Er. AnAnd kumAr mAuryA
ELECTRICAL & ELECTRONIC ENGINEERING
AUTOMATIC STREET LIGHT
CONTROL USING LDR
April 18, 2017 LDR BASE STREET LIGHT CONTROL 1
2. April 18, 2017 LDR BASE STREET LIGHT CONTROL 2
Unnecessary use of energy.
There is no use of street light
in day time and man power .
April 18, 2017 LDR BASE STREET LIGHT CONTROL 3
Many of the people have a phobia of darkness so that to assist
them in such situation we have explained a simple circuit . It
will automatically turn on street light in the way of LEDs or
BULBs coupled with relay. Working this circuit is very much easy
and also the power consumed by the circuit is very low because
of the few components used in circuit.
April 18, 2017 LDR BASE STREET LIGHT CONTROL 6
o The LM358 has consists of two independent, high gain,
internally frequency compensated operational amplifiers
which were designed specifically to operate from a single
power supply over a wide range of voltages.
o Operation from split power supplies is also possible and the
low power supply current drain is independent of the
magnitude of the power supply voltage.
o The LM358 and LM2904 are available in a chip sized package
using National’s micro SMD package technology.
April 18, 2017 LDR BASE STREET LIGHT CONTROL 8
o Relay is an electrically operated switch .
o Current flowing through the coil of the relay creates a
magnetic field which attracts a lever and changes the switch
o It has 3-pin, 4-pin, 5-pin etc.….. But we have use 5-pin in our
9. LIGHT DEPANDENT RESISTOR (LDR)
April 18, 2017 LDR BASE STREET LIGHT CONTROL 9
o Sensitivity depends on
intensity of light.
o Resistance of LDR decrease
with increase in intensity
of light and vive-versa
April 18, 2017 LDR BASE STREET LIGHT CONTROL 10
o As no input state the COM
is connected to NC and
when operating V is
applied to relay coil get
energized and COM is now
April 18, 2017 LDR BASE STREET LIGHT CONTROL 11
o It is a passive component having two terminals that are used
to mange the current flow in the circuit.
o A current that flows via a resistor is directly proportional to
the voltage that appeared into resistor
o Two types:
(1) Fixed value resistor
(2) Variable resistor
April 18, 2017 LDR BASE STREET LIGHT CONTROL 13
o A capacitor (originally known as a condenser) is a passive
two terminal electrical component used to store electrical
energy temporarily in an electric field.
o The forms of practical capacitors vary widely, but all contain
at least two electrical conductors separated by a dielectric
o The conductors can be thin films ,foils or sintered beads of
metal or conductive electrolyte, etc.
o The nonconducting dielectric acts to increase the capacitor's
charge capacity. A dielectric can be glass, ceramic, plastic
film, air, vacuum, paper, mica, oxid layer etc.
15. BC547 TRANSISTOR
April 18, 2017 LDR BASE STREET LIGHT CONTROL 15
o It is a general purpose silicon, NPN bipolar junction
transistor. It is used for amplification and switch purpose
o Here, for switching purpose biased so that it remains on if
there is signal at its base other
wise completely off
April 18, 2017 LDR BASE STREET LIGHT CONTROL 16
o The lamp is used as the load for the output.
o In place of lamp LEDs and BULBs are used.