Holiday Workshop Objectives:
To introduce newcomers to Electronics investigations using a 'Breadboard'
To introduce newcomers to resistors and their purpose in a circuit through making a vehicle with working lights
To extend second time students to transistors through the making of a touch sensitive circuit
To create scenery linked to the making of a car and the a road/rail crossing
The day started with a small exercise in diagrammatical representation of various electronic parts such as resistors and transistors. Most didn't really have much idea of which picture matched the diagrams so that gave me a picture of how much I would have to explain.
Next we started making the background of our scenery using modelling plaster. This is always fun and hands on. The reason for starting with the scenery rather than the electronics is simply that the modelling plaster needs to have time to set and dry before we move on to the next stage.
Directly after this we went back to the electronics. Four of the five students were new to electronics so we started with the basics of making the car wheels then led onto the explanation of how a breadboard aids in making circuits that can be tested and developed.
Here the students are making the wheel axles underneath the breadboards.
Once the students had fixed the axles and wheels onto their breadboards, they returned to the scenery in order to paint the surface with a brown paint to cover up the white modelling plaster.
Whilst waiting for this to dry, we returned to the detail of the electronics of the vehicle. We were trying to make the LED lights work as well as activating the propeller using a switch mechanism.
A very happy student who, quite quickly and to her surprise and enthusiasm, managed to get the vehicle to work.
Here is an example of the vehicle working.
Next, we went back to the scenery and painted PVA glue on all but the rocky outcrop, laying out the track to see where not to paint PVA glue on.
Then the ballast under the rails was added.
More greenery was added as well as the road crossing.
Then drills were used to make holes for the trees to be planted.
We ran out of time a bit so laying the road properly became a bit of an issue.
Finally, we added the background scenery.
This workshop was quite ambitious and to squeeze all this into four hours was always going to be a challenge. However, most of the objectives were achieved.
The more experienced student attempted a crossing light circuit whereby touching two exposed wires switches on an LED light. He wired up the rails so that when he touched the rails, the light would switch on. This is trickier than one would imagine as it involved a transistor that, when the circuit is complete (touching the exposed wires), changes the flow of the electricity through to the LED light.
So what were the successes and failures of this workshop?
The newcomers were all successful in creating a working electric vehicle with working lights
We all used resistors in the circuits and the reason for this was explained to them
The more experienced student made progress with the introduction of a transistor with a touch sensitive light circuit. He was also able to wire up the track so when he touched the track, the light turned on.
All the students successfully completed a road and rail crossing scene
The failures were:
We needed more time to perfect the scenery.
The resources were a little short on modelling plaster and ballast for the railway tracks
The trees were too small and not really enough of them
The resistor used was a 470 ohm resistor, not a 510 ohm resistor. This could possibly be the reason why the battery seemed to be straining to cope with the power for both lights and motor.
Lesson to be learned:
Find a 510 ohm resistor and see if that makes a difference to power consumption on the 9V battery
Lengthen the workshop to 2.00pm or try to be less ambitious with the scenery building.
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