need schematic of a 230v-12v/24v 2AMP power supply

plz can u give me sch of a powersupply that is capable of providing 24 and 12 v at the same time... which transformer would be used ...

and hw much differnce of cost does such a transformer have with a simple transformer having one olp only

Max power output = 24 x 2 = 48 VA,
Max cost = 48 x 5 = 240 Rs. (Indian Rupee).
Possibly a 12 V Center tap 3A May do the job and costs about 100Rs. (2.25$).

Leftmost is +12V, center is 0V and rightmost is -12V.

So you get 24 volt from left & right.

are these prices from indian based companies or are these almost standard.. can u help by giving some info about suppliers.. iam in oman and would need some 50 pcs or even more later about 500...

The price is more or less same in the electronics market. Vary Max upto 20% if the is distant from Electronics center. Please mind that, in remote place also, if you want higher quantity, you may got lower price. I dont have idea about outside market.
For example, Power LED of 1 watt available at 1$ over net before 2 year. Now price slashed, taxes reduced, available in Kolkata Market, but price is Rs. 70 (While Rs.48 = 1 $ ). But 4" 8Ohm speaker you can get at Rs27 as manufactured localy. 500 Pcs of 1N4007 I just purchased in Rs140. (Rs48 = 1$). Lens modules of power LEDs are not found for streetlight till now in Kolkata Market. However, marketing needs large travel over foot minimum 2.5 KM if you throughly search different shops in kolkata including Bimla Chawcks/3C Madan Street's or other Madan Street's Top Floor to basement, Shyam Electronics Path to Raltron, and other shops around locations Shibaji, Geminy, UP Electronics, Naba Bharat, Cheap Radio, Amit Electronics, Naresh, etc.

Marketing is a art and no one can teach

I just choose the shop with gathere and watch the rates with component till asking me required for. If I choose not to take from them just ask for the component not with him or the Current Rate and comes back. Asking current rate will give you about competitive price or counter question What Quantity ? My question will be the packaged quantity (Box/Packet)? Definitely you get better price than other.