Battery Powered circuits. Anyone got any good diagrams ?

Hi Folks

I have to take some students through making a piece of audio gear. Obviously I would like them to make Neve, API, UREI etc

Not a problem you say, but there is a budget restriction of £20 per person. This makes if difficult to make anything which is mains powered.

So has anyone got any good circuits they can suggest for a mic pre, or maybe an opto compressor. The circuits need to be simple because the students are novices.

I was looking at the green pre & the forsell opto but was wondering if they would be happy running from 2 x 9v batteries.

Hi Rob,

did you see the opto compressor at john hollis' site?

http://www.hollis.co.uk/john/flatline.jpg

It's supposed to be a guitar compressor but it should work for other sources too. Pretty simple.

Stewart

Guitar pedal effects. Fuzz boxes. Easy to build. Battery powered. Lot's of schematics all over the web.

/Anders

Some other problems to think about...

I have just put together a practical class for 1st year undergraduate chemists building DIY photometers, which is basically an LED source, LDR as detector and op amp to amplify the signal. I tested my original plan on a guinea-pig student over the summer who had no soldering or layout experience. She worked very slowly and did a very inefficient layout. I realised that if the experiment was to be done in a day, with time to use the device for some chemistry, I had to simplify things. I have ended up doing a layout and getting PCBs manufactured - for 100 the price was not really any more expensive than bad use of perfboard /copper clad board.

I ran the experiment with some 12-16 year old 'gifted and talented' students a couple of weeks ago and they all managed to build the thing OK (with some help). Their soldering was terrible - it's a really hard thing to teach IMO.

Cheers!
Stewart

Thanks folks

Zebra

I know what your saying about trying to teach soldering, its the same old thing "the more you do it the better you get", but that is life.

The PCB thing isn`t so bad, because where I teach they have their own PCB manufacturing facility (which proves to be very useful on ocassion).

Yup. I'm running this again in the spring and this time we are having a 'how to solder' workshop before we dive into the experiment. Hopefully this should help a lot for thsoe who haven't used an iron before.