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The ICT in Schools Initiative of the Department of Education and Science Basic Electronics.
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Transcript of The ICT in Schools Initiative of the Department of Education and Science Basic Electronics.
The ICT in Schools’ Initiative of the Department of Education and Science
Basic Electronics
The ICT in Schools’ Initiative of the Department of Education and Science
Electric Circuit
Components are connected together with electrical wire to form a closed loop.
Components are represented by symbols
The ICT in Schools’ Initiative of the Department of Education and Science
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
The ICT in Schools’ Initiative of the Department of Education and Science
Electric CircuitElectric Current is the flow of electrons around a circuit.
Electrons have a negative charge
The ICT in Schools’ Initiative of the Department of Education and Science
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
The ICT in Schools’ Initiative of the Department of Education and Science
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
The ICT in Schools’ Initiative of the Department of Education and Science
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.
The ICT in Schools’ Initiative of the Department of Education and Science
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
The ICT in Schools’ Initiative of the Department of Education and Science
Electric CircuitResistance 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
The ICT in Schools’ Initiative of the Department of Education and Science
Ohm’s Law
Voltage , Current & Resistance are calculated using Ohm’s Law
IxRV
V
I RR
VI
I
VR
The ICT in Schools’ Initiative of the Department of Education and Science
Series Circuit•Components are connected one after the other•There is only one path for current to flow around
The ICT in Schools’ Initiative of the Department of Education and Science
Series Circuit•The current at all points in a series circuit is equal
The ICT in Schools’ Initiative of the Department of Education and Science
Series CircuitThe voltage is shared between the components in a series circuit.
•Components of equal resistance – voltage is shared equally
The ICT in Schools’ Initiative of the Department of Education and Science
Series CircuitThe voltage is shared between the components in a series circuit.
•Components of unequal resistance – voltage is shared proportionally
The ICT in Schools’ Initiative of the Department of Education and Science
Parallel Circuit•Components are connected side by side•There is more than one path for current to flow around
The ICT in Schools’ Initiative of the Department of Education and Science
Parallel CircuitThe voltage across each path is always the same as the applied voltage
• When component resistance in each path is the same
The ICT in Schools’ Initiative of the Department of Education and Science
Parallel CircuitThe voltage across each path is always the same as the applied voltage
• When component resistance in each path is different
The ICT in Schools’ Initiative of the Department of Education and Science
Parallel CircuitThe voltage across each path is always the same as the applied voltage
• When there is more than one component in a path
The ICT in Schools’ Initiative of the Department of Education and Science
Parallel Circuit•The current is divided between the paths proportionally (Ohm’s Law)
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlSPST Switch:
Polarity connection determines direction of rotation
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlDPDT Switch:
• Forward and reverse control of motor
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlDPDT Switch
+V
C3
C4
C1
0V
C2
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlDPDT Switch: Wiring Diagram
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlDPDT Switch: Wiring Diagram
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlDPDT Switch: Wiring Diagram
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlDPDT Switch: Wiring Diagram
+V
0V
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlForward and reverse control of motor with limit switches
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlForward and reverse control of motor with limit switches
Wiring Diagram
+V
0V
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlForward and reverse control of motor with limit switches
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlForward and reverse control of motor with limit switches
Wiring Diagram
+V
0V
The ICT in Schools’ Initiative of the Department of Education and Science
Motor ControlWill SW1 and SW2 act as limit switches in this circuit?
The ICT in Schools’ Initiative of the Department of Education and Science
SensorsLight Dependent Resistor (LDR)
• Resistance increases as darkness increases
The ICT in Schools’ Initiative of the Department of Education and Science
SensorsThermistor
• Resistance decreases as the temperature increases
The ICT in Schools’ Initiative of the Department of Education and Science
TransistorActs as a switch
Voltage > 0.6V-0.7V between the base and emitter transistor is on
Collector EmitterBase
BFY51
Collector
BFY51
EmitterBaseCollector
BFY51
Collector Base
BFY51
Collector Base EmitterBase
E
B
C
The ICT in Schools’ Initiative of the Department of Education and Science
TransistorVoltage Divider circuit is used to create the turn on voltage between the base and emitter.
The ICT in Schools’ Initiative of the Department of Education and Science
LDR Transistor Circuit An LDR changes the voltage according to light levels
Dark = LED on
The ICT in Schools’ Initiative of the Department of Education and Science
Relay A relay is a switch used to turn other circuits on and off
DPDT switch
Coil terminals are part of controlling circuit
The ICT in Schools’ Initiative of the Department of Education and Science
Relay
Position A
The ICT in Schools’ Initiative of the Department of Education and Science
Relay
Position A
P1NC1 NO2
The ICT in Schools’ Initiative of the Department of Education and Science
Relay
Position B
The ICT in Schools’ Initiative of the Department of Education and Science
Relay
Position B
P2NC2
NO2
The ICT in Schools’ Initiative of the Department of Education and Science
Relay