HNC

1 Pages 373 Words

Report

As part of my HNC I was asked to Design, Manufacture and Test a circuit that would control both traffic lights and motor situated on a model of the Kincardine Bridge. The specification I was given was that the circuit board could be no bigger than 100 x 160mm and could cost no more than £50. Taking the specification into account I searched for components I would use to construct the circuit making sure the price was under the £50 limit (the total cost was £42.99). The second task I undertook was to design a board within the required size (the final size was 89 x 74mm) but I ran into problems with the design because of this there was a total of 20 designs before the board was ready to be manufactured, some of the problems are listed below.

SIL Reed relay pins were the wrong size
Earth connections were missing
LED’s were over-lapping
The pins on the 7406 were connected the wrong way round

Once the PCB was designed, the board was then manufactured. The manufacturing process can be found in Appendix page 2`. The next stage was to test and populate the board, continuity testing was done by using a multi-meter to check for open and short circuits and then hand soldering all the components in place. The population process took me around 3 hours instead of the 2 hours planned as I had to de-solder my wire links as they were not of an acceptable standard.

The final process was to test the finished PCB, this was done by testing the outputs on the board as they all worked first time I had no extra fault finding/debugging to do.


Conclusion

As the circuit worked first time I proved that I would be capable of undergoing projects like this in the future. The main reason for the circuit working was the amount of time I spent at the design process. This would save companies money in real life, as there would be no waste of materials. I also feel that my project skills are improving, as there is a big difference bet...