Resistors can be either linear or non-linear. Linear resistors have resistance values that do not change with applied voltage, temperature, or light intensity, and include fixed resistors like carbon composition, thin film, thick film, and wire wound resistors. Non-linear resistors have resistance values that vary under those conditions, and include thermistors, photoresistors, and varistors. Variable linear resistors allow controlling current and voltage and include wire wound, potentiometer, and trimmer types. Modern circuits often use surface mount technology resistors which are deposited as thin films on ceramic chips.

1. Resistors

5. Resistor
Linear
Fixed
Carbon
Compositi
on
Thin
Film
Thick
Film
Wire
Woun
d
Variable
Wire
Wound
Potentio
meter
Tri
mme
r
Non Linear
Ther
mist
or
Photo
Resistor
Varistor

6. Linear Resistors
– Resistors through which the current is directly
proportional to the applied voltage, are called
linear resistors.
– Such resistors have a property that their
resistance values do not change with the variation
in applied voltage, temperature or light intensity.
– The linear resistors are of two types, Fixed and
variable.

7. Non Linear Resistor
– Resistors through which the current is not directly
proportional to the applied voltage, are called
non- linear resistors.
– Such resistors have a property that their
resistance values change with the variation in
applied voltage, temperature or light intensity.
– The linear resistors are of three types, Thermistor,
Photo-resistor and varistor.

8. Fixed Resistor
• These are resistors whose
values do not change with
variations in applied voltage,
temperature and light
intensity and they do not
have the provision to change
by their construction also.
• These are available with
Radial and Axial leads.

9. Fixed Resistor
• Fixed Resistors are of 4
types
– Carbon composition
– Thin film
– Thick film
– Wire wound

10. Carbon Composition Resistor
• These resistors are made by mixing carbon powder
and insulating binders to produce desired value of
resistance.
• These are within ±10% of the desired value
(Tolerance).
• Available in 1Ω to 22M Ω .

11. Thin Film Resistor
• These are made by depositing a very thin layer of
conducting material on an insulated rod, tube or plate
made of ceramic or glass.
• They can be
– Carbon film resistors
– Metal film resistors

12. Thick Film Resistor
• Similar to thin film, These are made by depositing a
layer of conducting material on an insulated rod, tube
or plate made of ceramic or glass.
• They can be
– Metal oxide film resistors: oxidizing tin chloride on a
heated glass substrate
– Bulk property film resistors – like metal film resistors
– Cermet film resistor: coating of metal alloy along with
insulating material on a ceramic substrate

13. Wire-wound resistors
• Nichrome wire on
a ceramic film
• The wire is coated
with an insulated
material.

14. Variable Linear Resistors
• Used to control current flow and
provide desired amounts of voltage in
electric circuits.
• The values are varied from 0 to a
specific value.
• Types
– Wire wound
– Potentiometer
– Trimmer

15. Wire wound
• Wire wound on a
ceramic core and
covered with an
insulated coating

16. Potentiometer
• 3 terminal variable
resistor
• Wiper connected to
control shaft.
• Movement provides
a continuous
variation in
resistance between
middle terminal and
either outside
terminal.

17. Trimmer

18. SMT (Surface Mount Technology)
• Many modern circuits use SMT resistors.
• Their manufacture involves depositing a film of resistive
material such as tin oxide on a tiny ceramic chip.
• The edges of the resistor are then accurately ground, or cut
with a laser to give a precise resistance (which depends on
the width of the resistor film), across the ends of the device.
• Tolerances may be as low as ±0.02%. Contacts at each end
are soldered directly onto the conductive print on the circuit
board, usually by automatic assembly methods. S
• MT resistors normally have a very low power dissipation.
• Their main advantage is that very high component density
can be achieved.

19. SMT (Surface Mount Technology)

20. SMT (Surface Mount Technology)

21. SMT (Surface Mount Technology)