I think i fixed some of the problem
I am using following circuit, made following changes;
I have replaced R2 resistor with Potentiometer -- 25k. like this one
It's three pint, a, b, c
a is connected to ground b is connected to r1 resistor and adj c I don't know where this goes....
--------------------------- Added 1N4002 diods across voltage regulator -connected to in and out pins.
-------------------------- Also input capisitor is a big one.
Finally on output voltage I have added 35v tantalum capacitor.
---------------------
I am able to control the voltage, however I am not get zero at all..
resister for testing current 1kohm (measure by dimm) 992ohms
This is the output. input voltage is 15.12 (regulated adaptor)
current 15.29ma
------------ minimum voltage 1.281v current 1.29mA
maximum 14.26v+ current 13.63mA
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I want miminum voltage to be 0, how do i do that? Also my regulated adaptor has two output 15v and 30v, and I will be using 30v b/c some of the circuit require 20v --- like series, and parallel circuits and few more complex circuits -- school work. I am very new to this stuff
-- like two weeks.