Communication Signals

Basic Circuits

Fox Valley Technical CollegeAppleton, WI

Pictorial Diagram of A Simple Electric Circuit

Battery

Lamps

Wire Conductor

Current Flow

+ -Voltage Source

A Schematic Diagram for the Simple Circuit

VS

Lamps

BatteryOr

DC Voltage SupplyPL1 PL2

Hardware Pictorial and Schematic of a Closed Circuit Using a SPST switch for

control

Closed Circuit Path => Current Flows

VI

-

+

Closed SwitchOff On

+ -

Hardware Pictorial and Schematic of an Open Circuit Using a SPST switch for

control

Broken Circuit Path => NO Current Flow

V -

+

Open SwitchOff On

+ -

Example: Pictorial of a SPDT switch controlling two lamps

Lamp 1

Lamp 2

2

1

Switch+-

Example: Schematic of a SPDT switch controlling two lamps

Lamp 1

Lamp 2

SW

1

2

V-

+ Lamp 1

Lamp 2

SW1

2

V-

+

Switch Symbols

Single-pole rotary(6-position)DPST DPDT

SPST-NOSPDT

SPST-NC NOPB NCPB

Break-MakePB

Typical Mechanical Switches

Construction View of a Typical Toggle Switch

Symbols for Ground

ChassisGround

ACGround

DCGround

A Simple Circuit Schematic Using Ground Symbols

I

-

+

12 V

0 V

Ground Symbol

Schematic Symbols Introduced So Far

LampsGroundsRheostatPotentio-meter

Fuse

RotarySwitch

Circuit Breaker

OhmmeterAmmeterVoltmeter

ResistorBattery

SPST-NOSPDT

SPST-NC NOPB NCPBBreak-Make

PB

DPSTDPDT

A V ΩT

Thermistor PhotoResistor

Watch the video clip and see if you can tell what kind of

circuit this is!

http://www.teachertube.com/view_video.php?viewkey=9c7de745bd6b6d1a7a86

Series Circuit

• One path for current. So all components have the same current through them.

• But components have different voltages consistent with the voltage – current relationship for each type of component.

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IS

IS

IS

+V1− +V2− +V3−

+V5−+V6−

+V4−

Watch the video clip and again, see if you can tell what

kind of circuit this one is.

http://www.teachertube.com/view_video.php?viewkey=318031eedd5700a8d3d2

Parallel Circuit

• One voltage source. So all components have the same voltage across them.

• But the components have different currents consistent with the voltage – current relationship for each type of component.

+VS−

VS

+VS−

+VS−

+VS−

+VS−

I1 I2 I3 I4 I5

Series-Parallel Circuit

Most circuits are a combination of series and parallel circuits.

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