Design of a Motor Speed Sampling, Amplification, Filtering and Display Circuit - Report Example

Design of a Motor Speed Sampling, Amplification, Filtering and Display Circuit Name: Course: Lecturer: Institution: City & State: Date: Design of a Motor Speed Sampling, Amplification, Filtering and Display Circuit Introduction For the creation of a signal that can be recognized by human senses, or other systems, signals must be converted to analog mode. This is possible when one uses digital to analog converters (DAC) that convert digital to analog. In electronics, DAC converts a digital system to analog. The digital system is usually a binary code while for the analog signal appears as current, electric charge or voltage. DAC have a frequently been used development of audio signals in music players, video signals in televisions are also a modification of the digital signal. Manufacture of DACs involves the use of integrated circuits. The architect of the DACs gives the manufactures distinct advantage and disadvantages. This report gives a description and analysis on a different circuit designs based on the current amplification, motor speed monitoring and sampling filtering circuit. Part 1 of this report gives an explanation and design of analog to digital designs that involve the use of current amplifier and low pass filter. Part 2 entails the design of 8-bit counter and design of 4-7-segment decoder that displays signal on the LED. Objectives This report aims to create the circuits used for motor speed sampling, amplification, filtering and display. This would assist in determining the appropriate circuit arrangement and the necessary connections that can assist in achieving the desired circuit and proper optimization. Part 1: Analogue and digital circuit design and optimization Generally, there is a need to change the digital signals to analog to ease in understanding to humans and non-analog systems. An analog to digital converter tool helps in conversion of this signal to discrete digital presentation. If a reverse is required, a DAC converts the digital to analog signal. Usually and ADC has significant errors. To mention, they include non-linearity, aperture error and quantization error. The opening error occurs when digitalizing a time variant signal and they are caused by clock jitter. Quantization error occurs due the difference between the digitalized signal and the analog signal or the original signal. This difference gives the magnitude of the quantization error, which is from zero to half of one LSB. Due to finite resolution in representation o f digital signals, which is an unavoidable problem in all ADCs, they result to quantization error. Non-linearity Physical deformity in ADC leads to non-linearity. This makes the signal output have a deviation from the linear input to a non-linear output. This error can be reduced or eliminated through calibration of the ADC. Aperture error When the actual sampling time appears to be unreliable due to clock jitter, there is an error in this situation associated with time, t. For instance, if one wants to digitize a sine wave, this would eventually lead to such an error. Estimation can be done through a sine wave and clock jitter,  and  respectively. Which gives,. For a DC, the error is zero\, and for small frequencies\, it is small. When signals have higher amplitudes, they have significant weight. To avoid these effects, quantizing error is related. Hence, the jitter requirements. Low-pass filter A circuit that slowly offers switch to low frequency signals is a low pass filter. Due to its failing to provide passage for low frequency signal, it is difficult for it to provide selection of high frequency signals. These filters are of two types, namely: capacitive and inductive low pass filter. Inductive low pass filter As the frequency increases, there is resultant increase in inductors’ impedance. Using the color analysis, higher impedance starts to prevent the development of high frequency signal to the load. This is as indicated below Figure 1: AS the frequency increases, inductive low pass filter falls off Circuit diagram for a low-pass filter is shown below Capacitive low pass filter In the capacitive low-pass filter, the impedance tends to increase with frequency. This means that load resistance and the low impendence are parallel hence, they prevent passage of high frequency signals, thus dropping voltage across a series connected resistor, in the circuit\, below Capacitive low pass filter has only a capacitor and a resistor for it to work. The diagram below is a frequency and the response of the capacitive low pass filter When converting AC-DC the most advantageous device is the inductive low pass filter. The filter filters the AC waveform and rectifies the AC to DC allowing only real DC to accept. To the contrary, a capacitive low pass filter will require an addition of a small filter resistor. This is for rectification of the output power. Therefore, the best model to choose is the inductive low pass filter. Cut off frequency is calculated using:. For the analog system\, given   in addition, a frequency of 100 Hz. Therefore, the cutoff frequency  7-segment display decoder Parts required for the design of a 7-segment display decoder Common cathode LED display BCD to 7-segment decoder DIP switch (eight-position) Seven resistors each of 470Ω One battery 2-3V The following diagram is a picture of a 7-segement display decoder An illustration of the connection 4511 is the driving circuit for the above 7-segment decoder. Output diagram connection in protues Operating principle When the 4-bit BCD value is inputted, there is energization that generates the output that make the decimal digits of the 7-segment on the LED display. The design for the BCD data has the plan that includes A, B, C, and D….format. This arrangement is in ascending order of the numbers. Because, for each LED segment, there must be a relative resistor; then it is important to use the seven resistors. These should be connected between the terminals of the display and the terminals of 4511 output. When the circuit is completed, near the four switches. This should be in a binary sequence and used in checking the display in the LED display. The scope for binary input in this case is 0000 to 1001 to get an output LED display of 1-9. The output is as indicated in the table below Truth table for the 7-segment LED display Current sampling/amplification circuit An amplification circuit has a port, which is a pair of terminals of the circuit. Across the ports, there is a voltage,  and current,  flowing through. The above diagram is an amplification network connection for the current and voltage across the terminals. It