Mechatronics Notes PDF

Lecture 4: - Chopper: DC-DC converter (Buck,boost) - Rectifier: AC-DC converter - Inverter: DC-AC convertor - Matri converter: AC-AC converter - Matrix converter = rectifier + inverter - Analog has an infinite number of increments - Digital signals are discrete (f...

Lecture 4: - Chopper: DC-DC converter (Buck,boost) - Rectifier: AC-DC converter - Inverter: DC-AC convertor - Matri converter: AC-AC converter - Matrix converter = rectifier + inverter - Analog has an infinite number of increments - Digital signals are discrete (finite): there is a limited set of value through which they can be represented - Analog systems are exposed to noise and signal degradation especially over long distances - Analog signals are continuous, the prevision is limited by noise and quality of components - Small variations in Analog signals can lead to inaccuracies in measurement or control - Digital systems have delays due to signal conversion and processing - Digital systems need more energy to process and handle data - Digital systems are more complex to design and debug - Analog systems have infinite resolutions - Digital systems have limited resolution - Digital systems are easier to program and reconfigure whereas analog systems are faster and smoother real-time but harder to modify once implemented - For analog, 0.1% accuracy is good, for digital adding more circuitry increases accuracy - Analog max storage time is in minutes, digital max storage time is years - Faster circuits are analog, highest frequency circuits are analog - Analog designers need years of experience whereas digital designers can program easily - Hybrid systems use analog and digital components for example a sensor may produce analog data which is later converted to digital to be processed by a microcontroller  - 1 or 0 is called bit, 4 bits is a nibble, 8 bits is a byte, a word is a group of bits that is a multiple of a byte - Binary simplifies the design of circuits, memory and data storage - Max number represented by n bits = 2^n - 1 - Min number of bits to represent a number = log2(Num + 1) (round up or down) - 1 = on/True 0 = off/false Lecture 5: - Tesla invented AC, Thomas Edison invented the light bulb - Edison brought Tesla in  - Resistive load is normal, inductive load current lags by pi/2 (+pi/2), capacitive load current leads by pi/2 (-pi/2) - Active power (KW), power that powers equipment to perform useful work - Reactive power (KVAR), power that a magnetic equipment (transformer, motors, relay) needs to produce he magnetizing flux (not useful) - Apparent Power (KVA) is the vector summation of KW and KVAR (Coffee + Froth) - ADC converts continuous analog signal to discrete digital values - ADC allows digital systems to process real-world analog data (temp, voltage, pressure) - Signal conversion is done by sampling the analog signal at regular intervals and quantizing the sampled values into a finite set of data codes - Digitization is done by dividing the analog signal into discrete steps based on resolution. The more bits the ADC has, the finer the resolution and more accurate the representation of the original signal - Resolution is commonly 8-bit, 10-bit, 12-bit or 16-bit - Sampling rate is how frequently the ADC samples the analog signal in samples per second, the higher the more accurate - Input range is the voltage range of the ADC that defines the min and max voltages that the ADC can measure. Any voltage outside this results in inaccurate conversion - ADCs are sensitive to noise - ADCs, especially at high speeds, consume a lot of power - High speed ADCs may have less precision, so you need to choose the in between - ADC applications: sensors, gather and process data, communication systems, control systems, audio and music - Quantizing the sampled signal is approximated to the nearest value within a range - Old ADC models used to have less bits than newer - New models can do GHZ processing for radar and video - New models are more power efficient - Higher performance ADC cost more - ADC converts analog signals to binary (encoding) - If the amplitude of the analog signal is above a certain value, it is considered a 1 - Step size (Q) = Voltagemax - Voltagemin / Nstates (Smaller is better) - Increasing resolution and sample rate improve accuracy - ADC voltage reading = Nstates/Voltage range X (Voltage - Voltage minimum) - ADC voltage reading = 1/Q X (Voltage - Voltageminimum) - To convert voltage to binary, get the reading value, round it, then divide by 2 - Nstates is 2^Nbits - Nyquist rule: Use a sampling frequency at least twice as high as the maximum frequency to avoid aliasing (effect that cause different signals to become indistinguishable when sampled, happens when input signal changes much faster than sampling rate) - Camera FPM vs RPM - Aliasing - Minimum sampling frequency >= 2 x frequency max Lecture 6: - Or gate with inverted inputs = and gate with inverted output - And gate with inverted input = or gate with inverted output - Or gate with inverted input and output = and gate - And gate with inverted input and output = or gate - Double not = yes - Kmaps are graphical method to simplify algebra expressions, they reduce number of logic gates required and optimize the circuit - Kmaps are useful for up to 4-6 variables - - Each group should be as large as possible - Group 1s in straight lines up or down or on ends - Groups can overlap - Parity checker checks for possible error- can be even or odd checker - Parity checker counts if the total number of ones is odd or even to verify no errors