generate high voltage using LM555 with a transformer
You need to determine how much power you need to transfer. From your wiki, I think you need plenty of peak power, and this circuit won't do that. 

You don't actually need a transformer -- a flyback converter (boost DC/DC converter) will work, although you will need a high duty cycle to get 230 V from 12 V at high power. At low power, you can use discontinuous conduction, and simpler control (maybe even a 555). 

To get started, use a single inductor between supply (12V) and a switch transistor (rated at > 230 V). drive the transistor on with the 555 for a time so that Ipeak = Vsupply*T_on/L, and Ipeak reaches the peak you need (related to the power you need). Then turn off the transistor, and the collector voltage will spike up (because of the inductance) to a high value -- use your D1 &amp; C7 to rectify that. If you limit may duty cycle from the 555 to &lt; 90 %, your circuit won't run away. Regulated the output by masking pulses when VOUT > 230 V.