Graphic Design & Printing TechnologyTransistor:A transistor is a device that regulates current or voltage flow and
acts as a switch or gate for electronic signals. A transistor amplifies, oscillates,
or switches the flow of current between two terminals. Transistors consist of
three layers of a semiconductor material, each capable of carrying a current.
The transistor’s three-layer structure contains an N-type semiconductor layer
sandwiched between P-type layers (a PNP configuration) or a P-type layer
between N-type layers (an NPN configuration).
Integrated circuit (IC):A device made of interconnected electronic components
such as transistors, resistors, and capacitors, that are etched or imprinted onto
a tiny slice of a semiconducting material such as silicon or germanium. An IC
can function as an amplifier, oscillator, timer, counter, computer memory, micro
processor etc.
Mechanical components
Gears:- A gear is a rotating machine part having cut teeth which mesh with
teeth in another part to transmit or receive force and motion. Main types of
gears seen on a printing machine are the following:
Spur gear: Spur gears are the most common type of gears and have straight
teeth and are parallel to the axis of the wheel. The advantages of spur
gears are their simplicity in design, economy of manufacture and mainte-
nance. Spur gears are known as slow speed gears. These gears are com-
paratively noisy.
Helical gear: Helical gears have their teeth cut at an angle to the face of
the gear. Their teeth are inclined to the axis of the shafts in the form of a
helix, hence the name helical gears. These gears are usually used as high
speed gears. It can take higher loads than similarly sized spur gears. the
motion of helical gears is smoother and quieter than the motion of spur
gears.
Bevel gear:Bevel gears are gears where the axes of the two shafts inter-
sect and the tooth-bearing faces of the gears themselves are conically
shaped. Bevel gears are most often mounted on shafts that are 90o apart,
but can be designed to work at other angles as well. The teeth on bevel
gears can be straight or spiral.
Worm gear:Worm gears are used when large gear reductions are needed.
It is a gear arrangement in which a worm (which is a gear in the form of a