Modifying LM350 need help!

Discussion in 'The Projects Forum' started by ayane, Sep 30, 2009.

  1. ayane

    Thread Starter Active Member

    May 3, 2009
    hi, i had built a simple regulating with this ic with sets the voltage ouput around close to 19v.

    r1- 120 ohms and r2 1680ohms.. The ic i bought is the adjustable output voltage type. My input is 21V

    I was wondering how do i modify this circuit so that i can multiple voltage outputs?..such as 15v,16v,18,19,20,etc..

    Any ics that can be used?..prefer those with high output current of about 3A..thx..
  2. t06afre

    AAC Fanatic!

    May 11, 2009
    You could perhaps use a potentiometer and a knob with a scale. Or buy a cheap panel instrument
  3. rickmartin

    New Member

    Sep 26, 2009
    If you are talking about SELECTING specific voltage outputs, rather than having the continuous control a pot provides, you could replace the pot with fixed resistors and switch them into the circuit with a multi-pole switch. You would have to use the pot, first, to get the proper resistance for each output voltage. The LM350 is a really sweet regulator. I have used them to drive 3055 transistors for high current applications and never had one fail.