Basic Electronics Tutorial
Electricity Fundamentals
Electricity
"Electricity Basics" {Read only the first section of this web page and then click the back button to return to the tutorial page}
Q1. What are free electrons? {answer this question in your own words}
Q1.Answer:
Lab1: Follow the instructions for Project1 : Light Controlled Bird
This is an introductory project which gives you extra guidance on how to insert components, connect signal wires
and power supplies to your circuits.
"Generators, Volts and Amps" { Read only this section of the link and then click back to the tutorial}
Q2. Using the water pump as an example describe in simple terms what Water "Voltage" and "Current" would be?
Q2.Answer:
Lab2: Project 261: Experiment of Electromagnetic Induction
Q2Lab. Why did the LED light up the moment you opened OR closed the switch?
Q2Lab.Answer:
"Circuits" { read only the "circuits" page}
Q3. For electrons to flow they need a path. This path is known as (circle your answer)
A). Wire
B). Circuit
C). Switch
Lab3: Project 281: Circuit Continuity Tester
Q3.Lab. What can this circuit be used for?
Q3.Lab.Answer:
Q4. Give an example of an electrical device in your house which
A). Has a high power rating in Kilo-Watt hours?
AND
B). Has a very low power rating in Kilo-Watt hours?
Q4A.Answer:
Q4B.Answer:
Lab4: Select a lab of your choice from the "Sonic Zoo & Sound Factory" section 6 of your lab books
Q5. Using Ohms Law I = V/r . If a lighting circuit in your house "Shorts" out. Describe in your own words what might happen to the circuit. Hint:: A "Short" means a circuit has a very low resistance , r, to ground.
Note:: there is no single correct answer.
Q5.Answer:
Lab5: Project 8 Introducing the Resistor & Project 9 Parallel Resistor
Q5.Lab. Given Ohms Law I= V/r where V is the voltage across the resistor of resistance ,r. What happens to the current I, in the parallel circuit?
Hint1: For the parallel circuit , r, is the effective resistance of both resistors. Careful though... effective resistance does not mean Resistance 1 + Resistance 2
Hint2: The Voltage across the parallel circuit is the same for each resistor.
Q5.Lab.Answer
"Direct Current & Alternating Current"
Q6. Consider this. The higher the current flowing through a cable the hotter the cable will get. This is because the cable is not a perfect conductor and so has a small...but not zero resistance, r . While this heating effect is handy for electric heating elements it is lost energy in most other applications.
A.) By using Ohms Law from question five describe why increasing the AC voltage is a smart thing to do for electricity transmission.
Q6A.Answer:
B.) Super Conductors present a very, very low internal resistance, r . when used for transmitting power.
Using the relationship that Electrical Power = Voltage(V) x Current(I), P = IV and considering Ohms law describe some of the strange properties that Super Conductors might display.
((Hint:: you need to consider what a very low r will do to either Voltage (V) or Current (I) using Ohms law and then apply your findings to the P = I x V relationship. )
((Note :: In a transmission system the total power represents the amount of total energy successfully transferred plus the total energy lost on the journey (mostly as heat).
Power Transmitted equals Power Transferred + Power Lost. ))
Q6B.Answer:
Lab6: Project 60 "DC - DC Convertor"
Batteries
"Battery Chemistry: Voltaic Pile"
"Battery Chemistry: Daniell Cell"
Q7. There are lots of different types of batteries around. If I have two batteries, one small rectangular 6 volt zinc-carbon battery and the other a large, heavy 12 volt lead-acid battery.
A.) Without knowing what I intend to use each for can you give me an example of how each might be used?
Q7A.Answer:
B.) Given the relative size difference in both batteries which one do you think can provide the most current?
Q7B.Answer:
Lab7: Project of your choice from "Radio Circuits" section.
Note: Most of the radio circuits need an antenna which you connect your circuit to. There should be an antenna available in your classroom.
Electric Motors
"Armature, Commutator & Brushes"
Q8. Why do we need a magnet in a DC electric motor ? (A DC electric motor is a key component in you lego robotics kit)
Q8.Answer:
Lab8: Project of your choice from "Putting Electronics to Work" section
Components
"Wires" , "Fuses" & "Connectors"
Q9. A fuse is designed to "blow" before the electrical circuit is damaged. The fuse filament "burns out" because it is suddenly heated.
A. Use this information to decide whether a fuse burns out it's filament due to a sudden high voltage or a sudden high current?
Q9A.Answer:
B. What could happen to an electrical circuit in your house that makes a circuit breaker (fancy fuse) very important? (Note:: no single answer to this question)
Q9B.Answer:
Lab9: Project 44 "Door Alarm"
Q10. When the capacitor is hooked up to a bulb and a battery ( like in the diagram for the Capacitor Basics lesson) then the bulb will light until the capacitor has charged up. When the light bulb goes out after the capacitor charges what do you think can be said for the Voltage measured across the capacitor leads (legs).
