ferric ring is not magnetic ring. Ferric is made of compressed iron powder. It will not attract small screws or nails. There are some descriptions on this link:
Weekend Projects with Bre Pettis: Make a Joule Thief - Evil Mad Scientist Laboratories
http://www.evilmadscientist.com/article.php/joulethiefThe copper wires used in this project is commonly called as SWG wires or transformer wires in electrical shop. The bigger the SWG number the smaller the diameter the wire. For your project, I think the wire is about SWG 30. Here we normally use British terms. SWG=standard wire gauge and AWG=American wire gauge.
tekiding WROTE:as i said in the thread for "DS1307 RTC interface with PIC16F877A" is it possible to integrate between this two circuit..,the buzzer will replace switch 1 in this stimulator.when the alarm is activated,it will trigger the stimulator..
in theory the PR12 will act as switch 1 in stimulator whereas the stimulator act as buzzer/alarm.
Cannot comment on this one as I am also not sure. Why not just do the thing that you can do and worry about that later? May be some other members here can solve that for you.
If you describe the purpose of this project may be we can give you better suggestion to accomplish your goal.
Allen