EVALUATION- changes to final design

In the brief from Dr Tony House he stated that we needed to make a solar powered light which would be kept outside in his garden. This means that it has to be robust so it can withstand the wind, rain and most of all salt spray. It has to turn on and off by itself. Dr Tony also asked for a dimmer switch and we only had a budget of $30 to work with.

At first I was thinking about making my light out of stainless steel. But this would have been far to expensive so my next option was aluminium. I decided to use aluminium for lots of reasons one of which is that aluminium is low cost and its easy to work with as it is soft and does not rust so it would meet the brief and look good for a long time.

After deciding about what material to use I came up with the idea of the design for my light and drew it in my book.My teacher gave me the idea of using 4 solar panels but this would not have worked with my idea .I could not use a halogen light as it wouldn't produce enough power to power the battery pack or light. Instead I used a 1w 6v solar panel that completely blew my budget.

I then modified the design of my light to accommodate the solar panel.I also thought of using a 6v lead acid rechargeable battery. After discussing that idea with the teacher we decided not to as it would take up to much space and cost too much and the solar panel would not recharge the battery as it need a charging voltage higher than 6v.So instead I used 4 AA rechargeable batteries in a battery holder which gave me 6v.

To drive the light I modified the circuit that I made earlier in the year by connecting the wires of the 6v circuit which already had a dimmer switch and
a LDR ect. But my idea for what light to use was debated between me and the teacher and so in the end we decided to use a about 1watt LED cluster.
The construction of the shell of the box went well as I had a plan to make it to big so that I would not have to use the cam machine.

So I ended up scribing out two nets on two different sheets of aluminium which went 100% the way I had planed. Then I used the gulateen to cut where possible. I had to sit down and use a piecing saw to cut out the other bits. To cut out the centre I drilled out lots of holes just inside the outline. Then I used a flat head screwdiver to knock out the bits between the holes
I the filed the sides nice and smooth..

Then it came time for me to make the brackets.I could have used the cam machine for this but I did not as it was giving other people hell. I just marked one out on a strip of aluminium and I centre punched the holes and drilled them out. Then I used this as a template and I made 3 more the same. Then I bent them 90° in the metal bender I drilled holes in the bottom ½ of the box and riveted them on.

Then it was time to cut out the Perspex so I measured out a strip and got someone to help me cut it using the band saw. To get a nice flat line the teacher put it on the belt sander for a bit. It did the job but I would not do it that way next time as the sanded side went all black and (shit) as it melted. Then I cut it into 4 pieces and fitted them to the inside of the box. I drilled out the holes and riveted them on but before that I had to make all the rivets that I used shorter. It took a long time but in the end it gave a far nicer finish.

Then I fitted the circuit and all other wiring and attached the light holder and fitted the top using 2.5 mm self tapping screws. Then I glued on the solar panel with super glue , which did not work. I ended up attaching it with silicone. I then left it to charge up in the sun. When I tested it everything worked the way it should have. I was ready happy with the way it has turned out as a lot of time and work had gone into making work. Next time I would add a cone to the top inside of my box to help make the light reflex more.

Problems encountered:

one of the problems i encountered was that the 6v 1w solar panel would not have power to recharge the lead acid battery which i was going to use

also the 1st circuit i tested which was out of a warehouse light i tested it using the led light and 4AA -6v batterys over heated and just did not work so i used the circuit i made earler in the year

the two nets would not fit in cam machine so had to be cut out using a piecing saw

Michael ballinger 11dtm us 90050