You can get everything you need from your local high street and
whatsmore the following link will take you to all the information you
will need to construct your own device and there is even a tutorial to
show you how to use it.
This is a genuine invitation for you to get involved in a real "Off the
wall" development in watercolour art. Just click on the link and give
it a whirl, you will not be dissapointed.
http://myweb.tiscali.co.uk/jvsalmon/charger/charger_index.html