I'm working on boost converter intending to convert5v to higher voltages and giving this output to 7812. But 2577 giving output as 5 v itself, ie is not boosting the signal in using following circuit
Capacitance value is not visible fyi it is 680 microfarad. However, note i can obtain 12 v as no load voltage, but it's regulation is very poor, voltage is dropping to as low as 1.25 volts when applied to load.
I suspect the inductor that you are using may not be suitable. Can you post a picture of the inductor that you are using and the specifications. (DC resistance, Current rating and any other data given in the specifications.)