shows the output and the input terminals of an amplifier. A wave function formed from the previous connection is a function of time in relation to voltage or current. At the input, the waveform to amplify is amplified, and then a larger waveform appears at the output. This input waveform can be either a voltage or a valid input. Type of Amplifier Input Output Voltage,  Voltage,  Voltage,  Transresistance,  Current,  Voltage,  Current,  Current,  Current,  Transconductance,  Voltage,  Current,  From the above table,,, and  are transfer functions of amplification obtained as  , where x is any given input. Having the above in mind, it is therefore, necessary to realize that a given ideal port is never affected by the input source resistance, similarly, the output source resistance does not affect the ideal output port. A general circuit connection of an amplifier is shown below Building a current amplifier circuit For the current amplifier circuit\, the input current needs current divider attenuation and second and third output current attenuation. Thus, for a given current amplifier,. This is achievable as  approaches infinity for an open circuit and when, . From the given current amplifier connection, gain obtained is given as  The above diagram is a current amplifier circuit connection. It is essential to know that, for an appreciable current amplifier, the design should approach ideal conditions such that the overall gain of the amplifier is not interrupted. The table below is summarizes the effect on the inputs. Port Ideal Resistance Current input Zero Voltage input Open (infinite) Voltage output Zero Current output Open An 8-bit synchronous counter by using D-type flip-flops f In this successive approximation counter, it gives a search for binary algorithm in action. This is summarized using the words: move to the centre pointer of the non-excluded range. In this design, an 8-bit ADC has an expected input voltage of -2 V to 3 V. Therefore, letting the output be  when input is 0 V, and 11112 =15 for the input of 3 V. So the LSB gives a voltage of 3/15 =0.2 V. Using an arbitrary voltage of 2.09 V, the SAR outputs one result depending on the comparator; this is either a TRUE or FALSE. If the current is too small, the comparator gives a HIGH, and if the current is too high it gives a LOW. The following occurs in the SAR Add 1 to MSB, if current is too small, that is, (); or Subtract 1 from MSB, if the current is too high, i.e, () Where:  clock cycle given from the relationship below Design of a 4-to-7 decoder for the Seven-Segment display In this section, I will design a 7-segment display decoder commonly used to display a particular number representation using a display composed of seven LED segments. The diagram below represents a 7-segment display decoder, which converts a 4-bit binary number into a collection of symbols for display For the 4 to 7 segment display decoder, the hexagonal representation of the obtained data is as shown below. Design problems For the 4 to 7--segment decoder, there are problems associated with the buffered devices, in that they are highly affected by the oscillations associated with the output. Another issue is in order to display the figures in LED; there must be a 4 to 7--segment decoder. Moreover, there is a design problem associated with the differentiation of the ICs that make six and nine, since six looks like a b while nine looks like a flipped p. Methods of improvement For achieving the best quality display, it is necessary to control the display brightness in the sense that the numbers will have a clear vision. 6 and 9 should be easy to analyse and differentiate when programming the display code and have a distinctive value. Conclusions Industrial PLCs use the 7-segment display in their systems to determine the required output. Interfacing the PLC helps one to grasp the concept behind the electronic components and how they work. Although the LED and LCD they all display the signal, in this case LED are of interest in the sense that they are commonly use. When a signal passes through the 7-segment decoder display it makes the LED important. All the display from digital to analogue uses binary form to transmit the signal for the human eye and any other device and machine which cannot read the digital signal so it display it as analogue. A 4-bit latch converts/multiplexes the digits to a desirable form. This is possible through control of each latch and using a four line switching which converts to the 7-segement decoder display. The 7-segement LED display means that, there are 7-contrable segments. These segments are because each segment has a connection to the LED based display. Modifying the circuit helps one to treat each digit displayed as a 4-bit location signal in BCD data. Based on the desired model\, 7-segment decoder has two classes, which are designed to use common anode while others use common cathode. In this method, it is easy to display each number separately. Four data switches are desirable when planning to create an equivalent of 0-9 digits. When planning to use the logic counter it is necessary to have them programmed in an ascending order. This way the bits can toggle directly as per the related logic. For instance, bit one links with the bit 0, which is a high logic. Moreover, when high logic is zero nad1 then, when bit 0, bit 1 and bit2 are all high bit 3 toggles. The use of synchronous counters is mostly applicable to the development and running of finite machines with complex and more stable transitions. This way it is possible to determine a single number taking the initial position of all counts to be at zero, which is followed by an arbitrary long chain of numbers. During all phases of engineering design simulation plays a crucial role in that, one is able to develop the design from scratch to the final stages following each stage and phase (Jeruchim, Balaban, & Shanmugan, 2000). This helps in ensuring that the complete design does follow the required iterations. Therefore, proper design of communication devices is an ideal way to acquire better designs. In this case, includes calculation of SNR as an ideal low-pass filter. Bandwidth and signal distortion is applied in the design to degrade the noise ratio to be lower than 2 DB in the SNR. The design must always reach the desired objectives. Development of the circuits used for motor speed sampling, amplification, filtering and display are the main objectives desired in this report. This is in the sense that the desired characteristics have been attained. Bibliography Jeruchim, C., Balaban, P., & Shanmugan K. (2000). Simulation of communication systems: Modeling, methodology, and techniques, New York: Springer Read More

