The High Voltage Ringer

Whilst on a 3 year stag-do, that is sometimes called "University", I picked up some knowledge of electronics. Apart from dabling with a Raspberry Pi recently I haven't relly done much in the way of practical electronics for 20 years!!
Never mind, I vaguely remember it being fairly simple, especially when someone has done some of the schematics for you - thanks again Port-a-rotary.
Luckily I also spend 2 years programming assembler for flight control systems - so hopefully this may come in useful.

So using this fantastic schematic from http://www.sparkfun.com/tutorials/50
I ordered the required bits from Farnell.

Plan is to build it up on a breadboard to get it running - the bell ringer I have looks slightly different from the one on the above link.
Ah but I hear you ask, where are you getting your power from for the beadboard, well I had this great idea (I actually stole it from http://www.wd5gnr.com/power.htm) and here it is:

Using a spare power connector from inside my PC and some screw-down posts from an old breadboard I now have this. To connect the wires to the connector I just put a blob of solder on each wire and, using carefully calculated parameters, stuffed them in hard enough so they didn't fall out.

The 10V is actually 12V, but not to worry, I'll only be using the 5V.

[EDIT: This power supply has turned out to be anything but smooth, it fails to drive the PIC correctly - I have resorted to 3 AA batteries in series giving 4.5 volts.]

The inverting switching regulator

Getting 57V from 5V (or 3.5V)

I built this bit first (M34063A) to make sure I could get the required voltage out, the only difference I made was not including the 0.25 Ohm resitor (or 4 x 1 Ohm in parallel). This is replaced by the red wire loop - which I measured at 0.1 Ohm - near enough for me.

When I'd got the required voltage out - 57V - (NOTE: I also got 57V with an input of 3.5V from 2 AA cells) I connected it up to the H-bridge:

I then connected it up to the phone ringer solonoids to see if it would move.
I got one 'ding'!
At this point, and after re-reading the instructions on http://www.sparkfun.com/tutorials/50 I realised I needed an oscillator input signal into the H-Bridge - obvious really :)
I assume this will be representative of the output from the GSM unit (or the Nokia)
On the above website they mention using the PIC to create a 22Hz Oscillator, but as I hadn't got round to figuring out this bit yet, I scratched my head, and in the absence of a frequency generator I decided to use a 555 timer.