A6 LT6 Flashcards
How is the emitter identified in a transistor symbol?
Arrow from P-type to N-type
What are the advantages of a transistor compared to a relay circuit?
Solid-state, no moving parts.
What occurs when a small emitter-to-base current is established in a transistor?
A much larger emitter-to-collector current can occur.
What is the difference between the emitter and collector regions of a BJT?
N-type
To operate an NPN transistor, what is the requirement for the emitter?
It must be negative
What happens when a transistor is saturated?
It is fully open
What does a transistor do
1, turns on a off
Amplifys
What happens if the P-type layer is removed?
Load current flows through N-type regions
How is the base-emitter junction biased in all transistor circuits?
Forward-biased
What happens when the base current is increased in a transistor circuit?
Decreases internal collector-to-emitter resistance
To operate an NPN transistor, what is the requirement for the base?
It must be positive
How is an NPN transistor constructed?
N-type/P-type/N-type
What does the base layer of P-type semiconductor do?
Blocks conduction through load circuit
How is the collector biased in all transistor circuits?
Reverse-biased
To operate an NPN transistor, what is the requirement for the collector?
It must be positive
What does the transistor act like when it is cut off?
an open switch
How is a PNP transistor constructed?
P-type/N-type/P-type
Where do electrons move once they enter the base in a control circuit?
Towards the collector
To operate a PNP transistor, what is the requirement for the emitter?
It must be positive
What can transistors be compared to for simple applications like ohmmeter testing?
Back-to-back diodes
What does a transistor do in electronics?
Regulates current
Which way does the emitter arrow point in an NPN transistor?
From P- to N-type semiconductor
To operate a PNP transistor, what is the requirement for the base?
It must be negative
What is the actual source of current for a transistor?
DC power supply like a battery
What allows a much larger current to pass through to the collector region and the load circuit?
Decreasing base resistance
What materials are most transistors made of?
Silicon semiconductor
What happens when the control circuit is open in a transistor circuit?
No current flows.
What are the are the 3 places on a transistor
Collector, Base, Emitter
What does the beta of a transistor express?
Magnitude of collector current controlled by a specific value of base current
How can you calculate the value of base current if collector current and beta are known?
By dividing collector current by beta.
