15V      .------.
-----o---| 7812 |---o----> 12V
         '--.---'   |
              |      _|_
              |      --- 470 uF
            |       |
           _|_     _|_


This is the diagram I am using, the current draw out is 450 m-600 mA
only.
Any circuit improvement required to prevent output voltage oscillation ?

James


-----Original Message-----
From: Padman, Nash [mailto:nash.padman@TL2K.CO.UK]
Sent: 14 April 2003 7:44
Subject: Re: [EE]: 7812 Unstable

                James

                Can you place a circuit diagram of the your design so we
can
analysis


                np

 -----Original Message-----
From:   Quah [mailto:asiact@TM.NET.MY]
Sent:   15 April 2003 17:38
To:     PICLIST@MITVMA.MIT.EDU
Subject:        [EE]: 7812 Unstable

I am using ST 7812 regulator the problem I face is the voltage out I get
normally is constant 11.9 or 12.03 V.  Some of the parts after use for
fews day or 1 month, the voltage out drop to 8.9 V and it is unstable
waving between 8.9 to 11.9 V. What is the reason of this and how to
avoid this ?

James

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