its a cost effective project and already available online shopping

1. GUDLAVALLERU ENGINEERING COLLEGE
LINE FOLLOWER ROBOT
Guide: Submitted BY:
Mr.M.H.SUNDEEP SINGH P.SHARUKH KHAN
(14481A04F9)

2. Abstract
• A resistance switch needs two electrodes to be physically in contact with
something electrically conductive (for example a finger) to operate. They
work by lowering the resistance between two pieces of metal. It is thus
much simpler in construction compared to the capacitance switch. Placing
one or two fingers across the plates achieves a turn on or closed state.
Removing the finger(s) from the metal pieces turns the device off.
• One implementation of a resistance touch switch would be two
Darlington-paired transistors where the base of the first transistor is
connected to one of the electrodes.
• Also, an N-Channel, enhancement-mode, metal oxide field effect
transistor can be used. Its gate can be connected to one of the electrodes
and the other electrode through a resistance to a positive voltage.

3. Contents
• Introduction
• Circuit diagram
• Block diagram
• Components
• Working
• Applications
• Advantages
• Limitations
• References

4. CIRCUIT DIAGRAM

5. components
• RESISTORS (270 ohm and 100k ohm)
• TRANSISTORS (bc547 -2)
• LED(1)
• CONNECTING WIRES(2)

6. Working
• The resistance of the object touching the electrodes
will come into the picture in the working of resistive
touch sensors. For example, when finger touches the
surface, the small resistance of the finger allows some
current to flow through it, completing a circuit. The
transistor acts as a switch. The resistor Rp is used to
protect the transistor from any possible short circuit
of the electrodes. The resistor Rb is used to keep the
base at the ground when the circuit is open, i.e. there
is no finger. When both the electrodes are touched,
small current flows through the finger and the
transistor switches ON, as a result the load becomes
active

7. Applications
• This is ideally useful for making touch
operated doorbells , buzzer , toys etc .
• It also used in door knobs & in relays .
• Use this project to make remote operated
switch , light operated switch & clap switch .

8. Advantages
• The switch can be used for switching AC as
well as DC.
• It is best to use a 9V-12V DC regulated or
unregulated power supply. It is used in
various applications due to its quicker
response .
• Low cost

9. Disadvantages
• It will be damage if the input DC voltage go
over 15V .

10. References
www.wikipedia.com
www.roboticsindia.com
www.kpsec.freeuk.com
www.electronicprojects.com