Inductive low pass filter As the frequency increases, there is resultant increase in inductors’ impedance. Using the color analysis, higher impedance starts to prevent the development of high frequency signal to the load. This is as indicated below Figure 1: AS the frequency increases, inductive low pass filter falls off Circuit diagram for a low-pass filter is shown below Capacitive low pass filter In the capacitive low-pass filter, the impedance tends to increase with frequency. This means that load resistance and the low impendence are parallel hence, they prevent passage of high frequency signals, thus dropping voltage across a series connected resistor, in the circuit\, below Capacitive low pass filter has only a capacitor and a resistor for it to work.

The diagram below is a frequency and the response of the capacitive low pass filter When converting AC-DC the most advantageous device is the inductive low pass filter. The filter filters the AC waveform and rectifies the AC to DC allowing only real DC to accept. To the contrary, a capacitive low pass filter will require an addition of a small filter resistor. This is for rectification of the output power. Therefore, the best model to choose is the inductive low pass filter. Cut off frequency is calculated using:.

For the analog system\, given   in addition, a frequency of 100 Hz. Therefore, the cutoff frequency  7-segment display decoder Parts required for the design of a 7-segment display decoder Common cathode LED display BCD to 7-segment decoder DIP switch (eight-position) Seven resistors each of 470Ω One battery 2-3V The following diagram is a picture of a 7-segement display decoder An illustration of the connection 4511 is the driving circuit for the above 7-segment decoder. Output diagram connection in protues Operating principle When the 4-bit BCD value is inputted, there is energization that generates the output that make the decimal digits of the 7-segment on the LED display.

The design for the BCD data has the plan that includes A, B, C, and D….format. This arrangement is in ascending order of the numbers. Because, for each LED segment, there must be a relative resistor; then it is important to use the seven resistors. These should be connected between the terminals of the display and the terminals of 4511 output. When the circuit is completed, near the four switches. This should be in a binary sequence and used in checking the display in the LED display. The scope for binary input in this case is 0000 to 1001 to get an output LED display of 1-9.

The output is as indicated in the table below Truth table for the 7-segment LED display Current sampling/amplification circuit An amplification circuit has a port, which is a pair of terminals of the circuit. Across the ports, there is a voltage,  and current,  flowing through. The above diagram is an amplification network connection for the current and voltage across the terminals. It shows the output and the input terminals of an amplifier. A wave function formed from the previous connection is a function of time in relation to voltage or current.

At the input, the waveform to amplify is amplified, and then a larger waveform appears at the output. This input waveform can be either a voltage or a valid input. Type of Amplifier Input Output Voltage,  Voltage,  Voltage,  Transresistance,  Current,  Voltage,  Current,  Current,  Current,  Transconductance,  Voltage,  Current,  From the above table,,, and  are transfer functions of amplification obtained as  , where x is any given input. Having the above in mind, it is therefore, necessary to realize that a given ideal port is never affected by the input source resistance, similarly, the output source resistance does not affect the ideal output port.

A general circuit connection of an amplifier is shown below Building a current amplifier circuit For the current amplifier circuit\, the input current needs current divider attenuation and second and third output current attenuation.

Read More