Please help me with this VOLTMETER

Please help me measuring AC voltage with this VOLTMETER

I want to measure household voltage...that is about 200V - 250V AC

I saw this project with the ADC IC ICL7107 here

but the problem is this measures DC voltage....

Please suggest me how will i measure the 250V ac current....???

First of all, why do you want to measure the AC mains voltage?

Do you just want to measure the voltage every now and again?
In that case just buy a cheap DMM, you can buy them for £5 or so in the UK. A complete instant and safe solution.

Or..

Do you want to have a permanent monitor displaying the current mains voltage?
In that case you will need a supply for the DVM module, +5v and -5v from a quick look at the attached circuit.
You can do this using a transformer and a couple of rectifiers, capacitors and 3-terminal voltage regulators.
Then you will need a second transformer to provide an isolated signal to measure the voltage, a rectifier, resistors and a capacitor to convert the AC to DC and filter and scale the signal to the range of the basic DVM.

JimB

Actually i want to add two of these voltmeters on the input and output of a 1kv 220volt step up transformer and monitor it all the time....

and moreover i want to use the seven segment display so that it is visible from a little far all the time...