The Workbench

The Workbench
Making my Dreams a Reality

Wednesday, October 7, 2009

Solar Power, Competitions, and Rats

Hey Guys,

Been a long time since I last posted. I had been bsy for a while, and then forgot to post...

On with the show!

First a picture of my workbench (before I gave it a quick tidy):

Been busy as you can tell!

I've been tinkering with some cheap solar lights to make a node for my data logger. I wanted a self-sufficient wireless sensor - and so it was born. I've been asking about solar power on the PICAXE forum, and somebody has suggested that with a duty cycle like mine (0.041%) that I use a super capacitor... Currently I have a bulky battery pack made up of four 2500mAh NiMh AA cells. A super capacitor will be much much smaller, and will still have the current push I need. So long as it has the required capacitance to allow for about 50mA to be drawn for about 1.5s every one or two hours (1.23mA average versus 0.6mA average).

The two cells are wired in series, and can provide an open circuit voltage of about 6.3v, and a short circuit current of about 35mA. If these are enough to charge the batteries, then it is going to have plenty of juice to power my device. Overkill if you ask me... I'll make sure to increase the duty cycle to make use of extra energy. No use wasting it!

Science fair. I won big! I've ended up with $485 cash all up. First we had the school science fair, I gained automatic entry into the BOP regional finals as I was the only senior entry with my "microLOG" system. Next came the big day - too fast if you ask me! Dad and I drove to Rotorua, and I spent the day telling judges about my project. I talked to maybe 5 - 6 sets of judges (needed a drink real bad!). The next day I went along to prize-giving, and won four different awards - 1st for the IPENZ Engineering Award, 1st in Senior Technology, 1st in Radio Science, and I won a nomination for - the New Zealand National Science Fair. I was stunned! I won $450, an nomination for realise the dream, and I won a HAM radio receiver for 12 months!

I've built a half-wave dipole antenna for the 40 meter band. Works great! Lately I haven't had a chance to listen, as I have no ground, and the antenna has been temporarily cut down...

Mum has gone rat mental, and adopted another two rats. Whiskers and Bundles. Whiskers is white with a brown hood, and spots. Bundles looks the same as Delilah except a little darker, and a little bigger. After a week and a it in separate cages to avoid fights, they have all moved into the one cage. No major fights, so it seems everything has settled nicely.


Bundles (and Lilli):

That was a quick post on what I've been up to. Most of the work has gone into this:


I'll post again (eventually :-P)


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