Background History

I have been teaching electronics projects at keystage 3 as one of the projects in an 8-10 week rotation for some years now. I’ve always done the same circuit with the whole year group to keep things manageable but varied them from year to year when I feel the pupils, or I, are bored with them. Projects have included: Latching steady hand game, light activated alarm with time delay for setting, electric organ, plant pot moisture sensor, toothbrush timer. I usually put this project in year 9 and design and make the 200 pcb’s for the year group myself. I would produce some sheets – printouts from PCB Wizard, to show where the components go and line up trays of components on my desk, and then oversee that they put the right ones in the right place. This produced 80-90% successfully working circuits, poor soldering and misreading the sheets and pcb being the main culprits.
I am conscious that the pupils are simply copying, often from each other without thinking much about the electronics and certainly there is no element of designing, and of course not everyone wants a steady hand game.

Using QuickLink With Groups

This year I have been using QuickLink 123 Fastrack with the pcb’s supplied by QuickLink and have just taken my fourth group through the project ( class sizes 19-24 )

I have found this very successful in a number of ways:

1) The circuits all work –the pcbs are well laid out, clearly labelled screen printing, tracks and pads are large and not damaged by overheating, the plated pads form good solder joints.
2) I can allow many different circuits to be made at the same time in the group as each pupil has their own printout to follow. The program positions the components in the right place and gives the correct values.

The pupils can handle the program very easily and can relate the real world pcb to the circuit diagram which they printout and stick in their books for reference through the practical sessions. The only difference from before is that I need to put out a wider range of sensors and variable resistors, etc.
3) The pupils are more motivated to complete their chosen project.
4) With individual projects few pupils simply copy from each other.
5) They have found it interesting to work out the cost of their circuit using the component information and they were keen to try out the self marking test.

Timer Circuit for Nightlight

6) There is a real design element in the projects. After seeing the range of sensors and outputs they have come up with a wide range of applications.

They have then been able to produce more meaningful design work than before eg. Research into existing products, users and situation, individual specifications ( instead of all doing the same spec. for a toothbrush timer ). Evaluations are different for each project.

7) There is scope for a certain amount of differentiation/extension work eg. Some have wanted to add an extra output- an led as well as a buzzer. With a little thought there are pads on the pcb that can be used for this. Some have made pressure pads for the touch sensor and mounted the contacts on pieces of shaped plastic for water level sensors.

Wardrobe Automatic Light

8)There is also scope for more circuits to be made using the same pcb- replace the transistor with a thyristor to make a latching burglar alarm, put a resistor and capacitor on the input side to make a timer circuit.