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 -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.