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1. Switches
Electronics 1
CVHS

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

3. Electricity Generation
• Six Methods Used to Produce Electricity
– Chemical
– Magnetism
– Heat
– Friction
– Light
– Pressure

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

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

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

7. SPST Animation

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

9. SPDT Animation

10. Double Pole, Single Throw
• DPST
• 2 poles

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

12. DPST

13. DPST Animation

14. Double Pole, Double Throw
• DPDT
• 2 poles
• 2 separate closed positions

15. DPDT Animation

16. Switch Styles
Toggle Slide

17. Switch Styles
Rocker Push On/Off

18. Other Switches
• Momentary contact switches
–Push button switches
• Rotary switches

19. Momentary Contact
• Push Button Normally Open
• PBNO
• Red in color

20. PBNO

21. Momentary Contact
• Push Button Normally Closed
• PBNC
• Black in color

22. PBNC

23. Rotary Switches
• Used for complex circuits
• Can have multiple throws

24. Rotary Switch
• Example- Stereo input selector

25. #1) ?P?T

26. #2) ?P?T

27. #3) ?P?T

28. #4) ?P?T

29. #1) 3P1T

30. #2) 2P5T

31. #3) 3P2T

32. #4) 3P3T

33. 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?