Electrical current, voltage, resistance, capacitance, and inductance are a few of the basic elements of electronics and radio. Apart from current, voltage, resistance, capacitance, and inductance, there are many other interesting elements to electronic technology. ... Use Electronics Notes to learn electronics online.
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 non-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
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.
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.