This is a multi-part message in MIME format. ------=_NextPart_000_09BB_01C1DB22.60412E60 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit That's pretty much what I have -- circuit diagram attached. So why would it oscillate? The 12V supply should be fairly stable (at least any changes should not be high enough frequency to be called "oscillation"), and the output has a 33uF cap on it. So my guess is that the oscillation is being produced internally (within the 7805)? ----- Original Message ----- From: "michael brown" To: Sent: Wednesday, April 03, 2002 2:41 PM Subject: Re: [EE]: 7805 heating up... > > but it gets hot enough that I cannot leave my finger on it for more > > than 5-10 seconds. > > > Should it get this hot? > > Only when it's transmitting! Sounds like it is oscillating to me. Put a > .1uF cap on the input, near the pins on the regulator. Others here can > offer much better suggestions I'm sure. > > michael brown > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. 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