21-02-2012, 11:32 AM
EMBEDDED DESIGN FOR POWER SAVING SYSTEM FOR POWER OPTIMIZATION
1.Introduction
In this sophisticated world every activity is getting atomized with the help of electronic concepts. All the way so far we have seen that any controlling of parameters, measuring as well as testing of circuits or components is carried out with analogue instruments. So we decided to develop an Microcontroller aid which is helpful for the above purpose which is called as SMART POWER SAVING SYSTEM FOR POWER OPTIMIZATION.
The 'SMART POWER SAVING SYSTEM FOR POWER OPTIMIZATION’ project described here is a novel approach to control the speed of the Fan and intensity of Bulb automatically. This system is very useful in summer seasons, as during that period fan’s and light’s requirement are crucial. Since the available power source is limited, due to lack of water storage, it is advisable to use the available resources effectively. So this system controls the speed of the fan with respect to room’s temperature & intensity of Bulb is controlled by darkness of the room and hence prevents unnecessary power wastage. One more additional feature is: whenever human presence is detected in the room then only bulb puts ON.
The main feature of this system is the totally automatic control of the required physical parameter [Temperature, Darkness & Human Presence], simplicity of operation and flexibility. Because of its versatility, flexibility and ease of operation, this "SMART POWER SAVING SYSTEM FOR POWER OPTIMIZATION” project can be used for Industrial, Domestic and other similar fields very effectively.
In automation and instrument building we often are confronted by the necessity to precisely control rotational speed of a strong motor. In principle fans are the easiest to handle in this respect. Their speed can be controlled as a function of applied voltage. However fans are plugged with a lot of annoying characteristics, such as mechanical noise, torque dependent on voltage/speed etc...
In the Industries, this temperature controller can be used to control the Speed of the motor, temperature of a heater, furnace, or any other similar device. However, in the residence, this system can be used to vary the speed of the fan, intensity of the bulb or the temperature of the room heater.
It controls the speed of the Fan & intensity of Bulb by changing its mechanical regulator automatically, with reference to room temperature & darkness. Besides the removal of mechanical regulator’s necessity, it provides a visual indication of the speed of the Fan & intensity of Bulb. Thus user will not be walking upto the regulator to change the speed and he will come to know, at what speed the fan is running.
MAIN FEATURES OF THE PROJECT:
1. Simple in design, all the components required are easily available.
2. Walking up to the regulator board to change the fan speed is avoided.
3. Low power consumption, and compact size,
4. Higher power handling capacity, driving load of up to 1000 Watts (1kW).
5. Linear, smooth control of the fan speed & intensity of Bulb.
6. High reliability, due to the usage of power semiconductor devices,
7. Simple in operation, and low power consuming System, etc., due to usage of Microcontroller chip.
2. Block Diagram & its Explanation
In Brief: Temperature sensor will sense the temperature of the room and Light sensor will sense the darkness of the room. Corresponding variations are fed to respective Comparator stages. Comparator compares the signal voltage with the reference voltage. If both the voltages are same, the output of the comparator is zero. Otherwise has some value which corresponds to the difference between the two voltages. The range selector is responsible for the setting of reference voltage. Output of the comparator is applied to the Priority Encoder. Depending on the input to the priority encoder, its output pins go high in a sequence. Output of the priority encoder is applied to relay driver stage. Relay drivers activate respective relays and depending on which relay is energised speed of the fan & intensity of Bulb is set. These relays give the required predefined resistance value to the Triac switcher stage via Buffer & Driver stage. This Buffer & Driver stage isolates rest of the circuit from Triac Switcher Stage & then boosts signal to sufficient level. The Triac Switcher Stage finally executes the command, that means it rotates the Fan with required speed and glows Bulb with required intensity. The PIR unit detects the presence of the human in its vicinity and switches ON/OFF the bulb.The specially designed power supply supplies +12 V & +5V regulated voltages to the system.
The block diagram Fig 2.1 shows how the ‘MICROCONTROLLER BASED POWER SAVING’ System works, with the help of blocks. To understand the working philosophy, this Block Diagram can be divided into following Parts: Temperature & Light Sensors; Comparator; Priority Encoder; Driver; Buffer & Driver: Microcontroller Chip; LCD Module; Triac Switcher; Fan & Bulb; PIR Module and finally Power Supply Unit.
Temperature & Light Sensors: The Temperature & Light Sensors are fitted in the room, so that it can monitor the surrounding temperature & darkness accurately. These sensors generate variable voltages according to the sensed signals and fed to Comparator stage.
Comparator: Comparator compares the signal voltage with the reference voltage. If both the voltages are same, the output of the comparator is zero. Otherwise has some value which corresponds to the difference between the two voltages. The range selector is responsible for the setting of reference voltage. Output of the comparator is applied to the Priority Encoder.
Priority Encoder & Driver Stage: Depending on the input to the priority encoder, its output pins go high in a sequence. Output of the priority encoder is applied to relay driver stage. Relay drivers activate respective relays and depending on which relay is energised speed of the Fan and intensity of Bulb is set. These relays give the required predefined resistance value to the Triac switcher stage via Buffer & Driver stage.
