Sunday, 29 July 2007

Charge your batteries using the sun!

About 2 or 3 years ago I had it in mind to build a battery charger - the rate at which my family was getting through batteries was making my hair curl. At that time it was much cheaper to make your own out of a kit than to buy one in a shop. But then I suppose China happened and the price of chargers plummeted. So in the end I held out and finally bought one. Ok - not very adventurous but we needed one quickly before batteries bankrupted me.

My youngest wanted to have new batteries for his toy washing machine (don't ask) and that required a new set of rechargeables and, sadly (thinking of the double expense), a new charger.

But just take a look at our new battery charger in the picture...

It's solar powered - and also, as it should be, cheaper than the normal mains charger (about 50% cheaper, which is excellent). This is a little charger for charging up little cells (AAA,AA,C,D,...), but you can also get them large enough to charge up a car battery. Hook an inverter up to the car battery and you can power any 230V device (but pay attention to the power output of the inverter - you don't want to blow anything up). For a guilt-free gaming experience you can power your TV and Xbox using the sun!

There are three types of solar panel. Monocrystalline cells are cut from a single crystal of silicon. Polycrystalline, as the name suggests, is made from a number of crystals. The panels in our charger are polycrystalline. Can you see the way the sun is glinting of the crystals? The third type is amorphous and that's the kind you get in calculators (this type works better where the sun isn't out as often - e.g. around here).

According to Maplin (where I got this natty little thing from), if every mobile phone in the UK was charged with solar power the reduction in CO2 would be equivalent to planting an extra 292 million trees a year. So that can't be bad.

Oh, and what do you do with your old batteries? Throw them away? Well, what we should be doing is recycling them. Brussels (the city not the sprout) recycles 59% of its batteries. The UK recycles... err... 0.5% - which is pretty shameful considering they end up in a landfill (around here it is a big hole in the ground just up the road from Pershore) and they contain such delights as cadmium and mercury.

To buy a solar charger from Maplin click here.
You can pick up an inverter either from Maplin or from any camping shop.

Wednesday, 25 July 2007

Use recycled bits for your experiments!

Part of the joy of carrying out experiments at home is that you can use any old junk to do them. One charity who is making it their business to supply us home experimenters with any old junk is the Worcestershire Resource Exchange, based in the old locomotive works on Shrub Hill Industrial Estate in the middle of Worcester. We all went along on a visit organised by the Worcestershire Home Educators Group (all the junior members of my clan were or are being home educated). You have to join but individual membership is only £12 a year and you pay for your scrap either per hand basket or per trolley. And you don't have to haggle with a surly scrap man, either - which, believe me, is a bonus. I came away with the parts for a go-kart (wood, wheels and even a Jaguar marque to stick on the front), lots of wire - I have it in mind to make a foxhole radio and a simple motor at some stage - foam (padding for the go-kart seat at my little-one's insistence) and my wife came away with lots of good quality material. They also have an arts library which you can use to get ideas for your arts projects. Now, not that I'm wanting to sound snobby, but what's wrong with having the designs for some home experiments in there too?

Hopefully we will be back there soon for that ABS piping they had in stock. I reckon we will be up for some good spud gun experiments this summer.

Monday, 23 July 2007

Start of the summer hols...

The summer holiday for a private tutor basically means no work, sadly, so this summer I was going to follow on the YourMathsTutor 2007 Maths Workshops (which I'm happy to say seemed to go down really well with everyone) with some summer holiday science workshops. I was hoping to spend afternoons throughout the summer holiday with children on science projects - making foxhole radios, setting fire to things, explosions and that sort of thing - experiments that don't fit well into an hour's lesson. Really I wanted to do the sorts of experiments you should be allowed to do at school but thanks to health and safety (and perhaps sometimes a bit of laziness on the part of some teachers I've come across) children rarely get the chance to have a go at.

There was a lot of interest in this idea but unfortunately what with one thing and another going on through May and June this year I didn't get the chance to set this up. So instead, during the summer holiday lull, I'm going to be posting up to this blog projects that I'm carrying out both with the younger of my own children (to keep them off the streets) and with the few tutees that I am still seeing through the summer (I'm not going to be making anyone sit in front of a text book over the holidays - I'm not that cruel).

I Hope you enjoy having a go yourself. If you get stuck, or something doesn't make sense, or the experiment doesn't work, or it works first time (!) then please do post a comment. I'd love to hear how you get on.