Select A,B or C as your answer (circle your answer)
A. The voltage across the capacitor is the same as the voltage across the battery
B. The voltage across the capacitor is greater than the voltage across the battery
C. The voltage across the battery is greater than the voltage across the capacitor.
Lab10: Project 13 "Capacitors in series and in Parallel"
Q11. If after charging the capacitor we remove the battery and replace it with a wire link.
A. Describe what will happen to the bulb ?
(Hint:: A charge can supply a current for a period of time. Charge (Q) equals Current (I) x Time(t) )
Q11A.Answer:
B. Once the charge "runs out" what is the voltage across the capacitor leads?
Q11B.Answer:
Q11C. Give 3 examples of how a capacitor is used.
Q11C.Answer:
Lab11: Project 32 "Meet the Oscillator" & Project 33 "Changing Oscillation with Capacitor"
Q12. If an inductor tries to resist a change in current (I) through it can you guess (educated) what a capacitor tries to resist any change in? (Hint:: were interested here in what is "across" the terminals of the capacitor)
Q12.Answer:
Lab12: Project 60 "DC-DC Convertor.
Q13. Give two examples of how inductors are used?
Q13.Answer:
Lab13: Project 104 "Meet the VCO"
Q14. When a capacitor repeatedly charges and discharges through a low resistance circuit it is said to oscillate.
The number of times the capacitor charges or discharges in every second is it's frequency of oscillation (resonant frequency).
A. What is happening to the voltage across the capacitor every second?
Q14A.Answer:
B. If I told you that a simple wire connection in a circuit can act like an inductor at high frequencies. What might happen in the circuit ,by accident if the designer is not careful.
Q14B.Answer:
Lab 14: Project 121 "Non-Inverting Amplifier" followed by Project 127 "VCO Using OP Amplifier"
This diode stuff may sound complicated . The easiest way to think of a diode is as an electrical "one-way" street.
When a voltage is applied across the diode's leads (legs) current will alway's flow in only one direction.
Q15. If I connected a diode in in series with an input sine wave signal which is AC (Alternating Current). What kind of signal might I expect to see at the output of the diode. (Hint:: AC means a constantly changing positive and negative +/- voltage & current)
Q15:Answer:
Lab 15: Project 10 "Meet the Diode"
"How a Transistor Works - Water Analogy"
Q16A. Explain in your own words how a transistor can be setup to act as a signal amplifier.
(Hint:: By amplification here I mean using a small input signal to control a larger output signal)
Q16A.Answer:
Lab 16: Project 14 "Meet the transistor" & Project 151 "Transistor OR Gate" & Project 152 "Transistor AND Gate"
This water analogy is the easiest way to think about a transistor. One little valve (in the base) controls the amount of water (or current ) flowing into the pipe (emitter). This is only one configuration of a transistor but is the most important.
"How a Transistor Really Works"
This Transistor stuff is pretty complicated. Don't worry if you don't get it.
A transistor today has two main jobs.
1. It acts as an amplifier in electronics circuits....just like the water analogy above.
2. Millions of transistors can be set up to work as mini switches. A switch is either on or off. In a digital sense this is the same as saying one or zero. The function of digital circuits is defined by the particular pattern of output "ones" and "zeroes" that are generated by a particular circuit for a given pattern of input "ones" and "zeroes".
These binary (on/off) circuits can be designed to perform a staggering amount of tasks from controlling how your washing machine at home cleans clothes to helping to land our next spaceship on Mars.
Q16B. Explain in your own words how a transistor can work like a switch and how these switches can be used to create lots of different digital functions
Q16B.Answer.
The following supplemental labs will give you a flavor for what digital circuits can do.
Supplemental Lab1(Digital): Project 183 " Transistorized Toggle Flip-Flop"
Supplemental Lab2(Digital): Project 185 " C-MOS J-K Flip-Flop"
Supplemental Lab3(Digital): Project 194 " Touch Switch Using NAND gate"
Semiconductors - the foundation on modern electronics
Supplemental Lab4(Digital): Project 195 "Half adder"
Supplemental Lab5(Digital): Project 197 "2-Line to 4-Line Decoder"
Supplemental Lab6(Digital): Project 209 "Binary Counter With Display"
Electronic Systems
"Introduction to How Radio Works" Follow the table of contents in sequence
If you don't have access to an AM radio in the classroom then the Project 68 "IC Radio" built in Lab 17 can be used to receive the signals transmitted in Labs 18 & 19. You will need to team up with another group who have an electronics lab kit though.
Lab 17: Project 68 "IC Radio"
Lab 18: Project 69 "Morse Code Transmitter"
Lab 19: Project 70 "AM. Transmitter"