Regulated power supply

Discussion in 'The Projects Forum' started by rahulr30, Jan 21, 2012.

  1. rahulr30

    Thread Starter New Member

    Jan 21, 2012
    4
    0
    Hi there,
    This is my first post here.
    Could some one suggest a regulator IC whch can provide +5, 0 and -5 V. Current capacity needed is 2A.
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    See this and just ask for the 7905 version of it.
     
  3. crutschow

    Expert

    Mar 14, 2008
    13,024
    3,236
    What is the voltage of the source of the power for the regulators?
     
  4. rahulr30

    Thread Starter New Member

    Jan 21, 2012
    4
    0
    Thanks for the reply. The input supply would be taken from a rectified power supply. But that would be flexible. I can modify the transformer turns to get required voltage for the regulator. Basically i am looking at a single +ve supply as the supply.
     
  5. crutschow

    Expert

    Mar 14, 2008
    13,024
    3,236
    You need a dual (plus and minus) supply if you want plus and minus outputs using simple linear regulators such as the 7805 and 7905. That's readily generated by a center-tapped transformer output winding and a single bridge rectifier.

    You can get plus and minus from a single supply voltage if you use a switching regulator. They are more efficient, but significantly more complex.
     
  6. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    The 780X and 790X are not 2A rated devices. Try the LT1085 series devices.
     
  7. PaulEE

    Member

    Dec 23, 2011
    423
    32
    Unless you incorporate series pass transistors...
    :)
     
  8. rahulr30

    Thread Starter New Member

    Jan 21, 2012
    4
    0
    Hi thanks for the replies,
    I would like to stick with the switching regulator.
    Could someone give some references regarding this?
     
  9. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    Now you added some new info. The latter switching regulator. Does this have a single voltage output or a dual voltage output (like +/- voltage). And also do you need 2 ampere on both output. Or can you settle for less current on the negative supply. It is quite common that the current needed from the negative supply is less than the positive supply.
     
  10. rahulr30

    Thread Starter New Member

    Jan 21, 2012
    4
    0
    I need +5 -5 V as mentioned before. 2 A required at both supplies.
     
  11. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    True, but that's such a bad idea I always forget about that. The pass transitors then have no current limit protection. Power supplies that don't have current limit protection are fuses.....:eek:
     
  12. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    You still have not said what the input voltage is.

    The easiest way would be a flyback switcher with dual outputs and the +5V is used for voltage feedback. national makes some simple switcher products that do that.
     
Loading...