As known the electric energy is one of the most important factor of development, but
using it causes bad environmental impacts due to depending on fuel as the source of
electrical generation. Using renewable energy is still limited and needs a huge
fixed costs,
so it is important to reduce electrical consumption by monitoring and controlling
equipment to achieve its function with lower consumption. HVAC sector is the most
consumption part in buildings, therefor any saving in this sector will affect manifestly on
the total electrical consumption in the building and this is done by control system. Control
systems are in continuous improving, so it is needed to exploit them in saving electrical
energy.
In this research, studying control of VAV system and designing fuzzy logic
controller to drive supply fan in order to reduce its electrical consumption, this is
performed through designing practical prototype of the supply fan with its tools and
software which are designed to view the electrical energy saving which we gain it by using
fuzzy logic controller.
Since Electroencephalogram (EEG) signals have very small magnitude, it's very hard
to capture these signals without having noise (produced by surrounding artifacts) affect the
real EEG signals, so it is necessary to use Filters to remove noise.
Th
is work proposes a design of an electronic circuit using a microcontroller, an
instrumentation amplifier and an operational amplifier able to capture EEG signals, convert
the captured signals from analog state to digital one and send the converted signal (digital
signal) to a group of three digital filters.
This paper gives a design of three digital elliptic filters ready to be used in real time
filtering of EEG signals (which preliminary represents the condition of the brain) making
the software part which complements the hardware part in the EEG signals capturing
system.
Finally we are going to show the way of using the designed electronic circuit with
the three designed digital filters, demonstrate and discuss the results of this work.
We have used Eagle 6.6 software to design and draw the circuit, CodeVision AVR
3.12 software to write the program downloaded on the microcontroller, Mathworks
MATLAB 2014a software to design the three digital filters and Mathworks MATLAB
2014a Simulink tool to make the appropriate experiments and get the results.
The re-use of return air in central conditioning systems is one of the most important
procedures for saving power consumption. However, the requested fresh air of the people
existed within the conditioning space imposes determining the number of ti
mes to be used.
This research aims to link the work of the central conditioning system (heating) of a
facility with the number of people existing within this facility by modifying the ratio of
mixed fresh air and return air to save the electrical power consumption. Also, to raise the
temperature of the mixture air by controlling the flow of hot water continuously rather than
using on-off technique. As well as, to respond to any change in the number of people and
get rid of repeated machine starting.
Our research has been done by using specialized physical model consisted of test
room, heat and movement sensors, pump, water tank, heat exchanger and air mixing
blades. These devices are controlled by microcontroller type PIC16F877A.
The experimentally obtained results showed the ability of controlling the amount of
return air depending on the number of people and controlling the speed of the pump
continuously providing a saving of electrical energy consumption up to 68% compared
with the case of full speed.
