A general question would be to probe and bring out what the students already know about electronics from the deepest and farthest corners of their minds.
- electrons exist and move around
- Oh and they can move in certain directions together too.
- But why move in certain direction? what fun in all this? – While moving, the desperation of moving can be used to get some output.
- This desperation can be measured – called Voltage
- How many electrons are desperate can be called current
- But if so many desperate people wish to move to a certain direction, can they all move in one go? What if the road is narrow? or if the bus is old? or if there’s no road!!
- We could explain a little bit of welding here, because of the stool making workshop.
- But there’s something that makes the voltage and current not independent of each other!! – Mr. Ohm comes in here. How can one explain resistance? Toll booth could be a nice example or a police checkpoint or Pune Metro?
- What happens at a traffic jam? Frustration and boredom, equivalent to the heat created in a wire due to resistance.
- Now what if too much traffic is let go on a narrow road? Too much jam/heat at the bottleneck = fights and bursting of the road down. If on both sides there is water, the traffic is stuck, else it will find paths and try to make new roads – the same as it happens on a circuit board where chaos reigns can keeps life interesting (many first hand experiences) 😉
- But why moving so much traffic from one place to another? What use? Traffic movement implies its an important road. Construct a nice one, build some hotels and shops, and make money. In electronics this could be making some work done by human manipulators.
- Like traffic, the electrons can be made to go about many circles in the city before it can cross the city to its destination. All the while adding to the chaos, the heat of the city, the jams, etc. But all this activity leads to businesses of buses and cars, of shops and stuff. The potential difference of distance between home and office divided by the manipulative city (load) inbetween with manipulators (politicians, bureaucrats, companies, etc ) constantly trying to get the best out of desperate citizens.
- One old Mr. Lorenz and Mr. Maxwell figured out how to convert the side drift effect (businesses and viewership and consumerism) that moving traffic produces to make engines! Like our economy, if there’s no traffic between distant places the local market will be saturated and wont be able to harness the energy to drive or grow economy. The current and magnetism analog could be extended further, but that’s enough for now.
- So how can electrons/people be manipulated?
- The simplest is make a road and put a toll booth on it – the resistor.
- Then vary the toll opening and closing to get variable traffic flow.
- Then pass this traffic over a small diaphragm to make some sound – a beeper or make some light.
- A transistor could be the use of some traffic to affect the flow of another traffic route, or to use a police man to switch on or off a traffic flow or control it ever more slightly – a transistor!
- Capacitor?
- Inductor?
- Diode? – thats easy – a one way street.
- Switch – a gate like thing, like on a toll booth.
- Heater – a large road with too much traffic to flow through it…