the npn transistor as a circuit element. collector base emitter “tin can” transistors replace...

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The NPN transistor as a circuit element

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Page 1: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

The NPN transistor as a circuit element

Page 2: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

CollectorBase

Emitter

“Tin Can”

Transistors Replace Mechanical SwitchesTransistors Replace Mechanical Switches

NPN-Transistor

Page 3: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

The 1960’s transistorThe 1960’s transistor

Collector OR Drain

Base OR Gate Emitter OR

Source

The “Tin Can”

NPN-Transistor

Transistors are constructed differently and this fact is reflected in the names that are given to the pins. As a first pass at this technology, it will not hurt to associate the names in pairs.

However, ultimately the operational principles for the pins with similar names is not the same for different types of transistors.

it isn’t tin and it isn’t a can!

Page 4: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

Collector

Base

Emitter

Silicon structure with extra electrons in its structure

Silicon structure with extra electrons in its structure

Silicon structure with a shortage of electrons in its structure

n-type material

p-type material

Bipolar Junction TransistorBipolar Junction Transistor

NPN-Transistor

n p n

Page 5: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

Collector

Emitter

Base

negativeterminal

positiveterminal

If this switch is closed, the light will turn on if the switch in the base circuit is closed.

Gro

un

d

con

necti

on

Ground connection

Ground connection

Simple Switching Circuit Example

NPN-Transistor

Bipolar Junction TransistorBipolar Junction Transistor

This switch now controls the light. If it is closed, the light will go on.

n p n

Page 6: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

Collector

Emitter

Base

negativeterminal

positiveterminal

electron flow

Gro

un

d

con

necti

on

Ground connection

Ground connection

Simple Switching Circuit Example

NPN-Transistor

Bipolar Junction TransistorBipolar Junction Transistor

Page 7: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

Collector

Emitter

negativeterminal

positiveterminal Base

Ground connection

Ground connection

Gro

un

d

con

necti

on

NPN-Transistor

Another view of the npn transistor switch circuit

Page 8: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

Collector

Emitternegativeterminal

positiveterminal Base

Ground connection

Ground connectionG

roun

d co

nnec

tion

This new cartoon is a little closer to reality since it includes a drawing of a real npn transistor with its correct pin locations.

This new cartoon is a little closer to reality since it includes a drawing of a real npn transistor with its correct pin locations.

BaseEmitter

Gro

un

d

con

necti

on

Negative terminal positive

terminal

Ground connection

Collector

NPN-Transistor

NTE 198

Notice that the base connection is not in the middle of the device package even though inside the package the base is in the middle of the device.

Notice that the base connection is not in the middle of the device package even though inside the package the base is in the middle of the device.

Page 9: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

NTE 198

BaseEmitter

Negative terminal

positiveterminal

Ground connection

Emitter

Base

Collector

NPN-Transistor

Page 10: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

Negative terminal

positiveterminal

Ground connection

Emitter

Base

Collector

NPN-Transistor

Page 11: The NPN transistor as a circuit element. Collector Base Emitter “Tin Can” Transistors Replace Mechanical Switches NPN-Transistor

Negative terminal

positiveterminal

Ground connection

Emitter

Base

Collector