Electronic Components Flashcards
Limits the flow of electrons through a circuit.
Resistor
Where is a resistor used?
Virtually every electronic device, such as phones & ACs.
A resistor whose resistance can be adjusted using a knob.
Potentiometer
Where is a potentiometer used?
In dimmer switches & volume knobs, & oven knobs.
A resistor whose resistance varies depending on the amount of light which strikes it.
Photocell/LDR Resistor
If a photocell is exposed to a lot of light, then…
It will have a lower resistance.
Where are photocells used?
Night lights & robotics (sensors)
A device which stores an electric charge as a current flows through it.
Capacitor
Where are capacitors used?
Used as decouplers to suppress high frequency noise, power supply filters, & are used in cameras.
A device which allows an electric current to flow in only one direction.
Diode
Where are diodes used?
They are used in rectifiers to convert AC to DC electricity.
A device which emits light when a current passes through it.
LED
Device which translates changes in current flow into sound waves.
Speaker
How does a speaker work?
Current causes either an attractive or repulsive force between a magnet & a coil of wire. These forces cause the cone to move, thus creating sound waves.
Once this component is turned on by a current at its gate, it requires the voltage across the anode & cathode to be removed before it stops conducting.
SCR
When the text on an SCR is facing towards you, the pins are labelled from left to right as:
Cathode, Anode, Gate
When are SCRs used?
They are used in applications where high voltages & currents are present, & are used to control alternating currents.
Where are transistors used?
They are used in microprocessors & ICs. They can communicate using binary code.
Device which amplifies current & acts like a switch.
Transistor
A diode is forward-biased if…
Its anode is connected to the positive side, & its cathode is connected to the negative side of an external source of current.
What happens in a forward-biased diode?
The free electrons in cathode will pass the depletion zone & go into the anode, where they will then combine with the holes (become valence electrons) & leave through the left end of the anode. As they leave, they will leave behind holes for other electrons to combine with.
