LED Driving Directly by Mains

http://www.screwfix.com/cats/A354537/Lighting-Lamps/Electronic-Transformers/Electronic-Transformers

This is so simple and basic (just buy a power supply ) that you must have dozens of unstated limitations. So when and if you feel like telling us that this must be a supply with a minimum efficiency of X%, able to withstand weather conditions of Y, take no more space than 0.Z m³, endure a minimum acceleration of AAA m s^-2, provide remote control via BBBBBBB protocol, that costs less than MMM¢ and the MTBF is at least Q millennia. Maybe then we can help you. Or you just might want to do your own work by clicking here.

Dude sorrrrrrrrrry

Ok i explain my requirements in detail. as follows

1. Input voltage = 230Vac

2. Variable output voltage 9V to 15V

3. Maximum output current 1A

4. Efficiency about 90%

5. and the most important size is circular with diameter of 3cm

mmmmmm.....the right stuff ...make sure you have plenty of them!

@ CraziestOzzy

Yaar u r still in the old ages and still using the fire for lighting. I asked abt LEDs driving

hi you can use standard smps power packs available in the market. even the cell phone chargers can be used. you may refer circuits today or red free circuits sites for various designs on this requirement. may be a step down transformer with prim 230V AC and with a secondary rated for 15 volt ac @ 1amp, a 2 amp bridge rectifier with suitable filter circuits and a variable regulator chip LM317 can take care of your requirement. beware the LEDs are constant current devices. refer manufacturers data for LED. and fabricate a suitable power supply for the. most of the present high bright say white LEDs are rated for 3 to 3.5 Volt DC with a current of 25 to 150 mA again refer mfg data.

seetharaman

visit: http://www.national.com/mpf/LM/LM317.html#Overview

Sound like you want to do a power light for your power supply.

Just use a resistor to limit the current across the led to 20mA at 9Vdc.

if the supply is 9Vdc it will be brighter then when it is 15Vdc

Look here first:-

http://en.wikipedia.org/wiki/LED_circuit#Lighting_LEDs_on_mains

http://www.ledsmagazine.com/features/3/5/2

Also, some electronics companies can sell you a finished product.....

Some LEDs are made for 230 volts as here:-

http://www.conrad.de/ce/de/product/180837/LED-230V-WARM-WHITE-AN3231-ACRICHE/SHOP_AREA_26436