure).
What are the main challenges of ADC’s (3)?
- noise sensitivity
- power consumption
- trade-off between speed and accuracy
What are some applications of ADC’s (5)?
- sensors
- data acquisition systems
- communication systems
- control systems
- audio and music
What are the main consideration what choosing an ADC(4)?
- resolution
- sampling rate
- power consumption
- cost
What are the 3 main steps for analog to digital conversion (3) ?
- sampling, conversion of a continuous signal to a discrete time signal
- quantizing, converting a discrete signal to a discrete amplitude signal
- converting the discrete signal to a binary word
How can you improve the accuracy of an ADC’s A/D conversion (2)?
- increase resolution
- increase sampling rate
What is aliasing ? Why does it happen? How can you avoid it?
- Effect that causes different signals to become indistinguishable when sampled
- Happens when input signal is changing much faster than the sample rate.
- Have the sampling frequency at least twice as high as the maximum frequency
