20-09-2016, 03:28 PM
1455434835-SPEEDCONTROLOFSTEPPERMOTORUSINGRF2new1.doc (Size: 533 KB / Downloads: 5)
Abstract
Today, industrial applications demand real-time access to information for making intelligent decisions. Current generation control and monitoring systems are capable of sharing information over the network and are being increasingly employed for real-time decision support. These applications require stringent reliability and low latency, translating to specific design issues for the underlying system.
Intelligent wireless sensor-based controls have thus drawn significant attention recently. Industrial applications typically employ different types of sensors (thermal, photo, magneto, pressure, accelerometers, gyros, etc.), often deployed within the same network, having different interfaces and supporting different protocols for data and communications. In addition, the problems are exacerbated when different RF communication links have to be used for satisfying the requirements of bandwidth, delay, jitter, range, noise immunity, costs. etc., for communication had proposed a generic reconfigurable wireless interface for interfacing such sensors and the formation of systems from them.
This project uses an RF Interface to control the speed of a stepper motor. A Microcontroller based card is developed to decode the control signals received from the computer via RF. This card is interfaced to the Stepper Motor Controller via Driver. The control signals from computer after getting decoded are fed to the Stepper Motor Controller through Driver to produce the necessary control action.
The power supply consists of ac voltage transformer, diode rectifier, ripple filter, and voltage regulators. The transformer is an AC device, which increases or decreases the input supply voltage without change in frequency. There are 2 types of transformers. One of Step-up and the other is Step-down. Here we are using a Step-down transformer, which decreases the 230 supply volts to 12 volts. The rectifier is a device which converts an AC voltage to the pulsating DC voltage. Here IN4007 diodes are used as rectifiers. A bridge type full wave rectifier is constructed using these diodes, as its efficiency is 81.2% and ripple factor is 0.482.
After the rectification, the output voltage signal contains both an average dc component and a time varying ac component called the ripple. To reduce or eliminate the ac component, one needs low pass filter(s). similarly we are connecting a 7805 to the 7812 regulator o/p, to generate 5volts. An LED in series to a 100ohms resistor is connected in parallel to the output voltage to indicate the supply. And also a switch is connected in series to the o/p voltage terminal to ON/OFF the supply.
Transformer:
Definition:
The transformer is a static electro-magnetic device that transforms one alternating voltage (current) into another voltage (current). However, power remains the some during the transformation. Transformers play a major role in the transmission and distribution of ac power.
Principle:
Transformer works on the principle of mutual induction. A transformer consists of laminated magnetic core forming the magnetic frame. Primary and secondary coils are wound upon the two cores of the magnetic frame, linked by the common magnetic flux. When an alternating voltage is applied across the primary coil, a current flows in the primary coil producing magnetic flux in the transformer core. This flux induces voltage in secondary coil.
Transformers are classified as: -
(a) Based on position of the windings with respect to core i.e.
(1) Core type transformer
(2) Shell type transformer
(b) Transformation ratio:
(1) Step up transformer
(2) Step down transformer
DIODES:
It is a two terminal device consisting of a P-N junction formed either of Ge or Si crystal. The P and N type regions are referred to as anode and cathode respectively. Commercially available diodes usually have some means to indicate which lead is P and which lead is N.
RESISTORS:
A Resistor is a heat-dissipating element and in the electronic circuits it is mostly used for either controlling the current in the circuit or developing a voltage drop across it, which could be utilized for many applications. There are various types of resistors, which can be classified according to a number of factors depending upon:
Material used for fabrication
Wattage and physical size
Intended application
Ambient temperature rating
Cost
CAPACITORS:
The fundamental relation for the capacitance between two flat plates separated by a dielectric material is given by:-
C=0.08854KA/D
Where: -
C= capacitance in pf.
K= dielectric constant
A=Area per plate in square cm.
D=Distance between two plates in cm
LED (Light Emitting Diodes):
As its name implies it is a diode, which emits light when forward biased. Charge carrier recombination takes place when electrons from the N-side cross the junction and recombine with the holes on the P side. Electrons are in the
higher conduction band on the N side whereas holes are in the lower valence band on the P side. During recombination, some of the energy is given up in the form of heat and light. In the case of semiconductor materials like Gallium
arsenide (GaAs), Gallium phoshide (Gap) and Gallium arsenide phoshide (GaAsP) a greater percentage of energy is released during recombination and is given out in the form of light. LED emits no light when junction is reverse biased.