Electronics 2

Act 2

• Series and Parallel Circuit
• AC and DC, Batteries
• Measuring voltage, current and resistance
• Circuit diagrams

AC and DC

• What are AC and DC? Click here
• AC : Alternating Current Where the flow of electricity continually changes direction in a circuit. ( From AC mains )
• DC: Direct Current where current constantly flows in one direction only. ( From Batteries , Solar panel )
• Most small/ portable l electronics devices runs on DC ( phones, torch light etc)
• Some small/portable electronics devices runs on rechargeable batteries which allows them to be connected to AC mains to charge the batteries. ( laptop)
• Some devices requires very very large current such that it is not practical to power them using batteries. As such, these devices needs to be connected and powered directly by AC mains. ( Oven , Television , Electric oven )

What is a battery ? Click here. They comes in various sizes and Type.

• The most common types of batteries you can buy in shops like ntuc are 1.5 v.
• Regardless of their sizes ( AAA,AA,C,D) they are 1.5V
• PP3 is a 9V battery
• Other types of batteries include
  • Alkaline batteries 1.5V
  • CR2032 coin cell - 3V
  • Rechargeable batteries ( Lithium Ion) 3.7V - commonly used on your Laptop, cellphone

You can read more about different battery types here

Task 2

Click on this link to build the circuit 1 . Answer the questions below

1. Click on the battery, resistor and changes the values of the voltage and resistance what do you observe when you click on the switch and the value changes?
2. Reverse the orientation of the battery, what do you observe?
3. Modify the circuit below such that when the switch is on, two or more light bulb will be turned on.

Design Task

You are tasked to design lighting for a 2 room hdb flat. The customer request the following:

• Able to turn on/off all lights in living room, bed room and kitchen at the same time when they are home or leaving home.
• Able to switch on or off the lights in kitchen, living room and bedroom independently.

Design and draw your circuit , test you design using the simulator. Build you circuit using the following

• batteries
• LED
• Resistors
• Switches

State any design constrain you may have.