How LM317 regulates the voltages

[smhn72@gmail.com]

I want to connect the three Pins of LM317 to take a 3v DC and facing trouble to connect the PINS in this way that it will give me 3v

i have a step down transformer of 15v 3ah and i have used a brige rectifier to convert this 15v ac in to DC and now the main issue is that i want to convert this 15v dc to 3v dc

for this i m using LM 317


Plz any body help me how i can regulate this 15dc to 3dc the voltage

 

[alexan_e]

Use this scheme **broken link removed** and calculate the resistor for 3v.

I suppose there is a capacitor after the diode bridge.

 

[Tahmid]

All your required information is in the LM317 datasheet:

Fairchild: www.fairchildsemi.com/ds/LM/LM317.pdf
TI: www.ti.com/lit/ds/symlink/lm117.pdf

From the Fairchild datasheet:

From the TI datasheet: