PWM Pulse Width Research Articles

Comparison of DC Motor Speed Calculation Efficiency between Inductive Proximity Sensor and Rotary Encoder

This study examines the level of effectiveness and efficiency of a sensor on the calculation of the rotational speed (RPM) of a DC motor, considering that the calculation of the rotational speed of an electric motor, both AC motors and DC motors, greatly influences the output of the system. the speed of motor rotation is very influential in several fields, such as power generation, which will affect the output voltage that will be generated. There are many methods for measuring the rotational speed of a motor, including using an inductive proximity sensor and a rotary encoder combined with a PLC as a control center and data processor so that the rotational speed can be read. the output of the proximity sensor and rotary encoder will be connected to the PLC input pin so that data will appear in the form of a pulse value which can be seen in the program that has been made. The data obtained will be processed in a program that uses special instructions, namely PRV. In comparison, the speed of a dc motor will be changed using a PWM module or pulse width modulation to adjust the rotational speed of the motor. From the results of experiments that have been carried out using the proximity sensor, it gives an average motor speed reading of 6420 Rpm with an error of -10.3, and experiments carried out using a rotary encoder give an average motor speed reading of 6409.3 Rpm with an error of 0.4 so that it can be concluded that the use of a rotary encoder is more accurate than the use of a proximity sensor to calculate motor speed.

Control of a CNC laser engraver machine for non-metallic materials

The present work consists of the development of a control system by means of a microprocessor for a prototype of engraving of non-metallic materials using a semiconductor laser, which has the purpose of carrying out said process without the use of any image processing software as they do. other common marketing devices. This prototype is based on a Cartesian positioning robot, built with a 20mm structural aluminum profile, a 450nm wavelength laser module at 1W of power adjustable by PWM pulse width modulation, 3 motors with Nema 17 bipolar steps, an ATMega2560 microcontroller and a CNC shield card. As a result, we obtain a prototype of a laser engraver with a microcontroller control system, which according to the tests carried out has an efficiency of 95%, capable of carrying out a maximum of 27 engraving processes every 60 minutes with a 30-minute break and that does not use image processing software.

Design, construction and implementation of relative humidity and temperature climatic chamber for metrology laboratory

For the calibration of thermohygrometers it is necessary to have a means of generating temperature and relative humidity for this reason in this development we will build a climatic chamber which will generate and control these two magnitudes. For the generation of temperature a thermoresistance was used and the decrease of relative humidity was done through a silica gel trap through which the air inside the chamber is recirculated with the use of a vacuum pump. On the other hand, an ultrasonic humidity generator also known as fogger was used to increase the relative humidity. For the construction of the chamber, acrylic was used as the main material, since it is translucent and facilitates the visualization of the thermohygrometers’ indications. For the control of the process variables such as temperature and relative humidity, an Arduino card was used, which through PWM pulse width modulation, the control was performed achieving a variation of 0.3 °C and 2 %RH, which will be evaluated by an accredited laboratory in the characterization of isothermal media certified by ONAC, since it is in this way that the inhomogeneity, stability and thermal load of the medium, components that affect the uncertainty of the instruments under calibration, are evaluated. It should be remembered that this development was carried out in order to create an air medium with which temperature and relative humidity measuring instruments can be calibrated in the metrology laboratory VALIDACIONES Y METROLOGIA LM S.A.S., since it is in the process of growth and one of its main objectives is to be accredited in the magnitudes of temperature and relative humidity before the accreditation body in Colombia (ONAC), which is the entity that will finally give the technical approval to release the chamber and put it into operation.

Analysis Of 12- Level Cycloconverter To Minimize Thd (Total Harmonic Distortion) Level In 3-Phase Induction Motor

These harmonics are higher than essential frequencies and cause Total Harmonics Distortion (THD) which increases the rms current and generates more warmth in the load. Numerous techniques are used to suppress the harmonics to limit the warmth in the load. Another procedure is utilized in this work to limit THD and the method to beat the low exhibition of a traditional PWM (pulse width tweak) control. In this work, the desired output voltage is accomplished by contrasting the desired sinusoidal waveform (adjusting signal) with a high frequency three-sided waveform (transporter signal). Industrial applications demands high force and long life expectancy motor drives. Three phase motor drives have restricted force density consequently Multiphase motor drives are better solutions for high force density and substantial loads. In this work a 12 level cycloconverter is designed to drive three Phase load. The loads used in the industries almost nonlinear loads like motors. Thusly, because of these nonlinear loads extra harmonics incited at the output of the 12 level cycloconverter drive with major frequency. The harmonics and THD got using our proposed technique is thought about using Mat lab/Simulink

Level Transducer Circuit Implemented by Ultrasonic Sensor and Controlled with Arduino Nano for its Application in a Water Tank of a Fire System

This article aims to describe the design of a circuit of a level transducer implemented by means of an ultrasonic sensor and controlled by Arduino Nano, applied to a water tank of a firefighting system. Initially, the integration of the Siemens 1212C programmable logic controller is described, in the connection between the sensor, the controller and the interfaces that allow to generate the monitoring, control and data recording, conditioned by a PWM pulse width modulated signal controlled by Arduino Nano. When developing the research and performing an analysis of the linear regression model, it is established that the behavior of the controlled variable with respect to time, generates a linear voltage response in the range of 0 to 10 volts; expressing in terms of correlational relationship a factor of R2 equal to 0.997, thus establishing that the designed transducer does not show susceptibility to noise or disturbances in the start-up of the firefighting system.

A Digital Implementation Method of Control Inner Loop of Ship-borne Servo System Based on PWM Power Amplifier

In order to realize the full digitalization and miniaturization of the ship-borne antenna servo system, a fully digital inner loop design method can be used to adjust the digital PID parameters through DA or AD conversion between signals. Large scale integrated circuits, such as PWM pulse width modulation amplifiers, can be used to achieve the desired antenna motion and response characteristics and achieve the acquisition and tracking of space targets and command control. The digital design scheme proposed below is simple, stable and reliable, and has certain universality.

Modeling of power supplies for power modulators with LTspice

This paper is showing simulations of power supplies for repetitive power modulators using LTspice. We are presenting power supplies with single-phase and three-phase AC input and the effects of the rectifier stages on AC input current waveforms in both cases. We are also presenting the resulting power factor including circuits for electronic power factor correction. LTspice models for electronic power factor correction using cycle-by-cycle switching as well as time-averaged models are presented. The time-averaged models replace the PWM (pulse width nodulation) switch with a transformer model with variable duty cycle. They are valid for a range of DC-DC converters. We are extending the time-averaged model for operation in continuous (CCM) and discontinuous (DCM) conduction mode and presenting results that show the fidelity of these models by comparison to cycle-by-cycle results. We are providing the detailed mathematical derivation for the DCM model expansion in the appendix. Time-averaged models do not have to keep track of thousands of steep switching transitions and can run orders of magnitude faster than cycle-by-cycle switch-mode models. Results using the time-averaged model are presented for a power supply with primary (wave-shaping) and cascaded secondary feedback control that regulates the output voltage of the converter.

Marine Gear Reducer Design Device of Lubricating Oil Temperature Control System

Signal of PLC controller by PID operation after the output of numerical simulation between 0~1, and solid state relay can receive only signal, digital or switched on or off. Only connected the two, temperature control system can be realized. The experimental approach is to learn from PWM pulse width modulation technology, the numerical analog PID controller output into the heating time in a cycle, namely, solid state relay on time. By this method, the indirect control heating rod of equivalent power, the power output of the heating rod according to the control signal of controller output, so as to realize marine gear oil temperature PID regulation. This paper designs the control system used in the experiment. The temperature control experiment system; design of the electrical schematic diagram of the temperature control system, including two parts electrical schematic diagram of control circuit and main circuit of temperature control system design process. At the same time, the experimental scheme is designed. Analysis of the mechanism of temperature balance control object, and focus on the temperature within the experimental results are analyzed.

The Simulation Analysis of the High Speed Switch Valve Control the Cartridge Valve Based on AMEsim

To establish the mathematical model of the system of high speed switch valve control the cartridge valve based on analyzing the working principle of the system,and then to analyze the impact of selecting different input signal of high speed solenoid valve and different duty cycle of PWM pulse width modulated signal through simulation software AMSEsim. The results obtained in the high-frequency performance is not very satisfactory, but in the low signal and moderate duty cycle, high-speed switch valve can be good linear control of the cartridge valve.

Common-Mode Voltage Characteristics of Matrix Converter According to PWM Method

The matrix converter (MxC) is an ac-to-ac conversion device that can generate variable magnitude variable frequency output voltage. Nine bi-directional switches of MxC allow PWM control of output voltages and input currents. PWM switching needs “switch commutations” from one switch to another. During the switch commutations, however, unwanted voltage error occurs similar to the dead time effects in Voltage Source Inverter (VSI). When PWM pulse width is narrower than the time required for the commutation, voltage error increases rapidly. This voltage distortion is critical in the low speed operation as system becomes sensitive to even a small voltage error. In this paper, a new PWM strategy is proposed for improving voltage control performance in the low voltage region. Based on the input and output voltage information, PWM pulse-widths are controlled to avoid incomplete commutations. The feasibility of the proposed method is proved by simulation and experimental results. In addition, common mode voltage characteristics of MxC are discussed. Common-mode voltage and dv/dt cause motor bearing and ground leakage currents through the parasitic capacitances. Leakage current creates noise problems that can interfere with other equipment. Common-mode voltage characteristics of MxC are presented and discussed using two PWM methods. Simulated and experimental results are presented. Common-mode voltage of two-level VSI and MxC are also compared.

23.3: Wide Temperature Operation STN LCDs Addressed by MLA for Automobile Applications

AbstractWe have developed a new color STN LCD suitable for automobile applications. It provides fast response time, high contrast ratio and 32 gray shades in the wide range of the operation temperature −30°C to 80°C. The operation temperature has been extended by utilizing the MLA Multi Line Addressing technology and the panel technology with a new optical design. The new gray shading technique appropriate for MLA has been realized with the combination of the PWM Pulse Width Modulation and FRC Frame Rate Control gray shading.

An efficient method of PWM waveform generation using a microprocessor

A Z-80 microprocessor-based control for a three-phase PWM inverter employing thyristors is discussed. This PWM inverter combines the advantages of hardware modules and software algorithms to improve the flexibility and accuracy of the operation. A floating point arithmetic unit developed in software forms a vital link of the software structure that calculates the PWM pulsewidths from the basic equation of a regular sampled PWM. During PWM waveform generation the inherent time delay involved in the execution of instructions in the interrupt subroutines results in shifting of the edges of the PWM pulses and thus introduces a certain degree of harmonic distortion. The cumulative nature of this time delay will alter the frequency of the output waveform in a continuous way. By employing a suitable hardware structure the time delay involved in the interrupt subroutine is minimized to a great extent and the cumulative effect of the time delay is nullified. To handle the interrupts arising during PWM waveform generation a simple and novel interrupt controller that is capable of handling the interrupts effectively is built around conventional TTL ICs instead of using a standard integrated interrupt controller module like 8259.

An AT89C52 Microcontroller Based High Resolution PWM Controller for 3-Phase Voltage Source Inverters

A novel technique for generating real time high resolution pulse width modulated patterns for a three phase voltage source inverter is presented in this paper. An AT89C52 microcontroller computes the PWM pulse widths on carrier cycle basis based on the input frequency. The microcontroller send the pulse width information for the three phases to a memory minimized ROM lookup table, which is scanned by a binary counter to generate the real time PWM patterns. The on board timer of AT89C52 is utilized to generate programmed clock for the scanning binary counter. The overall design is hardware minimized and compact that makes it feasible for low cost high performance ac drive applications. The proposed PWM controller supports variable frequency variable voltage operation for wide range and hence is ideally suited for industrial drives requiring wide speed variations. Keywords: Pulse width modulation, Microcontroller application, Voltage source inverter, variable speed ac drives.