Dual stabilized PS, filtering?

Discussion in 'The Projects Forum' started by kubeek, Apr 23, 2008.

  1. kubeek

    Thread Starter AAC Fanatic!

    Sep 20, 2005
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    I am planning to build a low noise power supply, +-15V, 0.3A.
    There will be standard bridge and center tapped transformer, but I was thinking about using a CLC filter, or something similar for the raw DC part, to block line garbage.

    What kind of regulator should I use, to get really low noise? How do 78xx behave reagarding to noise and regulation?
     
  2. Pich

    Active Member

    Mar 11, 2008
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    Will it be adjustible or fixed output? For the amount of current draw a standard input filter is OK, (1000uf).
     
  3. kubeek

    Thread Starter AAC Fanatic!

    Sep 20, 2005
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    I know that standard cap on the input is ok, but I want something more :)
    It will be fixed voltage, for powering microphone preamp and things like that.
     
  4. Pich

    Active Member

    Mar 11, 2008
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    Then a 78xx and 79xx will be OK. A 10uf tatalum cap on both outputs will do a good job of filtering high frequencies. Make shure that your input voltage to the regulators is at least 4 volts above output voltage under load. The noise should be in the microvolt range.
     
  5. SgtWookie

    Expert

    Jul 17, 2007
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    The 78xx and 79xx series of regulators are tried and true, but they're rather "long in the tooth". You might consider some more modern "low dropout" regulators as an alternative.
     
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