Table of Contents
Introduction:
Power Line Device Switching System is one of the most common and useful consumer electronics gadgets in the world today. It incorporates both Communication & Digital Electronics filed. They provide us with countless conveniences in our daily lives.
As the device is so much popular and part of every-day-activities, many add-on circuits are constructed to make it a still more feature-rich instrument. And one such add-on feature is this system which allows the user to switch ON/OFF loads from the remote end. It finds applications in homes, offices, and even in industries.
The use of power line communication networks has attracted much attention and has become a mature subject of research in the last few years. Power Line telecommunications is a rapidly evolving technology, aiming at the utilization of electricity power lines for the transmission of data. Thus, the emerging PLT technology opens up new opportunities for the mass provision of local access at a reasonable cost. In addition, PLT can provide a multitude of new services to the users which are difficult to implement by other technologies including SCADA (e.g., remote electricity meter reading, appliance control, and maintenance, energy management,) and large-scale applications for home automation
This system performs the following operations:
- It senses the “real” Power Line Device Switching System ring.
- Automatically switches the call to this system, after predefined rings.
- Switches ON/OFF The load depends upon the key pressed by the caller.
Block diagram explanation:
Power supply unit
This section needs two voltages viz., +12 V & +5 V, as working voltages. Hence specially designed power supply is constructed to get regulated power supplies.
Microcontroller:
The Atmel AT89 series is an Intel 8051-compatible family of 8-bit microcontrollers (µCs) manufactured by the Atmel Corporation. Based on the Intel 8051 core, the AT89 series remains very popular as general-purpose microcontrollers, due to their industry standard instruction set, and low unit cost. This allows a great amount of legacy code to be reused without modification in new applications. While considerably less powerful than the newer AT90 series of AVR RISC microcontrollers, new product development has continued with the AT89 series for the aforementioned advantages.
Preamplifier:
A preamplifier (preamp) is an electronic amplifier that prepares a small electrical signal for further amplification or processing. A preamplifier is often placed close to the sensor to reduce the effects of noise and interference. It is used to boost the signal strength to drive the cable to the main instrument without significantly degrading the signal-to-noise ratio(SNR).
Buffers
Buffers do not affect the logical state of a digital signal (i.e. a logic 1 input results in a logic 1 output whereas logic 0 input results in a logic 0 output). Buffers are normally used to provide extra current drive at the output but can also be used to regularize the logic present at an interface
Drivers
This section is used to drive the relay where the output is the complement of input which is applied to the drive but the current will be amplified
Relays
It is an electromagnetic device that is used to drive the load connected across the relay and the o/p of the relay can be connected to the controller or load for further processing.
Methodology:
Here is a Power Line Device Switching System operated device control circuit which enables switching ‘on’ and ‘off’ of appliances through Power Line Device Switching System lines. It can be used to switch appliances from any distance, overcoming the limited range of infrared and radio remote control. The pressed key information will be transmitted to the receiver via a power line. At the receiver, the devices will be turned ON based on the signal received from the transmitter.
Advantages:
1. Effective in implementation.
2. Low power consumption and compact Microcontroller chips are used.
3. High reliability, due to the usage of semiconductor devices.
4. Easy to use.
Disadvantages:
- The model should be placed with a power supply at any time.
- One-time investment cost
Applications:
- This SYSTEM can be used with individual homes Government Offices Business establishments Educational Institutes, or anywhere where Power Line Carrier Communications are used.
- The circuit is very useful when you want to operate appliances kept at your home, sitting in your office.
- It can be used in industries for remote operation of devices.
