OK... so you have not yet built the voltage multiplier part of the circuit, right? And you are using a different transformer. OK.
When you are measuring your output, are you looking across the transformer secondary?
Please check the DC resistances of the primary and secondary of the transformer you are using, with the transformer disconnected from the rest of the circuit.
Please check to make sure you have the Darlington transistor BD679 connected properly. The pinout from the ST data sheet is indicated on my edit of your diagram below.
no iam measuring the output without connecting the transformer and it reads arround 6v(DMM in dc mode). transformer secondary shows 0v when connected. The resistance is 2ohm primary & 220 ohm secondary. the transformer looks like centre tapped but no resistance for the other terminals. i have connected the transistor correctly . Now i have made the voltage multiplier & when i connected it to the 555 circuit no voltage output. since the voltage multiplier needs ac or pulsating dc to work..i think the 555 is not doing its oscillation. what should i do??
I guess you do not have an oscilloscope. What kind of DMM are you using, does it have a "frequency" setting?
Almost all DMMs will do a fair averaging when set to DC and measuring an oscillating DC pulse signal. This circuit produces such a signal, and when I measure the Pin 3 output with respect to Ground (Pin 1) I get "around" 6V (with 12 volt supply) using either a very cheap 4 dollar DMM or a Fluke 87-III. The Fluke reports a frequency just over 2 kHz, which agrees with the oscilloscope's measurement also. See the images below.
(Your voltage measurements of the 555 side of the circuit should be made with respect to the Ground, Pin 1 negative power supply rail, unless you are measuring the output side of the transformer, in which case they should be across the transformer secondary itself.)
No, the Pin 7 is not connected in this circuit.
I think the fact that you are getting your "around" 6V probably means your circuit IS oscillating, and there is something else wrong on the output side. You certainly should be able to measure _something_ on the secondary of the transformer otherwise.
What are you using for a power supply? This circuit will switch the output of the power supply directly into the transformer primary, and if your primary is 2 ohms DC resistance, at 12 volts that means I = V/R or 6 amps during the ON state of the pulse. (Neglecting the resistance of the transistor and inductive impedance of the primary). Some power supplies may see this as a direct short circuit and shut down or fold back.
Just to check the 555/transistor part of the circuit, try connecting an LED + 1k resistor instead of the transformer primary.
(Personally, I would use a mosfet instead of the Darlington transistor in this application.....)