The fans used at our homes operate using a single phase induction motor. By providing the control to change the speed of the fan, the speed of that motor is actually varied. Using the traditional method of operating through the rotor knob on the switch board is inconvenient. This project provides a remote way of controlling the speed of the motor by using pulse width modulation control to regulate the voltage going to the single phase induction motor wherein the triggering of a triac is delayed by a certain value using an autocoupler circuit with a PIC microcontroller, sent from an Android based smart phone application for the load.
Electricity has being a major challenge in our homes, offices and workshop 9most especially in the rural environment has being a major problem) in fact it has being on and off; therefore the stress of walking to and fro in other to turn on and off our induction motor based appliances respectively is challenge and undemanding. Everyone now uses android phone containing different apps so with the induction motor application installed on the phone, one can easily controls and regulate the appliances at their comfort thereby solving the problem of moving to and fro in controlling the appliances
It controls the speed of an induction motor by an android application on an android smart phone. This is achieved by constructing an alternating current (AC) induction motor enabled rotation fan that its speed can be gotten hold of and be controlled by an android application on an android smart phone.
The project is constructed in such a way that any device with a built-in induction motor can be controlled with the android application in a much the device is plugged on it.
There is need for improvement of quality product many industrial application requires adjustable speed and constant speed due to rapid advance in automation and process control the field of adjustable speed drives continuously. In recent technology, various alternate techniques are available for the selection of speed of drive system. Up to the 1980‟s the dc motor was the choice for variable speed drive application. Induction motors are using any application such as Industrial drives control, automotive control, etc. In past few years there has been a great demand in industry for adjustable speed drives. Fan, pump, Compressors, domestic applications and paper machines etc… In this area DC motor was very popular but having many disadvantages so that microcontroller transformed research and development toward control of ac drive. When the three phase supply is not available for domestic and commercial application, there we are using single phase induction motor which is one of the most widely used type of low power motor in the world. An induction or asynchronous motor is a type of AC motor where power is supplied to the rotor by means of electromagnetic induction, rather than by slip rings and commutator as in slip-ring AC motors. It has a squirrel-cage rotor identical to a single phase and 3-phase motor winding on the stator. There are various methods for controlling the speed of AC motors. There are several of method available for speed control of ac motor one of the method is two vary frequency and voltage of motor. Speed modulation of a single-phase motor is usually achieved either by some electrical means, such as reducing supply voltage by auto-transformer, or by switching windings to change the number of motor poles for different operating condition as required. For changing the speed of capacitor run motor as shown in voltage control is best method, but it allows only limited speed range to be obtained. Now frequency acts as interesting alternative to voltage control. The most appropriator actuators for variable speed drive is seem to be capacitor run drive. In this project the speed of induction motor, control with the help of android applications that comes under wireless technology. Android application use here as a transmitter and remote control in order to control the speed of induction motor with the help of Bluetooth as a receiver.
Single phase induction motors are used in many domestic electrical appliances like in ceiling fans, pumps, washing machines, etc. It may be necessary to change the speed of motors used. (Arago, 1888, United State of America)
By varying the voltage applied to the motor, the speed can be changed. In earlier days a variable resistance was connected in series with the motor in which a portion of the input voltage was dropped in the resistance and the remaining voltage was made available across the motor.
The speed of the motor and torque developed was convenient but a good amount of power was lost in the variable resistance and hence the method was not efficient. Resistance controllers as for example, used in controlling speed of fans, are gradually being replaced by solid state controllers.
3 Working Principle
The operation of the induction motor controller using PIC microcontroller is explained as follows:
When the system is powered ON, the HC-05 bluetooth module is initialize and ready to receive message from the Bluetooth enabled device (android phone using the app ‘‘BluetoothElectronics’’), the microcontroller receives data from the Bluetooth module using serial communication universal serial asynchronous receiver transmitter (USART),as programmed, when data is received, the microcontroller check if the command is to increase or decrease the speed of the induction motor.
The IC MOC3021 Opto-Isolator and a triac driver is used to isolate the AC of the induction motor from the digital DC part of the microcontroller, the Opto-Isolator consist of photo diode and a photo triac whichmake it possible to drive an AC device with digital DC voltage of the microcontroller.