5. Relay
A relay is an electrically operated
switch. Many relays use an
electromagnet to operate a
switching mechanism
mechanically, but other operating
principles are also used. Relays are
used where it is necessary to
control a circuit by a low-power
signal (with complete electrical
isolation between control and
controlled circuits), or where
several circuits must be controlled
by one signal. Relays were used
extensively in telephone exchanges
and early computers to perform
logical operations.
6. Push To ‘ON’ Switch
A push-button (also spelled pushbutton) (press-button in
the UK) or simply button is a simple switch mechanism
for controlling some aspect of a machine or a process.
Buttons are typically made out of hard material, usually
plastic or metal. The surface is usually flat or shaped to
accommodate the human finger or hand, so as to be
easily depressed or pushed.
7. Buzzer
A piezoelectric sensor is a device that uses the
piezoelectric effect to measure pressure, acceleration,
strain or force by converting them to an electrical signal
8. Resistor
A resistor is a two-terminal
passive electronic component
which implements electrical
resistance as a circuit
element. When a voltage V is
applied across the terminals
of a resistor, a current I will
flow through the resistor in
direct proportion to that
voltage
9. Capacitor
A capacitor (formerly known as condenser)
is a device for storing electric charge. The
forms of practical capacitors vary
widely, but all contain at least two
conductors separated by a non-conductor.
Capacitors used as parts of electrical
systems, for example, consist of metal
foils separated by a layer of insulating
film.
10. Transistor
A transistor is a semiconductor device
used to amplify and switch electronic
signals. It is made of a solid piece of
semiconductor material, with at least
three terminals for connection to an
external circuit. A voltage or current
applied to one pair of the transistor's
terminals changes the current flowing
through another pair of terminals.
Because the controlled (output)
power can be much more than the
controlling (input) power, the
transistor provides amplification of a
signal.
11. Diode
In electronics, a diode is a two-terminal
electronic component that conducts
electric current in only one direction.
The term usually refers to a
semiconductor diode, the most
common type today. This is a crystalline
piece of semiconductor material
connected to two electrical terminals.[1]
A vacuum tube diode (now little used
except in some high-power technologies)
is a vacuum tube with two electrodes: a
plate and a cathode.
12. Application
They are as Follows:
This Circuit Saves Time & Electricity.
It Helps To Prevent From Dozing off While Studying
by Sounding a Beep at a Fixed Time Interval.
The Circuit Is Capable of Switching off The Light , Fan
and other Appliances Automatically in The Room.
13. Operation of The Product
The circuit is built around IC 555, transistors BC547, relay
RL1 and buzzer.
The 555(IC) is configured as an monostable multi vibrator
to generate clock for the timer (IC2) .
The reset of ICs, transistors T1, T2 and T3 drive the buzzer
to sound an intermediate beep.
If IC2 is not reset through S1 at that time, around 1 minute
later the output of gate N4 goes high and transistor T4
conducts.
As the output of the gate N4 is connected to the clock
input pin 10 of IC2 through diode D, further counting stops
and the relay RL1 energizes to deactivate all the
appliances. This state changes only when IC1 is reset by
pressing switch S1.
15. IC555
The 555 timer IC is a very simple device to use. With very few extra
components it can be used as an ASTABLE timer to make flashing light circuit
or to make a loud speaker produce a sound and it can be used as a
MONOSTABLE circuit to switch a device on AFTER a set time or to switch a
device on FOR a set time.
The 555 makes it easy to get accurate time delays.
17. Transformer
The transformer serves to convert the ac line voltage to a
voltage level more appropriate to the needs of the
circuit to be powered. At the same time, the
transformer provides electrical isolation between the ac
line and the circuit being powered, which is an
important safety consideration.
18. Rectifier
The next step is to force current to flow in one direction
only, preventing the alternations that occur in the
transformer and the ac line. This process is known as
rectification, and the circuit that accomplishes the task
is the rectifier.
19. Filter
Its job is to reduce the pulses from the rectifier to a much
smaller ripple voltage. No filter configuration can be
absolutely perfect, but a properly designed filter will
provide a dc output voltage with only a small ac ripple.
20. Regulator
Voltage regulator ICs are available with fixed (typically
5, 12 and 15V) or variable output voltages. They are
also rated by the maximum current they can pass. Most
regulators include some automatic protection from
excessive current and overheating.
22. Conclusion
ANTI SLEEP ALARM
Precisely we have seen that when we set the particular
resistance in the variable resistors, its output comes
within a particular time set by the user. Thus we can
use this product for our home appliance for switching
purpose to save time and electricity.
23. Thank You For Joining Us!
The Project Members Are As Follows…
NILADRI DUTTA <ECE 2ND YR,4TH SEM>
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