Switches Electronics 1 CVHS

Basic Elements of a Circuit Three Essential Elements Load Complete Path Power Source Additional Elements Control Device Protective Device

Electricity Generation Six Methods Used to Produce Electricity Chemical Magnetism Heat Friction Light Pressure

Basic Switch Function To open and close a circuit Open (no connection) Closed (connection) Control device Does not consume power

Schematic Terms Pole- what the switch armature is connected to • Throw- the closed position of the switch Pole Throw

Single Pole, Single Throw SPST 1 pole, 1 throw Example- room lights

SPST Animation

Single Pole, Double Throw SPDT 1 pole 2 throws, 2 closed positions

SPDT Animation

Double Pole, Single Throw DPST 2 poles

Double Pole, Single Throw Not 2 throws because of mechanical connection Both armatures make contact at same time- one closed position

DPST

DPST Animation

Double Pole, Double Throw DPDT 2 poles 2 separate closed positions

DPDT Animation

Switch Styles Toggle Slide

Switch Styles Rocker Push On/Off

Other Switches Momentary contact switches Push button switches Rotary switches

Momentary Contact Push Button Normally Open PBNO Red in color

PBNO

Momentary Contact Push Button Normally Closed PBNC Black in color

PBNC

Rotary Switches Used for complex circuits Can have multiple throws

Rotary Switch Example- Stereo input selector

#1) ?P?T

#2) ?P?T

#3) ?P?T

#4) ?P?T

#1) 3P1T

#2) 2P5T

#3) 3P2T

#4) 3P3T

Review What are the three basic parts of a circuit? What else can a circuit include? What are the six sources of energy? What is the main function of a switch? What is the difference between a throw and a pole? What other types of switches are available?