basics of elec..ppt
DESCRIPTION
BASICS OF ELEC..pptTRANSCRIPT
RESISTORS• Resistors are used to limit current or divide
voltage and in some cases, generate heat.
• Used for driving circuit which requires low current and voltage than available.
• A two terminal non-polarised component.
• Unit of resistance is ohm.
• Notation for resistance
O- for ohm
K- for kilo ohm
M- for mega ohm
Contd…
CAPACITORS• A two terminal electronic component which
stores energy in form of charge.
• capacitance is a measure of a capacitor's ability to store charge.
• A large capacitance means that more charge can be stored.
• Capacitance is measured in Farads(F) but prefixes like µF and pF for smaller values.
Types of capacitors • Polarized
which have specified positive and negative terminals.
• Non-polarized
no defined polarity for terminals.
Practical use• Used for making timer circuits, when used
with resistance.
• Used in clipper, clamper circuit.
• Used for providing instantaneous large power as in flashlight of cameras.
• Used in DC filter circuits.
Types of diodes• LED i.e Light Emitting Diodes
These diodes emit light when provided with power supply.
Practical use• Used for making gates
• Used for making rectifiers
• Used as a switch
• LED as indicators
• Photodiodes as light detector
TRANSISTOR• A transistor is a semiconductor device
commonly used to amplify or switch electronic signals.
• Device with three terminals where one terminal can be use to control the flow of current through the other two terminals.
n-p-n as straight switch• When base of n-p-n is connected with
logic high voltage then it short circuit emitter and collector (SWITCH ON).
• When base of n-p-n is connected with logic low voltage then it open circuit both emitter and collector (SWITCH OFF).
p-n-p as inverted switch• When base of p-n-p is connected with
logic high voltage then it open circuit emitter and collector (SWITCH OFF).
• When base of p-n-p is connected with logic low voltage then it short circuit both emitter and collector (SWITCH ON).