1. Basic Electronics

2. Electric Circuit
Components are connected together with electrical wire to form a closed loop.
Components are represented by symbols

3. Electric Circuit
Electrical wire used to connect components is a conductor.
A conductor allows electric current to flow through it easily.
Good conductors include: copper, gold, silver, tin
Copper wire is generally used as it is most cost effective.
All electrical wires have a plastic cover.
Plastic is an insulator.
An insulator does not allow current to flow through it.
Avoids electric shock.
Insulators include: plastic, glass, wood

4. Electric Circuit
Electric Current is the flow of electrons around a circuit.
Electrons have a negative charge

5. Electric Circuit Electric current is measured with an Ammeter
The ammeter is placed into the circuit (in series)
Unit of measurement is the Ampere or ‘amp’
Represented by the letter I

6. Electric Circuit
EMF (electromotive force) is the force that makes electrons flow around a circuit.
EMF is often called Voltage and is provided by the battery.
Higher voltage = more current

7. Electric Circuit Voltage is measured using a Voltmeter.
The voltmeter is placed across a component (in parallel)
Unit of measurement is the Volt.
Represented by letter V.

8. Electric Circuit
Resistance is the opposition to the flow of electric current.
All components have resistance.
Electrical wire has resistance.
Unit of measurement is the Ohm (Ω)
Represented by the letter R

9. Electric Circuit
Resistance is the opposition to the flow of electric current.
All components have resistance.
Electrical wire has resistance.
Unit of measurement is the Ohm (Ω)
Represented by the letter R

10. Ohm’s Law
Voltage , Current & Resistance are calculated using Ohm’s Law V I R

11. Series Circuit Components are connected one after the other
There is only one path for current to flow around

12. Series Circuit
The current at all points in a series circuit is equal

13. Series Circuit
The voltage is shared between the components in a series circuit.
Components of equal resistance – voltage is shared equally

14. Series Circuit
The voltage is shared between the components in a series circuit.
Components of unequal resistance – voltage is shared proportionally

15. Parallel Circuit Components are connected side by side
There is more than one path for current to flow around

16. Parallel Circuit
The voltage across each path is always the same as the applied voltage
When component resistance in each path is the same

17. Parallel Circuit
The voltage across each path is always the same as the applied voltage
When component resistance in each path is different

18. Parallel Circuit
The voltage across each path is always the same as the applied voltage
When there is more than one component in a path

19. Parallel Circuit
The current is divided between the paths proportionally (Ohm’s Law)

20. Motor Control SPST Switch:
Polarity connection determines direction of rotation

21. Motor Control
DPDT Switch:
Forward and reverse control of motor

22. Motor Control
DPDT Switch +V C3 C4 C1 0V C2

23. Motor Control
DPDT Switch: Wiring Diagram

24. Motor Control
DPDT Switch: Wiring Diagram

25. Motor Control
DPDT Switch: Wiring Diagram

26. Motor Control
DPDT Switch: Wiring Diagram +V 0V

27. Motor Control
Forward and reverse control of motor with limit switches

28. Motor Control Forward and reverse control of motor with limit switches
Wiring Diagram +V 0V

29. Motor Control
Forward and reverse control of motor with limit switches

30. Motor Control Forward and reverse control of motor with limit switches
Wiring Diagram +V 0V

31. Motor Control
Will SW1 and SW2 act as limit switches in this circuit?

32. Sensors Light Dependent Resistor (LDR)
Resistance increases as darkness increases

33. Sensors
Thermistor
Resistance decreases as the temperature increases

34. Transistor Acts as a switch
Voltage > 0.6V-0.7V between the base and emitter transistor is on
Collector
Emitter
Base
BFY51 E B C

35. Transistor
Voltage Divider circuit is used to create the turn on voltage between the base and emitter.

36. LDR Transistor Circuit
An LDR changes the voltage according to light levels
Dark = LED on

37. Relay A relay is a switch used to turn other circuits on and off
Coil terminals are part of controlling circuit
DPDT switch

38. Relay
Position A

39. Relay
Position A
NC1
NO2 P1

40. Relay
Position B

41. Relay
Position B
NO2
NC2 P2

42. Relay